===================================================================
@@ -1,3 +1,7 @@
+2011-04-22 Nicola Pero <nicola.pero@meta-innovation.com>
+
+ * Makefile.in (ENABLE_MAINTAINER_RULES): New.
+
2011-04-22 Jakub Jelinek <jakub@redhat.com>
PR c/48716
===================================================================
@@ -104,10 +104,15 @@ cc1plus$(exeext): $(CXX_OBJS) cc1plus-checksum.o $
+$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
$(CXX_OBJS) cc1plus-checksum.o $(BACKEND) $(LIBS) $(BACKENDLIBS)
-# Special build rules.
+ifeq ($(ENABLE_MAINTAINER_RULES), true)
+# Special build rule. This is a maintainer rule, that is only
+# available when GCC is configured with --enable-maintainer-mode. In
+# other cases, it is not available to avoid triggering rebuilds if a
+# user has the source checked out with unusual timestamps.
$(srcdir)/cp/cfns.h: $(srcdir)/cp/cfns.gperf
gperf -o -C -E -k '1-6,$$' -j1 -D -N 'libc_name_p' -L ANSI-C \
- $(srcdir)/cp/cfns.gperf > $(srcdir)/cp/cfns.h
+ $(srcdir)/cp/cfns.gperf --output-file $(srcdir)/cp/cfns.h
+endif
#^L
# Build hooks:
===================================================================
@@ -1,3 +1,10 @@
+2011-04-23 Nicola Pero <nicola.pero@meta-innovation.com>
+
+ * Make-lang.in ($(srcdir)/cp/cfns.h): Enable the rule only in
+ maintainer mode. Use the --output-file option of gperf instead of
+ > to prevent creating an empty cp/cfns.h when gperf is not
+ available.
+
2011-04-20 Jason Merrill <jason@redhat.com>
* semantics.c (finish_compound_literal): Don't put an array
===================================================================
@@ -165,8 +165,19 @@ C_STRICT_WARN = @c_strict_warn@
NOCOMMON_FLAG = @nocommon_flag@
# This is set by --disable-maintainer-mode (default) to "#"
+# FIXME: 'MAINT' will always be set to an empty string, no matter if
+# --disable-maintainer-mode is used or not. This is because the
+# following will expand to "MAINT := " in maintainer mode, and to
+# "MAINT := #" in non-maintainer mode, but because '#' starts a comment,
+# they mean exactly the same thing for make.
MAINT := @MAINT@
+# The following provides the variable ENABLE_MAINTAINER_RULES that can
+# be used in language Make-lang.in makefile fragments to enable
+# maintainer rules. So, ENABLE_MAINTAINER_RULES is 'true' in
+# maintainer mode, and '' otherwise.
+@MAINT@ ENABLE_MAINTAINER_RULES = true
+
# These are set by --enable-checking=valgrind.
RUN_GEN = @valgrind_command@
VALGRIND_DRIVER_DEFINES = @valgrind_path_defines@
> We have a --enable-maintainer-mode configure option. Thanks - I had missed that option. It's an excellent suggestion - here is a new patch that uses it. :-) Ok to commit ? Thanks PS: Regarding how I detect --enable-maintainer-mode in this new patch, cp/Make-lang.in is used at it is, without going through configure, so I can't use @MAINT@ in it. I can't use MAINT either, because it's always empty. I added a FIXME as the intention in the code was probably different. I could actually fix MAINT to end up being exactly '#' when --disable-maintainer-mode is used, but why would we want that ? It would be a literal value, which you can't use to comment out bits of code in the same way as you can with @MAINT@. Of course, people may still try, and waste time trying to figure out why it doesn't work. It just doesn't make sense; you can't comment out make code by putting a variable with a value of '#' in front of something. If you ask me, I'd just remove the MAINT variable altogether - it's a bad idea and would/will confuse people. I added a new readable variable instead, ENABLE_MAINTAINER_RULES, which is 'true' or empty, so you can do ifeq ($(ENABLE_MAINTAINER_RULES), true) ... maintainer rules ... endif which is readable, expressive, simple and robust.