[PATCH stable 6.1 v2 0/5] perf build fixes

[PATCH stable 6.1 v2 0/5] perf build fixes

[Florian Fainelli]

This patch series contains "perf" build fixes specific to 6.1. We have
seen occasional build failures in our CI looking like these:

util/parse-events-bison.c: In function 'yy_symbol_print':
util/parse-events-bison.c:901: error: unterminated #if
  901 | #if YYDEBUG
      |
util/parse-events-bison.c:1020:62: error: '_p' undeclared (first use in this function)
 1020 |   yy_symbol_value_print (yyo, yykind, yyvaluep, yylocationp, _parse_state, scanner);
      |                                                              ^~
util/parse-events-bison.c:1020:62: note: each undeclared identifier is reported only once for each function it appears in
util/parse-events-bison.c:1020:64: error: expected ')' at end of input
 1020 |   yy_symbol_value_print (yyo, yykind, yyvaluep, yylocationp, _parse_state, scanner);
      |                         ~                                      ^
      |                                                                )
 1021 |   YYFPRINTF (yyo, ")");
      |
util/parse-events-bison.c:1020:3: error: too few arguments to function 'yy_symbol_value_print'
 1020 |   yy_symbol_value_print (yyo, yykind, yyvaluep, yylocationp, _parse_state, scanner);
      |   ^~~~~~~~~~~~~~~~~~~~~
util/parse-events-bison.c:991:1: note: declared here
  991 | yy_symbol_value_print (FILE *yyo,
      | ^~~~~~~~~~~~~~~~~~~~~

which are resolved by these patches.

Changes in v2:

- backport change adding version-lt3 macro
- added fix for "perf build: Disable fewer bison warnings" per Sasha's review

Arnaldo Carvalho de Melo (2):
  tools build: Add 3-component logical version comparators
  perf build: Remove -Wno-unused-but-set-variable from the flex flags
    when building with clang < 13.0.0

Ian Rogers (3):
  perf build: Conditionally define NDEBUG
  perf parse-events: Make YYDEBUG dependent on doing a debug build
  perf build: Disable fewer bison warnings

 tools/perf/Makefile.config     |  1 +
 tools/perf/util/Build          | 32 +++++++++++++++++++++++++-------
 tools/perf/util/expr.y         |  4 +++-
 tools/perf/util/parse-events.y |  3 +++
 tools/perf/util/pmu.y          |  3 +++
 tools/scripts/utilities.mak    | 20 ++++++++++++++++++++
 6 files changed, 55 insertions(+), 8 deletions(-)

-- 
2.34.1

[PATCH stable 6.1 v2 1/5] perf build: Conditionally define NDEBUG

[Florian Fainelli]

From: Ian Rogers <irogers@google.com>

commit 616b14b47a86d880ba21a363440f20f82152d8f2 upstream

When a build is done without DEBUG=1 then define NDEBUG. This will
compile out asserts and other debug code.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230330183827.1412303-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
 tools/perf/Makefile.config | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 249f3d841563..c54692976001 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -228,6 +228,7 @@ ifndef DEBUG
 endif
 
 ifeq ($(DEBUG),0)
+CORE_CFLAGS += -DNDEBUG=1
 ifeq ($(CC_NO_CLANG), 0)
   CORE_CFLAGS += -O3
 else
-- 
2.34.1

[PATCH stable 6.1 v2 2/5] perf parse-events: Make YYDEBUG dependent on doing a debug build

[Florian Fainelli]

From: Ian Rogers <irogers@google.com>

commit d4ce60190e08d84f88937019defa5e3d23409ac1 upstream

YYDEBUG enables line numbers and other error helpers in the generated
parse-events-bison.c. These shouldn't be generated when debugging
isn't enabled.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230911170559.4037734-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
 tools/perf/util/parse-events.y | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index be8c51770051..dbc350a2c382 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -6,7 +6,9 @@
 
 %{
 
+#ifndef NDEBUG
 #define YYDEBUG 1
+#endif
 
 #include <fnmatch.h>
 #include <stdio.h>
-- 
2.34.1

[PATCH stable 6.1 v2 3/5] perf build: Disable fewer bison warnings

[Florian Fainelli]

From: Ian Rogers <irogers@google.com>

commit ddc8e4c966923ad1137790817157c8a5f0301aec upstream

If bison is version 3.8.2, reduce the number of bison C warnings
disabled. Earlier bison versions have all C warnings disabled. Avoid
implicit declarations of yylex by adding the declaration in the C
file. A header can't be included as a circular dependency would occur
due to the lexer using the bison defined tokens.

