[PATCH v1 0/6] Simplify C/C++ compiler flags

[PATCH v1 0/6] Simplify C/C++ compiler flags

[Ian Rogers]

Some compiler flags have been brought forward in the perf build but
without any explicit need, for example -ggdb3. Some warnings were
disabled but the underlying warning could be addressed. Try to reduce
the number of compiler options used in the perf build, to enable
Wextra for C++, and to disable fewer compiler warnings.

Ian Rogers (6):
  perf bpf-loader: Remove unneeded diagnostic pragma
  perf build: Don't always set -funwind-tables and -ggdb3
  perf build: Add Wextra for C++ compilation
  perf build: Disable fewer flex warnings
  perf build: Disable fewer bison warnings
  perf build: Remove -Wno-redundant-decls in 2 cases

 tools/perf/Makefile.config     |  9 ++++-----
 tools/perf/util/Build          | 18 ++++++------------
 tools/perf/util/bpf-filter.y   |  2 ++
 tools/perf/util/bpf-loader.c   |  3 ---
 tools/perf/util/c++/Build      |  3 +++
 tools/perf/util/expr.y         |  4 +++-
 tools/perf/util/parse-events.c |  1 -
 tools/perf/util/parse-events.y |  1 +
 tools/perf/util/pmu.y          |  3 +++
 9 files changed, 22 insertions(+), 22 deletions(-)

-- 
2.41.0.487.g6d72f3e995-goog

[PATCH v1 1/6] perf bpf-loader: Remove unneeded diagnostic pragma

[Ian Rogers]

Added during the progress to libbpf 1.0 the deprecated functions are
no longer used and so the pragma can be removed.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/bpf-loader.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 44cde27d6389..8f4c76f2265a 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -32,9 +32,6 @@
 
 #include <internal/xyarray.h>
 
-/* temporarily disable libbpf deprecation warnings */
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-
 static int libbpf_perf_print(enum libbpf_print_level level __attribute__((unused)),
 			      const char *fmt, va_list args)
 {
-- 
2.41.0.487.g6d72f3e995-goog

[PATCH v1 2/6] perf build: Don't always set -funwind-tables and -ggdb3

[Ian Rogers]

Commit 6a40cd90f5de ("perf tools: Add libunwind dependency for DWARF
CFI unwinding") added libunwind support but also -funwind-tables and
-ggdb3 to the standard build. These build flags aren't necessary so
remove, set -g when DEBUG is enabled for the build.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index a9cfe83638a9..14709a6bd622 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -246,6 +246,9 @@ ifeq ($(CC_NO_CLANG), 0)
 else
   CORE_CFLAGS += -O6
 endif
+else
+  CORE_CFLAGS += -g
+  CXXFLAGS += -g
 endif
 
 ifdef PARSER_DEBUG
@@ -324,8 +327,6 @@ FEATURE_CHECK_LDFLAGS-disassembler-four-args = -lbfd -lopcodes -ldl
 FEATURE_CHECK_LDFLAGS-disassembler-init-styled = -lbfd -lopcodes -ldl
 
 CORE_CFLAGS += -fno-omit-frame-pointer
-CORE_CFLAGS += -ggdb3
-CORE_CFLAGS += -funwind-tables
 CORE_CFLAGS += -Wall
 CORE_CFLAGS += -Wextra
 CORE_CFLAGS += -std=gnu11
@@ -333,8 +334,6 @@ CORE_CFLAGS += -std=gnu11
 CXXFLAGS += -std=gnu++14 -fno-exceptions -fno-rtti
 CXXFLAGS += -Wall
 CXXFLAGS += -fno-omit-frame-pointer
-CXXFLAGS += -ggdb3
-CXXFLAGS += -funwind-tables
 CXXFLAGS += -Wno-strict-aliasing
 
 HOSTCFLAGS += -Wall
-- 
2.41.0.487.g6d72f3e995-goog

[PATCH v1 3/6] perf build: Add Wextra for C++ compilation

[Ian Rogers]

Commit d58ac0bf8d1e ("perf build: Add clang and llvm compile and
linking support") added -Wall and -Wno-strict-aliasing for CXXFLAGS,
but not -Wextra. -Wno-strict-aliasing is no longer necessary, adding
-Wextra for CXXFLAGS requires adding -Wno-unused-parameter clang.cpp
and clang-test.cpp for LIBCLANGLLVM=1 to build.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config | 2 +-
 tools/perf/util/c++/Build  | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 14709a6bd622..fe7afe6d8529 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -333,8 +333,8 @@ CORE_CFLAGS += -std=gnu11
 
