Re: [PATCH] perf: fix wrong DEBUG configuration

[Arnaldo Carvalho de Melo]

Em Tue, May 26, 2015 at 11:13:32AM +0200, Martin LiÅka escreveu:
> On 05/25/2015 08:32 PM, Ingo Molnar wrote:
> >
> >* Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> >
> >>Em Mon, May 25, 2015 at 01:12:44PM +0200, Martin LiÅka escreveu:
> >>>On 05/25/2015 01:09 PM, Ingo Molnar wrote:
> >>>>
> >>>>* Martin LiÅka <mliska@xxxxxxx> wrote:
> >>>>
> >>>>>>>Right optimize debugging experience is given by passing -Og to
> >>>>>>>compiler. Assign default value for pointers that are identified by
> >>>>>>>compiler as non-initialized.
> >>>>>>
> >>>>>>s/Right optimize debugging experience is given/
> >>>>>>   Correct debugging experience is given/
> >>>>
> >>>>>Right debugging experience is given by passing -Og to compiler.
> >>>>
> >>>>So I fixed the spelling here once already :-/ If you want to use
> >>>>'right' in this context then use it like this:
> >>>>
> >>>>   The right debugging experience is given by ...
> >>>>
> >>>>Or you can use what I suggested first:
> >>>>
> >>>>   Correct debugging experience is given by ...
> >>>>
> >>>>Thanks,
> >>>>
> >>>>	Ingo
> >>>>
> >>>
> >>>Sorry Ingo for that, I overlooked that correction :)
> >>
> >>Are you ok with this Ingo?
> >
> >Yeah, certainly!
> >
> >>I can apply, but there seems to be two patches folded here, one that
> >>sets the possibly unitiliazed variables to NULL, and could be the
> >>first in the series, and the other, that deals with multiple
> >>versions of gcc and how should we ask something from them.
> >
> >Yeah.
> >
> >Thanks,
> >
> >	Ingo
> >
> 
> Hello.
> 
> As Arnaldo pointed, I split the patch to following 2 smaller patches.

Thanks, but how did you generated the two attached patches? 

 [acme@ssdandy linux]$ git am /wb/0001-perf-Fix-compiler-warnings.patch 
  Patch format detection failed.

So I'll fix it up manually, next time please try:

  git format-patch -n HEAD^^..

Or equivalent,

- Arnaldo


 
> Thanks,
> Martin

> Assign default value for pointers that are identified by the compiler as
> non-initialized.
> 
> Signed-off-by: Martin Liska <mliska@xxxxxxx>
> Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
> ---
>  tools/perf/arch/common.c            | 2 +-
>  tools/perf/util/symbol.c            | 2 +-
>  tools/perf/util/trace-event-parse.c | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
> index 49776f1..b7bb42c 100644
> --- a/tools/perf/arch/common.c
> +++ b/tools/perf/arch/common.c
> @@ -61,7 +61,7 @@ const char *const mips_triplets[] = {
>  static bool lookup_path(char *name)
>  {
>  	bool found = false;
> -	char *path, *tmp;
> +	char *path, *tmp = NULL;
>  	char buf[PATH_MAX];
>  	char *env = getenv("PATH");
>  
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 82a31fd..a19fbd4 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -400,7 +400,7 @@ static struct symbol *symbols__find_by_name(struct rb_root *symbols,
>  					    const char *name)
>  {
>  	struct rb_node *n;
> -	struct symbol_name_rb_node *s;
> +	struct symbol_name_rb_node *s = NULL;
>  
>  	if (symbols == NULL)
>  		return NULL;
> diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
> index 25d6c73..d495741 100644
> --- a/tools/perf/util/trace-event-parse.c
> +++ b/tools/perf/util/trace-event-parse.c
> @@ -173,7 +173,7 @@ void parse_ftrace_printk(struct pevent *pevent,
>  	char *line;
>  	char *next = NULL;
>  	char *addr_str;
> -	char *fmt;
> +	char *fmt = NULL;
>  
>  	line = strtok_r(file, "\n", &next);
>  	while (line) {
> -- 
> 2.1.4
> 

> Currently, GCC optimizes -O6 same as -O3 level, thus change the value
> to -O3.
> Correct debugging experience is given by passing -Og to compiler.
> 
> Signed-off-by: Martin Liska <mliska@xxxxxxx>
> Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
> ---
>  tools/perf/config/Makefile      |  4 +++-
>  tools/perf/config/utilities.mak | 19 +++++++++++++++++++
>  2 files changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
> index e3b3724..47e4ae1 100644
> --- a/tools/perf/config/Makefile
> +++ b/tools/perf/config/Makefile
> @@ -129,7 +129,9 @@ ifndef DEBUG
>  endif
>  
>  ifeq ($(DEBUG),0)
> -  CFLAGS += -O6
> +  CFLAGS += -O3
> +else
> +  CFLAGS += $(call cc-option,-Og,-O0)
>  endif
>  
>  ifdef PARSER_DEBUG
> diff --git a/tools/perf/config/utilities.mak b/tools/perf/config/utilities.mak
> index c16ce83..0ebef09 100644
> --- a/tools/perf/config/utilities.mak
> +++ b/tools/perf/config/utilities.mak
> @@ -177,3 +177,22 @@ $(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2)))
>  endef
>  _ge_attempt = $(if $(get-executable),$(get-executable),$(call _gea_err,$(2)))
>  _gea_err  = $(if $(1),$(error Please set '$(1)' appropriately))
> +
> +# try-run
> +# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
> +# Exit code chooses option. "$$TMP" is can be used as temporary file and
> +# is automatically cleaned up.
> +try-run = $(shell set -e;		\
> +	TMP="$(TMPOUT).$$$$.tmp";	\
> +	TMPO="$(TMPOUT).$$$$.o";	\
> +	if ($(1)) >/dev/null 2>&1;	\
> +	then echo "$(2)";		\
> +	else echo "$(3)";		\
> +	fi;				\
> +	rm -f "$$TMP" "$$TMPO")
> +
> +# cc-option
> +# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
> +
> +cc-option = $(call try-run,\
> +	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
> -- 
> 2.1.4
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/