SQLite

         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         pager.lo parse.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo \
         sqlite3session.lo select.lo sqlite3rbu.lo status.lo stmt.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
         update.lo userauth.lo upsert.lo util.lo vacuum.lo \
         vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
         vdbetrace.lo vdbevtab.lo \
         wal.lo walker.lo where.lo wherecode.lo whereexpr.lo \
         window.lo utf.lo vtab.lo

# Object files for the amalgamation.
#
LIBOBJS1 = sqlite3.lo

# Determine the real value of LIBOBJ based on the 'configure' script

  $(TOP)/src/vdbe.h \
  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbeblob.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbesort.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbevtab.c \
  $(TOP)/src/vdbeInt.h \
  $(TOP)/src/vtab.c \
  $(TOP)/src/vxworks.h \
  $(TOP)/src/wal.c \
  $(TOP)/src/wal.h \
  $(TOP)/src/walker.c \
  $(TOP)/src/where.c \

  $(TOP)/src/utf.c \
  $(TOP)/src/util.c \
  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbevtab.c \
  $(TOP)/src/where.c \
  $(TOP)/src/wherecode.c \
  $(TOP)/src/whereexpr.c \
  $(TOP)/src/window.c \
  parse.c \
  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3_aux.c \

#SHELL_OPT += -DSQLITE_ENABLE_FTS5
SHELL_OPT += -DSQLITE_ENABLE_RTREE
SHELL_OPT += -DSQLITE_ENABLE_EXPLAIN_COMMENTS
SHELL_OPT += -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
SHELL_OPT += -DSQLITE_ENABLE_STMTVTAB
SHELL_OPT += -DSQLITE_ENABLE_DBPAGE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
SHELL_OPT += -DSQLITE_ENABLE_BYTECODE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_OFFSET_SQL_FUNC
SHELL_OPT += -DSQLITE_ENABLE_DESERIALIZE
FUZZERSHELL_OPT = -DSQLITE_ENABLE_JSON1
FUZZCHECK_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ
FUZZCHECK_OPT += -DSQLITE_MAX_MEMORY=50000000
FUZZCHECK_OPT += -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_OPT += -DSQLITE_ENABLE_DESERIALIZE
FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS4
FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS3_PARENTHESIS
#FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS5
FUZZCHECK_OPT += -DSQLITE_ENABLE_RTREE
FUZZCHECK_OPT += -DSQLITE_ENABLE_GEOPOLY
FUZZCHECK_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
FUZZCHECK_OPT += -DSQLITE_ENABLE_BYTECODE_VTAB
FUZZCHECK_SRC = $(TOP)/test/fuzzcheck.c $(TOP)/test/ossfuzz.c
DBFUZZ_OPT =

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	sqlite3.h libsqlite3.la sqlite3$(TEXE) $(HAVE_TCL:1=libtclsqlite3.la)

DBFUZZ2_OPTS = \
  -DSQLITE_THREADSAFE=0 \
  -DSQLITE_OMIT_LOAD_EXTENSION \
  -DSQLITE_ENABLE_DESERIALIZE \
  -DSQLITE_DEBUG \
  -DSQLITE_ENABLE_DBSTAT_VTAB \
  -DSQLITE_ENABLE_BYTECODE_VTAB \
  -DSQLITE_ENABLE_RTREE \
  -DSQLITE_ENABLE_FTS4 \
  -DSQLITE_ENABLE_FTS5

dbfuzz2$(TEXE):	$(TOP)/test/dbfuzz2.c sqlite3.c sqlite3.h
	$(CC) $(OPT_FEATURE_FLAGS) $(OPTS) -I. -g -O0 \
		-DSTANDALONE -o dbfuzz2 \

vdbesort.lo:	$(TOP)/src/vdbesort.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vdbesort.c

vdbetrace.lo:	$(TOP)/src/vdbetrace.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vdbetrace.c

vdbevtab.lo:	$(TOP)/src/vdbevtab.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vdbevtab.c

vtab.lo:	$(TOP)/src/vtab.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/vtab.c

wal.lo:	$(TOP)/src/wal.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/wal.c

walker.lo:	$(TOP)/src/walker.c $(HDR)

SHELL_SRC = \
	$(TOP)/src/shell.c.in \
        $(TOP)/ext/misc/appendvfs.c \
	$(TOP)/ext/misc/shathree.c \
	$(TOP)/ext/misc/fileio.c \
	$(TOP)/ext/misc/completion.c \
	$(TOP)/ext/misc/sqlar.c \
        $(TOP)/ext/misc/uint.c \
	$(TOP)/ext/expert/sqlite3expert.c \
	$(TOP)/ext/expert/sqlite3expert.h \
	$(TOP)/ext/misc/zipfile.c \
	$(TOP)/ext/misc/memtrace.c \
        $(TOP)/src/test_windirent.c

shell.c:	$(SHELL_SRC) $(TOP)/tool/mkshellc.tcl

TESTFIXTURE_FLAGS += -DTCLSH_INIT_PROC=sqlite3TestInit
TESTFIXTURE_FLAGS += -DSQLITE_SERVER=1 -DSQLITE_PRIVATE="" -DSQLITE_CORE
TESTFIXTURE_FLAGS += -DBUILD_sqlite
TESTFIXTURE_FLAGS += -DSQLITE_SERIES_CONSTRAINT_VERIFY=1
TESTFIXTURE_FLAGS += -DSQLITE_DEFAULT_PAGE_SIZE=1024
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_STMTVTAB
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_DBPAGE_VTAB
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_BYTECODE_VTAB
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_DESERIALIZE

TESTFIXTURE_SRC0 = $(TESTSRC2) libsqlite3.la
TESTFIXTURE_SRC1 = sqlite3.c
TESTFIXTURE_SRC = $(TESTSRC) $(TOP)/src/tclsqlite.c
TESTFIXTURE_SRC += $(TESTFIXTURE_SRC$(USE_AMALGAMATION))

# 5 == SQLITE_DEBUG_OS_TRACE: Enables output from the OSTRACE() macros.
# 6 == SQLITE_ENABLE_IOTRACE: Enables output from the IOTRACE() macros.
#
!IFNDEF DEBUG
DEBUG = 0
!ENDIF

# <<mark>>
# Disable use of the --linemacros argument to the mksqlite3c.tcl tool, which
# is used to build the amalgamation.
#
!IFNDEF NO_LINEMACROS
NO_LINEMACROS = 0
!ENDIF
# <</mark>>

# Enable use of available compiler optimizations?  Normally, this should be
# non-zero.  Setting this to zero, thus disabling all compiler optimizations,
# can be useful for testing.
#
!IFNDEF OPTIMIZATIONS
OPTIMIZATIONS = 2
!ENDIF

OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_FTS3=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_RTREE=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_GEOPOLY=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_JSON1=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_STMTVTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DBPAGE_VTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DBSTAT_VTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_BYTECODE_VTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DESERIALIZE=1
!ENDIF
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_COLUMN_METADATA=1
!ENDIF

# Should the session extension be enabled?  If so, add compilation options
# to enable it.

MKSQLITE3C_TOOL = $(TOP)\tool\mksqlite3c-noext.tcl
!ELSE
MKSQLITE3C_TOOL = $(TOP)\tool\mksqlite3c.tcl
!ENDIF
!ENDIF

!IFNDEF MKSQLITE3C_ARGS
!IF $(DEBUG)>1 && $(NO_LINEMACROS)==0
MKSQLITE3C_ARGS = --linemacros
!ELSE
MKSQLITE3C_ARGS =
!ENDIF
!IF $(USE_STDCALL)!=0 || $(FOR_WIN10)!=0
MKSQLITE3C_ARGS = $(MKSQLITE3C_ARGS) --useapicall
!ENDIF

         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         pager.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo \
         sqlite3session.lo select.lo sqlite3rbu.lo status.lo stmt.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
         update.lo upsert.lo util.lo vacuum.lo \
         vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
         vdbetrace.lo vdbevtab.lo wal.lo walker.lo where.lo wherecode.lo \
         whereexpr.lo \
         window.lo utf.lo vtab.lo
# <</mark>>

# Object files for the amalgamation.
#
LIBOBJS1 = sqlite3.lo

  $(TOP)\src\vdbe.c \
  $(TOP)\src\vdbeapi.c \
  $(TOP)\src\vdbeaux.c \
  $(TOP)\src\vdbeblob.c \
  $(TOP)\src\vdbemem.c \
  $(TOP)\src\vdbesort.c \
  $(TOP)\src\vdbetrace.c \
  $(TOP)\src\vdbevtab.c \
  $(TOP)\src\vtab.c \
  $(TOP)\src\wal.c \
  $(TOP)\src\walker.c \
  $(TOP)\src\where.c \
  $(TOP)\src\wherecode.c \
  $(TOP)\src\whereexpr.c \
  $(TOP)\src\window.c

FUZZERSHELL_COMPILE_OPTS = -DSQLITE_ENABLE_JSON1
FUZZCHECK_OPTS = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ -DSQLITE_MAX_MEMORY=50000000 -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_DESERIALIZE
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_FTS4
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_RTREE
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_GEOPOLY
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_DBSTAT_VTAB
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_BYTECODE_VTAB

FUZZCHECK_SRC = $(TOP)\test\fuzzcheck.c $(TOP)\test\ossfuzz.c
OSSSHELL_SRC = $(TOP)\test\ossshell.c $(TOP)\test\ossfuzz.c
DBFUZZ_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION
KV_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_DIRECT_OVERFLOW_READ
ST_COMPILE_OPTS = -DSQLITE_THREADSAFE=0

vdbesort.lo:	$(TOP)\src\vdbesort.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\vdbesort.c

vdbetrace.lo:	$(TOP)\src\vdbetrace.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\vdbetrace.c

vdbevtab.lo:	$(TOP)\src\vdbevtab.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\vdbevtab.c

vtab.lo:	$(TOP)\src\vtab.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\vtab.c

wal.lo:	$(TOP)\src\wal.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\wal.c

walker.lo:	$(TOP)\src\walker.c $(HDR)

# Source files that go into making shell.c
SHELL_SRC = \
	$(TOP)\src\shell.c.in \
	$(TOP)\ext\misc\appendvfs.c \
	$(TOP)\ext\misc\shathree.c \
	$(TOP)\ext\misc\fileio.c \
	$(TOP)\ext\misc\completion.c \
        $(TOP)\ext\misc\uint.c \
	$(TOP)\ext\expert\sqlite3expert.c \
	$(TOP)\ext\expert\sqlite3expert.h \
	$(TOP)\ext\misc\memtrace.c \
	$(TOP)\src\test_windirent.c

# If use of zlib is enabled, add the "zipfile.c" source file.
#

TESTFIXTURE_FLAGS = -DTCLSH_INIT_PROC=sqlite3TestInit -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERVER=1 -DSQLITE_PRIVATE=""
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_CORE $(NO_WARN)
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERIES_CONSTRAINT_VERIFY=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_DEFAULT_PAGE_SIZE=1024
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_STMTVTAB=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_DBPAGE_VTAB=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_BYTECODE_VTAB=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_JSON1=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_DESERIALIZE=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) $(TEST_CCONV_OPTS)

TESTFIXTURE_SRC0 = $(TESTEXT) $(TESTSRC2)
TESTFIXTURE_SRC1 = $(TESTEXT) $(SQLITE3C)
!IF $(USE_AMALGAMATION)==0

3.32.1

# 4 == SQLITE_WIN32_MALLOC_VALIDATE: Validate the Win32 native heap per call.
# 5 == SQLITE_DEBUG_OS_TRACE: Enables output from the OSTRACE() macros.
# 6 == SQLITE_ENABLE_IOTRACE: Enables output from the IOTRACE() macros.
#
!IFNDEF DEBUG
DEBUG = 0
!ENDIF


# Enable use of available compiler optimizations?  Normally, this should be
# non-zero.  Setting this to zero, thus disabling all compiler optimizations,
# can be useful for testing.
#
!IFNDEF OPTIMIZATIONS
OPTIMIZATIONS = 2

OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_FTS3=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_RTREE=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_GEOPOLY=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_JSON1=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_STMTVTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DBPAGE_VTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DBSTAT_VTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_BYTECODE_VTAB=1
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DESERIALIZE=1
!ENDIF
OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_COLUMN_METADATA=1
!ENDIF

# Should the session extension be enabled?  If so, add compilation options
# to enable it.

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.69 for sqlite 3.32.1.
#
#
# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
#
#
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.

subdirs=
MFLAGS=
MAKEFLAGS=

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.32.1'
PACKAGE_STRING='sqlite 3.32.1'
PACKAGE_BUGREPORT=''
PACKAGE_URL=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H

#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.32.1 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.32.1:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]

    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.32.1
generated by GNU Autoconf 2.69

Copyright (C) 2012 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit

  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno

} # ac_fn_c_check_header_mongrel
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.32.1, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{

test $as_write_fail = 0 && chmod +x $CONFIG_STATUS || ac_write_fail=1

cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
# Save the log message, to keep $0 and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.32.1, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@

Report bugs to the package provider."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
ac_cs_version="\\
sqlite config.status 3.32.1
configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

Copyright (C) 2012 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

Display all conflicts that are resolved by
<a href='#precrules'>precedence rules</a>.
<li><b>-q</b>
Suppress generation of the report file.
<li><b>-r</b>
Do not sort or renumber the parser states as part of optimization.
<li><b>-s</b>
Show parser statistics before exiting.
<li><b>-T<i>file</i></b>
Use <i>file</i> as the template for the generated C-code parser implementation.
<li><b>-x</b>
Print the Lemon version number.
</ul>

<h3>The Parser Interface</h3>

</pre>
is an error.</p>

<p>The precedence of non-terminals is transferred to rules as follows:
The precedence of a grammar rule is equal to the precedence of the
left-most terminal symbol in the rule for which a precedence is
defined.  This is normally what you want, but in those cases where
you want the precedence of a grammar rule to be something different,
you can specify an alternative precedence symbol by putting the
symbol in square braces after the period at the end of the rule and
before any C-code.  For example:</p>

<p><pre>
   expr = MINUS expr.  [NOT]
</pre></p>

<p>The <tt>%extra_context</tt> directive works the same except that it
is passed in on the ParseAlloc() or ParseInit() routines instead of
on Parse().

<a name='extractx'></a>
<h4>The <tt>%extra_context</tt> directive</h4>

The <tt>%extra_context</tt> directive instructs Lemon to add a 2nd parameter
to the parameter list of the ParseAlloc() and ParseInif() functions.  Lemon
doesn't do anything itself with these extra argument, but it does
store the value make it available to C-code action routines, destructors,
and so forth.  For example, if the grammar file contains:</p>

<p><pre>
    %extra_context { MyStruct *pAbc }
</pre></p>

<p>Then the ParseAlloc() and ParseInit() functions will have an 2nd parameter
of type "MyStruct*" and all action routines will have access to
a variable named "pAbc" that is the value of that 2nd parameter.</p>

<p>The <tt>%extra_argument</tt> directive works the same except that it
is passed in on the Parse() routine instead of on ParseAlloc()/ParseInit().

<a name='pfallback'></a>
<h4>The <tt>%fallback</tt> directive</h4>

<h4>The <tt>%token_type</tt> and <tt>%type</tt> directives</h4>

<p>These directives are used to specify the data types for values
on the parser's stack associated with terminal and non-terminal
symbols.  The values of all terminal symbols must be of the same
type.  This turns out to be the same data type as the 3rd parameter
to the Parse() function generated by Lemon.  Typically, you will
make the value of a terminal symbol be a pointer to some kind of
token structure.  Like this:</p>

<p><pre>
   %token_type    {Token*}
</pre></p>

<p>If the data type of terminals is not specified, the default value

proc squish {txt} {
  regsub -all {[[:space:]]+} $txt { }
}

proc do_setup_rec_test {tn setup sql res} {
  reset_db
  if {[info exists ::set_main_db_name]} {
    dbconfig_maindbname_icecube db
  }
  db eval $setup
  uplevel [list do_rec_test $tn $sql $res]
}

foreach {tn setup} {
  1 {
    if {![file executable $CMD]} { continue }

      $expert destroy

      set tst [subst -nocommands {set {} [squish [join {$result}]]}]
      uplevel [list do_test $tn $tst [string trim [squish $res]]]
    }
  }
  3 {
    if {[info commands sqlite3_expert_new]==""} { continue }
    set ::set_main_db_name 1
  }
  4 {
    if {![file executable $CLI]} { continue }

    proc do_rec_test {tn sql res} {
      set res [squish [string trim $res]]
      set tst [subst -nocommands { 
        squish [string trim [exec $::CLI test.db ".expert" {$sql;}]]
      }]

  $expert destroy

  uplevel [list do_test $tn [list set {} $candidates] $res]
}


reset_db
do_execsql_test 5.0 {
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d);

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
  INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
  INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
}
do_candidates_test 5.1 {
  SELECT * FROM t1,t2 WHERE (b=? OR a=?) AND (c=? OR d=?)
} {
  CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20 
  CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50 
  CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20 
  CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
}

do_candidates_test 5.2 {
  SELECT * FROM t1,t2 WHERE a=? AND b=? AND c=? AND d=?
} {
  CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 17
  CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5
}

do_execsql_test 5.3 {
  CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50 
  CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20 
  CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 16

  CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20 
  CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
  CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5

        "EXPLAIN QUERY PLAN %s", pStmt->zSql
    );
    while( rc==SQLITE_OK && sqlite3_step(pExplain)==SQLITE_ROW ){
      /* int iId = sqlite3_column_int(pExplain, 0); */
      /* int iParent = sqlite3_column_int(pExplain, 1); */
      /* int iNotUsed = sqlite3_column_int(pExplain, 2); */
      const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
      int nDetail;
      int i;

      if( !zDetail ) continue;
      nDetail = STRLEN(zDetail);

      for(i=0; i<nDetail; i++){
        const char *zIdx = 0;
        if( i+13<nDetail && memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
          zIdx = &zDetail[i+13];
        }else if( i+22<nDetail 
            && memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 
        ){
          zIdx = &zDetail[i+22];
        }
        if( zIdx ){
          const char *zSql;
          int nIdx = 0;
          while( zIdx[nIdx]!='\0' && (zIdx[nIdx]!=' ' || zIdx[nIdx+1]!='(') ){
            nIdx++;

    idxWriteFree(p->pWrite);
    idxHashClear(&p->hIdx);
    sqlite3_free(p->zCandidates);
    sqlite3_free(p);
  }
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

  }
  if( p->zLanguageid ){
    fts3Appendf(pRc, &zRet, ", ?");
  }
  sqlite3_free(zFree);
  return zRet;
}

/*
** Buffer z contains a positive integer value encoded as utf-8 text.
** Decode this value and store it in *pnOut, returning the number of bytes
** consumed. If an overflow error occurs return a negative value.
*/
int sqlite3Fts3ReadInt(const char *z, int *pnOut){
  u64 iVal = 0;
  int i;
  for(i=0; z[i]>='0' && z[i]<='9'; i++){
    iVal = iVal*10 + (z[i] - '0');
    if( iVal>0x7FFFFFFF ) return -1;
  }
  *pnOut = (int)iVal;
  return i;
}

/*
** This function interprets the string at (*pp) as a non-negative integer
** value. It reads the integer and sets *pnOut to the value read, then 
** sets *pp to point to the byte immediately following the last byte of
** the integer value.
**
** Only decimal digits ('0'..'9') may be part of an integer value. 
**
** If *pp does not being with a decimal digit SQLITE_ERROR is returned and
** the output value undefined. Otherwise SQLITE_OK is returned.
**
** This function is used when parsing the "prefix=" FTS4 parameter.
*/
static int fts3GobbleInt(const char **pp, int *pnOut){
  const int MAX_NPREFIX = 10000000;

  int nInt = 0;                   /* Output value */
  int nByte;

  nByte = sqlite3Fts3ReadInt(*pp, &nInt);
  if( nInt>MAX_NPREFIX ){
    nInt = 0;

  }
  if( nByte==0 ){
    return SQLITE_ERROR;
  }

  *pnOut = nInt;
  *pp += nByte;
  return SQLITE_OK;
}

/*
** This function is called to allocate an array of Fts3Index structures
** representing the indexes maintained by the current FTS table. FTS tables
** always maintain the main "terms" index, but may also maintain one or

  int rc = SQLITE_OK;             /* Return code */
  const char *zCsr = zNode;       /* Cursor to iterate through node */
  const char *zEnd = &zCsr[nNode];/* End of interior node buffer */
  char *zBuffer = 0;              /* Buffer to load terms into */
  i64 nAlloc = 0;                 /* Size of allocated buffer */
  int isFirstTerm = 1;            /* True when processing first term on page */
  sqlite3_int64 iChild;           /* Block id of child node to descend to */
  int nBuffer = 0;                /* Total term size */

  /* Skip over the 'height' varint that occurs at the start of every 
  ** interior node. Then load the blockid of the left-child of the b-tree
  ** node into variable iChild.  
  **
  ** Even if the data structure on disk is corrupted, this (reading two
  ** varints from the buffer) does not risk an overread. If zNode is a

    return FTS_CORRUPT_VTAB;
  }
  
  while( zCsr<zEnd && (piFirst || piLast) ){
    int cmp;                      /* memcmp() result */
    int nSuffix;                  /* Size of term suffix */
    int nPrefix = 0;              /* Size of term prefix */

  
    /* Load the next term on the node into zBuffer. Use realloc() to expand
    ** the size of zBuffer if required.  */
    if( !isFirstTerm ){
      zCsr += fts3GetVarint32(zCsr, &nPrefix);
      if( nPrefix>nBuffer ){
        rc = FTS_CORRUPT_VTAB;
        goto finish_scan;
      }
    }
    isFirstTerm = 0;
    zCsr += fts3GetVarint32(zCsr, &nSuffix);
    
    assert( nPrefix>=0 && nSuffix>=0 );
    if( nPrefix>zCsr-zNode || nSuffix>zEnd-zCsr || nSuffix==0 ){
      rc = FTS_CORRUPT_VTAB;

** the next position.
*/
static void fts3ReadNextPos(
  char **pp,                    /* IN/OUT: Pointer into position-list buffer */
  sqlite3_int64 *pi             /* IN/OUT: Value read from position-list */
){
  if( (**pp)&0xFE ){
    int iVal;
    *pp += fts3GetVarint32((*pp), &iVal);
    *pi += iVal;
    *pi -= 2;
  }else{
    *pi = POSITION_LIST_END;
  }
}

/*

            if( pLeft->pPhrase && pLeft->pPhrase->doclist.aAll ){
              Fts3Doclist *pDl = &pLeft->pPhrase->doclist;
              while( *pRc==SQLITE_OK && pLeft->bEof==0 ){
                memset(pDl->pList, 0, pDl->nList);
                fts3EvalNextRow(pCsr, pLeft, pRc);
              }
            }
            pRight->bEof = pLeft->bEof = 1;
          }
        }
        break;
      }
  
      case FTSQUERY_OR: {
        Fts3Expr *pLeft = pExpr->pLeft;

int sqlite3Fts3VarintLen(sqlite3_uint64);
void sqlite3Fts3Dequote(char *);
void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
void sqlite3Fts3CreateStatTable(int*, Fts3Table*);
int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc);
int sqlite3Fts3ReadInt(const char *z, int *pnOut);

/* fts3_tokenizer.c */
const char *sqlite3Fts3NextToken(const char *, int *);
int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 
    sqlite3_tokenizer **, char **
);

      int nKey = pKey->n;
      char cNext;

      /* If this is a "NEAR" keyword, check for an explicit nearness. */
      if( pKey->eType==FTSQUERY_NEAR ){
        assert( nKey==4 );
        if( zInput[4]=='/' && zInput[5]>='0' && zInput[5]<='9' ){


          nKey += 1+sqlite3Fts3ReadInt(&zInput[nKey+1], &nNear);