 CXXFLAGS += -std=gnu++14 -fno-exceptions -fno-rtti
 CXXFLAGS += -Wall
+CXXFLAGS += -Wextra
 CXXFLAGS += -fno-omit-frame-pointer
-CXXFLAGS += -Wno-strict-aliasing
 
 HOSTCFLAGS += -Wall
 HOSTCFLAGS += -Wextra
diff --git a/tools/perf/util/c++/Build b/tools/perf/util/c++/Build
index 613ecfd76527..8610d032ac19 100644
--- a/tools/perf/util/c++/Build
+++ b/tools/perf/util/c++/Build
@@ -1,2 +1,5 @@
 perf-$(CONFIG_CLANGLLVM) += clang.o
 perf-$(CONFIG_CLANGLLVM) += clang-test.o
+
+CXXFLAGS_clang.o += -Wno-unused-parameter
+CXXFLAGS_clang-test.o += -Wno-unused-parameter
-- 
2.41.0.487.g6d72f3e995-goog

[PATCH v1 4/6] perf build: Disable fewer flex warnings

[Ian Rogers]

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

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 96f4ea1d45c5..32239c4b0393 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -279,13 +279,9 @@ $(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
-  endif
+FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
+ifeq ($(FLEX_GE_264),1)
+  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
 else
   flex_flags := -w
 endif
-- 
2.41.0.487.g6d72f3e995-goog

[PATCH v1 5/6] perf build: Disable fewer bison warnings

[Ian Rogers]

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.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build          | 6 +++---
 tools/perf/util/bpf-filter.y   | 2 ++
 tools/perf/util/expr.y         | 4 +++-
 tools/perf/util/parse-events.y | 1 +
 tools/perf/util/pmu.y          | 3 +++
 5 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 32239c4b0393..20aa8545b127 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -291,9 +291,9 @@ CFLAGS_expr-flex.o          += $(flex_flags)
 CFLAGS_bpf-filter-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
+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/bpf-filter.y b/tools/perf/util/bpf-filter.y
index 07d6c7926c13..5dfa948fc986 100644
--- a/tools/perf/util/bpf-filter.y
+++ b/tools/perf/util/bpf-filter.y
@@ -9,6 +9,8 @@
 #include <linux/list.h>
 #include "bpf-filter.h"
 
+int perf_bpf_filter_lex(void);
+
 static void perf_bpf_filter_error(struct list_head *expr __maybe_unused,
 				  char const *msg)
 {
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index dd504afd8f36..65d54a6f29ad 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 454577f7aff6..251b7d2fde32 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 PE_ABORT(val) \
diff --git a/tools/perf/util/pmu.y b/tools/perf/util/pmu.y
index dff4e892ac4d..3d46cca3bb94 100644
--- a/tools/perf/util/pmu.y
+++ b/tools/perf/util/pmu.y
@@ -11,6 +11,9 @@
 #include <linux/bitmap.h>
 #include <string.h>
 #include "pmu.h"
+#include "pmu-bison.h"
+
+int perf_pmu_lex(YYSTYPE * yylval_param , void *yyscanner);
 
 #define ABORT_ON(val) \
 do { \
-- 
2.41.0.487.g6d72f3e995-goog

[PATCH v1 6/6] perf build: Remove -Wno-redundant-decls in 2 cases

[Ian Rogers]

Properly fix a warning and remove the -Wno-redundant-decls C flag.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build          | 2 --
 tools/perf/util/parse-events.c | 1 -
 2 files changed, 3 deletions(-)

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 20aa8545b127..b8f1e9ba8c6f 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -312,8 +312,6 @@ CFLAGS_find_bit.o      += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ET
 CFLAGS_rbtree.o        += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_libstring.o     += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_hweight.o       += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
-CFLAGS_parse-events.o  += -Wno-redundant-decls
-CFLAGS_expr.o          += -Wno-redundant-decls
 CFLAGS_header.o        += -include $(OUTPUT)PERF-VERSION-FILE
 CFLAGS_arm-spe.o       += -I$(srctree)/tools/arch/arm64/include/
 
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 926d3ac97324..ac315e1be2bc 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -35,7 +35,6 @@
 #ifdef PARSER_DEBUG
 extern int parse_events_debug;
 #endif
-int parse_events_parse(void *parse_state, void *scanner);
 static int get_config_terms(struct list_head *head_config,
 			    struct list_head *head_terms __maybe_unused);
 
-- 
2.41.0.487.g6d72f3e995-goog

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[James Clark]

On 28/07/2023 07:49, Ian Rogers wrote:
> If flex is version 2.6.4, reduce the number of flex C warnings
> disabled. Earlier flex versions have all C warnings disabled.

