From 55f8fcfd08cbf15d65d61dd2db934b6c3171cf06 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 11 Jan 2023 22:07:22 -0500 Subject: dirstamp: switch to a pattern rule We can leverage $(@D) to generate a single pattern rule for all dirstamp rules. This saves many lines in the output -- normally we create 2 rules (or 6 lines) per subdir, and projects that use subdirs tend to use them quite a bit. In the most extreme & unlikely case (1 subdir, no depdir support), the line count is the same. In every other case, it's always a win. Looking at a few real world projects, the line deltas: * GNU libgloss: +3 -66 * GNU newlib: +3 -714 * GNU sim: +3 -138 There shouldn't be any concerns about portability with $(@D) because: (0) This has been in POSIX (and beyond) for decades, (1) We only generate this rule iff we know the dirstamp is in a subdir (so we'd never have a case where $(@D) would expand to the cwd, and that is where a few implementations are known to be buggy), (2) We already rely on $(@D) in our depdir code, and have since 2014 (the Automake 1.16 release). --- bin/automake.in | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/bin/automake.in b/bin/automake.in index 1c13a3187..139d5ad93 100644 --- a/bin/automake.in +++ b/bin/automake.in @@ -7893,6 +7893,14 @@ sub require_build_directory $directory_map{$directory} = $dirstamp; $directory_map{$cdir} = $dirstamp; + # Generate the pattern rule only once. + if (! vardef ('am__dirstamp', TRUE)) + { + $output_rules .= ("%/\$(am__dirstamp):\n" + . "\t\@\$(MKDIR_P) \$(\@D)\n" + . "\t\@: >>\$\@\n"); + } + # Set a variable for the dirstamp basename. define_pretty_variable ('am__dirstamp', TRUE, INTERNAL, '$(am__leading_dot)dirstamp'); @@ -7900,10 +7908,6 @@ sub require_build_directory # Directory must be removed by 'make distclean'. $clean_files{$dirstamp} = DIST_CLEAN; - $output_rules .= ("$dirstamp:\n" - . "\t\@\$(MKDIR_P) $directory\n" - . "\t\@: >>$dirstamp\n"); - return $dirstamp; } -- cgit v1.2.1