Re: [Man-db-devel] [PATCH] Fix parallel building by using pattern rules in makefiles

[Colin Watson]

On Fri, Sep 18, 2015 at 05:01:24PM +0200, Nikola Forró wrote:
> When building man-db with more simultaneous jobs it could happen
> that the "replace.sed" file was not completely generated at the time
> when substitution was taking place, so the resulting man pages contained
> unsubstituted placeholders.
> This patch fixes it by replacing suffix rules (which cannot have
> prerequisites) with pattern rules that have "replace.sed" file
> as a prerequisite, so they are run only after "replace.sed"
> is completely generated.

Unfortunately, it's my understanding that some people rely on being able
to build man-db with non-GNU versions of make which don't support
pattern rules.  Automake supports this provided that you don't ignore
its warnings, which indeed are treated as errors in man-db's tree so you
must have gone to some special effort to ignore them, or perhaps just
not run ./autogen.sh:

  automake: warnings are treated as errors
  man/Rules.man:37: warning: '%'-style pattern rules are a GNU make extension
  man/Makefile.am:44:   'man/Rules.man' included from here
  man/Rules.man:41: warning: '%'-style pattern rules are a GNU make extension
  man/Makefile.am:44:   'man/Rules.man' included from here
  man/Rules.man:44: warning: '%'-style pattern rules are a GNU make extension
  man/Makefile.am:44:   'man/Rules.man' included from here
  [... much more of the same ...]
  autoreconf: automake failed with exit status: 1

Could you please try this patch to man/Rules.man instead (and either run
autoreconf -fi, or propagate the same patch to man/{,*/}Makefile.in if
for some reason you can't do that)?  I think it should handle this
without either needing to resort to pattern rules or trying to use
prerequisites with suffix rules, which as you rightly point out is
invalid.

diff --git a/man/Rules.man b/man/Rules.man
index 4ce8ac0..55ff35d 100644
--- a/man/Rules.man
+++ b/man/Rules.man
@@ -34,18 +34,17 @@ endif
 replace.sed: $(top_builddir)/man/replace.sin
        $(AM_V_GEN)sed -e 's,%REPLACE_CONFIG_FILE%,$(config_file),g' 
$(top_builddir)/man/replace.sin > $@
 
-.man1.1: replace.sed
+$(MANS): replace.sed
+
+.man1.1:
        $(AM_V_at)$(MKDIR_P) man1
-       @$(MAKE) $(AM_MAKEFLAGS) replace.sed
        $(AM_V_GEN)program=`echo '$@' | sed -e 's/\.1//' -e 's,.*/,,' -e 
'$(program_transform_name)'`; \
        sed -f replace.sed -e "s,%program%,$$program,g" $< > $@
-.man5.5: replace.sed
+.man5.5:
        $(AM_V_at)$(MKDIR_P) man5
-       @$(MAKE) $(AM_MAKEFLAGS) replace.sed
        $(AM_V_GEN)sed -f replace.sed $< > $@
-.man8.8: replace.sed
+.man8.8:
        $(AM_V_at)$(MKDIR_P) man8
-       @$(MAKE) $(AM_MAKEFLAGS) replace.sed
        $(AM_V_GEN)program=`echo '$@' | sed -e 's/\.8//' -e 's,.*/,,' -e 
'$(program_transform_name)'`; \
        sed -f replace.sed -e "s,%program%,$$program,g" $< > $@
 

Thanks,

-- 
Colin Watson                                       address@hidden