Fix pg_config.h make rule

According to the Autoconf documentation, there should be a make rule

pg_config.h: stamp-h

so that with the right setup around this, a change in pg_config.h.in
will trigger a rebuild of everything that depends on pg_config.h.  But
this doesn't always work, sometimes you need to run make twice to get
everything up to date after a change of pg_config.h.in.

The fix is to write the rule as

pg_config.h: stamp-h ;

instead (with an empty command instead of no command).  This is what
Automake-generated makefiles effectively do, so it seems safe to be on
this side.

It's not actually clear why this is (apparently) more correct.  It's
been posted to

without response so far.

diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 51c2102b7426aa1abca60c90d837dc2089d707af..e10c86cd311a3fb08da1e9675cf65873658d34b1 100644 (file)
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -536,18 +536,18 @@ $(top_builddir)/src/Makefile.global: $(top_srcdir)/src/Makefile.global.in $(top_
 # unnecessarily. Therefore we make config.status update a timestamp file
 # stamp-h every time it runs, so that we don't trigger this rule every time.
 # (We do trigger the null rule for stamp-h to pg_config.h every time; so it's
-# important for that rule to be null!)
+# important for that rule to be empty!)
 #
 # Of course you need to turn on dependency tracking to get any
 # dependencies on pg_config.h.
-$(top_builddir)/src/include/pg_config.h: $(top_builddir)/src/include/stamp-h
+$(top_builddir)/src/include/pg_config.h: $(top_builddir)/src/include/stamp-h ;
 
 $(top_builddir)/src/include/stamp-h: $(top_srcdir)/src/include/pg_config.h.in $(top_builddir)/config.status
    cd $(top_builddir) && ./config.status src/include/pg_config.h
 
 # Also remake ecpg_config.h from ecpg_config.h.in if the latter changed, same
 # logic as above.
-$(top_builddir)/src/interfaces/ecpg/include/ecpg_config.h: $(top_builddir)/src/interfaces/ecpg/include/stamp-h
+$(top_builddir)/src/interfaces/ecpg/include/ecpg_config.h: $(top_builddir)/src/interfaces/ecpg/include/stamp-h ;
 
  $(top_builddir)/src/interfaces/ecpg/include/stamp-h: $(top_builddir)/src/interfaces/ecpg/include/ecpg_config.h.in $(top_builddir)/config.status
    cd $(top_builddir) && ./config.status src/interfaces/ecpg/include/ecpg_config.h