Move bundled copy of sqlite one level deeper to better separate it...

third_party/sqlite/tool/vdbe-compress.tcl

-#!/usr/bin/tcl
-#
-# This script makes modifications to the vdbe.c source file which reduce
-# the amount of stack space required by the sqlite3VdbeExec() routine.
-#
-# The modifications performed by this script are optional.  The vdbe.c
-# source file will compile correctly with and without the modifications
-# performed by this script.  And all routines within vdbe.c will compute
-# the same result.  The modifications made by this script merely help
-# the C compiler to generate code for sqlite3VdbeExec() that uses less
-# stack space.
-#
-# Script usage:
-#
-#          mv vdbe.c vdbe.c.template
-#          tclsh vdbe-compress.tcl <vdbe.c.template >vdbe.c
-#
-# Modifications made:
-#
-# All modifications are within the sqlite3VdbeExec() function.  The
-# modifications seek to reduce the amount of stack space allocated by
-# this routine by moving local variable declarations out of individual
-# opcode implementations and into a single large union.  The union contains
-# a separate structure for each opcode and that structure contains the
-# local variables used by that opcode.  In this way, the total amount
-# of stack space required by sqlite3VdbeExec() is reduced from the
-# sum of all local variables to the maximum of the local variable space
-# required for any single opcode.
-#
-# In order to be recognized by this script, local variables must appear
-# on the first line after the open curly-brace that begins a new opcode
-# implementation.  Local variables must not have initializers, though they
-# may be commented.
-#
-# The union definition is inserted in place of a special marker comment
-# in the preamble to the sqlite3VdbeExec() implementation.
-#
-#############################################################################
-#
-set beforeUnion {}   ;# C code before union
-set unionDef {}      ;# C code of the union
-set afterUnion {}    ;# C code after the union
-set sCtr 0           ;# Context counter
-
-# Read program text up to the spot where the union should be
-# inserted.
-#
-while {![eof stdin]} {
-  set line [gets stdin]
-  if {[regexp {INSERT STACK UNION HERE} $line]} break
-  append beforeUnion $line\n
-}
-
-# Process the remaining text.  Build up the union definition as we go.
-#
-set vlist {}
-set seenDecl 0
-set namechars {abcdefghijklmnopqrstuvwxyz}
-set nnc [string length $namechars]
-while {![eof stdin]} {
-  set line [gets stdin]
-  if {[regexp "^case (OP_\\w+): \173" $line all operator]} {
-    append afterUnion $line\n
-    set vlist {}
-    while {![eof stdin]} {
-      set line [gets stdin]
-      if {[regexp {^ +(const )?\w+ \**(\w+)(\[.*\])?;} $line \
-           all constKeyword vname notused1]} {
-        if {!$seenDecl} {
-          set sname {}
-          append sname [string index $namechars [expr {$sCtr/$nnc}]]
-          append sname [string index $namechars [expr {$sCtr%$nnc}]]
-          incr sCtr
-          append unionDef "    struct ${operator}_stack_vars \173\n"
-          append afterUnion \
-             "#if 0  /* local variables moved into u.$sname */\n"
-          set seenDecl 1
-        }
-        append unionDef "    $line\n"
-        append afterUnion $line\n
-        lappend vlist $vname
-      } else {
-        break
-      }
-    }
-    if {$seenDecl} {
-      append unionDef   "    \175 $sname;\n"
-      append afterUnion "#endif /* local variables moved into u.$sname */\n"
-    }
-    set seenDecl 0
-  }
-  if {[regexp "^\175" $line]} {
-    append afterUnion $line\n
-    set vlist {}
-  } elseif {[llength $vlist]>0} {
-    append line " "
-    foreach v $vlist {
-      regsub -all "(\[^a-zA-Z0-9>.\])${v}(\\W)" $line "\\1u.$sname.$v\\2" line
-      regsub -all "(\[^a-zA-Z0-9>.\])${v}(\\W)" $line "\\1u.$sname.$v\\2" line
-    }
-    append afterUnion [string trimright $line]\n
-  } elseif {$line=="" && [eof stdin]} {
-    # no-op
-  } else {
-    append afterUnion $line\n
-  }
-}
-
-# Output the resulting text.
-#
-puts -nonewline $beforeUnion
-puts "  /********************************************************************"
-puts "  ** Automatically generated code"
-puts "  **"
-puts "  ** The following union is automatically generated by the"
-puts "  ** vdbe-compress.tcl script.  The purpose of this union is to"
-puts "  ** reduce the amount of stack space required by this function."
-puts "  ** See comments in the vdbe-compress.tcl script for details."
-puts "  */"
-puts "  union vdbeExecUnion \173"
-puts -nonewline $unionDef
-puts "  \175 u;"
-puts "  /* End automatically generated code"
-puts "  ********************************************************************/"
-puts -nonewline $afterUnion