From ea974028a049f2cea4bb6be963ee3e3844a03f6d Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Mon, 15 Jul 2024 13:32:43 -0700 Subject: [PATCH] tools build: Avoid circular .fixdep-in.o.cmd issues 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. Signed-off-by: Brian Norris Acked-by: Jiri Olsa Cc: Ian Rogers Cc: Josh Poimboeuf Cc: Masahiro Yamada Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Richter Link: https://lore.kernel.org/all/Zk-C5Eg84yt6_nml@google.com/ Link: https://lore.kernel.org/r/20240715203325.3832977-3-briannorris@chromium.org Signed-off-by: Arnaldo Carvalho de Melo --- 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 $@ $< -- 2.50.1