Build.include invokes the pre-processor via GCC in order to generate a dependency list for the input file. Since these options are passed using '-Wp,-M...,$(depfile)' it is important that $(depfile) does not contain any commas, so these are substituted with underscores. This substitution will break the build if the directory name of the output directory happens to include a comma, e.g. when using "aiaiai" for bisection testing:
| cc1: fatal error: x86/tools/objtool/fixdep.o: No such file or directory | compilation terminated. | cat: /tmp/aiaiai-test-patchset.qroS/before/obj.defconfig_x86/tools/objtool/.fixdep.o.d: No such file or directory | make[5]: *** [tools/objtool/fixdep.o] Error 1 We can address this by using -Xpreprocessor instead of -Wp, which allows us to pass down an unmodified pathname. Cc: Jiri Olsa <jo...@kernel.org> Cc: Dave Martin <dave.mar...@arm.com> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Ingo Molnar <mi...@kernel.org> Signed-off-by: Will Deacon <will.dea...@arm.com> --- As an aside, the way we currently pass the depfile to -MD appears to be in direct contradiction with the preprocessor documentation, although it does work with the cc1 implementation. tools/build/Build.include | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/tools/build/Build.include b/tools/build/Build.include index 418871d02ebf..e1914f8e2328 100644 --- a/tools/build/Build.include +++ b/tools/build/Build.include @@ -22,9 +22,7 @@ dot-target = $(dir $@).$(notdir $@) basetarget = $(basename $(notdir $@)) ### -# The temporary file to save gcc -MD generated dependencies must not -# contain a comma -depfile = $(subst $(comma),_,$(dot-target).d) +depfile = $(dot-target).d ### # Check if both arguments has same arguments. Result is empty string if equal. @@ -89,12 +87,12 @@ if_changed = $(if $(strip $(any-prereq) $(arg-check)), \ # - per target C flags # - per object C flags # - BUILD_STR macro to allow '-D"$(variable)"' constructs -c_flags_1 = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj)) +c_flags_1 = -Xpreprocessor -MD -Xpreprocessor $(depfile) -Xpreprocessor -MT -Xpreprocessor $@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj)) c_flags_2 = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(c_flags_1)) c_flags = $(filter-out $(CFLAGS_REMOVE_$(obj)), $(c_flags_2)) -cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj)) +cxx_flags = -Xpreprocessor -MD -Xpreprocessor $(depfile) -Xpreprocessor -MT -Xpreprocessor $@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj)) ### ## HOSTCC C flags -host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CHOSTFLAGS) -D"BUILD_STR(s)=\#s" $(CHOSTFLAGS_$(basetarget).o) $(CHOSTFLAGS_$(obj)) +host_c_flags = -Xpreprocessor -MD -Xpreprocessor $(depfile) -Xpreprocessor -MT -Xpreprocessor $@ $(CHOSTFLAGS) -D"BUILD_STR(s)=\#s" $(CHOSTFLAGS_$(basetarget).o) $(CHOSTFLAGS_$(obj)) -- 2.1.4