Hi Ian,

I get a build error with either this one or the bison warning change:

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

  util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
used [-Werror,-Wunused-but-set-variable]
    int yynerrs = 0;

I tried a clean build which normally fixes these kind of bison errors.
Let me know if you need any version info.

James

> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/Build | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 96f4ea1d45c5..32239c4b0393 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -279,13 +279,9 @@ $(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
> -  endif
> +FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
> +ifeq ($(FLEX_GE_264),1)
> +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
>  else
>    flex_flags := -w
>  endif

Re: [PATCH v1 1/6] perf bpf-loader: Remove unneeded diagnostic pragma

[James Clark]

On 28/07/2023 07:49, Ian Rogers wrote:
> Added during the progress to libbpf 1.0 the deprecated functions are
> no longer used and so the pragma can be removed.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/bpf-loader.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
> index 44cde27d6389..8f4c76f2265a 100644
> --- a/tools/perf/util/bpf-loader.c
> +++ b/tools/perf/util/bpf-loader.c
> @@ -32,9 +32,6 @@
>  
>  #include <internal/xyarray.h>
>  
> -/* temporarily disable libbpf deprecation warnings */
> -#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
> -
>  static int libbpf_perf_print(enum libbpf_print_level level __attribute__((unused)),
>  			      const char *fmt, va_list args)
>  {

Acked-by: James Clark <james.clark@arm.com>

Re: [PATCH v1 2/6] perf build: Don't always set -funwind-tables and -ggdb3

[James Clark]

On 28/07/2023 07:49, Ian Rogers wrote:
> Commit 6a40cd90f5de ("perf tools: Add libunwind dependency for DWARF
> CFI unwinding") added libunwind support but also -funwind-tables and
> -ggdb3 to the standard build. These build flags aren't necessary so
> remove, set -g when DEBUG is enabled for the build.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/Makefile.config | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index a9cfe83638a9..14709a6bd622 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -246,6 +246,9 @@ ifeq ($(CC_NO_CLANG), 0)
>  else
>    CORE_CFLAGS += -O6
>  endif
> +else
> +  CORE_CFLAGS += -g
> +  CXXFLAGS += -g
>  endif
>  
>  ifdef PARSER_DEBUG
> @@ -324,8 +327,6 @@ FEATURE_CHECK_LDFLAGS-disassembler-four-args = -lbfd -lopcodes -ldl
>  FEATURE_CHECK_LDFLAGS-disassembler-init-styled = -lbfd -lopcodes -ldl
>  
>  CORE_CFLAGS += -fno-omit-frame-pointer
> -CORE_CFLAGS += -ggdb3
> -CORE_CFLAGS += -funwind-tables
>  CORE_CFLAGS += -Wall
>  CORE_CFLAGS += -Wextra
>  CORE_CFLAGS += -std=gnu11
> @@ -333,8 +334,6 @@ CORE_CFLAGS += -std=gnu11
>  CXXFLAGS += -std=gnu++14 -fno-exceptions -fno-rtti
>  CXXFLAGS += -Wall
>  CXXFLAGS += -fno-omit-frame-pointer
> -CXXFLAGS += -ggdb3
> -CXXFLAGS += -funwind-tables
>  CXXFLAGS += -Wno-strict-aliasing
>  
>  HOSTCFLAGS += -Wall

Acked-by: James Clark <james.clark@arm.com>

Re: [PATCH v1 3/6] perf build: Add Wextra for C++ compilation

[James Clark]