Committer notes:

Some recent versions of gcc and clang (noticed on Alpine Linux 3.17,
edge, clearlinux, fedora 37, etc.

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/20230728064917.767761-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
[florian: Remove non-existent tools/perf/util/bpf-filter.y in 6.1.y]
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Change-Id: I62327ddbe816008197053a9234a92d9c253a2c5d
---
 tools/perf/util/Build          | 12 ++++++++----
 tools/perf/util/expr.y         |  4 +++-
 tools/perf/util/parse-events.y |  1 +
 tools/perf/util/pmu.y          |  3 +++
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 2c364a9087a2..036f9780b398 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -269,10 +269,14 @@ CFLAGS_parse-events-flex.o  += $(flex_flags)
 CFLAGS_pmu-flex.o           += $(flex_flags)
 CFLAGS_expr-flex.o          += $(flex_flags)
 
-bison_flags := -DYYENABLE_NLS=0
-BISON_GE_35 := $(shell expr $(shell $(BISON) --version | grep bison | sed -e 's/.\+ \([0-9]\+\).\([0-9]\+\)/\1\2/g') \>\= 35)
-ifeq ($(BISON_GE_35),1)
-  bison_flags += -Wno-unused-parameter -Wno-nested-externs -Wno-implicit-function-declaration -Wno-switch-enum -Wno-unused-but-set-variable -Wno-unknown-warning-option
+# 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;
+
+bison_flags := -DYYENABLE_NLS=0 -Wno-unused-but-set-variable
+BISON_GE_382 := $(shell expr $(shell $(BISON) --version | grep bison | sed -e 's/.\+ \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 382)
+ifeq ($(BISON_GE_382),1)
+  bison_flags += -Wno-switch-enum
 else
   bison_flags += -w
 endif
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 635e562350c5..b8745d564b78 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -7,6 +7,8 @@
 #include "util/debug.h"
 #define IN_EXPR_Y 1
 #include "expr.h"
+#include "expr-bison.h"
+int expr_lex(YYSTYPE * yylval_param , void *yyscanner);
 %}
 
 %define api.pure full
@@ -56,7 +58,7 @@
 static void expr_error(double *final_val __maybe_unused,
 		       struct expr_parse_ctx *ctx __maybe_unused,
 		       bool compute_ids __maybe_unused,
-		       void *scanner,
+		       void *scanner __maybe_unused,
 		       const char *s)
 {
 	pr_debug("%s\n", s);
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index dbc350a2c382..42d4414760e3 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -20,6 +20,7 @@
 #include "parse-events.h"
 #include "parse-events-bison.h"
 
+int parse_events_lex(YYSTYPE * yylval_param, YYLTYPE * yylloc_param , void *yyscanner);
 void parse_events_error(YYLTYPE *loc, void *parse_state, void *scanner, char const *msg);
 
 #define ABORT_ON(val) \
diff --git a/tools/perf/util/pmu.y b/tools/perf/util/pmu.y
index e675d79a0274..ae88d2d2dd6a 100644
--- a/tools/perf/util/pmu.y
+++ b/tools/perf/util/pmu.y
@@ -9,6 +9,9 @@
 #include <linux/bitmap.h>
 #include <string.h>
 #include "pmu.h"
+#include "pmu-bison.h"
+
+int perf_pmu_lex(void);
 
 #define ABORT_ON(val) \
 do { \
-- 
2.34.1

[PATCH stable 6.1 v2 4/5] tools build: Add 3-component logical version comparators

[Florian Fainelli]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

commit a9b451509565d40a5ca3b41c39a2b758cdbc5355 upstream

The next cset needs to compare if a flex version is greater or
equal/less than another, but since there is no canonical, generally
available way to compare versions in the command line (sort -V, yeah,
but...), just use awk to canonicalize the versions like is also done in
scripts/rust_is_available.sh.

