Re: PATCH: More Makefile cleanups

[neroden at twcny dot rr dot com (Nathanael Nerode)]

Mark Mitchell wrote:
>I'll give the build maintainers some time to reject the patch before
>checking this in.

Most of the patch (deleting all the redundant rules) is fine.  The new 
generic rules, however, could use some improvement.

>+ genprogs=genconfig genflags gencodes genemit genopinit genrecog genextract \
>+        genpeep genattr genoutput
>+ 
>+ genobjs=$(genprogs:%=%.o) read-rtl.o gensupport.o genattrtab.o \
>+         genautomata.o gengenrtl.o genpreds.o gengtype.o \
>+       genconstants.o gen-protos.o scan.o fix-header.o scan-decls.o \
>+       gencheck.o dummy-conditions.o genconditions.o
>+ 
>+ $(genprogs:%=%$(buildextext)): \
>+       %$(build_exeext): %.o  $(BUILD_RTL) $(BUILD_SUPPORT) \
>+               $(BUILD_PRINT) $(BUILD_ERRORS) $(BUILD_LIBDEPS)
>+       $(CC_FOR_BUILD) $(BUILD_CFLAGS) $(BUILD_LDFLAGS) -o $@ \
>+               $< $(BUILD_RTL) $(BUILD_SUPPORT) $(BUILD_PRINT) \
>+               $(BUILD_ERRORS) $(BUILD_LIBS)
This is confusing to read at first glance, especially if one is not
used to static pattern rules.  It's oddly formatted and uncommented.  It 
also contains an important typo.

I suggest something like the following instead:
---
# Names of programs built and run on the build system.
genprognames=genconfig genflags gencodes genemit genopinit genrecog genextract \
       genpeep genattr genoutput

# Actual executable names for these programs, with possible .exe 
# suffix.
genprogs = $(genprognames:%=%$(build_exeext))

# Object files for these programs.
genobjs=$(genprogs:%=%.o) read-rtl.o gensupport.o genattrtab.o \
        genautomata.o gengenrtl.o genpreds.o gengtype.o \
        genconstants.o gen-protos.o scan.o fix-header.o scan-decls.o \
        gencheck.o dummy-conditions.o genconditions.o

# General rule for building programs to run on the build system.
$(genprogs): %$(build_exeext): %.o
	$(CC_FOR_BUILD) $(BUILD_CFLAGS) $(BUILD_LDFLAGS) -o $@ $< \
	    $(BUILD_RTL) $(BUILD_SUPPORT) $(BUILD_PRINT) $(BUILD_ERRORS) \
	    $(BUILD_LIBS)

# Dependencies shared by all the programs built to run on the 
# build system.
$(genprogs): $(BUILD_RTL) $(BUILD_SUPPORT) $(BUILD_PRINT) $(BUILD_ERRORS) \
             $(BUILD_LIBDEPS)

---
OK, Mark?

>+ 
>+ $(genobjs): %.o : %.c
>+       $(CC_FOR_BUILD) -c $(BUILD_CFLAGS) $(BUILD_CPPFLAGS) $(INCLUDES) $< $(OUTPUT_OPTION)
>+ 

This last rule is fine...

-- 
Nathanael Nerode  <neroden at gcc.gnu.org>
http://home.twcny.rr.com/nerode/neroden/fdl.html