On 28/07/2023 07:49, Ian Rogers wrote:
> Commit d58ac0bf8d1e ("perf build: Add clang and llvm compile and
> linking support") added -Wall and -Wno-strict-aliasing for CXXFLAGS,
> but not -Wextra. -Wno-strict-aliasing is no longer necessary, adding
> -Wextra for CXXFLAGS requires adding -Wno-unused-parameter clang.cpp
> and clang-test.cpp for LIBCLANGLLVM=1 to build.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/Makefile.config | 2 +-
>  tools/perf/util/c++/Build  | 3 +++
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 14709a6bd622..fe7afe6d8529 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -333,8 +333,8 @@ CORE_CFLAGS += -std=gnu11
>  
>  CXXFLAGS += -std=gnu++14 -fno-exceptions -fno-rtti
>  CXXFLAGS += -Wall
> +CXXFLAGS += -Wextra
>  CXXFLAGS += -fno-omit-frame-pointer
> -CXXFLAGS += -Wno-strict-aliasing
>  
>  HOSTCFLAGS += -Wall
>  HOSTCFLAGS += -Wextra
> diff --git a/tools/perf/util/c++/Build b/tools/perf/util/c++/Build
> index 613ecfd76527..8610d032ac19 100644
> --- a/tools/perf/util/c++/Build
> +++ b/tools/perf/util/c++/Build
> @@ -1,2 +1,5 @@
>  perf-$(CONFIG_CLANGLLVM) += clang.o
>  perf-$(CONFIG_CLANGLLVM) += clang-test.o
> +
> +CXXFLAGS_clang.o += -Wno-unused-parameter
> +CXXFLAGS_clang-test.o += -Wno-unused-parameter

Acked-by: James Clark <james.clark@arm.com>

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Arnaldo Carvalho de Melo]

Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> 
> 
> On 28/07/2023 07:49, Ian Rogers wrote:
> > If flex is version 2.6.4, reduce the number of flex C warnings
> > disabled. Earlier flex versions have all C warnings disabled.
> 
> Hi Ian,
> 
> I get a build error with either this one or the bison warning change:
> 
>   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> 
>   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> used [-Werror,-Wunused-but-set-variable]
>     int yynerrs = 0;
> 
> I tried a clean build which normally fixes these kind of bison errors.
> Let me know if you need any version info.

Trying to build it with the command line above I get:

  CC      util/expr.o
  CC      util/parse-events.o
  CC      util/parse-events-flex.o
util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
            if ( ! yyg->yy_state_buf )
            ^
util/parse-events-flex.c:7501:9: note: previous statement is here
        if ( ! yyg->yy_state_buf )
        ^
1 error generated.
make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
make[4]: *** Waiting for unfinished jobs....
  LD      util/scripting-engines/perf-in.o
make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
make[2]: *** Waiting for unfinished jobs....
  CC      pmu-events/pmu-events.o
  LD      pmu-events/pmu-events-in.o
make[1]: *** [Makefile.perf:242: sub-make] Error 2
make: *** [Makefile:70: all] Error 2

⬢[acme@toolbox perf-tools-next]$ clang --version
clang version 14.0.5 (Fedora 14.0.5-2.fc36)
Target: x86_64-redhat-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
⬢[acme@toolbox perf-tools-next]$

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Arnaldo Carvalho de Melo]

Em Fri, Jul 28, 2023 at 10:59:38AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> > 
> > 
> > On 28/07/2023 07:49, Ian Rogers wrote:
> > > If flex is version 2.6.4, reduce the number of flex C warnings
> > > disabled. Earlier flex versions have all C warnings disabled.
> > 
> > Hi Ian,
> > 
> > I get a build error with either this one or the bison warning change:
> > 
> >   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> > 
> >   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> > used [-Werror,-Wunused-but-set-variable]
> >     int yynerrs = 0;
> > 
> > I tried a clean build which normally fixes these kind of bison errors.
> > Let me know if you need any version info.
> 
> Trying to build it with the command line above I get:
> 
>   CC      util/expr.o
>   CC      util/parse-events.o
>   CC      util/parse-events-flex.o
> util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
>             if ( ! yyg->yy_state_buf )
>             ^
> util/parse-events-flex.c:7501:9: note: previous statement is here
>         if ( ! yyg->yy_state_buf )
>         ^

I added this to the patch to get it moving:

make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
⬢[acme@toolbox perf-tools-next]$ git diff
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 32239c4b0393c319..afa93eff495811cf 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt

 FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
 ifeq ($(FLEX_GE_264),1)
-  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
+  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
 else
   flex_flags := -w
 endif
⬢[acme@toolbox perf-tools-next]$


