On Mon, Jul 15, 2024 at 01:32:43PM -0700, Brian Norris wrote: > The 'fixdep' tool is used to post-process dependency files for various > reasons, and it runs after every object file generation command. This > even includes 'fixdep' itself. > > In Kbuild, this isn't actually a problem, because it uses a single > command to generate fixdep (a compile-and-link command on fixdep.c), and > afterward runs the fixdep command on the accompanying .fixdep.cmd file. > > In tools/ builds (which notably is maintained separately from Kbuild), > fixdep is generated in several phases: > > 1. fixdep.c -> fixdep-in.o > 2. fixdep-in.o -> fixdep > > Thus, fixdep is not available in the post-processing for step 1, and > instead, we generate .cmd files that look like: > > ## from tools/objtool/libsubcmd/.fixdep.o.cmd > # cannot find fixdep (/path/to/linux/tools/objtool/libsubcmd//fixdep) > [...] > > These invalid .cmd files are benign in some respects, but cause problems > in others (such as the linked reports). > > Because the tools/ build system is rather complicated in its own right > (and pointedly different than Kbuild), I choose to simply open-code the > rule for building fixdep, and avoid the recursive-make indirection that > produces the problem in the first place. > > Link: https://lore.kernel.org/all/Zk-C5Eg84yt6_nml@xxxxxxxxxx/ > Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx> > --- > > (no changes since v3) > > Changes in v3: > - Drop unnecessary tools/build/Build Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> so usually Arnaldo takes changes for tools/build, Arnaldo, could you please take a look? but still there'are the tools/lib/bpf bits.. thanks, jirka > > tools/build/Build | 3 --- > tools/build/Makefile | 11 ++--------- > 2 files changed, 2 insertions(+), 12 deletions(-) > delete mode 100644 tools/build/Build > > diff --git a/tools/build/Build b/tools/build/Build > deleted file mode 100644 > index 76d1a4960973..000000000000 > --- a/tools/build/Build > +++ /dev/null > @@ -1,3 +0,0 @@ > -hostprogs := fixdep > - > -fixdep-y := fixdep.o > diff --git a/tools/build/Makefile b/tools/build/Makefile > index 17cdf01e29a0..fea3cf647f5b 100644 > --- a/tools/build/Makefile > +++ b/tools/build/Makefile > @@ -43,12 +43,5 @@ ifneq ($(wildcard $(TMP_O)),) > $(Q)$(MAKE) -C feature OUTPUT=$(TMP_O) clean >/dev/null > endif > > -$(OUTPUT)fixdep-in.o: FORCE > - $(Q)$(MAKE) $(build)=fixdep > - > -$(OUTPUT)fixdep: $(OUTPUT)fixdep-in.o > - $(QUIET_LINK)$(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ $< > - > -FORCE: > - > -.PHONY: FORCE > +$(OUTPUT)fixdep: $(srctree)/tools/build/fixdep.c > + $(QUIET_CC)$(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ $< > -- > 2.45.2.993.g49e7a77208-goog > >
