psql: Output dir and dependency generation for sql_help

This is in preparation for building postgres with meson / ninja.

When building with meson, commands are run at the root of the build tree. Add
an option to put build output into the appropriate place. This can be utilized
by src/tools/msvc/ for a minor simplification, which also provides some
coverage for the new option.

To deal with dependencies to the variable set of input files to this script,
add an option to generate a dependency file (which meson / ninja can consume).

Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com

Author: anarazel

src/bin/psql/Makefile

@@ -56,7 +56,7 @@ sql_help.c: sql_help.h
 	touch $@
 
 sql_help.h: create_help.pl $(wildcard $(REFDOCDIR)/*.sgml)
-	$(PERL) $< $(REFDOCDIR) $*
+	$(PERL) $< --docdir $(REFDOCDIR) --basename $*
 
 psqlscanslash.c: FLEXFLAGS = -Cfe -p -p
 psqlscanslash.c: FLEX_NO_BACKUP=yes

src/bin/psql/create_help.pl

@@ -21,33 +21,43 @@
 
 use strict;
 use warnings;
+use Getopt::Long;
 
-my $docdir = $ARGV[0] or die "$0: missing required argument: docdir\n";
-my $hfile = $ARGV[1] . '.h'
-  or die "$0: missing required argument: output file\n";
-my $cfile = $ARGV[1] . '.c';
+my $docdir        = '';
+my $outdir        = '.';
+my $depfile       = '';
+my $hfilebasename = '';
 
-my $hfilebasename;
-if ($hfile =~ m!.*/([^/]+)$!)
-{
-	$hfilebasename = $1;
-}
-else
-{
-	$hfilebasename = $hfile;
-}
+GetOptions(
+	'docdir=s'   => \$docdir,
+	'outdir=s'   => \$outdir,
+	'basename=s' => \$hfilebasename,
+	'depfile=s'  => \$depfile,) or die "$0: wrong arguments";
+
+$docdir        or die "$0: missing required argument: docdir\n";
+$hfilebasename or die "$0: missing required argument: basename\n";
+
+my $hfile = $hfilebasename . '.h';
+my $cfile = $hfilebasename . '.c';
 
 my $define = $hfilebasename;
 $define =~ tr/a-z/A-Z/;
 $define =~ s/\W/_/g;
 
 opendir(DIR, $docdir)
   or die "$0: could not open documentation source dir '$docdir': $!\n";
-open(my $hfile_handle, '>', $hfile)
+open(my $hfile_handle, '>', "$outdir/$hfile")
   or die "$0: could not open output file '$hfile': $!\n";
-open(my $cfile_handle, '>', $cfile)
+open(my $cfile_handle, '>', "$outdir/$cfile")
   or die "$0: could not open output file '$cfile': $!\n";
 
+my $depfile_handle;
+if ($depfile)
+{
+	open($depfile_handle, '>', $depfile)
+	  or die "$0: could not open output file '$depfile': $!\n";
+}
+
 print $hfile_handle "/*
  * *** Do not change this file by hand. It is automatically
  * *** generated from the DocBook documentation.
@@ -98,6 +108,9 @@
 	my ($cmdid, @cmdnames, $cmddesc, $cmdsynopsis);
 	$file =~ /\.sgml$/ or next;
 
+	print $depfile_handle "$outdir/$cfile $outdir/$hfile: $docdir/$file\n"
+	  if ($depfile);
+
 	open(my $fh, '<', "$docdir/$file") or next;
 	my $filecontent = join('', <$fh>);
 	close $fh;
@@ -216,4 +229,5 @@
 
 close $cfile_handle;
 close $hfile_handle;
+close $depfile_handle if ($depfile);
 closedir DIR;

src/tools/msvc/Solution.pm

@@ -692,9 +692,8 @@ sub GenerateFiles
 	if (IsNewer('src/bin/psql/sql_help.h', 'src/bin/psql/create_help.pl'))
 	{
 		print "Generating sql_help.h...\n";
-		chdir('src/bin/psql');
-		system("perl create_help.pl ../../../doc/src/sgml/ref sql_help");
-		chdir('../../..');
+		my $psql = 'src/bin/psql';
+		system("perl $psql/create_help.pl --docdir doc/src/sgml/ref --outdir $psql --basename sql_help");
 	}
 
 	if (IsNewer('src/common/kwlist_d.h', 'src/include/parser/kwlist.h'))