        }
      }

      /* At this point this is probably a keyword. But for that to be true,
      ** the next byte must contain either whitespace, an open or close
      ** parenthesis, a quote character, or EOF. 
      */

  assert( p->flag==FTS3_MATCHINFO_LHITS_BM || p->flag==FTS3_MATCHINFO_LHITS );
  if( p->flag==FTS3_MATCHINFO_LHITS ){
    iStart = pExpr->iPhrase * p->nCol;
  }else{
    iStart = pExpr->iPhrase * ((p->nCol + 31) / 32);
  }

  if( pIter ) while( 1 ){
    int nHit = fts3ColumnlistCount(&pIter);
    if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){
      if( p->flag==FTS3_MATCHINFO_LHITS ){
        p->aMatchinfo[iStart + iCol] = (u32)nHit;
      }else if( nHit ){
        p->aMatchinfo[iStart + (iCol+1)/32] |= (1 << (iCol&0x1F));
      }

  if( idxNum==1 ){
    const char *zByte = (const char *)sqlite3_value_text(apVal[0]);
    int nByte = sqlite3_value_bytes(apVal[0]);
    pCsr->zInput = sqlite3_malloc64(nByte+1);
    if( pCsr->zInput==0 ){
      rc = SQLITE_NOMEM;
    }else{
      if( nByte>0 ) memcpy(pCsr->zInput, zByte, nByte);
      pCsr->zInput[nByte] = 0;
      rc = pTab->pMod->xOpen(pTab->pTok, pCsr->zInput, nByte, &pCsr->pCsr);
      if( rc==SQLITE_OK ){
        pCsr->pCsr->pTokenizer = pTab->pTok;
      }
    }
  }

  /* Check that the doclist does not appear to extend past the end of the
  ** b-tree node. And that the final byte of the doclist is 0x00. If either 
  ** of these statements is untrue, then the data structure is corrupt.
  */
  if( pReader->nDoclist > pReader->nNode-(pReader->aDoclist-pReader->aNode)
   || (pReader->nPopulate==0 && pReader->aDoclist[pReader->nDoclist-1])
   || pReader->nDoclist==0
  ){
    return FTS_CORRUPT_VTAB;
  }
  return SQLITE_OK;
}

/*

  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
  */
  sqlite3_stmt *pStmt;
  int rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_bind_int64(pStmt, 1, iAbsLevel+1);
  sqlite3_bind_int64(pStmt, 2, 
      (((u64)iAbsLevel/FTS3_SEGDIR_MAXLEVEL)+1) * FTS3_SEGDIR_MAXLEVEL
  );

  *pbMax = 0;
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    *pbMax = sqlite3_column_type(pStmt, 0)==SQLITE_NULL;
  }
  return sqlite3_reset(pStmt);

  i64 *piEndBlock,
  i64 *pnByte
){
  const unsigned char *zText = sqlite3_column_text(pStmt, iCol);
  if( zText ){
    int i;
    int iMul = 1;
    u64 iVal = 0;
    for(i=0; zText[i]>='0' && zText[i]<='9'; i++){
      iVal = iVal*10 + (zText[i] - '0');
    }
    *piEndBlock = (i64)iVal;
    while( zText[i]==' ' ) i++;
    iVal = 0;
    if( zText[i]=='-' ){
      i++;
      iMul = -1;
    }
    for(/* no-op */; zText[i]>='0' && zText[i]<='9'; i++){
      iVal = iVal*10 + (zText[i] - '0');
    }
    *pnByte = ((i64)iVal * (i64)iMul);
  }
}


/*
** A segment of size nByte bytes has just been written to absolute level
** iAbsLevel. Promote any segments that should be promoted as a result.

      }
    }

    /* If nSeg is less that zero, then there is no level with at least
    ** nMin segments and no hint in the %_stat table. No work to do.
    ** Exit early in this case.  */
    if( nSeg<=0 ) break;

    assert( nMod<=0x7FFFFFFF );
    if( iAbsLevel<0 || iAbsLevel>(nMod<<32) ){
      rc = FTS_CORRUPT_VTAB;
      break;
    }

    /* Open a cursor to iterate through the contents of the oldest nSeg 
    ** indexes of absolute level iAbsLevel. If this cursor is opened using 
    ** the 'hint' parameters, it is possible that there are less than nSeg
    ** segments available in level iAbsLevel. In this case, no work is
    ** done on iAbsLevel - fall through to the next iteration of the loop 
    ** to start work on some other level.  */

struct Fts5VocabTable {
  sqlite3_vtab base;
  char *zFts5Tbl;                 /* Name of fts5 table */
  char *zFts5Db;                  /* Db containing fts5 table */
  sqlite3 *db;                    /* Database handle */
  Fts5Global *pGlobal;            /* FTS5 global object for this database */
  int eType;                      /* FTS5_VOCAB_COL, ROW or INSTANCE */
  unsigned bBusy;                 /* True if busy */
};

struct Fts5VocabCursor {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pStmt;            /* Statement holding lock on pIndex */
  Fts5Table *pFts5;               /* Associated FTS5 table */

  Fts5VocabTable *pTab = (Fts5VocabTable*)pVTab;
  Fts5Table *pFts5 = 0;
  Fts5VocabCursor *pCsr = 0;
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = 0;
  char *zSql = 0;

  if( pTab->bBusy ){
    pVTab->zErrMsg = sqlite3_mprintf(
       "recursive definition for %s.%s", pTab->zFts5Db, pTab->zFts5Tbl
    );
    return SQLITE_ERROR;
  }
  zSql = sqlite3Fts5Mprintf(&rc,
      "SELECT t.%Q FROM %Q.%Q AS t WHERE t.%Q MATCH '*id'",
      pTab->zFts5Tbl, pTab->zFts5Db, pTab->zFts5Tbl, pTab->zFts5Tbl
  );
  if( zSql ){
    rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);
  }
  sqlite3_free(zSql);
  assert( rc==SQLITE_OK || pStmt==0 );
  if( rc==SQLITE_ERROR ) rc = SQLITE_OK;

  pTab->bBusy = 1;
  if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
    i64 iId = sqlite3_column_int64(pStmt, 0);
    pFts5 = sqlite3Fts5TableFromCsrid(pTab->pGlobal, iId);
  }
  pTab->bBusy = 0;

  if( rc==SQLITE_OK ){
    if( pFts5==0 ){
      rc = sqlite3_finalize(pStmt);
      pStmt = 0;
      if( rc==SQLITE_OK ){
        pVTab->zErrMsg = sqlite3_mprintf(

do_execsql_test 10.7.2 {
  SELECT * FROM t2 WHERE term>?;
}
do_execsql_test 10.7.3 {
  SELECT * FROM t2 WHERE term=?;
}

# 2020-02-16  Detect recursively define fts5vocab() tables.
# Error found by dbsqlfuzz.
#
reset_db
do_execsql_test 11.100 {
  CREATE VIRTUAL TABLE t3 USING fts5vocab(rowid , 'col');
  CREATE VIRTUAL TABLE rowid USING fts5vocab(rowid , 'instance');
} {}
do_catchsql_test 11.110 {
  SELECT rowid+1,rowid, * FROM t3 WHERE null>rowid ;
} {1 {SQL logic error}}

finish_test

2  COMPILATION AND USAGE

  The easiest way to compile and use the ICU extension is to build
  and use it as a dynamically loadable SQLite extension. To do this
  using gcc on *nix:

    gcc -fPIC -shared icu.c `pkg-config --libs --cflags icu-uc icu-io` \
        -o libSqliteIcu.so

  You may need to add "-I" flags so that gcc can find sqlite3ext.h
  and sqlite3.h. The resulting shared lib, libSqliteIcu.so, may be
  loaded into sqlite in the same way as any other dynamically loadable
  extension.

    /* There are now 4 possibilities:
    **
    **     1. uPattern is an unescaped match-all character "%",
    **     2. uPattern is an unescaped match-one character "_",
    **     3. uPattern is an unescaped escape character, or
    **     4. uPattern is to be handled as an ordinary character
    */
    if( uPattern==MATCH_ALL && !prevEscape && uPattern!=(uint32_t)uEsc ){
      /* Case 1. */
      uint8_t c;

      /* Skip any MATCH_ALL or MATCH_ONE characters that follow a
      ** MATCH_ALL. For each MATCH_ONE, skip one character in the 
      ** test string.
      */

        if( icuLikeCompare(zPattern, zString, uEsc) ){
          return 1;
        }
        SQLITE_ICU_SKIP_UTF8(zString);
      }
      return 0;

    }else if( uPattern==MATCH_ONE && !prevEscape && uPattern!=(uint32_t)uEsc ){
      /* Case 2. */
      if( *zString==0 ) return 0;
      SQLITE_ICU_SKIP_UTF8(zString);

    }else if( uPattern==(uint32_t)uEsc && !prevEscape ){
      /* Case 3. */
      prevEscape = 1;

    }else{
      /* Case 4. */
      uint32_t uString;
      SQLITE_ICU_READ_UTF8(zString, uString);

/*
** 2020-04-20
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements a VFS shim that writes a checksum on each page
** of an SQLite database file.  When reading pages, the checksum is verified
** and an error is raised if the checksum is incorrect.
**
** COMPILING
**
** This extension requires SQLite 3.32.0 or later.  It uses the
** sqlite3_database_file_object() interface which was added in
** version 3.32.0, so it will not link with an earlier version of
** SQLite.
**
** To build this extension as a separately loaded shared library or
** DLL, use compiler command-lines similar to the following:
**
**   (linux)    gcc -fPIC -shared cksumvfs.c -o cksumvfs.so
**   (mac)      clang -fPIC -dynamiclib cksumvfs.c -o cksumvfs.dylib
**   (windows)  cl cksumvfs.c -link -dll -out:cksumvfs.dll
**
** You may want to add additional compiler options, of course,
** according to the needs of your project.
**
** If you want to statically link this extension with your product,
** then compile it like any other C-language module but add the
** "-DSQLITE_CKSUMVFS_STATIC" option so that this module knows that
** it is being statically linked rather than dynamically linked
**
** LOADING
**
** To load this extension as a shared library, you first have to
** bring up a dummy SQLite database connection to use as the argument
** to the sqlite3_load_extension() API call.  Then you invoke the
** sqlite3_load_extension() API and shutdown the dummy database
** connection.  All subsequent database connections that are opened
** will include this extension.  For example:
**
**     sqlite3 *db;
**     sqlite3_open(":memory:", &db);
**     sqlite3_load_extention(db, "./cksumvfs");
**     sqlite3_close(db);
**
** If this extension is compiled with -DSQLITE_CKSUMVFS_STATIC and
** statically linked against the application, initialize it using
** a single API call as follows:
**
**     sqlite3_cksumvfs_init();
**
** Cksumvfs is a VFS Shim. When loaded, "cksmvfs" becomes the new
** default VFS and it uses the prior default VFS as the next VFS
** down in the stack.  This is normally what you want.  However, it
** complex situations where multiple VFS shims are being loaded,
** it might be important to ensure that cksumvfs is loaded in the
** correct order so that it sequences itself into the default VFS
** Shim stack in the right order.
**
** USING
**
** Open database connections using the sqlite3_open() or 
** sqlite3_open_v2() interfaces, as normal.  Ordinary database files
** (without a checksum) will operate normally.  Databases with 
** checksums will return an SQLITE_IOERR_DATA error if a page is
** encountered that contains an invalid checksum.
**
** Checksumming only works on databases that have a reserve-bytes
** value of exactly 8.  The default value for reserve-bytes is 0.
** Hence, newly created database files will omit the checksum by
** default.  To create a database that includes a checksum, change
** the reserve-bytes value to 8 by runing:
**
**    int n = 8;
**    sqlite3_file_control(db, 0, SQLITE_FCNTL_RESERVED_BYTES, &n);
**
** If you do this immediately after creating a new database file,
** before anything else has been written into the file, then that
** might be all that you need to do.  Otherwise, the API call
** above should be followed by:
**
**    sqlite3_exec(db, "VACUUM", 0, 0, 0);
**
** It never hurts to run the VACUUM, even if you don't need it.
** If the database is in WAL mode, you should shutdown and
** reopen all database connections before continuing.
**
** From the CLI, use the ".filectrl reserve_bytes 8" command, 
** followed by "VACUUM;".
**
** Note that SQLite allows the number of reserve-bytes to be
** increased but not decreased.  So if a database file already
** has a reserve-bytes value greater than 8, there is no way to
** activate checksumming on that database, other than to dump
** and restore the database file.  Note also that other extensions
** might also make use of the reserve-bytes.  Checksumming will
** be incompatible with those other extensions.
**
** VERIFICATION OF CHECKSUMS
**
** If any checksum is incorrect, the "PRAGMA quick_check" command
** will find it.  To verify that checksums are actually enabled
** and running, use the following query:
**
**   SELECT count(*), verify_checksum(data)
**     FROM sqlite_dbpage
**    GROUP BY 2;
**
** There are three possible outputs form the verify_checksum()
** function: 1, 0, and NULL.  1 is returned if the checksum is
** correct.  0 is returned if the checksum is incorrect.  NULL
** is returned if the page is unreadable.  If checksumming is
** enabled, the read will fail if the checksum is wrong, so the
** usual result from verify_checksum() on a bad checksum is NULL.
**
** If everything is OK, the query above should return a single
** row where the second column is 1.  Any other result indicates
** either that there is a checksum error, or checksum validation
** is disabled.
**
** CONTROLLING CHECKSUM VERIFICATION
**
** The cksumvfs extension implements a new PRAGMA statement that can
** be used to disable, re-enable, or query the status of checksum
** verification:
**
**    PRAGMA checksum_verification;          -- query status
**    PRAGMA checksum_verification=OFF;      -- disable verification
**    PRAGMA checksum_verification=ON;       -- re-enable verification
**
** The "checksum_verification" pragma will return "1" (true) or "0"
** (false) if checksum verification is enabled or disabled, respectively.
** "Verification" in this context means the feature that causes
** SQLITE_IOERR_DATA errors if a checksum mismatch is detected while
** reading.  Checksums are always kept up-to-date as long as the
** reserve-bytes value of the database is 8, regardless of the setting
** of this pragma.  Checksum verification can be disabled (for example)
** to do forensic analysis of a database that has previously reported
** a checksum error.
**
** The "checksum_verification" pragma will always respond with "0" if
** the database file does not have a reserve-bytes value of 8.  The
** pragma will return no rows at all if the cksumvfs extension is
** not loaded.
**
** IMPLEMENTATION NOTES
**
** The checksum is stored in the last 8 bytes of each page.  This
** module only operates if the "bytes of reserved space on each page"
** value at offset 20 the SQLite database header is exactly 8.  If
** the reserved-space value is not 8, this module is a no-op.
*/
#ifdef SQLITE_CKSUMVFS_STATIC
# include "sqlite3.h"
#else
# include "sqlite3ext.h"
  SQLITE_EXTENSION_INIT1
#endif
#include <string.h>
#include <assert.h>


/*
** Forward declaration of objects used by this utility
*/
typedef struct sqlite3_vfs CksmVfs;
typedef struct CksmFile CksmFile;

/*
** Useful datatype abbreviations
*/
#if !defined(SQLITE_CORE)
  typedef unsigned char u8;
  typedef unsigned int u32;
#endif

/* Access to a lower-level VFS that (might) implement dynamic loading,
** access to randomness, etc.
*/
#define ORIGVFS(p)  ((sqlite3_vfs*)((p)->pAppData))
#define ORIGFILE(p) ((sqlite3_file*)(((CksmFile*)(p))+1))

/* An open file */
struct CksmFile {
  sqlite3_file base;    /* IO methods */
  const char *zFName;   /* Original name of the file */
  char computeCksm;     /* True to compute checksums.
                        ** Always true if reserve size is 8. */
  char verifyCksm;      /* True to verify checksums */
  char isWal;           /* True if processing a WAL file */
  char inCkpt;          /* Currently doing a checkpoint */
  CksmFile *pPartner;   /* Ptr from WAL to main-db, or from main-db to WAL */
};

/*
** Methods for CksmFile
*/
static int cksmClose(sqlite3_file*);
static int cksmRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int cksmWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
static int cksmTruncate(sqlite3_file*, sqlite3_int64 size);
static int cksmSync(sqlite3_file*, int flags);
static int cksmFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int cksmLock(sqlite3_file*, int);
static int cksmUnlock(sqlite3_file*, int);
static int cksmCheckReservedLock(sqlite3_file*, int *pResOut);
static int cksmFileControl(sqlite3_file*, int op, void *pArg);
static int cksmSectorSize(sqlite3_file*);
static int cksmDeviceCharacteristics(sqlite3_file*);
static int cksmShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
static int cksmShmLock(sqlite3_file*, int offset, int n, int flags);
static void cksmShmBarrier(sqlite3_file*);
static int cksmShmUnmap(sqlite3_file*, int deleteFlag);
static int cksmFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
static int cksmUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);

/*
** Methods for CksmVfs
*/
static int cksmOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
static int cksmDelete(sqlite3_vfs*, const char *zName, int syncDir);
static int cksmAccess(sqlite3_vfs*, const char *zName, int flags, int *);
static int cksmFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
static void *cksmDlOpen(sqlite3_vfs*, const char *zFilename);
static void cksmDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
static void (*cksmDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
static void cksmDlClose(sqlite3_vfs*, void*);
static int cksmRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int cksmSleep(sqlite3_vfs*, int microseconds);
static int cksmCurrentTime(sqlite3_vfs*, double*);
static int cksmGetLastError(sqlite3_vfs*, int, char *);
static int cksmCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
static int cksmSetSystemCall(sqlite3_vfs*, const char*,sqlite3_syscall_ptr);
static sqlite3_syscall_ptr cksmGetSystemCall(sqlite3_vfs*, const char *z);
static const char *cksmNextSystemCall(sqlite3_vfs*, const char *zName);

static sqlite3_vfs cksm_vfs = {
  3,                            /* iVersion (set when registered) */
  0,                            /* szOsFile (set when registered) */
  1024,                         /* mxPathname */
  0,                            /* pNext */
  "cksmvfs",                    /* zName */
  0,                            /* pAppData (set when registered) */ 
  cksmOpen,                     /* xOpen */
  cksmDelete,                   /* xDelete */
  cksmAccess,                   /* xAccess */
  cksmFullPathname,             /* xFullPathname */
  cksmDlOpen,                   /* xDlOpen */
  cksmDlError,                  /* xDlError */
  cksmDlSym,                    /* xDlSym */
  cksmDlClose,                  /* xDlClose */
  cksmRandomness,               /* xRandomness */
  cksmSleep,                    /* xSleep */
  cksmCurrentTime,              /* xCurrentTime */
  cksmGetLastError,             /* xGetLastError */
  cksmCurrentTimeInt64,         /* xCurrentTimeInt64 */
  cksmSetSystemCall,            /* xSetSystemCall */
  cksmGetSystemCall,            /* xGetSystemCall */
  cksmNextSystemCall            /* xNextSystemCall */
};

static const sqlite3_io_methods cksm_io_methods = {
  3,                              /* iVersion */
  cksmClose,                      /* xClose */
  cksmRead,                       /* xRead */
  cksmWrite,                      /* xWrite */
  cksmTruncate,                   /* xTruncate */
  cksmSync,                       /* xSync */
  cksmFileSize,                   /* xFileSize */
  cksmLock,                       /* xLock */
  cksmUnlock,                     /* xUnlock */
  cksmCheckReservedLock,          /* xCheckReservedLock */
  cksmFileControl,                /* xFileControl */
  cksmSectorSize,                 /* xSectorSize */
  cksmDeviceCharacteristics,      /* xDeviceCharacteristics */
  cksmShmMap,                     /* xShmMap */
  cksmShmLock,                    /* xShmLock */
  cksmShmBarrier,                 /* xShmBarrier */
  cksmShmUnmap,                   /* xShmUnmap */
  cksmFetch,                      /* xFetch */
  cksmUnfetch                     /* xUnfetch */
};

/* Do byte swapping on a unsigned 32-bit integer */
#define BYTESWAP32(x) ( \
    (((x)&0x000000FF)<<24) + (((x)&0x0000FF00)<<8)  \
  + (((x)&0x00FF0000)>>8)  + (((x)&0xFF000000)>>24) \
)

/* Compute a checksum on a buffer */
static void cksmCompute(
  u8 *a,           /* Content to be checksummed */
  int nByte,       /* Bytes of content in a[].  Must be a multiple of 8. */
  u8 *aOut         /* OUT: Final 8-byte checksum value output */
){
  u32 s1 = 0, s2 = 0;
  u32 *aData = (u32*)a;
  u32 *aEnd = (u32*)&a[nByte];
  u32 x = 1;

  assert( nByte>=8 );
  assert( (nByte&0x00000007)==0 );
  assert( nByte<=65536 );

  if( 1 == *(u8*)&x ){
    /* Little-endian */
    do {
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
    }while( aData<aEnd );
  }else{
    /* Big-endian */
    do {
      s1 += BYTESWAP32(aData[0]) + s2;
      s2 += BYTESWAP32(aData[1]) + s1;
      aData += 2;
    }while( aData<aEnd );
    s1 = BYTESWAP32(s1);
    s2 = BYTESWAP32(s2);
  }
  memcpy(aOut, &s1, 4);
  memcpy(aOut+4, &s2, 4);
}

/*
** SQL function:    verify_checksum(BLOB)
**
** Return 0 or 1 if the checksum is invalid or valid.  Or return
** NULL if the input is not a BLOB that is the right size for a
** database page.
*/
static void cksmVerifyFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int nByte;
  u8 *data;
  u8 cksum[8];
  data = (u8*)sqlite3_value_blob(argv[0]);
  if( data==0 ) return;
  if( sqlite3_value_type(argv[0])!=SQLITE_BLOB ) return;
  nByte = sqlite3_value_bytes(argv[0]);
  if( nByte<512 || nByte>65536 || (nByte & (nByte-1))!=0 ) return;
  cksmCompute(data, nByte-8, cksum);
  sqlite3_result_int(context, memcmp(data+nByte-8,cksum,8)==0);
}

/*
** Close a cksm-file.
*/
static int cksmClose(sqlite3_file *pFile){
  CksmFile *p = (CksmFile *)pFile;
  if( p->pPartner ){
    assert( p->pPartner->pPartner==p );
    p->pPartner->pPartner = 0;
    p->pPartner = 0;
  }
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xClose(pFile);
}

/*
** Set the computeCkSm and verifyCksm flags, if they need to be
** changed.
*/
static void cksmSetFlags(CksmFile *p, int hasCorrectReserveSize){
  if( hasCorrectReserveSize!=p->computeCksm ){
    p->computeCksm = p->verifyCksm = hasCorrectReserveSize;
    if( p->pPartner ){
      p->pPartner->verifyCksm = hasCorrectReserveSize;
      p->pPartner->computeCksm = hasCorrectReserveSize;
    }
  }
}

/*
** Read data from a cksm-file.
*/
static int cksmRead(
  sqlite3_file *pFile, 
  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  int rc;
  CksmFile *p = (CksmFile *)pFile;
  pFile = ORIGFILE(pFile);
  rc = pFile->pMethods->xRead(pFile, zBuf, iAmt, iOfst);
  if( rc==SQLITE_OK ){
    if( iOfst==0 && iAmt>=100 && memcmp(zBuf,"SQLite format 3",16)==0 ){
      u8 *d = (u8*)zBuf;
      char hasCorrectReserveSize = (d[20]==8);
      cksmSetFlags(p, hasCorrectReserveSize);
    }
    /* Verify the checksum if
    **    (1) the size indicates that we are dealing with a complete
    **        database page
    **    (2) checksum verification is enabled
    **    (3) we are not in the middle of checkpoint
    */
    if( iAmt>=512           /* (1) */
     && p->verifyCksm       /* (2) */
     && !p->inCkpt          /* (3) */
    ){
      u8 cksum[8];
      cksmCompute((u8*)zBuf, iAmt-8, cksum);
      if( memcmp((u8*)zBuf+iAmt-8, cksum, 8)!=0 ){
        sqlite3_log(SQLITE_IOERR_DATA,
           "checksum fault offset %lld of \"%s\"",
           iOfst, p->zFName);
        rc = SQLITE_IOERR_DATA;
      }
    }
  }
  return rc;
}