There was a problem spotted in linux-next where a bashism, here
documents, aka the '<<<' stdin redirector, for strings to be used as the
stdin for awk. Use $(shell echo | awk ...) instead.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
 tools/scripts/utilities.mak | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tools/scripts/utilities.mak b/tools/scripts/utilities.mak
index 172e47273b5d..d69d0345cc23 100644
--- a/tools/scripts/utilities.mak
+++ b/tools/scripts/utilities.mak
@@ -177,3 +177,23 @@ $(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2)))
 endef
 _ge_attempt = $(or $(get-executable),$(call _gea_err,$(2)))
 _gea_err  = $(if $(1),$(error Please set '$(1)' appropriately))
+
+# version-ge3
+#
+# Usage $(call version-ge3,2.6.4,$(FLEX_VERSION))
+#
+# To compare if a 3 component version is greater or equal to another, first use
+# was to check the flex version to see if we can use compiler warnings as
+# errors for one of the cases flex generates code C compilers complains about.
+
+version-ge3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) >= (10000000 * $$4 + 10000 * $$5 + $$6)) }')
+
+# version-lt3
+#
+# Usage $(call version-lt3,2.6.2,$(FLEX_VERSION))
+#
+# To compare if a 3 component version is less thjan another, first use was to
+# check the flex version to see if we can use compiler warnings as errors for
+# one of the cases flex generates code C compilers complains about.
+
+version-lt3 = $(shell echo "$(1).$(2)" | awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) < (10000000 * $$4 + 10000 * $$5 + $$6)) }')
-- 
2.34.1

[PATCH stable 6.1 v2 5/5] perf build: Remove -Wno-unused-but-set-variable from the flex flags when building with clang < 13.0.0

[Florian Fainelli]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

clang < 13.0.0 doesn't grok -Wno-unused-but-set-variable, so just remove
it to avoid:

  error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option]
  make[4]: *** [/git/perf-6.5.0-rc4/tools/build/Makefile.build:128: /tmp/build/perf/util/pmu-flex.o] Error 1
  make[4]: *** Waiting for unfinished jobs....

Fixes: ddc8e4c966923ad1 ("perf build: Disable fewer bison warnings")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZNUSWr52jUnVaaa%2F@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Change-Id: I8db8a372d1e83d26fbe8beda2bcf4d1a871a2b80
---
 tools/perf/util/Build | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 036f9780b398..43f74f5b96f8 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -1,3 +1,6 @@
+include $(srctree)/tools/scripts/Makefile.include
+include $(srctree)/tools/scripts/utilities.mak
+
 perf-y += arm64-frame-pointer-unwind-support.o
 perf-y += annotate.o
 perf-y += block-info.o
@@ -265,15 +268,22 @@ ifeq ($(FLEX_GE_26),1)
 else
   flex_flags := -w
 endif
-CFLAGS_parse-events-flex.o  += $(flex_flags)
-CFLAGS_pmu-flex.o           += $(flex_flags)
-CFLAGS_expr-flex.o          += $(flex_flags)
 
 # 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;
 
 bison_flags := -DYYENABLE_NLS=0 -Wno-unused-but-set-variable
+
+# Old clangs don't grok -Wno-unused-but-set-variable, remove it
+ifeq ($(CC_NO_CLANG), 0)
+  CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
+  ifeq ($(call version-lt3,$(CLANG_VERSION),13.0.0),1)
+    bison_flags := $(subst -Wno-unused-but-set-variable,,$(bison_flags))
+    flex_flags := $(subst -Wno-unused-but-set-variable,,$(flex_flags))
+  endif
+endif
+
 BISON_GE_382 := $(shell expr $(shell $(BISON) --version | grep bison | sed -e 's/.\+ \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 382)
 ifeq ($(BISON_GE_382),1)
   bison_flags += -Wno-switch-enum
@@ -286,6 +296,10 @@ ifeq ($(BISON_LT_381),1)
   bison_flags += -DYYNOMEM=YYABORT
 endif
 
