On Tue, Jul 16, 2024 at 12:55 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote: > > 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.. I think it should be fine for libbpf bits to go through Arnaldo's tree and get back to bpf-next eventually. Unlikely that we'll have any conflict in libbpf's Makefile specifically, we rarely change it. > > 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 > > > > >