/*
** Write data to a cksm-file.
*/
static int cksmWrite(
  sqlite3_file *pFile,
  const void *zBuf,
  int iAmt,
  sqlite_int64 iOfst
){
  CksmFile *p = (CksmFile *)pFile;
  pFile = ORIGFILE(pFile);
  if( iOfst==0 && iAmt>=100 && memcmp(zBuf,"SQLite format 3",16)==0 ){
    u8 *d = (u8*)zBuf;
    char hasCorrectReserveSize = (d[20]==8);
    cksmSetFlags(p, hasCorrectReserveSize);
  }
  /* If the write size is appropriate for a database page and if
  ** checksums where ever enabled, then it will be safe to compute
  ** the checksums.  The reserve byte size might have increased, but
  ** it will never decrease.  And because it cannot decrease, the
  ** checksum will not overwrite anything.
  */
  if( iAmt>=512
   && p->computeCksm
   && !p->inCkpt
  ){
    cksmCompute((u8*)zBuf, iAmt-8, ((u8*)zBuf)+iAmt-8);
  }
  return pFile->pMethods->xWrite(pFile, zBuf, iAmt, iOfst);
}

/*
** Truncate a cksm-file.
*/
static int cksmTruncate(sqlite3_file *pFile, sqlite_int64 size){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xTruncate(pFile, size);
}

/*
** Sync a cksm-file.
*/
static int cksmSync(sqlite3_file *pFile, int flags){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xSync(pFile, flags);
}

/*
** Return the current file-size of a cksm-file.
*/
static int cksmFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  CksmFile *p = (CksmFile *)pFile;
  pFile = ORIGFILE(p);
  return pFile->pMethods->xFileSize(pFile, pSize);
}

/*
** Lock a cksm-file.
*/
static int cksmLock(sqlite3_file *pFile, int eLock){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xLock(pFile, eLock);
}

/*
** Unlock a cksm-file.
*/
static int cksmUnlock(sqlite3_file *pFile, int eLock){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xUnlock(pFile, eLock);
}

/*
** Check if another file-handle holds a RESERVED lock on a cksm-file.
*/
static int cksmCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xCheckReservedLock(pFile, pResOut);
}

/*
** File control method. For custom operations on a cksm-file.
*/
static int cksmFileControl(sqlite3_file *pFile, int op, void *pArg){
  int rc;
  CksmFile *p = (CksmFile*)pFile;
  pFile = ORIGFILE(pFile);
  if( op==SQLITE_FCNTL_PRAGMA ){
    char **azArg = (char**)pArg;
    assert( azArg[1]!=0 );
    if( sqlite3_stricmp(azArg[1],"checksum_verification")==0 ){
      char *zArg = azArg[2];
      if( zArg!=0 ){
        if( (zArg[0]>='1' && zArg[0]<='9')
         || sqlite3_strlike("enable%",zArg,0)==0
         || sqlite3_stricmp("yes",zArg)==0
         || sqlite3_stricmp("on",zArg)==0
        ){
          p->verifyCksm = p->computeCksm;
        }else{
          p->verifyCksm = 0;
        }
        if( p->pPartner ) p->pPartner->verifyCksm = p->verifyCksm;
      }
      azArg[0] = sqlite3_mprintf("%d",p->verifyCksm);
      return SQLITE_OK;
    }else if( p->computeCksm && azArg[2]!=0
           && sqlite3_stricmp(azArg[1], "page_size")==0 ){
      /* Do not allow page size changes on a checksum database */
      return SQLITE_OK;
    }
  }else if( op==SQLITE_FCNTL_CKPT_START || op==SQLITE_FCNTL_CKPT_DONE ){
    p->inCkpt = op==SQLITE_FCNTL_CKPT_START;
    if( p->pPartner ) p->pPartner->inCkpt = p->inCkpt;
  }
  rc = pFile->pMethods->xFileControl(pFile, op, pArg);
  if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){
    *(char**)pArg = sqlite3_mprintf("cksm/%z", *(char**)pArg);
  }
  return rc;
}

/*
** Return the sector-size in bytes for a cksm-file.
*/
static int cksmSectorSize(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xSectorSize(pFile);
}

/*
** Return the device characteristic flags supported by a cksm-file.
*/
static int cksmDeviceCharacteristics(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xDeviceCharacteristics(pFile);
}

/* Create a shared memory file mapping */
static int cksmShmMap(
  sqlite3_file *pFile,
  int iPg,
  int pgsz,
  int bExtend,
  void volatile **pp
){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmMap(pFile,iPg,pgsz,bExtend,pp);
}

/* Perform locking on a shared-memory segment */
static int cksmShmLock(sqlite3_file *pFile, int offset, int n, int flags){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmLock(pFile,offset,n,flags);
}

/* Memory barrier operation on shared memory */
static void cksmShmBarrier(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  pFile->pMethods->xShmBarrier(pFile);
}

/* Unmap a shared memory segment */
static int cksmShmUnmap(sqlite3_file *pFile, int deleteFlag){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmUnmap(pFile,deleteFlag);
}

/* Fetch a page of a memory-mapped file */
static int cksmFetch(
  sqlite3_file *pFile,
  sqlite3_int64 iOfst,
  int iAmt,
  void **pp
){
  CksmFile *p = (CksmFile *)pFile;
  if( p->computeCksm ){
    *pp = 0;
    return SQLITE_OK;
  }
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xFetch(pFile, iOfst, iAmt, pp);
}

/* Release a memory-mapped page */
static int cksmUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xUnfetch(pFile, iOfst, pPage);
}

/*
** Open a cksm file handle.
*/
static int cksmOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  CksmFile *p;
  sqlite3_file *pSubFile;
  sqlite3_vfs *pSubVfs;
  int rc;
  pSubVfs = ORIGVFS(pVfs);
  if( (flags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_WAL))==0 ){
    return pSubVfs->xOpen(pSubVfs, zName, pFile, flags, pOutFlags);
  }
  p = (CksmFile*)pFile;
  memset(p, 0, sizeof(*p));
  pSubFile = ORIGFILE(pFile);
  p->base.pMethods = &cksm_io_methods;
  rc = pSubVfs->xOpen(pSubVfs, zName, pSubFile, flags, pOutFlags);
  if( rc ) goto cksm_open_done;
  if( flags & SQLITE_OPEN_WAL ){
    sqlite3_file *pDb = sqlite3_database_file_object(zName);
    p->pPartner = (CksmFile*)pDb;
    assert( p->pPartner->pPartner==0 );
    p->pPartner->pPartner = p;
    p->isWal = 1;
    p->computeCksm = p->pPartner->computeCksm;
  }else{
    p->isWal = 0;
    p->computeCksm = 0;
  }
  p->zFName = zName;
cksm_open_done:
  if( rc ) pFile->pMethods = 0;
  return rc;
}

/*
** All other VFS methods are pass-thrus.
*/
static int cksmDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync);
}
static int cksmAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  return ORIGVFS(pVfs)->xAccess(ORIGVFS(pVfs), zPath, flags, pResOut);
}
static int cksmFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nOut, 
  char *zOut
){
  return ORIGVFS(pVfs)->xFullPathname(ORIGVFS(pVfs),zPath,nOut,zOut);
}
static void *cksmDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath);
}
static void cksmDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg);
}
static void (*cksmDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
  return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym);
}
static void cksmDlClose(sqlite3_vfs *pVfs, void *pHandle){
  ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle);
}
static int cksmRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);
}
static int cksmSleep(sqlite3_vfs *pVfs, int nMicro){
  return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);
}
static int cksmCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);
}
static int cksmGetLastError(sqlite3_vfs *pVfs, int a, char *b){
  return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
}
static int cksmCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
  return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
}
static int cksmSetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_syscall_ptr pCall
){
  return ORIGVFS(pVfs)->xSetSystemCall(ORIGVFS(pVfs),zName,pCall);
}
static sqlite3_syscall_ptr cksmGetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName
){
  return ORIGVFS(pVfs)->xGetSystemCall(ORIGVFS(pVfs),zName);
}
static const char *cksmNextSystemCall(sqlite3_vfs *pVfs, const char *zName){
  return ORIGVFS(pVfs)->xNextSystemCall(ORIGVFS(pVfs), zName);
}

/* Register the verify_checksum() SQL function.
*/
static int cksmRegisterFunc(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc;
  if( db==0 ) return SQLITE_OK;
  rc = sqlite3_create_function(db, "verify_checksum", 1,
                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                   0, cksmVerifyFunc, 0, 0);
  return rc;
}

/*
** Register the cksum VFS as the default VFS for the system.
** Also make arrangements to automatically register the "verify_checksum()"
** SQL function on each new database connection.
*/
static int cksmRegisterVfs(void){
  int rc = SQLITE_OK;
  sqlite3_vfs *pOrig;
  if( sqlite3_vfs_find("cksum")!=0 ) return SQLITE_OK;
  pOrig = sqlite3_vfs_find(0);
  cksm_vfs.iVersion = pOrig->iVersion;
  cksm_vfs.pAppData = pOrig;
  cksm_vfs.szOsFile = pOrig->szOsFile + sizeof(CksmFile);
  rc = sqlite3_vfs_register(&cksm_vfs, 1);
  if( rc==SQLITE_OK ){
    rc = sqlite3_auto_extension((void(*)(void))cksmRegisterFunc);
  }
  return rc;
}

#if defined(SQLITE_CKSUMVFS_STATIC)
/* This variant of the initializer runs when the extension is
** statically linked.
*/
int sqlite3_register_cksumvfs(const char *NotUsed){
  (void)NotUsed;
  return cksmRegisterVfs();
}
#endif /* defined(SQLITE_CKSUMVFS_STATIC */

#if !defined(SQLITE_CKSUMVFS_STATIC)
/* This variant of the initializer function is used when the
** extension is shared library to be loaded at run-time.
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
/* 
** This routine is called by sqlite3_load_extension() when the
** extension is first loaded.
***/
int sqlite3_cksumvfs_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg; /* not used */
  rc = cksmRegisterFunc(db, 0, 0);
  if( rc==SQLITE_OK ){
    
  }
  if( rc==SQLITE_OK ){
    rc = cksmRegisterVfs();
  }
  if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
  return rc;
}
#endif /* !defined(SQLITE_CKSUMVFS_STATIC) */

      if( rc ) return 2;
      sqlite3_result_int64(pCtx, nWrite);
    }
  }

  if( mtime>=0 ){
#if defined(_WIN32)
#if !SQLITE_OS_WINRT
    /* Windows */
    FILETIME lastAccess;
    FILETIME lastWrite;
    SYSTEMTIME currentTime;
    LONGLONG intervals;
    HANDLE hFile;
    LPWSTR zUnicodeName;

    if( hFile!=INVALID_HANDLE_VALUE ){
      BOOL bResult = SetFileTime(hFile, NULL, &lastAccess, &lastWrite);
      CloseHandle(hFile);
      return !bResult;
    }else{
      return 1;
    }
#endif
#elif defined(AT_FDCWD) && 0 /* utimensat() is not universally available */
    /* Recent unix */
    struct timespec times[2];
    times[0].tv_nsec = times[1].tv_nsec = 0;
    times[0].tv_sec = time(0);
    times[1].tv_sec = mtime;
    if( utimensat(AT_FDCWD, zFile, times, AT_SYMLINK_NOFOLLOW) ){

  p->nAlloc = nTotal;
  return SQLITE_OK;
}

/* Append N bytes from zIn onto the end of the JsonString string.
*/
static void jsonAppendRaw(JsonString *p, const char *zIn, u32 N){
  if( N==0 ) return;
  if( (N+p->nUsed >= p->nAlloc) && jsonGrow(p,N)!=0 ) return;
  memcpy(p->zBuf+p->nUsed, zIn, N);
  p->nUsed += N;
}

/* Append formatted text (not to exceed N bytes) to the JsonString.
*/

  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sha1", 1, 
                       SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                               0, sha1Func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha1_query", 1, 
                                 SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                                 sha1QueryFunc, 0, 0);
  }
  return rc;
}

** Utility functions sqlar_compress() and sqlar_uncompress(). Useful
** for working with sqlar archives and used by the shell tool's built-in
** sqlar support.
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <zlib.h>
#include <assert.h>

/*
** Implementation of the "sqlar_compress(X)" SQL function.
**
** If the type of X is SQLITE_BLOB, and compressing that blob using
** zlib utility function compress() yields a smaller blob, return the
** compressed blob. Otherwise, return a copy of X.

      sqlite3_result_int(ctx, sqlite3_stmt_readonly(pCur->pStmt));
      break;
    }
    case STMT_COLUMN_BUSY: {
      sqlite3_result_int(ctx, sqlite3_stmt_busy(pCur->pStmt));
      break;
    }
    default: {
      assert( i==STMT_COLUMN_MEM );
      i = SQLITE_STMTSTATUS_MEMUSED + 
            STMT_COLUMN_NSCAN - SQLITE_STMTSTATUS_FULLSCAN_STEP;
      /* Fall thru */
    }
    case STMT_COLUMN_NSCAN:
    case STMT_COLUMN_NSORT:
    case STMT_COLUMN_NAIDX:

/*
** 2020-04-14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements the UINT collating sequence.
**
** UINT works like BINARY for text, except that embedded strings
** of digits compare in numeric order.
**
**     *   Leading zeros are handled properly, in the sense that
**         they do not mess of the maginitude comparison of embedded
**         strings of digits.  "x00123y" is equal to "x123y".
**
**     *   Only unsigned integers are recognized.  Plus and minus
**         signs are ignored.  Decimal points and exponential notation
**         are ignored.
**
**     *   Embedded integers can be of arbitrary length.  Comparison
**         is *not* limited integers that can be expressed as a
**         64-bit machine integer.
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>

/*
** Compare text in lexicographic order, except strings of digits
** compare in numeric order.
*/
static int uintCollFunc(
  void *notUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const unsigned char *zA = (const unsigned char*)pKey1;
  const unsigned char *zB = (const unsigned char*)pKey2;
  int i=0, j=0, x;
  (void)notUsed;
  while( i<nKey1 && j<nKey2 ){
    x = zA[i] - zB[j];
    if( isdigit(zA[i]) ){
      int k;
      if( !isdigit(zB[j]) ) return x;
      while( i<nKey1 && zA[i]=='0' ){ i++; }
      while( j<nKey2 && zB[j]=='0' ){ j++; }
      k = 0;
      while( i+k<nKey1 && isdigit(zA[i+k])
             && j+k<nKey2 && isdigit(zB[j+k]) ){
        k++;
      }
      if( i+k<nKey1 && isdigit(zA[i+k]) ){
        return +1;
      }else if( j+k<nKey2 && isdigit(zB[j+k]) ){
        return -1;
      }else{
        x = memcmp(zA+i, zB+j, k);
        if( x ) return x;
        i += k;
        j += k;
      }
    }else if( x ){
      return x;
    }else{
      i++;
      j++;
    }
  }
  return (nKey1 - i) - (nKey2 - j);
}

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_uint_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  return sqlite3_create_collation(db, "uint", SQLITE_UTF8, 0, uintCollFunc);
}

  SQLITE_EXTENSION_INIT2(pApi);
  vstat_vfs.pVfs = sqlite3_vfs_find(0);
  vstat_vfs.base.szOsFile = sizeof(VStatFile) + vstat_vfs.pVfs->szOsFile;
  rc = sqlite3_vfs_register(&vstat_vfs.base, 1);
  if( rc==SQLITE_OK ){
    rc = vstatRegister(db, pzErrMsg, pApi);
    if( rc==SQLITE_OK ){
      rc = sqlite3_auto_extension((void(*)(void))vstatRegister);
    }
  }
  if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
  return rc;
}

    const char *zArg = argv[ii];
    if( zArg[0]=='+' ){
      pRtree->nAux++;
      sqlite3_str_appendf(pSql, ",%.*s", rtreeTokenLength(zArg+1), zArg+1);
    }else if( pRtree->nAux>0 ){
      break;
    }else{
      static const char *azFormat[] = {",%.*s REAL", ",%.*s INT"};
      pRtree->nDim2++;
      sqlite3_str_appendf(pSql, azFormat[eCoordType],
                          rtreeTokenLength(zArg), zArg);
    }
  }
  sqlite3_str_appendf(pSql, ");");
  zSql = sqlite3_str_finish(pSql);
  if( !zSql ){
    rc = SQLITE_NOMEM;
  }else if( ii<argc ){

do_execsql_test 18.0 {
  CREATE VIRTUAL TABLE rt0 USING rtree(c0, c1, c2);
  INSERT INTO rt0(c0,c1,c2) VALUES(9,2,3);
  SELECT c0 FROM rt0 WHERE rt0.c1 > '-1'; 
  SELECT rt0.c1 > '-1' FROM rt0;
} {9 1}

expand_all_sql db

# 2020-02-28 ticket e63b4d1a65546532
reset_db
do_execsql_test 19.0 {
  CREATE VIRTUAL TABLE rt0 USING rtree(a,b,c);
  INSERT INTO rt0(a,b,c) VALUES(0,0.0,0.0);
  CREATE VIEW v0(x) AS SELECT DISTINCT rt0.b FROM rt0;
  SELECT v0.x FROM v0, rt0;
} {0.0}
do_execsql_test 19.1 {
  SELECT v0.x FROM v0, rt0 WHERE v0.x = rt0.b;
} {0.0}

finish_test

    WITH s(i) AS (
      VALUES(1) UNION ALL SELECT i+1 FROM s WHERe i<10000
    )
    INSERT INTO t1 SELECT 'abcde', randomblob(16), i FROM s;
  }
  compare_db db db2
} {}

#------------------------------------------------------------------------
db2 close
reset_db

do_execsql_test 2.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
  INSERT INTO main.t1 VALUES(1, 2, 3), (4, 5, 6), (7, 8, 9);
}

do_test 2.1 {
  sqlite3session S db main
  S attach *
  db eval {
    BEGIN;
      INSERT INTO t1 VALUES(10, 11, 12);
      DELETE FROM t1 WHERE a=1;
      UPDATE t1 SET b='five', c='six' WHERE a=4;
  }

  set C [S changeset]
  db eval ROLLBACK
  S delete
  set {} {}
} {}

do_execsql_test 2.2 {
  CREATE TEMP TABLE t1(a INTEGER PRIMARY KEY, b, c);
  INSERT INTO temp.t1 VALUES(1, 2, 3), (4, 5, 6), (7, 8, 9);
}

set ::conflict [list]
proc xConflict {args} { lappend ::conflict $args ; return "" }
do_test 2.3 {
  sqlite3changeset_apply db $C xConflict
  set ::conflict
} {}
do_execsql_test 2.4 {
  SELECT * FROM main.t1;
  SELECT '****';
  SELECT * FROM temp.t1;
} {
  4 five six 7 8 9 10 11 12
  ****
  1 2 3 4 5 6 7 8 9
}


finish_test

){
  int i;
  const char *zSep = "";
  int rc = SQLITE_OK;
  SessionBuffer buf = {0, 0, 0};
  int nPk = 0;

  sessionAppendStr(&buf, "DELETE FROM main.", &rc);
  sessionAppendIdent(&buf, zTab, &rc);
  sessionAppendStr(&buf, " WHERE ", &rc);

  for(i=0; i<p->nCol; i++){
    if( p->abPK[i] ){
      nPk++;
      sessionAppendStr(&buf, zSep, &rc);

){
  int rc = SQLITE_OK;
  int i;
  const char *zSep = "";
  SessionBuffer buf = {0, 0, 0};

  /* Append "UPDATE tbl SET " */
  sessionAppendStr(&buf, "UPDATE main.", &rc);
  sessionAppendIdent(&buf, zTab, &rc);
  sessionAppendStr(&buf, " SET ", &rc);

  /* Append the assignments */
  for(i=0; i<p->nCol; i++){
    sessionAppendStr(&buf, zSep, &rc);
    sessionAppendIdent(&buf, p->azCol[i], &rc);

         notify.o opcodes.o os.o os_unix.o os_win.o \
         pager.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o \
         select.o sqlite3rbu.o status.o stmt.o \
         table.o threads.o tokenize.o treeview.o trigger.o \
         update.o upsert.o userauth.o util.o vacuum.o \
         vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbesort.o \
	 vdbetrace.o vdbevtab.o \
         wal.o walker.o where.o wherecode.o whereexpr.o \
         utf.o vtab.o window.o

LIBOBJ += sqlite3session.o

# All of the source code files.
#
SRC = \

  $(TOP)/src/vdbe.h \
  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbeblob.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbesort.c \
  $(TOP)/src/vdbetrace.c \
  $(TOP)/src/vdbevtab.c \
  $(TOP)/src/vdbeInt.h \
  $(TOP)/src/vtab.c \
  $(TOP)/src/vxworks.h \
  $(TOP)/src/wal.c \
  $(TOP)/src/wal.h \
  $(TOP)/src/walker.c \
  $(TOP)/src/where.c \

  $(TOP)/src/tokenize.c \
  $(TOP)/src/utf.c \
  $(TOP)/src/util.c \
  $(TOP)/src/vdbeapi.c \
  $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c \
  $(TOP)/src/vdbemem.c \
  $(TOP)/src/vdbevtab.c \
  $(TOP)/src/where.c \
  $(TOP)/src/wherecode.c \
  $(TOP)/src/whereexpr.c \
  parse.c \
  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3_aux.c \
  $(TOP)/ext/fts3/fts3_expr.c \

SHELL_OPT += -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_FTS5
SHELL_OPT += -DSQLITE_ENABLE_RTREE
SHELL_OPT += -DSQLITE_ENABLE_EXPLAIN_COMMENTS
SHELL_OPT += -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
SHELL_OPT += -DSQLITE_ENABLE_STMTVTAB
SHELL_OPT += -DSQLITE_ENABLE_DBPAGE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
SHELL_OPT += -DSQLITE_ENABLE_BYTECODE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_OFFSET_SQL_FUNC
FUZZERSHELL_OPT = -DSQLITE_ENABLE_JSON1
FUZZCHECK_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5
FUZZCHECK_OPT += -DSQLITE_MAX_MEMORY=50000000
FUZZCHECK_OPT += -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_OPT += -DSQLITE_ENABLE_DESERIALIZE
FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS4
FUZZCHECK_OPT += -DSQLITE_ENABLE_RTREE
FUZZCHECK_OPT += -DSQLITE_ENABLE_GEOPOLY
FUZZCHECK_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
FUZZCHECK_OPT += -DSQLITE_ENABLE_BYTECODE_VTAB
DBFUZZ_OPT =
KV_OPT = -DSQLITE_THREADSAFE=0 -DSQLITE_DIRECT_OVERFLOW_READ
ST_OPT = -DSQLITE_THREADSAFE=0

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#

DBFUZZ2_OPTS = \
  -DSQLITE_THREADSAFE=0 \
  -DSQLITE_OMIT_LOAD_EXTENSION \
  -DSQLITE_ENABLE_DESERIALIZE \
  -DSQLITE_DEBUG \
  -DSQLITE_ENABLE_DBSTAT_VTAB \
  -DSQLITE_ENABLE_BYTECODE_VTAB \
  -DSQLITE_ENABLE_RTREE \
  -DSQLITE_ENABLE_FTS4 \
  -DSQLITE_ENABLE_FTS5

dbfuzz2$(EXE):	$(TOP)/test/dbfuzz2.c sqlite3.c sqlite3.h
	$(TCCX) -I. -g -O0 -DSTANDALONE -o dbfuzz2$(EXE) \
	  $(DBFUZZ2_OPTS) $(TOP)/test/dbfuzz2.c sqlite3.c  $(TLIBS) $(THREADLIB)