+CFLAGS_parse-events-flex.o  += $(flex_flags)
+CFLAGS_pmu-flex.o           += $(flex_flags)
+CFLAGS_expr-flex.o          += $(flex_flags)
+
 CFLAGS_parse-events-bison.o += $(bison_flags)
 CFLAGS_pmu-bison.o          += -DYYLTYPE_IS_TRIVIAL=0 $(bison_flags)
 CFLAGS_expr-bison.o         += -DYYLTYPE_IS_TRIVIAL=0 $(bison_flags)
-- 
2.34.1

Re: [PATCH stable 6.1 v2 5/5] perf build: Remove -Wno-unused-but-set-variable from the flex flags when building with clang < 13.0.0

[Florian Fainelli]

On 5/20/26 09:33, Florian Fainelli wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> clang < 13.0.0 doesn't grok -Wno-unused-but-set-variable, so just remove
> it to avoid:
> 
>    error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option]
>    make[4]: *** [/git/perf-6.5.0-rc4/tools/build/Makefile.build:128: /tmp/build/perf/util/pmu-flex.o] Error 1
>    make[4]: *** Waiting for unfinished jobs....
> 
> Fixes: ddc8e4c966923ad1 ("perf build: Disable fewer bison warnings")
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Link: https://lore.kernel.org/lkml/ZNUSWr52jUnVaaa%2F@kernel.org/
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
> Change-Id: I8db8a372d1e83d26fbe8beda2bcf4d1a871a2b80

Argh, sorry the Change-Id snuck in there, let me know if you need me to 
resubmit.
-- 
Florian

Re: [PATCH stable 6.1 v2 5/5] perf build: Remove -Wno-unused-but-set-variable from the flex flags when building with clang < 13.0.0

[Greg KH]

On Wed, May 20, 2026 at 09:35:02AM -0700, Florian Fainelli wrote:
> On 5/20/26 09:33, Florian Fainelli wrote:
> > From: Arnaldo Carvalho de Melo <acme@redhat.com>
> > 
> > clang < 13.0.0 doesn't grok -Wno-unused-but-set-variable, so just remove
> > it to avoid:
> > 
> >    error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option]
> >    make[4]: *** [/git/perf-6.5.0-rc4/tools/build/Makefile.build:128: /tmp/build/perf/util/pmu-flex.o] Error 1
> >    make[4]: *** Waiting for unfinished jobs....
> > 
> > Fixes: ddc8e4c966923ad1 ("perf build: Disable fewer bison warnings")
> > Cc: Adrian Hunter <adrian.hunter@intel.com>
> > Cc: Ian Rogers <irogers@google.com>
> > Cc: Jiri Olsa <jolsa@kernel.org>
> > Cc: Namhyung Kim <namhyung@kernel.org>
> > Link: https://lore.kernel.org/lkml/ZNUSWr52jUnVaaa%2F@kernel.org/
> > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> > Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
> > Change-Id: I8db8a372d1e83d26fbe8beda2bcf4d1a871a2b80
> 
> Argh, sorry the Change-Id snuck in there, let me know if you need me to
> resubmit.

I got it, no worries.

Re: [PATCH stable 6.1 v2 5/5] perf build: Remove -Wno-unused-but-set-variable from the flex flags when building with clang < 13.0.0

[Greg KH]

On Wed, May 20, 2026 at 09:33:20AM -0700, Florian Fainelli wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> clang < 13.0.0 doesn't grok -Wno-unused-but-set-variable, so just remove
> it to avoid:
> 
>   error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option]
>   make[4]: *** [/git/perf-6.5.0-rc4/tools/build/Makefile.build:128: /tmp/build/perf/util/pmu-flex.o] Error 1
>   make[4]: *** Waiting for unfinished jobs....
> 
> Fixes: ddc8e4c966923ad1 ("perf build: Disable fewer bison warnings")
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Link: https://lore.kernel.org/lkml/ZNUSWr52jUnVaaa%2F@kernel.org/
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
> ---
>  tools/perf/util/Build | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 

Oops, no upstream git id?  What is it?

thanks,

greg k-h