> 1 error generated.
> make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> make[4]: *** Waiting for unfinished jobs....
>   LD      util/scripting-engines/perf-in.o
> make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> make[2]: *** Waiting for unfinished jobs....
>   CC      pmu-events/pmu-events.o
>   LD      pmu-events/pmu-events-in.o
> make[1]: *** [Makefile.perf:242: sub-make] Error 2
> make: *** [Makefile:70: all] Error 2
> 
> ⬢[acme@toolbox perf-tools-next]$ clang --version
> clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> Target: x86_64-redhat-linux-gnu
> Thread model: posix
> InstalledDir: /usr/bin
> ⬢[acme@toolbox perf-tools-next]$

-- 

- Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Ian Rogers]

On Fri, Jul 28, 2023 at 7:02 AM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Fri, Jul 28, 2023 at 10:59:38AM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> > >
> > >
> > > On 28/07/2023 07:49, Ian Rogers wrote:
> > > > If flex is version 2.6.4, reduce the number of flex C warnings
> > > > disabled. Earlier flex versions have all C warnings disabled.
> > >
> > > Hi Ian,
> > >
> > > I get a build error with either this one or the bison warning change:
> > >
> > >   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> > >
> > >   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> > > used [-Werror,-Wunused-but-set-variable]
> > >     int yynerrs = 0;
> > >
> > > I tried a clean build which normally fixes these kind of bison errors.
> > > Let me know if you need any version info.
> >
> > Trying to build it with the command line above I get:
> >
> >   CC      util/expr.o
> >   CC      util/parse-events.o
> >   CC      util/parse-events-flex.o
> > util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
> >             if ( ! yyg->yy_state_buf )
> >             ^
> > util/parse-events-flex.c:7501:9: note: previous statement is here
> >         if ( ! yyg->yy_state_buf )
> >         ^
>
> I added this to the patch to get it moving:
>
> make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> ⬢[acme@toolbox perf-tools-next]$ git diff
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 32239c4b0393c319..afa93eff495811cf 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
>
>  FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
>  ifeq ($(FLEX_GE_264),1)
> -  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
> +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
>  else
>    flex_flags := -w
>  endif
> ⬢[acme@toolbox perf-tools-next]$
>
>
> > 1 error generated.
> > make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> > make[4]: *** Waiting for unfinished jobs....
> >   LD      util/scripting-engines/perf-in.o
> > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> > make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> > make[2]: *** Waiting for unfinished jobs....
> >   CC      pmu-events/pmu-events.o
> >   LD      pmu-events/pmu-events-in.o
> > make[1]: *** [Makefile.perf:242: sub-make] Error 2
> > make: *** [Makefile:70: all] Error 2
> >
> > ⬢[acme@toolbox perf-tools-next]$ clang --version
> > clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> > Target: x86_64-redhat-linux-gnu
> > Thread model: posix
> > InstalledDir: /usr/bin
> > ⬢[acme@toolbox perf-tools-next]$

Thanks James/Arnaldo, I was trying to be aggressive in having more
flags, but it seems too aggressive. We should probably bring back the
logic to make this flag only added if it is supported:
  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
  endif
Arnaldo, is the misleading indentation in the bison generated code or
something copy-pasted from the parse-events.l ? If the latter we may
be able to fix the .l file to keep the warning.

Thanks,
Ian

> --
>
> - Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Arnaldo Carvalho de Melo]