SHELL_SRC = \
	$(TOP)/src/shell.c.in \
        $(TOP)/ext/misc/appendvfs.c \
	$(TOP)/ext/misc/shathree.c \
	$(TOP)/ext/misc/fileio.c \
	$(TOP)/ext/misc/completion.c \
	$(TOP)/ext/misc/sqlar.c \
        $(TOP)/ext/misc/uint.c \
	$(TOP)/ext/expert/sqlite3expert.c \
	$(TOP)/ext/expert/sqlite3expert.h \
	$(TOP)/ext/misc/zipfile.c \
	$(TOP)/ext/misc/memtrace.c \
	$(TOP)/ext/misc/dbdata.c \
        $(TOP)/src/test_windirent.c

#
TESTFIXTURE_FLAGS  = -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
TESTFIXTURE_FLAGS += -DSQLITE_SERVER=1 -DSQLITE_PRIVATE="" -DSQLITE_CORE
TESTFIXTURE_FLAGS += -DSQLITE_SERIES_CONSTRAINT_VERIFY=1
TESTFIXTURE_FLAGS += -DSQLITE_DEFAULT_PAGE_SIZE=1024
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_STMTVTAB
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_DBPAGE_VTAB
TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_BYTECODE_VTAB
TESTFIXTURE_FLAGS += -DTCLSH_INIT_PROC=sqlite3TestInit

testfixture$(EXE): $(TESTSRC2) libsqlite3.a $(TESTSRC) $(TOP)/src/tclsqlite.c
	$(TCCX) $(TCL_FLAGS) $(TESTFIXTURE_FLAGS)                            \
		$(TESTSRC) $(TESTSRC2) $(TOP)/src/tclsqlite.c                \
		-o testfixture$(EXE) $(LIBTCL) libsqlite3.a $(THREADLIB)

  /* Get a NULL terminated version of the new table name. */
  zName = sqlite3NameFromToken(db, pName);
  if( !zName ) goto exit_rename_table;

  /* Check that a table or index named 'zName' does not already exist
  ** in database iDb. If so, this is an error.
  */
  if( sqlite3FindTable(db, zName, zDb)
   || sqlite3FindIndex(db, zName, zDb)
   || sqlite3IsShadowTableOf(db, pTab, zName)
  ){
    sqlite3ErrorMsg(pParse, 
        "there is already another table or index with this name: %s", zName);
    goto exit_rename_table;
  }

  /* Make sure it is not a system table being altered, or a reserved name
  ** that the table is being renamed to.

  renameTestSchema(pParse, zDb, iDb==1);

exit_rename_table:
  sqlite3SrcListDelete(db, pSrc);
  sqlite3DbFree(db, zName);
  db->mDbFlags = savedDbFlags;
}

/*
** Write code that will raise an error if the table described by
** zDb and zTab is not empty.
*/
static void sqlite3ErrorIfNotEmpty(
  Parse *pParse,        /* Parsing context */
  const char *zDb,      /* Schema holding the table */
  const char *zTab,     /* Table to check for empty */
  const char *zErr      /* Error message text */
){
  sqlite3NestedParse(pParse,
     "SELECT raise(ABORT,%Q) FROM \"%w\".\"%w\"",
     zErr, zDb, zTab
  );
}

/*
** This function is called after an "ALTER TABLE ... ADD" statement
** has been parsed. Argument pColDef contains the text of the new
** column definition.
**
** The Table structure pParse->pNewTable was extended to include

  ** column must not be NULL.
  */
  if( pCol->colFlags & COLFLAG_PRIMKEY ){
    sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
    return;
  }
  if( pNew->pIndex ){
    sqlite3ErrorMsg(pParse,
         "Cannot add a UNIQUE column");
    return;
  }
  if( (pCol->colFlags & COLFLAG_GENERATED)==0 ){
    /* If the default value for the new column was specified with a 
    ** literal NULL, then set pDflt to 0. This simplifies checking
    ** for an SQL NULL default below.
    */
    assert( pDflt==0 || pDflt->op==TK_SPAN );
    if( pDflt && pDflt->pLeft->op==TK_NULL ){
      pDflt = 0;
    }
    if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
      sqlite3ErrorIfNotEmpty(pParse, zDb, zTab,
          "Cannot add a REFERENCES column with non-NULL default value");

    }
    if( pCol->notNull && !pDflt ){
      sqlite3ErrorIfNotEmpty(pParse, zDb, zTab,
          "Cannot add a NOT NULL column with default value NULL");

    }


    /* Ensure the default expression is something that sqlite3ValueFromExpr()
    ** can handle (i.e. not CURRENT_TIME etc.)
    */
    if( pDflt ){
      sqlite3_value *pVal = 0;
      int rc;
      rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);
      assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
      if( rc!=SQLITE_OK ){
        assert( db->mallocFailed == 1 );
        return;
      }
      if( !pVal ){
        sqlite3ErrorIfNotEmpty(pParse, zDb, zTab,
           "Cannot add a column with non-constant default");

      }
      sqlite3ValueFree(pVal);
    }
  }else if( pCol->colFlags & COLFLAG_STORED ){
    sqlite3ErrorIfNotEmpty(pParse, zDb, zTab, "cannot add a STORED column");

  }


  /* Modify the CREATE TABLE statement. */
  zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
  if( zCol ){
    char *zEnd = &zCol[pColDef->n-1];

    assert( db->mallocFailed );
    goto exit_begin_add_column;
  }
  memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
  for(i=0; i<pNew->nCol; i++){
    Column *pCol = &pNew->aCol[i];
    pCol->zName = sqlite3DbStrDup(db, pCol->zName);
    pCol->hName = sqlite3StrIHash(pCol->zName);
    pCol->zColl = 0;
    pCol->pDflt = 0;
  }
  pNew->pSchema = db->aDb[iDb].pSchema;
  pNew->addColOffset = pTab->addColOffset;
  pNew->nTabRef = 1;

** with tail recursion in tokenExpr() routine, for a small performance
** improvement.
*/
void *sqlite3RenameTokenMap(Parse *pParse, void *pPtr, Token *pToken){
  RenameToken *pNew;
  assert( pPtr || pParse->db->mallocFailed );
  renameTokenCheckAll(pParse, pPtr);
  if( ALWAYS(pParse->eParseMode!=PARSE_MODE_UNMAP) ){
    pNew = sqlite3DbMallocZero(pParse->db, sizeof(RenameToken));
    if( pNew ){
      pNew->p = pPtr;
      pNew->t = *pToken;
      pNew->pNext = pParse->pRename;
      pParse->pRename = pNew;
    }

      sNC.pParse = pWalker->pParse;
      sqlite3SelectPrep(sNC.pParse, p, &sNC);
      sqlite3WalkSelect(pWalker, p);
      sqlite3RenameExprlistUnmap(pWalker->pParse, pWith->a[i].pCols);
    }
  }
}

/*
** Unmap all tokens in the IdList object passed as the second argument.
*/
static void unmapColumnIdlistNames(
  Parse *pParse,
  IdList *pIdList
){
  if( pIdList ){
    int ii;
    for(ii=0; ii<pIdList->nId; ii++){
      sqlite3RenameTokenRemap(pParse, 0, (void*)pIdList->a[ii].zName);
    }
  }
}

/*
** Walker callback used by sqlite3RenameExprUnmap().
*/
static int renameUnmapSelectCb(Walker *pWalker, Select *p){
  Parse *pParse = pWalker->pParse;
  int i;

    }
  }
  if( ALWAYS(p->pSrc) ){  /* Every Select as a SrcList, even if it is empty */
    SrcList *pSrc = p->pSrc;
    for(i=0; i<pSrc->nSrc; i++){
      sqlite3RenameTokenRemap(pParse, 0, (void*)pSrc->a[i].zName);
      if( sqlite3WalkExpr(pWalker, pSrc->a[i].pOn) ) return WRC_Abort;
      unmapColumnIdlistNames(pParse, pSrc->a[i].pUsing);
    }
  }

  renameWalkWith(pWalker, p);
  return WRC_Continue;
}

      char *zName = pIdList->a[i].zName;
      if( 0==sqlite3_stricmp(zName, zOld) ){
        renameTokenFind(pParse, pCtx, (void*)zName);
      }
    }
  }
}


/*
** Parse the SQL statement zSql using Parse object (*p). The Parse object
** is initialized by this function before it is used.
*/
static int renameParseSql(
  Parse *p,                       /* Memory to use for Parse object */

  };
  int i;
  sqlite3 *db = pParse->db;
  Db *pDb;
  Vdbe *v = sqlite3GetVdbe(pParse);
  int aRoot[ArraySize(aTable)];
  u8 aCreateTbl[ArraySize(aTable)];
#ifdef SQLITE_ENABLE_STAT4
  const int nToOpen = OptimizationEnabled(db,SQLITE_Stat4) ? 2 : 1;
#else
  const int nToOpen = 1;
#endif

  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];

  /* Create new statistic tables if they do not exist, or clear them
  ** if they do already exist.
  */
  for(i=0; i<ArraySize(aTable); i++){
    const char *zTab = aTable[i].zName;
    Table *pStat;
    aCreateTbl[i] = 0;
    if( (pStat = sqlite3FindTable(db, zTab, pDb->zDbSName))==0 ){
      if( i<nToOpen ){
        /* The sqlite_statN table does not exist. Create it. Note that a 
        ** side-effect of the CREATE TABLE statement is to leave the rootpage 
        ** of the new table in register pParse->regRoot. This is important 
        ** because the OpenWrite opcode below will be needing it. */
        sqlite3NestedParse(pParse,
            "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
        );
        aRoot[i] = pParse->regRoot;
        aCreateTbl[i] = OPFLAG_P2ISREG;
      }
    }else{
      /* The table already exists. If zWhere is not NULL, delete all entries 
      ** associated with the table zWhere. If zWhere is NULL, delete the
      ** entire contents of the table. */
      aRoot[i] = pStat->tnum;

      sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);
      if( zWhere ){
        sqlite3NestedParse(pParse,
           "DELETE FROM %Q.%s WHERE %s=%Q",
           pDb->zDbSName, zTab, zWhereType, zWhere
        );
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
      }else if( db->xPreUpdateCallback ){
        sqlite3NestedParse(pParse, "DELETE FROM %Q.%s", pDb->zDbSName, zTab);
#endif
      }else{
        /* The sqlite_stat[134] table already exists.  Delete all rows. */
        sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  /* Open the sqlite_stat[134] tables for writing. */
  for(i=0; i<nToOpen; i++){
    assert( i<ArraySize(aTable) );
    sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3);
    sqlite3VdbeChangeP5(v, aCreateTbl[i]);
    VdbeComment((v, aTable[i].zName));
  }
}

/*
** Recommended number of samples for sqlite_stat4
*/
#ifndef SQLITE_STAT4_SAMPLES
# define SQLITE_STAT4_SAMPLES 24
#endif

/*
** Three SQL functions - stat_init(), stat_push(), and stat_get() -
** share an instance of the following structure to hold their state
** information.
*/
typedef struct StatAccum StatAccum;
typedef struct StatSample StatSample;
struct StatSample {
  tRowcnt *anEq;                  /* sqlite_stat4.nEq */
  tRowcnt *anDLt;                 /* sqlite_stat4.nDLt */
#ifdef SQLITE_ENABLE_STAT4
  tRowcnt *anLt;                  /* sqlite_stat4.nLt */
  union {
    i64 iRowid;                     /* Rowid in main table of the key */
    u8 *aRowid;                     /* Key for WITHOUT ROWID tables */
  } u;
  u32 nRowid;                     /* Sizeof aRowid[] */
  u8 isPSample;                   /* True if a periodic sample */
  int iCol;                       /* If !isPSample, the reason for inclusion */
  u32 iHash;                      /* Tiebreaker hash */
#endif
};                                                    
struct StatAccum {
  sqlite3 *db;              /* Database connection, for malloc() */
  tRowcnt nEst;             /* Estimated number of rows */
  tRowcnt nRow;             /* Number of rows visited so far */
  int nLimit;               /* Analysis row-scan limit */
  int nCol;                 /* Number of columns in index + pk/rowid */
  int nKeyCol;              /* Number of index columns w/o the pk/rowid */
  u8 nSkipAhead;            /* Number of times of skip-ahead */
  StatSample current;       /* Current row as a StatSample */
#ifdef SQLITE_ENABLE_STAT4
  tRowcnt nPSample;         /* How often to do a periodic sample */
  int mxSample;             /* Maximum number of samples to accumulate */

  u32 iPrn;                 /* Pseudo-random number used for sampling */
  StatSample *aBest;        /* Array of nCol best samples */
  int iMin;                 /* Index in a[] of entry with minimum score */
  int nSample;              /* Current number of samples */
  int nMaxEqZero;           /* Max leading 0 in anEq[] for any a[] entry */
  int iGet;                 /* Index of current sample accessed by stat_get() */
  StatSample *a;            /* Array of mxSample StatSample objects */
#endif
};

/* Reclaim memory used by a StatSample
*/
#ifdef SQLITE_ENABLE_STAT4
static void sampleClear(sqlite3 *db, StatSample *p){
  assert( db!=0 );
  if( p->nRowid ){
    sqlite3DbFree(db, p->u.aRowid);
    p->nRowid = 0;
  }
}
#endif

/* Initialize the BLOB value of a ROWID
*/
#ifdef SQLITE_ENABLE_STAT4
static void sampleSetRowid(sqlite3 *db, StatSample *p, int n, const u8 *pData){
  assert( db!=0 );
  if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);
  p->u.aRowid = sqlite3DbMallocRawNN(db, n);
  if( p->u.aRowid ){
    p->nRowid = n;
    memcpy(p->u.aRowid, pData, n);
  }else{
    p->nRowid = 0;
  }
}
#endif

/* Initialize the INTEGER value of a ROWID.
*/
#ifdef SQLITE_ENABLE_STAT4
static void sampleSetRowidInt64(sqlite3 *db, StatSample *p, i64 iRowid){
  assert( db!=0 );
  if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);
  p->nRowid = 0;
  p->u.iRowid = iRowid;
}
#endif


/*
** Copy the contents of object (*pFrom) into (*pTo).
*/
#ifdef SQLITE_ENABLE_STAT4
static void sampleCopy(StatAccum *p, StatSample *pTo, StatSample *pFrom){
  pTo->isPSample = pFrom->isPSample;
  pTo->iCol = pFrom->iCol;
  pTo->iHash = pFrom->iHash;
  memcpy(pTo->anEq, pFrom->anEq, sizeof(tRowcnt)*p->nCol);
  memcpy(pTo->anLt, pFrom->anLt, sizeof(tRowcnt)*p->nCol);
  memcpy(pTo->anDLt, pFrom->anDLt, sizeof(tRowcnt)*p->nCol);
  if( pFrom->nRowid ){
    sampleSetRowid(p->db, pTo, pFrom->nRowid, pFrom->u.aRowid);
  }else{
    sampleSetRowidInt64(p->db, pTo, pFrom->u.iRowid);
  }
}
#endif

/*
** Reclaim all memory of a StatAccum structure.
*/
static void statAccumDestructor(void *pOld){
  StatAccum *p = (StatAccum*)pOld;
#ifdef SQLITE_ENABLE_STAT4
  if( p->mxSample ){
    int i;
    for(i=0; i<p->nCol; i++) sampleClear(p->db, p->aBest+i);
    for(i=0; i<p->mxSample; i++) sampleClear(p->db, p->a+i);
    sampleClear(p->db, &p->current);
  }
#endif
  sqlite3DbFree(p->db, p);
}

/*
** Implementation of the stat_init(N,K,C,L) SQL function. The four parameters
** are:
**     N:    The number of columns in the index including the rowid/pk (note 1)
**     K:    The number of columns in the index excluding the rowid/pk.
**     C:    Estimated number of rows in the index
**     L:    A limit on the number of rows to scan, or 0 for no-limit 
**
** Note 1:  In the special case of the covering index that implements a
** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the
** total number of columns in the table.
**


** For indexes on ordinary rowid tables, N==K+1.  But for indexes on
** WITHOUT ROWID tables, N=K+P where P is the number of columns in the
** PRIMARY KEY of the table.  The covering index that implements the
** original WITHOUT ROWID table as N==K as a special case.
**
** This routine allocates the StatAccum object in heap memory. The return 
** value is a pointer to the StatAccum object.  The datatype of the
** return value is BLOB, but it is really just a pointer to the StatAccum
** object.
*/
static void statInit(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  StatAccum *p;
  int nCol;                       /* Number of columns in index being sampled */
  int nKeyCol;                    /* Number of key columns */
  int nColUp;                     /* nCol rounded up for alignment */
  int n;                          /* Bytes of space to allocate */
  sqlite3 *db = sqlite3_context_db_handle(context);   /* Database connection */
#ifdef SQLITE_ENABLE_STAT4
  /* Maximum number of samples.  0 if STAT4 data is not collected */
  int mxSample = OptimizationEnabled(db,SQLITE_Stat4) ?SQLITE_STAT4_SAMPLES :0;
#endif

  /* Decode the three function arguments */
  UNUSED_PARAMETER(argc);
  nCol = sqlite3_value_int(argv[0]);
  assert( nCol>0 );
  nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol;
  nKeyCol = sqlite3_value_int(argv[1]);
  assert( nKeyCol<=nCol );
  assert( nKeyCol>0 );

  /* Allocate the space required for the StatAccum object */
  n = sizeof(*p) 
    + sizeof(tRowcnt)*nColUp                  /* StatAccum.anEq */
    + sizeof(tRowcnt)*nColUp;                 /* StatAccum.anDLt */
#ifdef SQLITE_ENABLE_STAT4
  if( mxSample ){
    n += sizeof(tRowcnt)*nColUp                  /* StatAccum.anLt */
      + sizeof(StatSample)*(nCol+mxSample)       /* StatAccum.aBest[], a[] */
      + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample);
  }
#endif

  db = sqlite3_context_db_handle(context);
  p = sqlite3DbMallocZero(db, n);
  if( p==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }

  p->db = db;
  p->nEst = sqlite3_value_int64(argv[2]);
  p->nRow = 0;
  p->nLimit = sqlite3_value_int64(argv[3]);
  p->nCol = nCol;
  p->nKeyCol = nKeyCol;
  p->nSkipAhead = 0;
  p->current.anDLt = (tRowcnt*)&p[1];
  p->current.anEq = &p->current.anDLt[nColUp];

#ifdef SQLITE_ENABLE_STAT4

  p->mxSample = p->nLimit==0 ? mxSample : 0;
  if( mxSample ){
    u8 *pSpace;                     /* Allocated space not yet assigned */
    int i;                          /* Used to iterate through p->aSample[] */

    p->iGet = -1;

    p->nPSample = (tRowcnt)(p->nEst/(mxSample/3+1) + 1);
    p->current.anLt = &p->current.anEq[nColUp];
    p->iPrn = 0x689e962d*(u32)nCol ^ 0xd0944565*(u32)sqlite3_value_int(argv[2]);
  
    /* Set up the StatAccum.a[] and aBest[] arrays */
    p->a = (struct StatSample*)&p->current.anLt[nColUp];
    p->aBest = &p->a[mxSample];
    pSpace = (u8*)(&p->a[mxSample+nCol]);
    for(i=0; i<(mxSample+nCol); i++){
      p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
      p->a[i].anLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
      p->a[i].anDLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
    }
    assert( (pSpace - (u8*)p)==n );
  
    for(i=0; i<nCol; i++){
      p->aBest[i].iCol = i;
    }
  }
#endif

  /* Return a pointer to the allocated object to the caller.  Note that
  ** only the pointer (the 2nd parameter) matters.  The size of the object
  ** (given by the 3rd parameter) is never used and can be any positive
  ** value. */
  sqlite3_result_blob(context, p, sizeof(*p), statAccumDestructor);
}
static const FuncDef statInitFuncdef = {
  4,               /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statInit,        /* xSFunc */
  0,               /* xFinalize */
  0, 0,            /* xValue, xInverse */
  "stat_init",     /* zName */

** In other words, if we assume that the cardinalities of the selected
** column for pNew and pOld are equal, is pNew to be preferred over pOld.
**
** This function assumes that for each argument sample, the contents of
** the anEq[] array from pSample->anEq[pSample->iCol+1] onwards are valid. 
*/
static int sampleIsBetterPost(
  StatAccum *pAccum, 
  StatSample *pNew, 
  StatSample *pOld
){
  int nCol = pAccum->nCol;
  int i;
  assert( pNew->iCol==pOld->iCol );
  for(i=pNew->iCol+1; i<nCol; i++){
    if( pNew->anEq[i]>pOld->anEq[i] ) return 1;
    if( pNew->anEq[i]<pOld->anEq[i] ) return 0;

/*
** Return true if pNew is to be preferred over pOld.
**
** This function assumes that for each argument sample, the contents of
** the anEq[] array from pSample->anEq[pSample->iCol] onwards are valid. 
*/
static int sampleIsBetter(
  StatAccum *pAccum, 
  StatSample *pNew, 
  StatSample *pOld
){
  tRowcnt nEqNew = pNew->anEq[pNew->iCol];
  tRowcnt nEqOld = pOld->anEq[pOld->iCol];

  assert( pOld->isPSample==0 && pNew->isPSample==0 );
  assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) );

  if( (nEqNew>nEqOld) ) return 1;
  if( nEqNew==nEqOld ){
    if( pNew->iCol<pOld->iCol ) return 1;
    return (pNew->iCol==pOld->iCol && sampleIsBetterPost(pAccum, pNew, pOld));
  }
  return 0;
}

/*
** Copy the contents of sample *pNew into the p->a[] array. If necessary,
** remove the least desirable sample from p->a[] to make room.
*/
static void sampleInsert(StatAccum *p, StatSample *pNew, int nEqZero){
  StatSample *pSample = 0;
  int i;

  assert( IsStat4 || nEqZero==0 );

  /* StatAccum.nMaxEqZero is set to the maximum number of leading 0
  ** values in the anEq[] array of any sample in StatAccum.a[]. In
  ** other words, if nMaxEqZero is n, then it is guaranteed that there
  ** are no samples with StatSample.anEq[m]==0 for (m>=n). */
  if( nEqZero>p->nMaxEqZero ){
    p->nMaxEqZero = nEqZero;
  }
  if( pNew->isPSample==0 ){
    StatSample *pUpgrade = 0;
    assert( pNew->anEq[pNew->iCol]>0 );

    /* This sample is being added because the prefix that ends in column 
    ** iCol occurs many times in the table. However, if we have already
    ** added a sample that shares this prefix, there is no need to add
    ** this one. Instead, upgrade the priority of the highest priority
    ** existing sample that shares this prefix.  */
    for(i=p->nSample-1; i>=0; i--){
      StatSample *pOld = &p->a[i];
      if( pOld->anEq[pNew->iCol]==0 ){
        if( pOld->isPSample ) return;
        assert( pOld->iCol>pNew->iCol );
        assert( sampleIsBetter(p, pNew, pOld) );
        if( pUpgrade==0 || sampleIsBetter(p, pOld, pUpgrade) ){
          pUpgrade = pOld;
        }
      }
    }
    if( pUpgrade ){
      pUpgrade->iCol = pNew->iCol;
      pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol];
      goto find_new_min;
    }
  }

