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perf build: Disable fewer flex warnings

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If flex is version 2.6.4, reduce the number of flex C warnings
disabled. Earlier flex versions have all C warnings disabled.

Committer notes:

Added this to the list of ignored warnings to get it building on
a Fedora 36 machine with flex 2.6.4:

  -Wno-misleading-indentation

Noticed when building with:

  $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1

Take two:

We can't just try to canonicalize flex versions by just removing the
dots, as we end up with:

	2.6.4 >= 2.5.37

becoming:

	264 >= 2537

Failing the build on flex 2.5.37, so instead use the back to the past
added $(call version_ge3,$(FLEX_VERSION),2.6.4) variant to check for
that.

Making sure $(FLEX_VERSION) keeps the dots as we may want to use 'sort
-V' or something nicer when available everywhere.

Some other tweaks for other flex versions and combinations with gcc and
clang versions were added, notes on the patch.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230728064917.767761-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers 2023-07-27 23:49:15 -07:00 committed by Arnaldo Carvalho de Melo
parent a9b4515095
commit 10c775afa5
1 changed files with 18 additions and 6 deletions
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24
tools/perf/util/Build
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@ -1,3 +1,5 @@
include $(srctree)/tools/scripts/utilities.mak
perf-y += arm64-frame-pointer-unwind-support.o
perf-y += addr_location.o
perf-y += annotate.o
@ -279,16 +281,26 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
$(Q)$(call echo-cmd,bison)$(BISON) -v $< -d $(PARSER_DEBUG_BISON) $(BISON_FILE_PREFIX_MAP) \
-o $(OUTPUT)util/bpf-filter-bison.c -p perf_bpf_filter_
FLEX_GE_26 := $(shell expr $(shell $(FLEX) --version | sed -e 's/flex \([0-9]\+\).\([0-9]\+\)/\1\2/g') \>\= 26)
ifeq ($(FLEX_GE_26),1)
flex_flags := -Wno-switch-enum -Wno-switch-default -Wno-unused-function -Wno-redundant-decls -Wno-sign-compare -Wno-unused-parameter -Wno-missing-prototypes -Wno-missing-declarations
CC_HASNT_MISLEADING_INDENTATION := $(shell echo "int main(void) { return 0 }" | $(CC) -Werror -Wno-misleading-indentation -o /dev/null -xc - 2>&1 | grep -q -- -Wno-misleading-indentation ; echo $$?)
ifeq ($(CC_HASNT_MISLEADING_INDENTATION), 1)
flex_flags += -Wno-misleading-indentation
FLEX_VERSION := $(shell $(FLEX) --version | cut -d' ' -f2)
FLEX_GE_260 := $(call version-ge3,$(FLEX_VERSION),2.6.0)
ifeq ($(FLEX_GE_260),1)
flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
# Some newer clang and gcc version complain about this
# util/parse-events-bison.c:1317:9: error: variable 'parse_events_nerrs' set but not used [-Werror,-Wunused-but-set-variable]
# int yynerrs = 0;
flex_flags += -Wno-unused-but-set-variable
FLEX_LT_262 := $(call version-lt3,$(FLEX_VERSION),2.6.2)
ifeq ($(FLEX_LT_262),1)
flex_flags += -Wno-sign-compare
endif
else
flex_flags := -w
endif
CFLAGS_parse-events-flex.o += $(flex_flags)
CFLAGS_pmu-flex.o += $(flex_flags)
CFLAGS_expr-flex.o += $(flex_flags)