On Mon, 22 Aug 2016, Patrick Palka wrote: > Currently the dependencies of each build/*.o object file are manually > maintained within the Makefile and are rather incomplete. For instance > build/vec.o doesn't depend on hash-table.h even though vec.c includes > it. Because of this I ran into a rebuild failure after changing > hash-table.h. > > Any reason why automatic dependency generation is not used for the > build/*.o objects too? Here's a rather simple patch that achieves this. > The trick is to override the COMPILE.base variable in the build/%.o rule > and simply invoke the COMPILE and POSTCOMPILE commands in the recipe > just like the regular .c.o rule does. Even so, the manual dependencies > can't be completely removed because there are a number of header files > that are autogenerated so if they are not explicitly depended upon they > will never be generated, like bconfig.h. > > Bootstrapped on x86_64-pc-linux-gnu FWIW. >
Of course I forgot to make the Makefile actually include the generated dependency files... A more correct and thoroughly tested patch is pending assuming there's no reason to not use automatic dependencies for the build/*.o objects. > gcc/ChangeLog: > > * Makefile.in (build/%.o): Override the COMPILE.base variable > and change the recipe to just invoke $(COMPILE) followed by > $(POSTCOMPILE). Always depend on %.c. > --- > gcc/Makefile.in | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/gcc/Makefile.in b/gcc/Makefile.in > index 8d7cc51..b2a940a 100644 > --- a/gcc/Makefile.in > +++ b/gcc/Makefile.in > @@ -2527,9 +2527,12 @@ generated_files = config.h tm.h $(TM_P_H) $(TM_H) > multilib.h \ > # > # How to compile object files to run on the build machine. > > -build/%.o : # dependencies provided by explicit rule later > - $(COMPILER_FOR_BUILD) -c $(BUILD_COMPILERFLAGS) $(BUILD_CPPFLAGS) \ > - -o $@ $< > +build/%.o: COMPILE.base = $(COMPILER_FOR_BUILD) -c $(BUILD_COMPILERFLAGS) \ > + $(BUILD_CPPFLAGS) -o $@ > +build/%.o: %.c > + $(COMPILE) $< > + $(POSTCOMPILE) > + > > ## build/version.o is compiled by the $(COMPILER_FOR_BUILD) but needs > ## several C macro definitions, just like version.o > -- > 2.10.0.rc1.53.gfcb49dc > >
