Add output directory option to gen_node_support.pl

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.

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

Author: anarazel

src/backend/nodes/gen_node_support.pl

@@ -19,12 +19,19 @@
 use warnings;
 
 use File::Basename;
+use Getopt::Long;
 
 use FindBin;
 use lib "$FindBin::RealBin/../catalog";
 
 use Catalog;    # for RenameTempFile
 
+my $output_path = '.';
+
+GetOptions(
+	'outdir:s'       => \$output_path)
+  or die "$0: wrong arguments";
+
 
 # Test whether first argument is element of the list in the second
 # argument
@@ -576,7 +583,7 @@ sub elem
 # nodetags.h
 
 push @output_files, 'nodetags.h';
-open my $nt, '>', 'nodetags.h' . $tmpext or die $!;
+open my $nt, '>', "$output_path/nodetags.h$tmpext" or die "$output_path/nodetags.h$tmpext: $!";
 
 printf $nt $header_comment, 'nodetags.h';
 
@@ -620,13 +627,13 @@ sub elem
 # copyfuncs.c, equalfuncs.c
 
 push @output_files, 'copyfuncs.funcs.c';
-open my $cff, '>', 'copyfuncs.funcs.c' . $tmpext or die $!;
+open my $cff, '>', "$output_path/copyfuncs.funcs.c$tmpext" or die $!;
 push @output_files, 'equalfuncs.funcs.c';
-open my $eff, '>', 'equalfuncs.funcs.c' . $tmpext or die $!;
+open my $eff, '>', "$output_path/equalfuncs.funcs.c$tmpext" or die $!;
 push @output_files, 'copyfuncs.switch.c';
-open my $cfs, '>', 'copyfuncs.switch.c' . $tmpext or die $!;
+open my $cfs, '>', "$output_path/copyfuncs.switch.c$tmpext" or die $!;
 push @output_files, 'equalfuncs.switch.c';
-open my $efs, '>', 'equalfuncs.switch.c' . $tmpext or die $!;
+open my $efs, '>', "$output_path/equalfuncs.switch.c$tmpext" or die $!;
 
 printf $cff $header_comment, 'copyfuncs.funcs.c';
 printf $eff $header_comment, 'equalfuncs.funcs.c';
@@ -819,13 +826,13 @@ sub elem
 # outfuncs.c, readfuncs.c
 
 push @output_files, 'outfuncs.funcs.c';
-open my $off, '>', 'outfuncs.funcs.c' . $tmpext or die $!;
+open my $off, '>', "$output_path/outfuncs.funcs.c$tmpext" or die $!;
 push @output_files, 'readfuncs.funcs.c';
-open my $rff, '>', 'readfuncs.funcs.c' . $tmpext or die $!;
+open my $rff, '>', "$output_path/readfuncs.funcs.c$tmpext" or die $!;
 push @output_files, 'outfuncs.switch.c';
-open my $ofs, '>', 'outfuncs.switch.c' . $tmpext or die $!;
+open my $ofs, '>', "$output_path/outfuncs.switch.c$tmpext" or die $!;
 push @output_files, 'readfuncs.switch.c';
-open my $rfs, '>', 'readfuncs.switch.c' . $tmpext or die $!;
+open my $rfs, '>', "$output_path/readfuncs.switch.c$tmpext" or die $!;
 
 printf $off $header_comment, 'outfuncs.funcs.c';
 printf $rff $header_comment, 'readfuncs.funcs.c';
@@ -1130,7 +1137,7 @@ sub elem
 # now rename the temporary files to their final names
 foreach my $file (@output_files)
 {
-	Catalog::RenameTempFile($file, $tmpext);
+	Catalog::RenameTempFile("$output_path/$file", $tmpext);
 }
 
 
@@ -1144,7 +1151,7 @@ END
 	{
 		foreach my $file (@output_files)
 		{
-			unlink($file . $tmpext);
+			unlink("$output_path/$file$tmpext");
 		}
 	}
 

src/tools/msvc/Solution.pm

@@ -865,15 +865,12 @@ EOF
 		  utils/rel.h
 		);
 
-		chdir('src/backend/nodes');
+		my @node_files = map { "src/include/$_" } @node_headers;
 
-		my @node_files = map { "../../../src/include/$_" } @node_headers;
-
-		system("perl gen_node_support.pl @node_files");
-		open(my $f, '>', 'node-support-stamp')
+		system("perl src/backend/nodes/gen_node_support.pl --outdir src/backend/nodes @node_files");
+		open(my $f, '>', 'src/backend/nodes/node-support-stamp')
 		  || confess "Could not touch node-support-stamp";
 		close($f);
-		chdir('../../..');
 	}
 
 	if (IsNewer(