  /* If necessary, remove sample iMin to make room for the new sample. */
  if( p->nSample>=p->mxSample ){
    StatSample *pMin = &p->a[p->iMin];
    tRowcnt *anEq = pMin->anEq;
    tRowcnt *anLt = pMin->anLt;
    tRowcnt *anDLt = pMin->anDLt;
    sampleClear(p->db, pMin);
    memmove(pMin, &pMin[1], sizeof(p->a[0])*(p->nSample-p->iMin-1));
    pSample = &p->a[p->nSample-1];
    pSample->nRowid = 0;

    }
    assert( iMin>=0 );
    p->iMin = iMin;
  }
}
#endif /* SQLITE_ENABLE_STAT4 */

#ifdef SQLITE_ENABLE_STAT4
/*
** Field iChng of the index being scanned has changed. So at this point
** p->current contains a sample that reflects the previous row of the
** index. The value of anEq[iChng] and subsequent anEq[] elements are
** correct at this point.
*/
static void samplePushPrevious(StatAccum *p, int iChng){

  int i;

  /* Check if any samples from the aBest[] array should be pushed
  ** into IndexSample.a[] at this point.  */
  for(i=(p->nCol-2); i>=iChng; i--){
    StatSample *pBest = &p->aBest[i];
    pBest->anEq[i] = p->current.anEq[i];
    if( p->nSample<p->mxSample || sampleIsBetter(p, pBest, &p->a[p->iMin]) ){
      sampleInsert(p, pBest, i);
    }
  }

  /* Check that no sample contains an anEq[] entry with an index of

      int j;
      for(j=iChng; j<p->nCol; j++){
        if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j];
      }
    }
    p->nMaxEqZero = iChng;
  }

}
#endif /* SQLITE_ENABLE_STAT4 */





/*
** Implementation of the stat_push SQL function:  stat_push(P,C,R)
** Arguments:
**
**    P     Pointer to the StatAccum object created by stat_init()
**    C     Index of left-most column to differ from previous row
**    R     Rowid for the current row.  Might be a key record for
**          WITHOUT ROWID tables.
**

** The purpose of this routine is to collect statistical data and/or
** samples from the index being analyzed into the StatAccum object.
** The stat_get() SQL function will be used afterwards to
** retrieve the information gathered.
**
** This SQL function usually returns NULL, but might return an integer
** if it wants the byte-code to do special processing.
**
** The R parameter is only used for STAT4
*/
static void statPush(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int i;

  /* The three function arguments */
  StatAccum *p = (StatAccum*)sqlite3_value_blob(argv[0]);
  int iChng = sqlite3_value_int(argv[1]);

  UNUSED_PARAMETER( argc );
  UNUSED_PARAMETER( context );
  assert( p->nCol>0 );
  assert( iChng<p->nCol );

  if( p->nRow==0 ){
    /* This is the first call to this function. Do initialization. */
    for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1;
  }else{
    /* Second and subsequent calls get processed here */
#ifdef SQLITE_ENABLE_STAT4
    if( p->mxSample ) samplePushPrevious(p, iChng);
#endif

    /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply
    ** to the current row of the index. */
    for(i=0; i<iChng; i++){
      p->current.anEq[i]++;
    }
    for(i=iChng; i<p->nCol; i++){
      p->current.anDLt[i]++;
#ifdef SQLITE_ENABLE_STAT4
      if( p->mxSample ) p->current.anLt[i] += p->current.anEq[i];
#endif
      p->current.anEq[i] = 1;
    }
  }

  p->nRow++;
#ifdef SQLITE_ENABLE_STAT4
  if( p->mxSample ){
    tRowcnt nLt;
    if( sqlite3_value_type(argv[2])==SQLITE_INTEGER ){
      sampleSetRowidInt64(p->db, &p->current, sqlite3_value_int64(argv[2]));
    }else{
      sampleSetRowid(p->db, &p->current, sqlite3_value_bytes(argv[2]),
                                         sqlite3_value_blob(argv[2]));
    }
    p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345;




    nLt = p->current.anLt[p->nCol-1];

    /* Check if this is to be a periodic sample. If so, add it. */
    if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){
      p->current.isPSample = 1;
      p->current.iCol = 0;
      sampleInsert(p, &p->current, p->nCol-1);
      p->current.isPSample = 0;
    }

    /* Update the aBest[] array. */
    for(i=0; i<(p->nCol-1); i++){
      p->current.iCol = i;
      if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){
        sampleCopy(p, &p->aBest[i], &p->current);
      }
    }
  }else
#endif
  if( p->nLimit && p->nRow>(tRowcnt)p->nLimit*(p->nSkipAhead+1) ){
    p->nSkipAhead++;
    sqlite3_result_int(context, p->current.anDLt[0]>0);
  }
}

static const FuncDef statPushFuncdef = {
  2+IsStat4,       /* nArg */
  SQLITE_UTF8,     /* funcFlags */
  0,               /* pUserData */
  0,               /* pNext */
  statPush,        /* xSFunc */
  0,               /* xFinalize */

#define STAT_GET_NEQ   2          /* "neq" column of stat[34] entry */
#define STAT_GET_NLT   3          /* "nlt" column of stat[34] entry */
#define STAT_GET_NDLT  4          /* "ndlt" column of stat[34] entry */

/*
** Implementation of the stat_get(P,J) SQL function.  This routine is
** used to query statistical information that has been gathered into
** the StatAccum object by prior calls to stat_push().  The P parameter
** has type BLOB but it is really just a pointer to the StatAccum object.
** The content to returned is determined by the parameter J
** which is one of the STAT_GET_xxxx values defined above.
**
** The stat_get(P,J) function is not available to generic SQL.  It is
** inserted as part of a manually constructed bytecode program.  (See
** the callStatGet() routine below.)  It is guaranteed that the P
** parameter will always be a pointer to a StatAccum object, never a
** NULL.
**
** If STAT4 is not enabled, then J is always
** STAT_GET_STAT1 and is hence omitted and this routine becomes
** a one-parameter function, stat_get(P), that always returns the
** stat1 table entry information.
*/
static void statGet(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  StatAccum *p = (StatAccum*)sqlite3_value_blob(argv[0]);
#ifdef SQLITE_ENABLE_STAT4
  /* STAT4 has a parameter on this routine. */
  int eCall = sqlite3_value_int(argv[1]);
  assert( argc==2 );
  assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ 
       || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT
       || eCall==STAT_GET_NDLT 
  );
  assert( eCall==STAT_GET_STAT1 || p->mxSample );
  if( eCall==STAT_GET_STAT1 )
#else
  assert( argc==1 );
#endif
  {
    /* Return the value to store in the "stat" column of the sqlite_stat1
    ** table for this index.
    **
    ** The value is a string composed of a list of integers describing 
    ** the index. The first integer in the list is the total number of 
    ** entries in the index. There is one additional integer in the list 
    ** for each indexed column. This additional integer is an estimate of
    ** the number of rows matched by a equality query on the index using
    ** a key with the corresponding number of fields. In other words,
    ** if the index is on columns (a,b) and the sqlite_stat1 value is 
    ** "100 10 2", then SQLite estimates that:
    **
    **   * the index contains 100 rows,
    **   * "WHERE a=?" matches 10 rows, and
    **   * "WHERE a=? AND b=?" matches 2 rows.

    char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 );
    if( zRet==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }

    sqlite3_snprintf(24, zRet, "%llu", 
        p->nSkipAhead ? (u64)p->nEst : (u64)p->nRow);
    z = zRet + sqlite3Strlen30(zRet);
    for(i=0; i<p->nKeyCol; i++){
      u64 nDistinct = p->current.anDLt[i] + 1;
      u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
      sqlite3_snprintf(24, z, " %llu", iVal);
      z += sqlite3Strlen30(z);
      assert( p->current.anEq[i] );
    }
    assert( z[0]=='\0' && z>zRet );

    sqlite3_result_text(context, zRet, -1, sqlite3_free);
  }
#ifdef SQLITE_ENABLE_STAT4
  else if( eCall==STAT_GET_ROWID ){
    if( p->iGet<0 ){
      samplePushPrevious(p, 0);
      p->iGet = 0;
    }
    if( p->iGet<p->nSample ){
      StatSample *pS = p->a + p->iGet;
      if( pS->nRowid==0 ){
        sqlite3_result_int64(context, pS->u.iRowid);
      }else{
        sqlite3_result_blob(context, pS->u.aRowid, pS->nRowid,
                            SQLITE_TRANSIENT);
      }
    }

  statGet,         /* xSFunc */
  0,               /* xFinalize */
  0, 0,            /* xValue, xInverse */
  "stat_get",      /* zName */
  {0}
};

static void callStatGet(Parse *pParse, int regStat, int iParam, int regOut){
#ifdef SQLITE_ENABLE_STAT4
  sqlite3VdbeAddOp2(pParse->pVdbe, OP_Integer, iParam, regStat+1);
#elif SQLITE_DEBUG
  assert( iParam==STAT_GET_STAT1 );
#else
  UNUSED_PARAMETER( iParam );
#endif
  assert( regOut!=regStat && regOut!=regStat+1 );
  sqlite3VdbeAddFunctionCall(pParse, 0, regStat, regOut, 1+IsStat4,
                             &statGetFuncdef, 0);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/

  int iTabCur;                 /* Table cursor */
  Vdbe *v;                     /* The virtual machine being built up */
  int i;                       /* Loop counter */
  int jZeroRows = -1;          /* Jump from here if number of rows is zero */
  int iDb;                     /* Index of database containing pTab */
  u8 needTableCnt = 1;         /* True to count the table */
  int regNewRowid = iMem++;    /* Rowid for the inserted record */
  int regStat = iMem++;        /* Register to hold StatAccum object */
  int regChng = iMem++;        /* Index of changed index field */

  int regRowid = iMem++;       /* Rowid argument passed to stat_push() */

  int regTemp = iMem++;        /* Temporary use register */
  int regTemp2 = iMem++;       /* Second temporary use register */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regStat1 = iMem++;       /* Value for the stat column of sqlite_stat1 */
  int regPrev = iMem;          /* MUST BE LAST (see below) */
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
  Table *pStat1 = 0; 
#endif

    VdbeComment((v, "%s", pIdx->zName));

    /* Invoke the stat_init() function. The arguments are:
    ** 
    **    (1) the number of columns in the index including the rowid
    **        (or for a WITHOUT ROWID table, the number of PK columns),
    **    (2) the number of columns in the key without the rowid/pk
    **    (3) estimated number of rows in the index,



    */
    sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat+1);
    assert( regRowid==regStat+2 );
    sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regRowid);
#ifdef SQLITE_ENABLE_STAT4
    if( OptimizationEnabled(db, SQLITE_Stat4) ){
      sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regTemp);
      addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
      VdbeCoverage(v);
    }else
#endif
    {
      addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_Count, iIdxCur, regTemp, 1);
    }
    assert( regTemp2==regStat+4 );
    sqlite3VdbeAddOp2(v, OP_Integer, db->nAnalysisLimit, regTemp2);
    sqlite3VdbeAddFunctionCall(pParse, 0, regStat+1, regStat, 4,
                               &statInitFuncdef, 0);

    /* Implementation of the following:
    **
    **   Rewind csr
    **   if eof(csr) goto end_of_scan;
    **   regChng = 0
    **   goto next_push_0;
    **
    */


    sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
    addrNextRow = sqlite3VdbeCurrentAddr(v);

    if( nColTest>0 ){
      int endDistinctTest = sqlite3VdbeMakeLabel(pParse);
      int *aGotoChng;               /* Array of jump instruction addresses */
      aGotoChng = sqlite3DbMallocRawNN(db, sizeof(int)*nColTest);

        sqlite3VdbeAddOp2(v, OP_NotNull, regPrev, endDistinctTest);
        VdbeCoverage(v);
      }
      for(i=0; i<nColTest; i++){
        char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
        sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);
        VdbeComment((v, "%s.column(%d)", pIdx->zName, i));
        aGotoChng[i] = 
        sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);
        sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
        VdbeCoverage(v);
      }
      sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng);
      sqlite3VdbeGoto(v, endDistinctTest);
  
  
      /*
      **  chng_addr_0:
      **   regPrev(0) = idx(0)
      **  chng_addr_1:
      **   regPrev(1) = idx(1)
      **  ...
      */
      sqlite3VdbeJumpHere(v, addrNextRow-1);
      for(i=0; i<nColTest; i++){
        sqlite3VdbeJumpHere(v, aGotoChng[i]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
        VdbeComment((v, "%s.column(%d)", pIdx->zName, i));
      }
      sqlite3VdbeResolveLabel(v, endDistinctTest);
      sqlite3DbFree(db, aGotoChng);
    }
  
    /*
    **  chng_addr_N:
    **   regRowid = idx(rowid)            // STAT4 only
    **   stat_push(P, regChng, regRowid)  // 3rd parameter STAT4 only
    **   Next csr
    **   if !eof(csr) goto next_row;
    */
#ifdef SQLITE_ENABLE_STAT4
    if( OptimizationEnabled(db, SQLITE_Stat4) ){
      assert( regRowid==(regStat+2) );
      if( HasRowid(pTab) ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid);
      }else{
        Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
        int j, k, regKey;
        regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);
        for(j=0; j<pPk->nKeyCol; j++){
          k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[j]);
          assert( k>=0 && k<pIdx->nColumn );
          sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);
          VdbeComment((v, "%s.column(%d)", pIdx->zName, i));
        }
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid);
        sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol);
      }
    }
#endif
    assert( regChng==(regStat+1) );
    {
      sqlite3VdbeAddFunctionCall(pParse, 1, regStat, regTemp, 2+IsStat4,
                                 &statPushFuncdef, 0);
      if( db->nAnalysisLimit ){
        int j1, j2, j3;
        j1 = sqlite3VdbeAddOp1(v, OP_IsNull, regTemp); VdbeCoverage(v);
        j2 = sqlite3VdbeAddOp1(v, OP_If, regTemp); VdbeCoverage(v);
        j3 = sqlite3VdbeAddOp4Int(v, OP_SeekGT, iIdxCur, 0, regPrev, 1);
        VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, j1);
        sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, j2);
        sqlite3VdbeJumpHere(v, j3);
      }else{
        sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);
      }
    }

    /* Add the entry to the stat1 table. */
    callStatGet(pParse, regStat, STAT_GET_STAT1, regStat1);
    assert( "BBB"[0]==SQLITE_AFF_TEXT );
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
    sqlite3VdbeChangeP4(v, -1, (char*)pStat1, P4_TABLE);
#endif
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

    /* Add the entries to the stat4 table. */
#ifdef SQLITE_ENABLE_STAT4

    if( OptimizationEnabled(db, SQLITE_Stat4) && db->nAnalysisLimit==0 ){
      int regEq = regStat1;
      int regLt = regStat1+1;
      int regDLt = regStat1+2;
      int regSample = regStat1+3;
      int regCol = regStat1+4;
      int regSampleRowid = regCol + nCol;
      int addrNext;
      int addrIsNull;
      u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound;

      pParse->nMem = MAX(pParse->nMem, regCol+nCol);

      addrNext = sqlite3VdbeCurrentAddr(v);
      callStatGet(pParse, regStat, STAT_GET_ROWID, regSampleRowid);
      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);
      VdbeCoverage(v);
      callStatGet(pParse, regStat, STAT_GET_NEQ, regEq);
      callStatGet(pParse, regStat, STAT_GET_NLT, regLt);
      callStatGet(pParse, regStat, STAT_GET_NDLT, regDLt);
      sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0);
      VdbeCoverage(v);
      for(i=0; i<nCol; i++){
        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i);
      }
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample);
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp);

      rc = sqlite3ResolveExprNames(pName, pExpr);
    }else{
      pExpr->op = TK_STRING;
    }
  }
  return rc;
}

/*
** Return true if zName points to a name that may be used to refer to
** database iDb attached to handle db.
*/
int sqlite3DbIsNamed(sqlite3 *db, int iDb, const char *zName){
  return (
      sqlite3StrICmp(db->aDb[iDb].zDbSName, zName)==0
   || (iDb==0 && sqlite3StrICmp("main", zName)==0)
  );
}

/*
** An SQL user-function registered to do the work of an ATTACH statement. The
** three arguments to the function come directly from an attach statement:
**
**     ATTACH DATABASE x AS y KEY z
**

    if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){
      zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d", 
        db->aLimit[SQLITE_LIMIT_ATTACHED]
      );
      goto attach_error;
    }
    for(i=0; i<db->nDb; i++){

      assert( zName );
      if( sqlite3DbIsNamed(db, i, zName) ){
        zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
        goto attach_error;
      }
    }
  
    /* Allocate the new entry in the db->aDb[] array and initialize the schema
    ** hash tables.

#endif
    sqlite3BtreeLeave(pNew->pBt);
  }
  pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
  if( rc==SQLITE_OK && pNew->zDbSName==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }




































  sqlite3_free_filename( zPath );

  /* If the file was opened successfully, read the schema for the new database.
  ** If this fails, or if opening the file failed, then close the file and 
  ** remove the entry from the db->aDb[] array. i.e. put everything back the
  ** way we found it.
  */
  if( rc==SQLITE_OK ){

  UNUSED_PARAMETER(NotUsed);

  if( zName==0 ) zName = "";
  for(i=0; i<db->nDb; i++){
    pDb = &db->aDb[i];
    if( pDb->pBt==0 ) continue;
    if( sqlite3DbIsNamed(db, i, zName) ) break;
  }

  if( i>=db->nDb ){
    sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);
    goto detach_error;
  }
  if( i<2 ){

** checks out, these routines return 0.
*/
int sqlite3FixSrcList(
  DbFixer *pFix,       /* Context of the fixation */
  SrcList *pList       /* The Source list to check and modify */
){
  int i;

  struct SrcList_item *pItem;
  sqlite3 *db = pFix->pParse->db;
  int iDb = sqlite3FindDbName(db, pFix->zDb);

  if( NEVER(pList==0) ) return 0;

  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pFix->bTemp==0 ){
      if( pItem->zDatabase && iDb!=sqlite3FindDbName(db, pItem->zDatabase) ){
        sqlite3ErrorMsg(pFix->pParse,
            "%s %T cannot reference objects in database %s",
            pFix->zType, pFix->pName, pItem->zDatabase);
        return 1;
      }
      sqlite3DbFree(db, pItem->zDatabase);
      pItem->zDatabase = 0;
      pItem->pSchema = pFix->pSchema;
      pItem->fg.fromDDL = 1;
    }
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
    if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
    if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;

/*
** Attempt to set the page size of the destination to match the page size
** of the source.
*/
static int setDestPgsz(sqlite3_backup *p){
  int rc;
  rc = sqlite3BtreeSetPageSize(p->pDest,sqlite3BtreeGetPageSize(p->pSrc),0,0);
  return rc;
}

/*
** Check that there is no open read-transaction on the b-tree passed as the
** second argument. If there is not, return SQLITE_OK. Otherwise, if there
** is an open read-transaction, return SQLITE_ERROR and leave an error 

  int bUpdate                     /* True for an update, false otherwise */
){
  Pager * const pDestPager = sqlite3BtreePager(p->pDest);
  const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);
  int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);
  const int nCopy = MIN(nSrcPgsz, nDestPgsz);
  const i64 iEnd = (i64)iSrcPg*(i64)nSrcPgsz;







  int rc = SQLITE_OK;
  i64 iOff;

  assert( sqlite3BtreeGetReserveNoMutex(p->pSrc)>=0 );
  assert( p->bDestLocked );
  assert( !isFatalError(p->rc) );
  assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
  assert( zSrcData );

  /* Catch the case where the destination is an in-memory database and the
  ** page sizes of the source and destination differ. 
  */
  if( nSrcPgsz!=nDestPgsz && sqlite3PagerIsMemdb(pDestPager) ){
    rc = SQLITE_READONLY;
  }





















  /* This loop runs once for each destination page spanned by the source 
  ** page. For each iteration, variable iOff is set to the byte offset
  ** of the destination page.
  */
  for(iOff=iEnd-(i64)nSrcPgsz; rc==SQLITE_OK && iOff<iEnd; iOff+=nDestPgsz){
    DbPage *pDestPg = 0;
    Pgno iDest = (Pgno)(iOff/nDestPgsz)+1;

  */
  memset(&b, 0, sizeof(b));
  b.pSrcDb = pFrom->db;
  b.pSrc = pFrom;
  b.pDest = pTo;
  b.iNext = 1;





  /* 0x7FFFFFFF is the hard limit for the number of pages in a database
  ** file. By passing this as the number of pages to copy to
  ** sqlite3_backup_step(), we can guarantee that the copy finishes 
  ** within a single call (unless an error occurs). The assert() statement
  ** checks this assumption - (p->rc) should be set to either SQLITE_DONE 
  ** or an error code.  */
  sqlite3_backup_step(&b, 0x7FFFFFFF);

**
** This function is called when a free-list leaf page is removed from the
** free-list for reuse. It returns false if it is safe to retrieve the
** page from the pager layer with the 'no-content' flag set. True otherwise.
*/
static int btreeGetHasContent(BtShared *pBt, Pgno pgno){
  Bitvec *p = pBt->pHasContent;
  return p && (pgno>sqlite3BitvecSize(p) || sqlite3BitvecTestNotNull(p, pgno));
}

/*
** Clear (destroy) the BtShared.pHasContent bitvec. This should be
** invoked at the conclusion of each write-transaction.
*/
static void btreeClearHasContent(BtShared *pBt){

      if( iFree2>usableSize-4 ) return SQLITE_CORRUPT_PAGE(pPage);
      if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){
        u8 *pEnd = &data[cellOffset + nCell*2];
        u8 *pAddr;
        int sz2 = 0;
        int sz = get2byte(&data[iFree+2]);
        int top = get2byte(&data[hdr+5]);
        if( top>=iFree ){
          return SQLITE_CORRUPT_PAGE(pPage);
        }
        if( iFree2 ){
          if( iFree+sz>iFree2 ) return SQLITE_CORRUPT_PAGE(pPage);
          sz2 = get2byte(&data[iFree2+2]);
          if( iFree2+sz2 > usableSize ) return SQLITE_CORRUPT_PAGE(pPage);
          memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));

/*
** Invoke the busy handler for a btree.
*/
static int btreeInvokeBusyHandler(void *pArg){
  BtShared *pBt = (BtShared*)pArg;
  assert( pBt->db );
  assert( sqlite3_mutex_held(pBt->db->mutex) );
  return sqlite3InvokeBusyHandler(&pBt->db->busyHandler);

}

/*
** Open a database file.
** 
** zFilename is the name of the database file.  If zFilename is NULL
** then an ephemeral database is created.  The ephemeral database might

** bytes per page is left unchanged.
**
** If the iFix!=0 then the BTS_PAGESIZE_FIXED flag is set so that the page size
** and autovacuum mode can no longer be changed.
*/
int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
  int rc = SQLITE_OK;
  int x;
  BtShared *pBt = p->pBt;
  assert( nReserve>=0 && nReserve<=255 );
  sqlite3BtreeEnter(p);

  pBt->nReserveWanted = nReserve;
  x = pBt->pageSize - pBt->usableSize;
  if( nReserve<x ) nReserve = x;
  if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
    sqlite3BtreeLeave(p);
    return SQLITE_READONLY;
  }



  assert( nReserve>=0 && nReserve<=255 );
  if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
        ((pageSize-1)&pageSize)==0 ){
    assert( (pageSize & 7)==0 );
    assert( !pBt->pCursor );
    pBt->pageSize = (u32)pageSize;
    freeTempSpace(pBt);

}

/*
** Return the number of bytes of space at the end of every page that
** are intentually left unused.  This is the "reserved" space that is
** sometimes used by extensions.
**

** The value returned is the larger of the current reserve size and
** the latest reserve size requested by SQLITE_FILECTRL_RESERVE_BYTES.
** The amount of reserve can only grow - never shrink.
*/
int sqlite3BtreeGetRequestedReserve(Btree *p){
  int n1, n2;
  sqlite3BtreeEnter(p);
  n1 = (int)p->pBt->nReserveWanted;
  n2 = sqlite3BtreeGetReserveNoMutex(p);



  sqlite3BtreeLeave(p);
  return n1>n2 ? n1 : n2;
}


/*
** Set the maximum page count for a database if mxPage is positive.
** No changes are made if mxPage is 0 or negative.
** Regardless of the value of mxPage, return the maximum page count.

