Get `gn gen` to succeed on Windows

third_party/sqlite/src/tool/mksqlite3internalh.tcl

+#!/usr/bin/tclsh
+#
+# To build a single huge source file holding all of SQLite (or at
+# least the core components - the test harness, shell, and TCL 
+# interface are omitted.) first do
+#
+#      make target_source
+#
+# The make target above moves all of the source code files into
+# a subdirectory named "tsrc".  (This script expects to find the files
+# there and will not work if they are not found.)  There are a few
+# generated C code files that are also added to the tsrc directory.
+# For example, the "parse.c" and "parse.h" files to implement the
+# the parser are derived from "parse.y" using lemon.  And the 
+# "keywordhash.h" files is generated by a program named "mkkeywordhash".
+#
+# After the "tsrc" directory has been created and populated, run
+# this script:
+#
+#      tclsh mksqlite3c.tcl
+#
+# The amalgamated SQLite code will be written into sqlite3.c
+#
+
+# Begin by reading the "sqlite3.h" header file.  Count the number of lines
+# in this file and extract the version number.  That information will be
+# needed in order to generate the header of the amalgamation.
+#
+set in [open tsrc/sqlite3.h]
+set cnt 0
+set VERSION ?????
+while {![eof $in]} {
+  set line [gets $in]
+  if {$line=="" && [eof $in]} break
+  incr cnt
+  regexp {#define\s+SQLITE_VERSION\s+"(.*)"} $line all VERSION
+}
+close $in
+
+# Open the output file and write a header comment at the beginning
+# of the file.
+#
+set out [open sqlite3internal.h w]
+set today [clock format [clock seconds] -format "%Y-%m-%d %H:%M:%S UTC" -gmt 1]
+puts $out [subst \
+{/******************************************************************************
+** This file is an amalgamation of many private header files from SQLite
+** version $VERSION. 
+*/}]
+
+# These are the header files used by SQLite.  The first time any of these 
+# files are seen in a #include statement in the C code, include the complete
+# text of the file in-line.  The file only needs to be included once.
+#
+foreach hdr {
+   btree.h
+   btreeInt.h
+   hash.h
+   hwtime.h
+   keywordhash.h
+   opcodes.h
+   os_common.h
+   os.h
+   os_os2.h
+   pager.h
+   parse.h
+   sqlite3ext.h
+   sqlite3.h
+   sqliteInt.h
+   sqliteLimit.h
+   vdbe.h
+   vdbeInt.h
+} {
+  set available_hdr($hdr) 1
+}
+
+# 78 stars used for comment formatting.
+set s78 \
+{*****************************************************************************}
+
+# Insert a comment into the code
+#
+proc section_comment {text} {
+  global out s78
+  set n [string length $text]
+  set nstar [expr {60 - $n}]
+  set stars [string range $s78 0 $nstar]
+  puts $out "/************** $text $stars/"
+}
+
+# Read the source file named $filename and write it into the
+# sqlite3.c output file.  If any #include statements are seen,
+# process them approprately.
+#
+proc copy_file {filename} {
+  global seen_hdr available_hdr out
+  set tail [file tail $filename]
+  section_comment "Begin file $tail"
+  set in [open $filename r]
+  while {![eof $in]} {
+    set line [gets $in]
+    if {[regexp {^#\s*include\s+["<]([^">]+)[">]} $line all hdr]} {
+      if {[info exists available_hdr($hdr)]} {
+        if {$available_hdr($hdr)} {
+          section_comment "Include $hdr in the middle of $tail"
+          copy_file tsrc/$hdr
+          section_comment "Continuing where we left off in $tail"
+        }
+      } elseif {![info exists seen_hdr($hdr)]} {
+        set seen_hdr($hdr) 1
+        puts $out $line
+      }
+    } elseif {[regexp {^#ifdef __cplusplus} $line]} {
+      puts $out "#if 0"
+    } elseif {[regexp {^#line} $line]} {
+      # Skip #line directives.
+    } else {
+      puts $out $line
+    }
+  }
+  close $in
+  section_comment "End of $tail"
+}
+
+
+# Process the source files.  Process files containing commonly
+# used subroutines first in order to help the compiler find
+# inlining opportunities.
+#
+foreach file {
+   sqliteInt.h
+   sqlite3.h
+   btree.h
+   hash.h
+   os.h
+   pager.h
+   parse.h
+   sqlite3ext.h
+   vdbe.h
+} {
+  if {$available_hdr($file)} {
+    copy_file tsrc/$file
+  }
+}
+
+close $out