Em Fri, Jul 28, 2023 at 08:26:54AM -0700, Ian Rogers escreveu:
> On Fri, Jul 28, 2023 at 7:02 AM Arnaldo Carvalho de Melo
> <acme@kernel.org> wrote:
> >
> > Em Fri, Jul 28, 2023 at 10:59:38AM -0300, Arnaldo Carvalho de Melo escreveu:
> > > Em Fri, Jul 28, 2023 at 09:50:59AM +0100, James Clark escreveu:
> > > >
> > > >
> > > > On 28/07/2023 07:49, Ian Rogers wrote:
> > > > > If flex is version 2.6.4, reduce the number of flex C warnings
> > > > > disabled. Earlier flex versions have all C warnings disabled.
> > > >
> > > > Hi Ian,
> > > >
> > > > I get a build error with either this one or the bison warning change:
> > > >
> > > >   $ make LLVM=1 -C tools/perf NO_BPF_SKEL=1 DEBUG=1
> > > >
> > > >   util/pmu-bison.c:855:9: error: variable 'perf_pmu_nerrs' set but not
> > > > used [-Werror,-Wunused-but-set-variable]
> > > >     int yynerrs = 0;
> > > >
> > > > I tried a clean build which normally fixes these kind of bison errors.
> > > > Let me know if you need any version info.
> > >
> > > Trying to build it with the command line above I get:
> > >
> > >   CC      util/expr.o
> > >   CC      util/parse-events.o
> > >   CC      util/parse-events-flex.o
> > > util/parse-events-flex.c:7503:13: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
> > >             if ( ! yyg->yy_state_buf )
> > >             ^
> > > util/parse-events-flex.c:7501:9: note: previous statement is here
> > >         if ( ! yyg->yy_state_buf )
> > >         ^
> >
> > I added this to the patch to get it moving:
> >
> > make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> > ⬢[acme@toolbox perf-tools-next]$ git diff
> > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > index 32239c4b0393c319..afa93eff495811cf 100644
> > --- a/tools/perf/util/Build
> > +++ b/tools/perf/util/Build
> > @@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
> >
> >  FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
> >  ifeq ($(FLEX_GE_264),1)
> > -  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
> > +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
> >  else
> >    flex_flags := -w
> >  endif
> > ⬢[acme@toolbox perf-tools-next]$
> >
> >
> > > 1 error generated.
> > > make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> > > make[4]: *** Waiting for unfinished jobs....
> > >   LD      util/scripting-engines/perf-in.o
> > > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> > > make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> > > make[2]: *** Waiting for unfinished jobs....
> > >   CC      pmu-events/pmu-events.o
> > >   LD      pmu-events/pmu-events-in.o
> > > make[1]: *** [Makefile.perf:242: sub-make] Error 2
> > > make: *** [Makefile:70: all] Error 2
> > >
> > > ⬢[acme@toolbox perf-tools-next]$ clang --version
> > > clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> > > Target: x86_64-redhat-linux-gnu
> > > Thread model: posix
> > > InstalledDir: /usr/bin
> > > ⬢[acme@toolbox perf-tools-next]$
> 
> Thanks James/Arnaldo, I was trying to be aggressive in having more
> flags, but it seems too aggressive. We should probably bring back the
> logic to make this flag only added if it is supported:
>   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
>   endif
> Arnaldo, is the misleading indentation in the bison generated code or
> something copy-pasted from the parse-events.l ? If the latter we may
> be able to fix the .l file to keep the warning.

I haven't checked, lemme do it now.

- Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Arnaldo Carvalho de Melo]

Em Fri, Jul 28, 2023 at 03:10:05PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jul 28, 2023 at 08:26:54AM -0700, Ian Rogers escreveu:
> > On Fri, Jul 28, 2023 at 7:02 AM Arnaldo Carvalho de Melo
> > > I added this to the patch to get it moving:
> > >
> > > make: Leaving directory '/var/home/acme/git/perf-tools-next/tools/perf'
> > > ⬢[acme@toolbox perf-tools-next]$ git diff
> > > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > > index 32239c4b0393c319..afa93eff495811cf 100644
> > > --- a/tools/perf/util/Build
> > > +++ b/tools/perf/util/Build
> > > @@ -281,7 +281,7 @@ $(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filt
> > >
> > >  FLEX_GE_264 := $(shell expr $(shell $(FLEX) --version | sed -e  's/flex \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 264)
> > >  ifeq ($(FLEX_GE_264),1)
> > > -  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function
> > > +  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
> > >  else
> > >    flex_flags := -w
> > >  endif
> > > ⬢[acme@toolbox perf-tools-next]$
> > >
> > >
> > > > 1 error generated.
> > > > make[4]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:97: util/parse-events-flex.o] Error 1
> > > > make[4]: *** Waiting for unfinished jobs....
> > > >   LD      util/scripting-engines/perf-in.o
> > > > make[3]: *** [/var/home/acme/git/perf-tools-next/tools/build/Makefile.build:140: util] Error 2
> > > > make[2]: *** [Makefile.perf:682: perf-in.o] Error 2
> > > > make[2]: *** Waiting for unfinished jobs....
> > > >   CC      pmu-events/pmu-events.o
> > > >   LD      pmu-events/pmu-events-in.o
> > > > make[1]: *** [Makefile.perf:242: sub-make] Error 2
> > > > make: *** [Makefile:70: all] Error 2
> > > >
> > > > ⬢[acme@toolbox perf-tools-next]$ clang --version
> > > > clang version 14.0.5 (Fedora 14.0.5-2.fc36)
> > > > Target: x86_64-redhat-linux-gnu
> > > > Thread model: posix
> > > > InstalledDir: /usr/bin
> > > > ⬢[acme@toolbox perf-tools-next]$
> > 
> > Thanks James/Arnaldo, I was trying to be aggressive in having more
> > flags, but it seems too aggressive. We should probably bring back the
> > logic to make this flag only added if it is supported:
> >   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
> >   endif
> > Arnaldo, is the misleading indentation in the bison generated code or
> > something copy-pasted from the parse-events.l ? If the latter we may
> > be able to fix the .l file to keep the warning.
> 
> I haven't checked, lemme do it now.