** One or the other of the two processes must give way or there can be
** no progress.  By returning SQLITE_BUSY and not invoking the busy callback
** when A already has a read lock, we encourage A to give up and let B
** proceed.
*/
int sqlite3BtreeBeginTrans(Btree *p, int wrflag, int *pSchemaVersion){
  BtShared *pBt = p->pBt;
  Pager *pPager = pBt->pPager;
  int rc = SQLITE_OK;
  int bConcurrent = (p->db->eConcurrent && !ISAUTOVACUUM);

  sqlite3BtreeEnter(p);
  btreeIntegrity(p);

  /* If the btree is already in a write-transaction, or it
  ** is already in a read-transaction and a read-transaction
  ** is requested, this is a no-op.
  */
  if( p->inTrans==TRANS_WRITE || (p->inTrans==TRANS_READ && !wrflag) ){
    goto trans_begun;
  }
  assert( pBt->inTransaction==TRANS_WRITE || IfNotOmitAV(pBt->bDoTruncate)==0 );

  if( (p->db->flags & SQLITE_ResetDatabase) 
   && sqlite3PagerIsreadonly(pPager)==0 
  ){
    pBt->btsFlags &= ~BTS_READ_ONLY;
  }

  /* Write transactions are not possible on a read-only database */
  if( (pBt->btsFlags & BTS_READ_ONLY)!=0 && wrflag ){
    rc = SQLITE_READONLY;

  ** on page 1, the transaction cannot be opened. */
  rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);
  if( SQLITE_OK!=rc ) goto trans_begun;

  pBt->btsFlags &= ~BTS_INITIALLY_EMPTY;
  if( pBt->nPage==0 ) pBt->btsFlags |= BTS_INITIALLY_EMPTY;
  do {
    sqlite3PagerWalDb(pPager, p->db);

#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
    /* If transitioning from no transaction directly to a write transaction,
    ** block for the WRITER lock first if possible. */
    if( pBt->pPage1==0 && wrflag ){
      assert( pBt->inTransaction==TRANS_NONE );
      rc = sqlite3PagerWalWriteLock(pPager, 1);
      if( rc!=SQLITE_BUSY && rc!=SQLITE_OK ) break;
    }
#endif

    /* Call lockBtree() until either pBt->pPage1 is populated or
    ** lockBtree() returns something other than SQLITE_OK. lockBtree()
    ** may return SQLITE_OK but leave pBt->pPage1 set to 0 if after
    ** reading page 1 it discovers that the page-size of the database 
    ** file is not pBt->pageSize. In this case lockBtree() will update
    ** pBt->pageSize to the page-size of the file on disk.
    */
    while( pBt->pPage1==0 && SQLITE_OK==(rc = lockBtree(pBt)) );

    if( rc==SQLITE_OK && wrflag ){
      if( (pBt->btsFlags & BTS_READ_ONLY)!=0 ){
        rc = SQLITE_READONLY;
      }else{
        int exFlag = bConcurrent ? -1 : (wrflag>1);
        rc = sqlite3PagerBegin(pPager, exFlag, sqlite3TempInMemory(p->db));
        if( rc==SQLITE_OK ){
          rc = newDatabase(pBt);
        }else if( rc==SQLITE_BUSY_SNAPSHOT && pBt->inTransaction==TRANS_NONE ){
          /* if there was no transaction opened when this function was
          ** called and SQLITE_BUSY_SNAPSHOT is returned, change the error
          ** code to SQLITE_BUSY. */
          rc = SQLITE_BUSY;
        }
      }
    }
  
    if( rc!=SQLITE_OK ){
      (void)sqlite3PagerWalWriteLock(pPager, 0);
      unlockBtreeIfUnused(pBt);
    }
  }while( (rc&0xFF)==SQLITE_BUSY && pBt->inTransaction==TRANS_NONE &&
          btreeInvokeBusyHandler(pBt) );
  sqlite3PagerWalDb(pPager, 0);
#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
  if( rc==SQLITE_BUSY_TIMEOUT ) rc = SQLITE_BUSY;
#endif

  if( rc==SQLITE_OK ){
    if( p->inTrans==TRANS_NONE ){
      pBt->nTransaction++;
#ifndef SQLITE_OMIT_SHARED_CACHE
      if( p->sharable ){
        assert( p->lock.pBtree==p && p->lock.iTable==1 );

      ** the sub-journal is not already open, then it will be opened here.
      */
      int nSavepoint = p->db->nSavepoint;
      rc = sqlite3PagerOpenSavepoint(pBt->pPager, nSavepoint);
      if( rc==SQLITE_OK && nSavepoint ){
        rc = btreePtrmapBegin(pBt, nSavepoint);
      }
      rc = sqlite3PagerOpenSavepoint(pPager, p->db->nSavepoint);
    }
  }

  btreeIntegrity(p);
  sqlite3BtreeLeave(p);
  return rc;
}

        return rc;
      }
    }
    if( pBt->bDoTruncate ){
      sqlite3PagerTruncateImage(pBt->pPager, pBt->nPage);
    }
#endif
    if( rc==SQLITE_OK && ISCONCURRENT && p->db->eConcurrent==CONCURRENT_OPEN ){
      rc = btreeFixUnlocked(p);
    }
    if( rc==SQLITE_OK ){
      rc = sqlite3PagerCommitPhaseOne(pBt->pPager, p, zMaster, 0);
    }
    sqlite3BtreeLeave(p);
  }

  i64 iKey,
  int opcode,
  int eqOnly
){
  Btree *pBtree = pCsr->pBtree;
  sqlite3 *db = pBtree->db;
  if( db->bConcurrentReport
   && db->eConcurrent 
   && db->aDb[0].pBt==pBtree
   && sqlite3PagerIsWal(pBtree->pBt->pPager) 
  ){
    CursorScan *pNew;
    pNew = (CursorScan*)sqlite3MallocZero(sizeof(CursorScan));
    if( pNew==0 ) return SQLITE_NOMEM;
    pNew->pKeyInfo = sqlite3KeyInfoRef(pCsr->pKeyInfo);

  }
}

int sqlite3BtreeScanDirty(Btree *pBtree, Bitvec *pRead, PgHdr *pList){
  int rc = SQLITE_OK;
  sqlite3 *db = pBtree->db;
  if( db->bConcurrentReport
   && db->eConcurrent 
   && db->aDb[0].pBt==pBtree
  ){
    CursorScan *pNew;
    u32 *aPg = 0;
    PgHdr *p;
    int nPg = 0;

  const u8 *a, 
  int n
){
  int rc = SQLITE_OK;
  Btree *pBtree = pCsr->pBtree;
  sqlite3 *db = pBtree->db;
  if( db->bConcurrentReport
   && db->eConcurrent 
   && db->aDb[0].pBt==pBtree
   && sqlite3PagerIsWal(pBtree->pBt->pPager) 
  ){
    sqlite3 *db = pCsr->pBtree->db;
    CursorScan *pNew;
    pNew = (CursorScan*)sqlite3MallocZero(sizeof(CursorScan));
    if( pNew==0 ) return SQLITE_NOMEM;

  memcpy(pTmp, aData, pPg->pBt->usableSize);
#endif

  /* Remove cells from the start and end of the page */
  assert( nCell>=0 );
  if( iOld<iNew ){
    int nShift = pageFreeArray(pPg, iOld, iNew-iOld, pCArray);
    if( NEVER(nShift>nCell) ) return SQLITE_CORRUPT_BKPT;
    memmove(pPg->aCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);
    nCell -= nShift;
  }
  if( iNewEnd < iOldEnd ){
    int nTail = pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);
    assert( nCell>=nTail );
    nCell -= nTail;

    }
#endif
  }
  sqlite3BtreeLeave(p);
  return rc;
}


/*
** The first argument, pCur, is a cursor opened on some b-tree. Count the
** number of entries in the b-tree and write the result to *pnEntry.
**
** SQLITE_OK is returned if the operation is successfully executed. 
** Otherwise, if an error is encountered (i.e. an IO error or database
** corruption) an SQLite error code is returned.

    *pnEntry = 0;
    return SQLITE_OK;
  }

  /* Unless an error occurs, the following loop runs one iteration for each
  ** page in the B-Tree structure (not including overflow pages). 
  */
  while( rc==SQLITE_OK && !AtomicLoad(&db->u1.isInterrupted) ){
    int iIdx;                          /* Index of child node in parent */
    MemPage *pPage;                    /* Current page of the b-tree */

    /* If this is a leaf page or the tree is not an int-key tree, then 
    ** this page contains countable entries. Increment the entry counter
    ** accordingly.
    */

      rc = moveToChild(pCur, get4byte(findCell(pPage, iIdx)));
    }
  }

  /* An error has occurred. Return an error code. */
  return rc;
}


/*
** Return the pager associated with a BTree.  This routine is used for
** testing and debugging only.
*/
Pager *sqlite3BtreePager(Btree *p){
  return p->pBt->pPager;

    checkAppendMsg(pCheck, "invalid page number %d", iPage);
    return 1;
  }
  if( getPageReferenced(pCheck, iPage) ){
    checkAppendMsg(pCheck, "2nd reference to page %d", iPage);
    return 1;
  }
  if( AtomicLoad(&pCheck->db->u1.isInterrupted) ) return 1;
  setPageReferenced(pCheck, iPage);
  return 0;
}

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** Check that the entry in the pointer-map for page iChild maps to 

*/
int sqlite3BtreeExclusiveLock(Btree *p){
  int rc;
  Pgno pgno = 0;
  BtShared *pBt = p->pBt;
  assert( p->inTrans==TRANS_WRITE && pBt->pPage1 );
  sqlite3BtreeEnter(p);
  rc = sqlite3PagerExclusiveLock(pBt->pPager, 
    (p->db->eConcurrent==CONCURRENT_SCHEMA) ? 0 : pBt->pPage1->pDbPage,
    &pgno
  );
#ifdef SQLITE_OMIT_CONCURRENT
  assert( pgno==0 );
#else
  if( rc==SQLITE_BUSY_SNAPSHOT ){
    sqlite3PagerScanFailure(p, pBt->pPager);
  }
  if( rc==SQLITE_BUSY_SNAPSHOT && pgno ){

#endif
int sqlite3BtreeSetPagerFlags(Btree*,unsigned);
int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
int sqlite3BtreeGetPageSize(Btree*);
int sqlite3BtreeMaxPageCount(Btree*,int);
u32 sqlite3BtreeLastPage(Btree*);
int sqlite3BtreeSecureDelete(Btree*,int);
int sqlite3BtreeGetRequestedReserve(Btree*);
int sqlite3BtreeGetReserveNoMutex(Btree *p);
int sqlite3BtreeSetAutoVacuum(Btree *, int);
int sqlite3BtreeGetAutoVacuum(Btree *);
int sqlite3BtreeBeginTrans(Btree*,int,int*);
int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
int sqlite3BtreeCommitPhaseTwo(Btree*, int);
int sqlite3BtreeCommit(Btree*);

int sqlite3BtreeExclusiveLock(Btree *pBt);

#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
#endif
int sqlite3BtreeCursorIsValidNN(BtCursor*);


int sqlite3BtreeCount(sqlite3*, BtCursor*, i64*);


#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
#endif

#ifndef SQLITE_OMIT_WAL

#ifndef SQLITE_OMIT_AUTOVACUUM
  u8 autoVacuum;        /* True if auto-vacuum is enabled */
  u8 incrVacuum;        /* True if incr-vacuum is enabled */
  u8 bDoTruncate;       /* True to truncate db on commit */
#endif
  u8 inTransaction;     /* Transaction state */
  u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */

  u8 nReserveWanted;    /* Desired number of extra bytes per page */

  u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */
  u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u32 pageSize;         /* Total number of bytes on a page */
  u32 usableSize;       /* Number of usable bytes on each page */

#if SQLITE_USER_AUTHENTICATION
  /* Only the admin user is allowed to know that the sqlite_user table
  ** exists */
  if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
    return 0;
  }
#endif
  if( zDatabase ){
    for(i=0; i<db->nDb; i++){

      if( sqlite3StrICmp(zDatabase, db->aDb[i].zDbSName)==0 ) break;
    }
    if( i>=db->nDb ){
      /* No match against the official names.  But always match "main"
      ** to schema 0 as a legacy fallback. */
      if( sqlite3StrICmp(zDatabase,"main")==0 ){
        i = 0;
      }else{
        return 0;
      }
    }
    p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);

    if( p==0 && i==1 && sqlite3StrICmp(zName, MASTER_NAME)==0 ){
      /* All temp.sqlite_master to be an alias for sqlite_temp_master */
      p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, TEMP_MASTER_NAME);
    }
  }else{
    /* Match against TEMP first */
    p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, zName);
    if( p ) return p;
    /* The main database is second */
    p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, zName);
    if( p ) return p;
    /* Attached databases are in order of attachment */
    for(i=2; i<db->nDb; i++){
      assert( sqlite3SchemaMutexHeld(db, i, 0) );
      p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
      if( p ) break;
    }
  }
  return p;
}

/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table.  Return NULL if not found.  Also leave an
** error message in pParse->zErrMsg.

  int i;
  /* All mutexes are required for schema access.  Make sure we hold them. */
  assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
  for(i=OMIT_TEMPDB; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
    Schema *pSchema = db->aDb[j].pSchema;
    assert( pSchema );
    if( zDb && sqlite3DbIsNamed(db, j, zDb)==0 ) continue;
    assert( sqlite3SchemaMutexHeld(db, j, 0) );
    p = sqlite3HashFind(&pSchema->idxHash, zName);
    if( p ) break;
  }
  return p;
}

*/
void sqlite3DeleteColumnNames(sqlite3 *db, Table *pTable){
  int i;
  Column *pCol;
  assert( pTable!=0 );
  if( (pCol = pTable->aCol)!=0 ){
    for(i=0; i<pTable->nCol; i++, pCol++){
      assert( pCol->zName==0 || pCol->hName==sqlite3StrIHash(pCol->zName) );
      sqlite3DbFree(db, pCol->zName);
      sqlite3ExprDelete(db, pCol->pDflt);
      sqlite3DbFree(db, pCol->zColl);
    }
    sqlite3DbFree(db, pTable->aCol);
  }
}

      return;
    }
    p->aCol = aNew;
  }
  pCol = &p->aCol[p->nCol];
  memset(pCol, 0, sizeof(p->aCol[0]));
  pCol->zName = z;
  pCol->hName = sqlite3StrIHash(z);
  sqlite3ColumnPropertiesFromName(p, pCol);
 
  if( pType->n==0 ){
    /* If there is no type specified, columns have the default affinity
    ** 'BLOB' with a default size of 4 bytes. */
    pCol->affinity = SQLITE_AFF_BLOB;
    pCol->szEst = 1;

    }
  }
  assert( pPk->nColumn==j );
  assert( pTab->nNVCol<=j );
  recomputeColumnsNotIndexed(pPk);
}


#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Return true if pTab is a virtual table and zName is a shadow table name
** for that virtual table.
*/
int sqlite3IsShadowTableOf(sqlite3 *db, Table *pTab, const char *zName){
  int nName;                    /* Length of zName */
  Module *pMod;                 /* Module for the virtual table */

  if( !IsVirtual(pTab) ) return 0;
  nName = sqlite3Strlen30(pTab->zName);
  if( sqlite3_strnicmp(zName, pTab->zName, nName)!=0 ) return 0;
  if( zName[nName]!='_' ) return 0;
  pMod = (Module*)sqlite3HashFind(&db->aModule, pTab->azModuleArg[0]);
  if( pMod==0 ) return 0;
  if( pMod->pModule->iVersion<3 ) return 0;
  if( pMod->pModule->xShadowName==0 ) return 0;
  return pMod->pModule->xShadowName(zName+nName+1);
}
#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Return true if zName is a shadow table name in the current database
** connection.
**
** zName is temporarily modified while this routine is running, but is
** restored to its original value prior to this routine returning.
*/
int sqlite3ShadowTableName(sqlite3 *db, const char *zName){
  char *zTail;                  /* Pointer to the last "_" in zName */
  Table *pTab;                  /* Table that zName is a shadow of */


  zTail = strrchr(zName, '_');
  if( zTail==0 ) return 0;
  *zTail = 0;
  pTab = sqlite3FindTable(db, zName, 0);
  *zTail = '_';
  if( pTab==0 ) return 0;
  if( !IsVirtual(pTab) ) return 0;

  return sqlite3IsShadowTableOf(db, pTab, zName);
}
#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */


#ifdef SQLITE_DEBUG
/*
** Mark all nodes of an expression as EP_Immutable, indicating that
** they should not be changed.  Expressions attached to a table or
** index definition are tagged this way to help ensure that we do
** not pass them into code generator routines by mistake.
*/
static int markImmutableExprStep(Walker *pWalker, Expr *pExpr){
  ExprSetVVAProperty(pExpr, EP_Immutable);
  return WRC_Continue;
}
static void markExprListImmutable(ExprList *pList){
  if( pList ){
    Walker w;
    memset(&w, 0, sizeof(w));
    w.xExprCallback = markImmutableExprStep;
    w.xSelectCallback = sqlite3SelectWalkNoop;
    w.xSelectCallback2 = 0;
    sqlite3WalkExprList(&w, pList);
  }
}
#else
#define markExprListImmutable(X)  /* no-op */
#endif /* SQLITE_DEBUG */


/*
** This routine is called to report the final ")" that terminates
** a CREATE TABLE statement.
**
** The table structure that other action routines have been building
** is added to the internal hash tables, assuming no errors have

  if( p->pCheck ){
    sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);
    if( pParse->nErr ){
      /* If errors are seen, delete the CHECK constraints now, else they might
      ** actually be used if PRAGMA writable_schema=ON is set. */
      sqlite3ExprListDelete(db, p->pCheck);
      p->pCheck = 0;
    }else{
      markExprListImmutable(p->pCheck);
    }
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
  if( p->tabFlags & TF_HasGenerated ){
    int ii, nNG = 0;
    testcase( p->tabFlags & TF_HasVirtual );

      sqlite3ErrorMsg(pParse, "unable to open a temporary database "
        "file for storing temporary tables");
      pParse->rc = rc;
      return 1;
    }
    db->aDb[1].pBt = pBt;
    assert( db->aDb[1].pSchema );
    if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, 0, 0) ){
      sqlite3OomFault(db);
      return 1;
    }
  }
  return 0;
}

  int errCode,      /* extended error code */
  int onError,      /* Constraint type */
  char *p4,         /* Error message */
  i8 p4type,        /* P4_STATIC or P4_TRANSIENT */
  u8 p5Errmsg       /* P5_ErrMsg type */
){
  Vdbe *v = sqlite3GetVdbe(pParse);
  assert( (errCode&0xff)==SQLITE_CONSTRAINT || pParse->nested );
  if( onError==OE_Abort ){
    sqlite3MayAbort(pParse);
  }
  sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
  sqlite3VdbeChangeP5(v, p5Errmsg);
}

CollSeq *sqlite3FindCollSeq(
  sqlite3 *db,          /* Database connection to search */
  u8 enc,               /* Desired text encoding */
  const char *zName,    /* Name of the collating sequence.  Might be NULL */
  int create            /* True to create CollSeq if doesn't already exist */
){
  CollSeq *pColl;
  assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
  assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );
  if( zName ){
    pColl = findCollSeqEntry(db, zName, create);
    if( pColl ) pColl += enc-1;
  }else{
    pColl = db->pDfltColl;
  }



  return pColl;
}

/*
** Change the text encoding for a database connection. This means that
** the pDfltColl must change as well.
*/
void sqlite3SetTextEncoding(sqlite3 *db, u8 enc){
  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
  db->enc = enc;
  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
  ** strings is BINARY. 
  */
  db->pDfltColl = sqlite3FindCollSeq(db, enc, sqlite3StrBINARY, 0);
}

/*
** This function is responsible for invoking the collation factory callback
** or substituting a collation sequence of a different encoding when the
** requested collation sequence is not available in the desired encoding.
** 
** If it is not NULL, then pColl must point to the database native encoding 

#endif
#if SQLITE_ENABLE_ATOMIC_WRITE
  "ENABLE_ATOMIC_WRITE",
#endif
#if SQLITE_ENABLE_BATCH_ATOMIC_WRITE
  "ENABLE_BATCH_ATOMIC_WRITE",
#endif
#if SQLITE_ENABLE_BYTECODE_VTAB
  "ENABLE_BYTECODE_VTAB",
#endif
#if SQLITE_ENABLE_CEROD
  "ENABLE_CEROD=" CTIMEOPT_VAL(SQLITE_ENABLE_CEROD),
#endif
#if SQLITE_ENABLE_COLUMN_METADATA
  "ENABLE_COLUMN_METADATA",
#endif
#if SQLITE_ENABLE_COLUMN_USED_MASK

#endif
#if SQLITE_FTS5_ENABLE_TEST_MI
  "FTS5_ENABLE_TEST_MI",
#endif
#if SQLITE_FTS5_NO_WITHOUT_ROWID
  "FTS5_NO_WITHOUT_ROWID",
#endif



#if HAVE_ISNAN || SQLITE_HAVE_ISNAN
  "HAVE_ISNAN",
#endif
#if SQLITE_HOMEGROWN_RECURSIVE_MUTEX
  "HOMEGROWN_RECURSIVE_MUTEX",
#endif
#if SQLITE_IGNORE_AFP_LOCK_ERRORS

#endif
#if SQLITE_OMIT_BETWEEN_OPTIMIZATION
  "OMIT_BETWEEN_OPTIMIZATION",
#endif
#if SQLITE_OMIT_BLOB_LITERAL
  "OMIT_BLOB_LITERAL",
#endif



#if SQLITE_OMIT_CAST
  "OMIT_CAST",
#endif
#if SQLITE_OMIT_CHECK
  "OMIT_CHECK",
#endif
#if SQLITE_OMIT_COMPLETE

static const struct {
  u8 eType;           /* Transformation type code */
  u8 nName;           /* Length of th name */
  char *zName;        /* Name of the transformation */
  double rLimit;      /* Maximum NNN value for this transform */
  double rXform;      /* Constant used for this transform */
} aXformType[] = {
  { 0, 6, "second", 464269060800.0, 1000.0         },
  { 0, 6, "minute", 7737817680.0,   60000.0        },
  { 0, 4, "hour",   128963628.0,    3600000.0      },
  { 0, 3, "day",    5373485.0,      86400000.0     },
  { 1, 5, "month",  176546.0,       2592000000.0   },
  { 2, 4, "year",   14713.0,        31536000000.0  },
};

/*
** Process a modifier to a date-time stamp.  The modifiers are
** as follows:
**
**     NNN days

        break;
      }
    }
  }
  i = 0;
  if( iSchema>=0 ){
    pIdxInfo->aConstraintUsage[iSchema].argvIndex = ++i;
    pIdxInfo->aConstraintUsage[iSchema].omit = 1;
    pIdxInfo->idxNum |= 0x01;
  }
  if( iName>=0 ){
    pIdxInfo->aConstraintUsage[iName].argvIndex = ++i;
    pIdxInfo->idxNum |= 0x02;
  }
  if( iAgg>=0 ){

        if( nLocal<0 ) goto statPageIsCorrupt;
        pCell->nLocal = nLocal;
        assert( nPayload>=(u32)nLocal );
        assert( nLocal<=(nUsable-35) );
        if( nPayload>(u32)nLocal ){
          int j;
          int nOvfl = ((nPayload - nLocal) + nUsable-4 - 1) / (nUsable - 4);
          if( iOff+nLocal>nUsable || nPayload>0x7fffffff ){
            goto statPageIsCorrupt;
          }
          pCell->nLastOvfl = (nPayload-nLocal) - (nOvfl-1) * (nUsable-4);
          pCell->nOvfl = nOvfl;
          pCell->aOvfl = sqlite3_malloc64(sizeof(u32)*nOvfl);
          if( pCell->aOvfl==0 ) return SQLITE_NOMEM_BKPT;
          pCell->aOvfl[0] = sqlite3Get4byte(&aData[iOff+nLocal]);
          for(j=1; j<nOvfl; j++){
            int rc;

        iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
      }
      testcase( IsVirtual(pTab) );
      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,
                                 iTabCur, aToOpen, &iDataCur, &iIdxCur);
      assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
      assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
      if( eOnePass==ONEPASS_MULTI ){
        sqlite3VdbeJumpHereOrPopInst(v, iAddrOnce);
      }
    }
  