It comes directly from flex's m4 files:

https://github.com/westes/flex/blob/master/src/c99-flex.skl#L2044

So I'll keep the -Wno-misleading-indentation, ok?

- Arnaldo

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Arnaldo Carvalho de Melo]

Em Fri, Jul 28, 2023 at 12:05:56PM -0700, Ian Rogers escreveu:
> On Fri, Jul 28, 2023, 11:43 AM Arnaldo Carvalho de Melo <acme@kernel.org>
> > > I haven't checked, lemme do it now.

> > It comes directly from flex's m4 files:

> > https://github.com/westes/flex/blob/master/src/c99-flex.skl#L2044

> > So I'll keep the -Wno-misleading-indentation, ok?
 
> Makes sense, yes.

continuing, changed the version check to:

commit f4da4419574536691c6b7843b6c48a3f97240404
Author: Ian Rogers <irogers@google.com>
Date:   Thu Jul 27 23:49:15 2023 -0700

    perf build: Disable fewer flex warnings
    
    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 $(call version_ge3,2.6.4,$(FLEX_VERSION)) 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.
    
    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>

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index bb08149179e405ac..ae91e2786f1a4f55 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -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
@@ -279,13 +281,11 @@ $(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
-  endif
+FLEX_VERSION := $(shell $(FLEX) --version | cut -d' ' -f2)
+
+FLEX_GE_264 := $(call version_ge3,2.6.4,$(FLEX_VERSION))
+ifeq ($(FLEX_GE_264),1)
+  flex_flags := -Wno-redundant-decls -Wno-switch-default -Wno-unused-function -Wno-misleading-indentation
 else
   flex_flags := -w
 endif

--------------------------------------------------------------------------

with version_ge3 being:

commit aa9e655a4d755c3c75eb3d200d87a3b695f602cf
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
Date:   Mon Jul 31 16:19:21 2023 -0300

    tools build: Add a 3-component greater or equal version comparator
    
    The next cset needs to compare if a flex version is greater or equal
    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.
    
    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>

diff --git a/tools/scripts/utilities.mak b/tools/scripts/utilities.mak
index 172e47273b5d995a..568a6541ecf98075 100644
--- a/tools/scripts/utilities.mak
+++ b/tools/scripts/utilities.mak
@@ -177,3 +177,13 @@ $(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 anoter, 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 awk -F'.' '{ printf("%d\n", (10000000 * $$1 + 10000 * $$2 + $$3) >= (10000000 * $$4 + 10000 * $$5 + $$6)) }' <<< "$(1).$(2)")

Re: [PATCH v1 4/6] perf build: Disable fewer flex warnings

[Arnaldo Carvalho de Melo]

Em Mon, Jul 31, 2023 at 06:16:38PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jul 28, 2023 at 12:05:56PM -0700, Ian Rogers escreveu:
> > On Fri, Jul 28, 2023, 11:43 AM Arnaldo Carvalho de Melo <acme@kernel.org>
> > > > I haven't checked, lemme do it now.
> 
> > > It comes directly from flex's m4 files:
> 
> > > https://github.com/westes/flex/blob/master/src/c99-flex.skl#L2044
> 
> > > So I'll keep the -Wno-misleading-indentation, ok?
>  
> > Makes sense, yes.
> 
> continuing, changed the version check to:
     
>     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 $(call version_ge3,2.6.4,$(FLEX_VERSION)) 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.