    /* Set up a loop over the rowids/primary-keys that were found in the
    ** where-clause loop above.
    */
    if( eOnePass!=ONEPASS_OFF ){
      assert( nKey==nPk );  /* OP_Found will use an unpacked key */

    if( pIdx==pPk ) continue;
    if( iIdxCur+i==iIdxNoSeek ) continue;
    VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
        &iPartIdxLabel, pPrior, r1);
    sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
        pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
    sqlite3VdbeChangeP5(v, 1);  /* Cause IdxDelete to error if no entry found */
    sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
    pPrior = pIdx;
  }
}

/*
** Generate code that will assemble an index key and stores it in register

** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(const Expr *pExpr){
  int op;
  while( ExprHasProperty(pExpr, EP_Skip) ){
    assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
    pExpr = pExpr->pLeft;
    assert( pExpr!=0 );
  }
  op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);

}

/*
** Skip over any TK_COLLATE operators.
*/
Expr *sqlite3ExprSkipCollate(Expr *pExpr){
  while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
    assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
    pExpr = pExpr->pLeft;
  }   
  return pExpr;
}

/*
** Skip over any TK_COLLATE operators and/or any unlikely()
** or likelihood() or likely() functions at the root of an
** expression.
*/
Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
  while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){
    if( ExprHasProperty(pExpr, EP_Unlikely) ){
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      assert( pExpr->x.pList->nExpr>0 );
      assert( pExpr->op==TK_FUNCTION );
      pExpr = pExpr->x.pList->a[0].pExpr;
    }else{
      assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
      pExpr = pExpr->pLeft;
    }
  }   
  return pExpr;
}

/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return NULL.
**
** See also: sqlite3ExprNNCollSeq()
**
** The sqlite3ExprNNCollSeq() works the same exact that it returns the
** default collation if pExpr has no defined collation.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence.  Left operands take
** precedence over right operands.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, const Expr *pExpr){
  sqlite3 *db = pParse->db;
  CollSeq *pColl = 0;
  const Expr *p = pExpr;
  while( p ){
    int op = p->op;
    if( op==TK_REGISTER ) op = p->op2;
    if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER)
     && p->y.pTab!=0
    ){
      /* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally

** defautl collation sequence.
**
** See also: sqlite3ExprCollSeq()
**
** The sqlite3ExprCollSeq() routine works the same except that it
** returns NULL if there is no defined collation.
*/
CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, const Expr *pExpr){
  CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);
  if( p==0 ) p = pParse->db->pDfltColl;
  assert( p!=0 );
  return p;
}

/*
** Return TRUE if the two expressions have equivalent collating sequences.
*/
int sqlite3ExprCollSeqMatch(Parse *pParse, const Expr *pE1, const Expr *pE2){
  CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);
  CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);
  return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;
}

/*
** pExpr is an operand of a comparison operator.  aff2 is the
** type affinity of the other operand.  This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(const Expr *pExpr, char aff2){
  char aff1 = sqlite3ExprAffinity(pExpr);
  if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){
    /* Both sides of the comparison are columns. If one has numeric
    ** affinity, use that. Otherwise use no affinity.
    */
    if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
      return SQLITE_AFF_NUMERIC;

  }
}

/*
** pExpr is a comparison operator.  Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(const Expr *pExpr){
  char aff;
  assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
          pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
          pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
  assert( pExpr->pLeft );
  aff = sqlite3ExprAffinity(pExpr->pLeft);
  if( pExpr->pRight ){

/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(const Expr *pExpr, char idx_affinity){
  char aff = comparisonAffinity(pExpr);
  if( aff<SQLITE_AFF_TEXT ){
    return 1;
  }
  if( aff==SQLITE_AFF_TEXT ){
    return idx_affinity==SQLITE_AFF_TEXT;
  }
  return sqlite3IsNumericAffinity(idx_affinity);
}

/*
** Return the P5 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
*/
static u8 binaryCompareP5(
  const Expr *pExpr1,   /* Left operand */
  const Expr *pExpr2,   /* Right operand */
  int jumpIfNull        /* Extra flags added to P5 */
){
  u8 aff = (char)sqlite3ExprAffinity(pExpr2);
  aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
  return aff;
}

/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
**
** Argument pRight (but not pLeft) may be a null pointer. In this case,
** it is not considered.
*/
CollSeq *sqlite3BinaryCompareCollSeq(
  Parse *pParse, 
  const Expr *pLeft, 
  const Expr *pRight
){
  CollSeq *pColl;
  assert( pLeft );
  if( pLeft->flags & EP_Collate ){
    pColl = sqlite3ExprCollSeq(pParse, pLeft);
  }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
    pColl = sqlite3ExprCollSeq(pParse, pRight);

** appropriate for the comparison operator.
**
** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
** However, if the OP_Commuted flag is set, then the order of the operands
** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
** correct collating sequence is found.
*/
CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, const Expr *p){
  if( ExprHasProperty(p, EP_Commuted) ){
    return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
  }else{
    return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
  }
}

  int i;
  int regLeft = 0;
  int regRight = 0;
  u8 opx = op;
  int addrDone = sqlite3VdbeMakeLabel(pParse);
  int isCommuted = ExprHasProperty(pExpr,EP_Commuted);

  assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
  if( pParse->nErr ) return;
  if( nLeft!=sqlite3ExprVectorSize(pRight) ){
    sqlite3ErrorMsg(pParse, "row value misused");
    return;
  }
  assert( pExpr->op==TK_EQ || pExpr->op==TK_NE 
       || pExpr->op==TK_IS || pExpr->op==TK_ISNOT 

#endif
  ){
    nSize = EXPR_FULLSIZE;
  }else{
    assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
    assert( !ExprHasProperty(p, EP_FromJoin) ); 
    assert( !ExprHasProperty(p, EP_MemToken) );
    assert( !ExprHasVVAProperty(p, EP_NoReduce) );
    if( p->pLeft || p->x.pList ){
      nSize = EXPR_REDUCEDSIZE | EP_Reduced;
    }else{
      assert( p->pRight==0 );
      nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
    }
  }

      }
    }

    /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
    pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
    pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
    pNew->flags |= staticFlag;
    ExprClearVVAProperties(pNew);
    if( dupFlags ){
      ExprSetVVAProperty(pNew, EP_Immutable);
    }

    /* Copy the p->u.zToken string, if any. */
    if( nToken ){
      char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
      memcpy(zToken, p->u.zToken, nToken);
    }

void sqlite3ExprListSetName(
  Parse *pParse,          /* Parsing context */
  ExprList *pList,        /* List to which to add the span. */
  Token *pName,           /* Name to be added */
  int dequote             /* True to cause the name to be dequoted */
){
  assert( pList!=0 || pParse->db->mallocFailed!=0 );
  assert( pParse->eParseMode!=PARSE_MODE_UNMAP || dequote==0 );
  if( pList ){
    struct ExprList_item *pItem;
    assert( pList->nExpr>0 );
    pItem = &pList->a[pList->nExpr-1];
    assert( pItem->zEName==0 );
    assert( pItem->eEName==ENAME_NAME );
    pItem->zEName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
    if( dequote ){
      /* If dequote==0, then pName->z does not point to part of a DDL
      ** statement handled by the parser. And so no token need be added
      ** to the token-map.  */
      sqlite3Dequote(pItem->zEName);
      if( IN_RENAME_OBJECT ){
        sqlite3RenameTokenMap(pParse, (void*)pItem->zEName, pName);
      }
    }
  }
}

/*
** Set the ExprList.a[].zSpan element of the most recently added item
** on the expression list.

**   (2) the expression does originate in the ON or USING clause
**       of a LEFT JOIN, and
**   (3) the expression does not contain any EP_FixedCol TK_COLUMN
**       operands created by the constant propagation optimization.
**
** When this routine returns true, it indicates that the expression
** can be added to the pParse->pConstExpr list and evaluated once when
** the prepared statement starts up.  See sqlite3ExprCodeRunJustOnce().
*/
int sqlite3ExprIsConstantNotJoin(Expr *p){
  return exprIsConst(p, 2, 0);
}

/*
** Walk an expression tree.  Return non-zero if the expression is constant

      sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
      sqlite3VdbeJumpHere(v, addrOnce);
      return;
    }

    /* Begin coding the subroutine */
    ExprSetProperty(pExpr, EP_Subrtn);
    assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
    pExpr->y.sub.regReturn = ++pParse->nMem;
    pExpr->y.sub.iAddr =
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
    VdbeComment((v, "return address"));

    addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
  }

    int i;
    ExprList *pList = pExpr->x.pList;
    struct ExprList_item *pItem;
    int r1, r2;
    affinity = sqlite3ExprAffinity(pLeft);
    if( affinity<=SQLITE_AFF_NONE ){
      affinity = SQLITE_AFF_BLOB;
    }else if( affinity==SQLITE_AFF_REAL ){
      affinity = SQLITE_AFF_NUMERIC;
    }
    if( pKeyInfo ){
      assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
      pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
    }

    /* Loop through each expression in <exprlist>. */

  int i;                /* loop counter */
  int destStep2;        /* Where to jump when NULLs seen in step 2 */
  int destStep6 = 0;    /* Start of code for Step 6 */
  int addrTruthOp;      /* Address of opcode that determines the IN is true */
  int destNotNull;      /* Jump here if a comparison is not true in step 6 */
  int addrTop;          /* Top of the step-6 loop */ 
  int iTab = 0;         /* Index to use */
  u8 okConstFactor = pParse->okConstFactor;

  assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
  pLeft = pExpr->pLeft;
  if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
  zAff = exprINAffinity(pParse, pExpr);
  nVector = sqlite3ExprVectorSize(pExpr->pLeft);
  aiMap = (int*)sqlite3DbMallocZero(
      pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
  );

  ** vector, then it is stored in an array of nVector registers starting 
  ** at r1.
  **
  ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
  ** so that the fields are in the same order as an existing index.   The
  ** aiMap[] array contains a mapping from the original LHS field order to
  ** the field order that matches the RHS index.
  **
  ** Avoid factoring the LHS of the IN(...) expression out of the loop,
  ** even if it is constant, as OP_Affinity may be used on the register
  ** by code generated below.  */
  assert( pParse->okConstFactor==okConstFactor );
  pParse->okConstFactor = 0;
  rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
  pParse->okConstFactor = okConstFactor;
  for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
  if( i==nVector ){
    /* LHS fields are not reordered */
    rLhs = rLhsOrig;
  }else{
    /* Need to reorder the LHS fields according to aiMap */
    rLhs = sqlite3GetTempRange(pParse, nVector);

  if( eType==IN_INDEX_NOOP ){
    ExprList *pList = pExpr->x.pList;
    CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
    int labelOk = sqlite3VdbeMakeLabel(pParse);
    int r2, regToFree;
    int regCkNull = 0;
    int ii;

    assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
    if( destIfNull!=destIfFalse ){
      regCkNull = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
    }

    for(ii=0; ii<pList->nExpr; ii++){





      r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, &regToFree);

      if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
        sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
      }
      sqlite3ReleaseTempReg(pParse, regToFree);
      if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
        int op = rLhs!=r2 ? OP_Eq : OP_NotNull;
        sqlite3VdbeAddOp4(v, op, rLhs, labelOk, r2,

  assert( v!=0 );
  assert( pParse->iSelfTab!=0 );
  if( pParse->iSelfTab>0 ){
    iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
  }else{
    iAddr = 0;
  }
  sqlite3ExprCodeCopy(pParse, pCol->pDflt, regOut);
  if( pCol->affinity>=SQLITE_AFF_TEXT ){
    sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
  }
  if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
}
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */

        VdbeCoverage(v);
        sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
      }
      setDoNotMergeFlagOnCopy(v);
      sqlite3VdbeResolveLabel(v, endCoalesce);
      break;
    }
    case INLINEFUNC_iif: {
      Expr caseExpr;
      memset(&caseExpr, 0, sizeof(caseExpr));
      caseExpr.op = TK_CASE;
      caseExpr.x.pList = pFarg;
      return sqlite3ExprCodeTarget(pParse, &caseExpr, target);
    }

    default: {   
      /* The UNLIKELY() function is a no-op.  The result is the value
      ** of the first argument.
      */
      assert( nFarg==1 || nFarg==2 );
      target = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);

    return 0;
  }

expr_code_doover:
  if( pExpr==0 ){
    op = TK_NULL;
  }else{
    assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );
    op = pExpr->op;
  }
  switch( op ){
    case TK_AGG_COLUMN: {
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol;
      assert( pAggInfo!=0 );
      assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
      pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        return pCol->iMem;
      }else if( pAggInfo->useSortingIdx ){
        Table *pTab = pCol->pTab;
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                              pCol->iSorterColumn, target);
        if( pCol->iColumn<0 ){
          VdbeComment((v,"%s.rowid",pTab->zName));
        }else{
          VdbeComment((v,"%s.%s",pTab->zName,pTab->aCol[pCol->iColumn].zName));
          if( pTab->aCol[pCol->iColumn].affinity==SQLITE_AFF_REAL ){
            sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
          }
        }
        return target;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      int iTab = pExpr->iTable;
      int iReg;

        }else{
          aff = pExpr->affExpr;
        }
        if( aff>SQLITE_AFF_BLOB ){
          static const char zAff[] = "B\000C\000D\000E";
          assert( SQLITE_AFF_BLOB=='A' );
          assert( SQLITE_AFF_TEXT=='B' );




          sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,
                            &zAff[(aff-'B')*2], P4_STATIC);
        }
        return iReg;
      }
      if( iTab<0 ){
        if( pParse->iSelfTab<0 ){

        codeReal(v, pLeft->u.zToken, 1, target);
        return target;
#endif
      }else{
        tempX.op = TK_INTEGER;
        tempX.flags = EP_IntValue|EP_TokenOnly;
        tempX.u.iValue = 0;
        ExprClearVVAProperties(&tempX);
        r1 = sqlite3ExprCodeTemp(pParse, &tempX, &regFree1);
        r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
        sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
        testcase( regFree2==0 );
      }
      break;
    }

      VdbeCoverageIf(v, op==TK_NOTNULL);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
      sqlite3VdbeJumpHere(v, addr);
      break;
    }
    case TK_AGG_FUNCTION: {
      AggInfo *pInfo = pExpr->pAggInfo;
      if( pInfo==0
       || NEVER(pExpr->iAgg<0)
       || NEVER(pExpr->iAgg>=pInfo->nFunc)
      ){
        assert( !ExprHasProperty(pExpr, EP_IntValue) );
        sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
      }else{
        return pInfo->aFunc[pExpr->iAgg].iMem;
      }
      break;
    }

#ifndef SQLITE_OMIT_WINDOWFUNC
      if( ExprHasProperty(pExpr, EP_WinFunc) ){
        return pExpr->y.pWin->regResult;
      }
#endif

      if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
        /* SQL functions can be expensive. So try to avoid running them
        ** multiple times if we know they always give the same result */
        return sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
      }
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      assert( !ExprHasProperty(pExpr, EP_TokenOnly) );


      pFarg = pExpr->x.pList;

      nFarg = pFarg ? pFarg->nExpr : 0;
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      zId = pExpr->u.zToken;
      pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
      if( pDef==0 && pParse->explain ){
        pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);

#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      assert( pExpr->affExpr==OE_Rollback 
           || pExpr->affExpr==OE_Abort
           || pExpr->affExpr==OE_Fail
           || pExpr->affExpr==OE_Ignore
      );
      if( !pParse->pTriggerTab && !pParse->nested ){
        sqlite3ErrorMsg(pParse,
                       "RAISE() may only be used within a trigger-program");
        return 0;
      }
      if( pExpr->affExpr==OE_Abort ){
        sqlite3MayAbort(pParse);
      }
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      if( pExpr->affExpr==OE_Ignore ){
        sqlite3VdbeAddOp4(
            v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
        VdbeCoverage(v);
      }else{
        sqlite3HaltConstraint(pParse,
             pParse->pTriggerTab ? SQLITE_CONSTRAINT_TRIGGER : SQLITE_ERROR,
             pExpr->affExpr, pExpr->u.zToken, 0, 0);
      }

      break;
    }
#endif
  }
  sqlite3ReleaseTempReg(pParse, regFree1);
  sqlite3ReleaseTempReg(pParse, regFree2);
  return inReg;
}

/*
** Generate code that will evaluate expression pExpr just one time
** per prepared statement execution.
**
** If the expression uses functions (that might throw an exception) then
** guard them with an OP_Once opcode to ensure that the code is only executed
** once. If no functions are involved, then factor the code out and put it at
** the end of the prepared statement in the initialization section.
**
** If regDest>=0 then the result is always stored in that register and the
** result is not reusable.  If regDest<0 then this routine is free to 
** store the value whereever it wants.  The register where the expression 
** is stored is returned.  When regDest<0, two identical expressions might
** code to the same register, if they do not contain function calls and hence
** are factored out into the initialization section at the end of the
** prepared statement.
*/
int sqlite3ExprCodeRunJustOnce(
  Parse *pParse,    /* Parsing context */
  Expr *pExpr,      /* The expression to code when the VDBE initializes */
  int regDest       /* Store the value in this register */
){
  ExprList *p;
  assert( ConstFactorOk(pParse) );
  p = pParse->pConstExpr;
  if( regDest<0 && p ){
    struct ExprList_item *pItem;
    int i;
    for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
      if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){
        return pItem->u.iConstExprReg;
      }
    }
  }
  pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
  if( pExpr!=0 && ExprHasProperty(pExpr, EP_HasFunc) ){
    Vdbe *v = pParse->pVdbe;
    int addr;
    assert( v );
    addr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
    pParse->okConstFactor = 0;
    if( !pParse->db->mallocFailed ){
      if( regDest<0 ) regDest = ++pParse->nMem;
      sqlite3ExprCode(pParse, pExpr, regDest);
    }
    pParse->okConstFactor = 1;
    sqlite3ExprDelete(pParse->db, pExpr);
    sqlite3VdbeJumpHere(v, addr);
  }else{
    p = sqlite3ExprListAppend(pParse, p, pExpr);
    if( p ){
       struct ExprList_item *pItem = &p->a[p->nExpr-1];
       pItem->reusable = regDest<0;
       if( regDest<0 ) regDest = ++pParse->nMem;
       pItem->u.iConstExprReg = regDest;
    }
    pParse->pConstExpr = p;
  }
  return regDest;
}

/*
** Generate code to evaluate an expression and store the results
** into a register.  Return the register number where the results
** are stored.

  int r2;
  pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
  if( ConstFactorOk(pParse)
   && pExpr->op!=TK_REGISTER
   && sqlite3ExprIsConstantNotJoin(pExpr)
  ){
    *pReg  = 0;
    r2 = sqlite3ExprCodeRunJustOnce(pParse, pExpr, -1);
  }else{
    int r1 = sqlite3GetTempReg(pParse);
    r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
    if( r2==r1 ){
      *pReg = r1;
    }else{
      sqlite3ReleaseTempReg(pParse, r1);

** Generate code that will evaluate expression pExpr and store the
** results in register target.  The results are guaranteed to appear
** in register target.
*/
void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
  int inReg;

  assert( pExpr==0 || !ExprHasVVAProperty(pExpr,EP_Immutable) );
  assert( target>0 && target<=pParse->nMem );
  inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
  assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
  if( inReg!=target && pParse->pVdbe ){
    u8 op;
    if( ExprHasProperty(pExpr,EP_Subquery) ){
      op = OP_Copy;

** Generate code that will evaluate expression pExpr and store the
** results in register target.  The results are guaranteed to appear
** in register target.  If the expression is constant, then this routine
** might choose to code the expression at initialization time.
*/
void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
  if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){
    sqlite3ExprCodeRunJustOnce(pParse, pExpr, target);
  }else{
    sqlite3ExprCodeCopy(pParse, pExpr, target);
  }
}

/*
** Generate code that pushes the value of every element of the given
** expression list into a sequence of registers beginning at target.
**

        n--;
      }else{
        sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
      }
    }else if( (flags & SQLITE_ECEL_FACTOR)!=0
           && sqlite3ExprIsConstantNotJoin(pExpr)
    ){
      sqlite3ExprCodeRunJustOnce(pParse, pExpr, target+i);
    }else{
      int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
      if( inReg!=target+i ){
        VdbeOp *pOp;
        if( copyOp==OP_Copy
         && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
         && pOp->p1+pOp->p3+1==inReg

  int regFree1 = 0;
  int regFree2 = 0;
  int r1, r2;

  assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
  if( NEVER(v==0) )     return;  /* Existence of VDBE checked by caller */
  if( NEVER(pExpr==0) ) return;  /* No way this can happen */
  assert( !ExprHasVVAProperty(pExpr, EP_Immutable) );
  op = pExpr->op;
  switch( op ){
    case TK_AND:
    case TK_OR: {
      Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);
      if( pAlt!=pExpr ){
        sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);

  int regFree1 = 0;
  int regFree2 = 0;
  int r1, r2;

  assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
  if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
  if( pExpr==0 )    return;
  assert( !ExprHasVVAProperty(pExpr,EP_Immutable) );

  /* The value of pExpr->op and op are related as follows:
  **
  **       pExpr->op            op
  **       ---------          ----------
  **       TK_ISNULL          OP_NotNull
  **       TK_NOTNULL         OP_IsNull

      if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
    }else if( ALWAYS(pB->u.zToken!=0) && strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return 2;
    }
  }
  if( (pA->flags & (EP_Distinct|EP_Commuted))
     != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
  if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
    if( combinedFlags & EP_xIsSelect ) return 2;
    if( (combinedFlags & EP_FixedCol)==0
     && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
    if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
    if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
    if( pA->op!=TK_STRING
     && pA->op!=TK_TRUEFALSE
     && ALWAYS((combinedFlags & EP_Reduced)==0)
    ){
      if( pA->iColumn!=pB->iColumn ) return 2;
      if( pA->op2!=pB->op2 && pA->op==TK_TRUTH ) return 2;














      if( pA->op!=TK_IN && pA->iTable!=pB->iTable && pA->iTable!=iTab ){
        return 2;
      }
    }
  }
  return 0;
}

    ** a term of the form x=y does not prove that y is not null if x
    ** is the column of a virtual table */
    case TK_EQ:
    case TK_NE:
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE: {
      Expr *pLeft = pExpr->pLeft;
      Expr *pRight = pExpr->pRight;
      testcase( pExpr->op==TK_EQ );
      testcase( pExpr->op==TK_NE );
      testcase( pExpr->op==TK_LT );
      testcase( pExpr->op==TK_LE );
      testcase( pExpr->op==TK_GT );
      testcase( pExpr->op==TK_GE );
      /* The y.pTab=0 assignment in wherecode.c always happens after the
      ** impliesNotNullRow() test */
      if( (pLeft->op==TK_COLUMN && ALWAYS(pLeft->y.pTab!=0)
                               && IsVirtual(pLeft->y.pTab))
       || (pRight->op==TK_COLUMN && ALWAYS(pRight->y.pTab!=0)
                               && IsVirtual(pRight->y.pTab))
      ){
        return WRC_Prune;
      }
    }
    default:
      return WRC_Continue;
  }
}

/*
** Return true (non-zero) if expression p can only be true if at least

      }else{
        return WRC_Continue;
      }
    }
  }
  return WRC_Continue;
}










/*
** Analyze the pExpr expression looking for aggregate functions and
** for variables that need to be added to AggInfo object that pNC->pAggInfo
** points to.  Additional entries are made on the AggInfo object as
** necessary.
**
** This routine should only be called after the expression has been
** analyzed by sqlite3ResolveExprNames().
*/
void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
  Walker w;
  w.xExprCallback = analyzeAggregate;
  w.xSelectCallback = sqlite3WalkerDepthIncrease;
  w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
  w.walkerDepth = 0;
  w.u.pNC = pNC;
  w.pParse = 0;
  assert( pNC->pSrcList!=0 );
  sqlite3WalkExpr(&w, pExpr);
}

      sqlite3WhereEnd(pWInfo);
    }
  }

  /* Clean up the WHERE clause constructed above. */
  sqlite3ExprDelete(db, pWhere);
  if( iFkIfZero ){
    sqlite3VdbeJumpHereOrPopInst(v, iFkIfZero);
  }
}

/*
** This function returns a linked list of FKey objects (connected by
** FKey.pNextTo) holding all children of table pTab.  For example,
** given the following schema:

  sqlite3_value **argv
){
  const unsigned char *zA, *zB;
  u32 escape;
  int nPat;
  sqlite3 *db = sqlite3_context_db_handle(context);
  struct compareInfo *pInfo = sqlite3_user_data(context);
  struct compareInfo backupInfo;

#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
   || sqlite3_value_type(argv[1])==SQLITE_BLOB
  ){
#ifdef SQLITE_TEST
    sqlite3_like_count++;

    if( zEsc==0 ) return;
    if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
      sqlite3_result_error(context, 
          "ESCAPE expression must be a single character", -1);
      return;
    }
    escape = sqlite3Utf8Read(&zEsc);
    if( escape==pInfo->matchAll || escape==pInfo->matchOne ){
      memcpy(&backupInfo, pInfo, sizeof(backupInfo));
      pInfo = &backupInfo;
      if( escape==pInfo->matchAll ) pInfo->matchAll = 0;
      if( escape==pInfo->matchOne ) pInfo->matchOne = 0;
    }
  }else{
    escape = pInfo->matchSet;
  }
  zB = sqlite3_value_text(argv[0]);
  zA = sqlite3_value_text(argv[1]);
  if( zA && zB ){
#ifdef SQLITE_TEST

        }
        cntExpand++;
        if( (cntExpand&(cntExpand-1))==0 ){
          /* Grow the size of the output buffer only on substitutions
          ** whose index is a power of two: 1, 2, 4, 8, 16, 32, ... */
          u8 *zOld;
          zOld = zOut;
          zOut = sqlite3Realloc(zOut, (int)nOut + (nOut - nStr - 1));
          if( zOut==0 ){
            sqlite3_result_error_nomem(context);
            sqlite3_free(zOld);
            return;
          }
        }
      }

  pDef = sqlite3FindFunction(db, pExpr->u.zToken, nExpr, SQLITE_UTF8, 0);
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
  if( pDef==0 ) return 0;
#endif
  if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){
    return 0;
  }











  /* The memcpy() statement assumes that the wildcard characters are
  ** the first three statements in the compareInfo structure.  The
  ** asserts() that follow verify that assumption
  */
  memcpy(aWc, pDef->pUserData, 3);
  assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
  assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
  assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );

  if( nExpr<3 ){
    aWc[3] = 0;
  }else{
    Expr *pEscape = pExpr->x.pList->a[2].pExpr;
    char *zEscape;
    if( pEscape->op!=TK_STRING ) return 0;
    zEscape = pEscape->u.zToken;
    if( zEscape[0]==0 || zEscape[1]!=0 ) return 0;
    if( zEscape[0]==aWc[0] ) return 0;
    if( zEscape[0]==aWc[1] ) return 0;
    aWc[3] = zEscape[0];
  }

  *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
  return 1;
}

/*
** All of the FuncDef structures in the aBuiltinFunc[] array above
** to the global function hash table.  This occurs at start-time (as

#ifndef SQLITE_OMIT_FLOATING_POINT
    FUNCTION(round,              1, 0, 0, roundFunc        ),
    FUNCTION(round,              2, 0, 0, roundFunc        ),
#endif
    FUNCTION(upper,              1, 0, 0, upperFunc        ),
    FUNCTION(lower,              1, 0, 0, lowerFunc        ),
    FUNCTION(hex,                1, 0, 0, hexFunc          ),
    INLINE_FUNC(ifnull,          2, INLINEFUNC_coalesce, 0 ),
    VFUNCTION(random,            0, 0, 0, randomFunc       ),
    VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),
    FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
    DFUNCTION(sqlite_version,    0, 0, 0, versionFunc      ),
    DFUNCTION(sqlite_source_id,  0, 0, 0, sourceidFunc     ),
    FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
    FUNCTION(quote,              1, 0, 0, quoteFunc        ),

    LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
#endif
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
    FUNCTION(unknown,           -1, 0, 0, unknownFunc      ),
#endif
    FUNCTION(coalesce,           1, 0, 0, 0                ),
    FUNCTION(coalesce,           0, 0, 0, 0                ),
    INLINE_FUNC(coalesce,       -1, INLINEFUNC_coalesce, 0 ),
    INLINE_FUNC(iif,             3, INLINEFUNC_iif,      0 ),
  };
#ifndef SQLITE_OMIT_ALTERTABLE
  sqlite3AlterFunctions();
#endif
  sqlite3WindowFunctions();
  sqlite3RegisterDateTimeFunctions();
  sqlite3InsertBuiltinFuncs(aBuiltinFunc, ArraySize(aBuiltinFunc));

**
** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled
** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.
**
** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally
** disabled. The default value may be changed by compiling with the
** SQLITE_USE_URI symbol defined.



*/
#ifndef SQLITE_USE_URI



# define SQLITE_USE_URI 0

#endif

/* EVIDENCE-OF: R-38720-18127 The default setting is determined by the
** SQLITE_ALLOW_COVERING_INDEX_SCAN compile-time option, or is "on" if
** that compile-time option is omitted.
*/
#if !defined(SQLITE_ALLOW_COVERING_INDEX_SCAN)

        iReg = sqlite3TableColumnToStorage(pTab, i) + regNewData + 1;
        switch( onError ){
          case OE_Replace: {
            int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, iReg);
            VdbeCoverage(v);
            assert( (pCol->colFlags & COLFLAG_GENERATED)==0 );
            nSeenReplace++;
            sqlite3ExprCodeCopy(pParse, pCol->pDflt, iReg);
            sqlite3VdbeJumpHere(v, addr1);
            break;
          }
          case OE_Abort:
            sqlite3MayAbort(pParse);
            /* Fall through */
          case OE_Rollback:

#ifndef SQLITE_OMIT_CHECK
  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
    ExprList *pCheck = pTab->pCheck;
    pParse->iSelfTab = -(regNewData+1);
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    for(i=0; i<pCheck->nExpr; i++){
      int allOk;
      Expr *pCopy;
      Expr *pExpr = pCheck->a[i].pExpr;
      if( aiChng
       && !sqlite3ExprReferencesUpdatedColumn(pExpr, aiChng, pkChng)
      ){
        /* The check constraints do not reference any of the columns being
        ** updated so there is no point it verifying the check constraint */
        continue;
      }
      if( bAffinityDone==0 ){
        sqlite3TableAffinity(v, pTab, regNewData+1);
        bAffinityDone = 1;
      }
      allOk = sqlite3VdbeMakeLabel(pParse);
      sqlite3VdbeVerifyAbortable(v, onError);
      pCopy = sqlite3ExprDup(db, pExpr, 0);
      if( !db->mallocFailed ){
        sqlite3ExprIfTrue(pParse, pCopy, allOk, SQLITE_JUMPIFNULL);
      }
      sqlite3ExprDelete(db, pCopy);
      if( onError==OE_Ignore ){
        sqlite3VdbeGoto(v, ignoreDest);
      }else{
        char *zName = pCheck->a[i].zEName;
        if( zName==0 ) zName = pTab->zName;
        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */
        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,

    }else{
      addrUniqueOk = sqlite3VdbeMakeLabel(pParse);
    }
    if( bAffinityDone==0 && (pUpIdx==0 || pUpIdx==pIdx) ){
      sqlite3TableAffinity(v, pTab, regNewData+1);
      bAffinityDone = 1;
    }
    VdbeNoopComment((v, "prep index %s", pIdx->zName));
    iThisCur = iIdxCur+ix;


    /* Skip partial indices for which the WHERE clause is not true */
    if( pIdx->pPartIdxWhere ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
      pParse->iSelfTab = -(regNewData+1);

      addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
    }else{
      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
      assert( (pDest->tabFlags & TF_Autoincrement)==0 );
    }
    if( db->mDbFlags & DBFLAG_Vacuum ){
      sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);

      insFlags = OPFLAG_APPEND|OPFLAG_USESEEKRESULT;
    }else{
      insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;
    }
    sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
    sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
                      (char*)pDest, P4_TABLE);
    sqlite3VdbeChangeP5(v, insFlags);

        const char *zColl = pSrcIdx->azColl[i];
        if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
      }
      if( i==pSrcIdx->nColumn ){
        idxInsFlags = OPFLAG_USESEEKRESULT;
        sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
      }

    }else if( !HasRowid(pSrc) && pDestIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
      idxInsFlags |= OPFLAG_NCHANGE;
    }
    sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
    sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
    sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);
    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addr1);

#endif
  /* Version 3.31.0 and later */
  sqlite3_hard_heap_limit64,
  sqlite3_uri_key,
  sqlite3_filename_database,
  sqlite3_filename_journal,
  sqlite3_filename_wal,
  /* Version 3.32.0 and later */
  sqlite3_create_filename,
  sqlite3_free_filename,
  sqlite3_database_file_object,
};

/* True if x is the directory separator character
*/
#if SQLITE_OS_WIN
# define DirSep(X)  ((X)=='/'||(X)=='\\')
#else
# define DirSep(X)  ((X)=='/')
#endif

/*
** Attempt to load an SQLite extension library contained in the file
** zFile.  The entry point is zProc.  zProc may be 0 in which case a
** default entry point name (sqlite3_extension_init) is used.  Use
** of the default name is recommended.
**

    int ncFile = sqlite3Strlen30(zFile);
    zAltEntry = sqlite3_malloc64(ncFile+30);
    if( zAltEntry==0 ){
      sqlite3OsDlClose(pVfs, handle);
      return SQLITE_NOMEM_BKPT;
    }
    memcpy(zAltEntry, "sqlite3_", 8);
    for(iFile=ncFile-1; iFile>=0 && !DirSep(zFile[iFile]); iFile--){}
    iFile++;
    if( sqlite3_strnicmp(zFile+iFile, "lib", 3)==0 ) iFile += 3;
    for(iEntry=8; (c = zFile[iFile])!=0 && c!='.'; iFile++){
      if( sqlite3Isalpha(c) ){
        zAltEntry[iEntry++] = (char)sqlite3UpperToLower[(unsigned)c];
      }
    }

#endif
#ifdef SQLITE_ENABLE_RTREE
# include "rtree.h"
#endif
#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
# include "sqliteicu.h"
#endif

/*
** This is an extension initializer that is a no-op and always
** succeeds, except that it fails if the fault-simulation is set
** to 500.
*/
static int sqlite3TestExtInit(sqlite3 *db){
  (void)db;
  return sqlite3FaultSim(500);
}


/*
** Forward declarations of external module initializer functions
** for modules that need them.
*/
#ifdef SQLITE_ENABLE_FTS1
int sqlite3Fts1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_FTS2
int sqlite3Fts2Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_FTS5
int sqlite3Fts5Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_JSON1
int sqlite3Json1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
int sqlite3StmtVtabInit(sqlite3*);
#endif

/*
** An array of pointers to extension initializer functions for
** built-in extensions.
*/
static int (*const sqlite3BuiltinExtensions[])(sqlite3*) = {
#ifdef SQLITE_ENABLE_FTS1
  sqlite3Fts1Init,
#endif
#ifdef SQLITE_ENABLE_FTS2
  sqlite3Fts2Init,
#endif
#ifdef SQLITE_ENABLE_FTS3
  sqlite3Fts3Init,
#endif
#ifdef SQLITE_ENABLE_FTS5
  sqlite3Fts5Init,
#endif
#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
  sqlite3IcuInit,
#endif
#ifdef SQLITE_ENABLE_RTREE
  sqlite3RtreeInit,
#endif
#ifdef SQLITE_ENABLE_DBPAGE_VTAB
  sqlite3DbpageRegister,
#endif
#ifdef SQLITE_ENABLE_DBSTAT_VTAB
  sqlite3DbstatRegister,
#endif
  sqlite3TestExtInit,
#ifdef SQLITE_ENABLE_JSON1
  sqlite3Json1Init,
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
  sqlite3StmtVtabInit,
#endif
#ifdef SQLITE_ENABLE_BYTECODE_VTAB
  sqlite3VdbeBytecodeVtabInit,
#endif
};

#ifndef SQLITE_AMALGAMATION
/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
** contains the text of SQLITE_VERSION macro. 
*/
const char sqlite3_version[] = SQLITE_VERSION;
#endif

    if( rc==SQLITE_OK ){
      rc = sqlite3MemdbInit();
    }
#endif
    if( rc==SQLITE_OK ){
      sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
          sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
      sqlite3MemoryBarrier();
      sqlite3GlobalConfig.isInit = 1;
#ifdef SQLITE_EXTRA_INIT
      bRunExtraInit = 1;
#endif
    }
    sqlite3GlobalConfig.inProgress = 0;
  }

** argument.
**
** Return non-zero to retry the lock.  Return zero to stop trying
** and cause SQLite to return SQLITE_BUSY.
*/
static int sqliteDefaultBusyCallback(
  void *ptr,               /* Database connection */
  int count                /* Number of times table has been busy */

){
#if SQLITE_OS_WIN || HAVE_USLEEP
  /* This case is for systems that have support for sleeping for fractions of
  ** a second.  Examples:  All windows systems, unix systems with usleep() */
  static const u8 delays[] =
     { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
  static const u8 totals[] =
     { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
# define NDELAY ArraySize(delays)
  sqlite3 *db = (sqlite3 *)ptr;
  int tmout = db->busyTimeout;
  int delay, prior;














  assert( count>=0 );
  if( count < NDELAY ){
    delay = delays[count];
    prior = totals[count];
  }else{
    delay = delays[NDELAY-1];
    prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
  }
  if( prior + delay > tmout ){
    delay = tmout - prior;
    if( delay<=0 ) return 0;
  }
  sqlite3OsSleep(db->pVfs, delay*1000);
  return 1;
#else
  /* This case for unix systems that lack usleep() support.  Sleeping
  ** must be done in increments of whole seconds */
  sqlite3 *db = (sqlite3 *)ptr;
  int tmout = ((sqlite3 *)ptr)->busyTimeout;

  if( (count+1)*1000 > tmout ){
    return 0;
  }
  sqlite3OsSleep(db->pVfs, 1000000);
  return 1;
#endif
}

/*
** Invoke the given busy handler.
**
** This routine is called when an operation failed to acquire a
** lock on VFS file pFile.
**
** If this routine returns non-zero, the lock is retried.  If it
** returns 0, the operation aborts with an SQLITE_BUSY error.
*/
int sqlite3InvokeBusyHandler(BusyHandler *p){
  int rc;
  if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;








  rc = p->xBusyHandler(p->pBusyArg, p->nBusy);

  if( rc==0 ){
    p->nBusy = -1;
  }else{
    p->nBusy++;
  }
  return rc; 
}

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->busyHandler.xBusyHandler = xBusy;
  db->busyHandler.pBusyArg = pArg;
  db->busyHandler.nBusy = 0;

  db->busyTimeout = 0;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  if( ms>0 ){
    sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
                             (void*)db);
    db->busyTimeout = ms;

  }else{
    sqlite3_busy_handler(db, 0, 0);
  }
  return SQLITE_OK;
}

/*
** Cause any pending operation to stop at its earliest opportunity.
*/
void sqlite3_interrupt(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
    (void)SQLITE_MISUSE_BKPT;
    return;
  }
#endif
  AtomicStore(&db->u1.isInterrupted, 1);
}


/*
** This function is exactly the same as sqlite3_create_function(), except
** that it is designed to be called by internal code. The difference is
** that if a malloc() fails in sqlite3_create_function(), an error code

    sqlite3Error(db, rc);
  }
  rc = sqlite3ApiExit(db, rc);

  /* If there are no active statements, clear the interrupt flag at this
  ** point.  */
  if( db->nVdbeActive==0 ){
    AtomicStore(&db->u1.isInterrupted, 0);
  }

  sqlite3_mutex_leave(db->mutex);
  return rc;
#endif
}

** itself. When this function is called the *pFlags variable should contain
** the default flags to open the database handle with. The value stored in
** *pFlags may be updated before returning if the URI filename contains 
** "cache=xxx" or "mode=xxx" query parameters.
**
** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
** the VFS that should be used to open the database file. *pzFile is set to
** point to a buffer containing the name of the file to open.  The value
** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
** and is in the same format as names created using sqlite3_create_filename().
** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
** the value returned in *pzFile to avoid a memory leak.
**
** If an error occurs, then an SQLite error code is returned and *pzErrMsg
** may be set to point to a buffer containing an English language error 
** message. It is the responsibility of the caller to eventually release
** this buffer by calling sqlite3_free().
*/
int sqlite3ParseUri(

            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
  ){
    char *zOpt;
    int eState;                   /* Parser state when parsing URI */
    int iIn;                      /* Input character index */
    int iOut = 0;                 /* Output character index */
    u64 nByte = nUri+8;           /* Bytes of space to allocate */

    /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
    ** method that there may be extra parameters following the file-name.  */
    flags |= SQLITE_OPEN_URI;

    for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
    zFile = sqlite3_malloc64(nByte);
    if( !zFile ) return SQLITE_NOMEM_BKPT;

    memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
    zFile += 4;

    iIn = 5;
#ifdef SQLITE_ALLOW_URI_AUTHORITY
    if( strncmp(zUri+5, "///", 3)==0 ){
      iIn = 7;
      /* The following condition causes URIs with five leading / characters
      ** like file://///host/path to be converted into UNCs like //host/path.

      }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
        c = 0;
        eState = 1;
      }
      zFile[iOut++] = c;
    }
    if( eState==1 ) zFile[iOut++] = '\0';
    memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */


    /* Check if there were any options specified that should be interpreted 
    ** here. Options that are interpreted here include "vfs" and those that
    ** correspond to flags that may be passed to the sqlite3_open_v2()
    ** method. */
    zOpt = &zFile[sqlite3Strlen30(zFile)+1];
    while( zOpt[0] ){

        }
      }

      zOpt = &zVal[nVal+1];
    }

  }else{
    zFile = sqlite3_malloc64(nUri+8);
    if( !zFile ) return SQLITE_NOMEM_BKPT;
    memset(zFile, 0, 4);
    zFile += 4;
    if( nUri ){
      memcpy(zFile, zUri, nUri);
    }
    memset(zFile+nUri, 0, 4);

    flags &= ~SQLITE_OPEN_URI;
  }

  *ppVfs = sqlite3_vfs_find(zVfs);
  if( *ppVfs==0 ){
    *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
    rc = SQLITE_ERROR;
  }
 parse_uri_out:
  if( rc!=SQLITE_OK ){
    sqlite3_free_filename(zFile);
    zFile = 0;
  }
  *pFlags = flags;
  *pzFile = zFile;
  return rc;
}

    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return 0;
}






































/*
** This routine does the work of opening a database on behalf of
** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
** is UTF-8 encoded.
*/
static int openDatabase(
  const char *zFilename, /* Database filename UTF-8 encoded */
  sqlite3 **ppDb,        /* OUT: Returned database handle */
  unsigned int flags,    /* Operational flags */
  const char *zVfs       /* Name of the VFS to use */
){
  sqlite3 *db;                    /* Store allocated handle here */
  int rc;                         /* Return code */
  int isThreadsafe;               /* True for threadsafe connections */
  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
  int i;                          /* Loop counter */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();

#endif
#if defined(SQLITE_ENABLE_QPSG)
                 | SQLITE_EnableQPSG
#endif
#if defined(SQLITE_DEFAULT_DEFENSIVE)
                 | SQLITE_Defensive
#endif
#if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
                 | SQLITE_LegacyAlter
#endif
      ;
  sqlite3HashInit(&db->aCollSeq);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3HashInit(&db->aModule);
#endif

  /* Add the default collation sequence BINARY. BINARY works for both UTF-8

  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
  createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
  if( db->mallocFailed ){
    goto opendb_out;
  }






  /* Parse the filename/URI argument
  **
  ** Only allow sensible combinations of bits in the flags argument.  
  ** Throw an error if any non-sense combination is used.  If we
  ** do not block illegal combinations here, it could trigger
  ** assert() statements in deeper layers.  Sensible combinations

  assert( SQLITE_OPEN_READONLY  == 0x01 );
  assert( SQLITE_OPEN_READWRITE == 0x02 );
  assert( SQLITE_OPEN_CREATE    == 0x04 );
  testcase( (1<<(flags&7))==0x02 ); /* READONLY */
  testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
  testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
  if( ((1<<(flags&7)) & 0x46)==0 ){
    rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
  }else{
    rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
  }
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
    sqlite3_free(zErrMsg);

      rc = SQLITE_NOMEM_BKPT;
    }
    sqlite3Error(db, rc);
    goto opendb_out;
  }
  sqlite3BtreeEnter(db->aDb[0].pBt);
  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
  if( !db->mallocFailed ){
    sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
  }
  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is FULL; for the temp
  ** database it is OFF. This matches the pager layer defaults.  
  */
  db->aDb[0].zDbSName = "main";

  ** database schema yet. This is delayed until the first time the database
  ** is accessed.
  */
  sqlite3Error(db, SQLITE_OK);
  sqlite3RegisterPerConnectionBuiltinFunctions(db);
  rc = sqlite3_errcode(db);



  /* Load compiled-in extensions */

  for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
    rc = sqlite3BuiltinExtensions[i](db);
  }


  /* Load automatic extensions - extensions that have been registered
  ** using the sqlite3_automatic_extension() API.
  */
  if( rc==SQLITE_OK ){
    sqlite3AutoLoadExtensions(db);
    rc = sqlite3_errcode(db);
    if( rc!=SQLITE_OK ){
      goto opendb_out;
    }
  }

























































#ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
  /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
  ** option gives access to internal functions by default.  
  ** Testing use only!!! */
  db->mDbFlags |= DBFLAG_InternalFunc;
#endif

#ifdef SQLITE_ENABLE_SQLLOG
  if( sqlite3GlobalConfig.xSqllog ){
    /* Opening a db handle. Fourth parameter is passed 0. */
    void *pArg = sqlite3GlobalConfig.pSqllogArg;
    sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
  }
#endif



  sqlite3_free_filename(zOpen);
  return rc & 0xff;
}


/*
** Open a new database handle.
*/

      *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
      *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_DATA_VERSION ){
      *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
      int iNew = *(int*)pArg;
      *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
      if( iNew>=0 && iNew<=255 ){
        sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
      }
      rc = SQLITE_OK;
    }else{
      rc = sqlite3OsFileControl(fd, op, pArg);
    }
    sqlite3BtreeLeave(pBtree);
  }
  sqlite3_mutex_leave(db->mutex);