Please take a look at the tmp.perf-tools-next on the perf-tools-next git
tree, so far it passed on:

[perfbuilder@five ~]$ export BUILD_TARBALL=http://192.168.86.10/perf/perf-6.5.0-rc2.tar.xz
[perfbuilder@five ~]$ time dm
   1   131.37 almalinux:8                   : Ok   gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-18) , clang version 15.0.7 (Red Hat 15.0.7-1.module_el8.8.0+3466+dfcbc058) flex 2.6.1
   2   133.63 almalinux:9                   : Ok   gcc (GCC) 11.3.1 20221121 (Red Hat 11.3.1-4) , clang version 15.0.7 (Red Hat 15.0.7-2.el9) flex 2.6.4
   3   151.31 alpine:3.15                   : Ok   gcc (Alpine 10.3.1_git20211027) 10.3.1 20211027 , Alpine clang version 12.0.1 flex 2.6.4
   4   148.73 alpine:3.16                   : Ok   gcc (Alpine 11.2.1_git20220219) 11.2.1 20220219 , Alpine clang version 13.0.1 flex 2.6.4
   5   126.35 alpine:3.17                   : Ok   gcc (Alpine 12.2.1_git20220924-r4) 12.2.1 20220924 , Alpine clang version 15.0.7 flex 2.6.4
   6   125.43 alpine:3.18                   : Ok   gcc (Alpine 12.2.1_git20220924-r10) 12.2.1 20220924 , Alpine clang version 16.0.6 flex 2.6.4
   7   143.12 alpine:edge                   : Ok   gcc (Alpine 13.1.1_git20230520) 13.1.1 20230520 , Alpine clang version 16.0.4 flex 2.6.4
   8   102.10 amazonlinux:2                 : Ok   gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-15) , clang version 11.1.0 (Amazon Linux 2 11.1.0-1.amzn2.0.2) flex 2.5.37
   9    95.36 amazonlinux:2023              : Ok   gcc (GCC) 11.3.1 20221121 (Red Hat 11.3.1-4) , clang version 15.0.6 (Amazon Linux 15.0.6-3.amzn2023.0.2) flex 2.6.4
  10    96.15 amazonlinux:devel             : Ok   gcc (GCC) 11.3.1 20221121 (Red Hat 11.3.1-4) , clang version 15.0.6 (Amazon Linux 15.0.6-3.amzn2023.0.2) flex 2.6.4
  11   118.48 archlinux:base                : Ok   gcc (GCC) 12.2.0 , clang version 14.0.6 flex 2.6.4
  12   106.42 centos:stream                 : Ok   gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-18) , clang version 15.0.7 (Red Hat 15.0.7-1.module_el8.8.0+1258+af79b238) flex 2.6.1
  13   127.88 clearlinux:latest             : Ok   gcc (Clear Linux OS for Intel Architecture) 13.1.1 20230720 releases/gcc-13.1.0-353-g9aac37ab8a , clang version 16.0.6 flex 2.6.4
  14    88.12 debian:10                     : Ok   gcc (Debian 8.3.0-6) 8.3.0 , Debian clang version 11.0.1-2~deb10u1 flex 2.6.4
  15   113.56 debian:11                     : Ok   gcc (Debian 10.2.1-6) 10.2.1 20210110 , Debian clang version 13.0.1-6~deb11u1 flex 2.6.4
  16   122.58 debian:12                     : Ok   gcc (Debian 12.2.0-14) 12.2.0 , Debian clang version 14.0.6 flex 2.6.4
  17   130.89 debian:experimental           : Ok   gcc (Debian 12.3.0-5) 12.3.0 , Debian clang version 14.0.6 flex 2.6.4
  18    23.75 fedora:26                     : Ok   gcc (GCC) 7.3.1 20180130 (Red Hat 7.3.1-2)  flex 2.6.1
  19    23.52 fedora:27                     : Ok   gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-6)  flex 2.6.1
  20    24.66 fedora:28                     : Ok   gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2)  flex 2.6.1
  21    26.12 fedora:29                     : Ok   gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2)  flex 2.6.1
  22    26.06 fedora:30                     : Ok   gcc (GCC) 9.3.1 20200408 (Red Hat 9.3.1-2)  flex 2.6.4

Tomorrow I'll go back to perf-tools, to get what sat on linux-next
pending-fixes and a few other fixes (the one reported by Thomas, etc)
to send to Linus for v6.5.

- Arnaldo