[PATCH] tools-perf: Change -1 by false

[PATCH] tools-perf: Change -1 by false

[Peter Senna Tschudin]

Returning a negative value for a boolean function seem to have the
undesired effect of returning true. Replace -1 by false in a
bool-returning function.

The diff of the .s file before and after the change (for x86_64):
3907c3907
< 	movl	$1, %ebx
---
> 	xorl	%ebx, %ebx

while if -1 is replaced by true, the diff is empty.

This issue was found by the following Coccinelle semantic patch:
<smpl>
@@
identifier f;
constant C;
typedef bool;
@@
bool f (...){
<+...
* return -C;
...+>
}
</smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
---
 tools/perf/util/util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 49a5c6a..ce465b2 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -639,7 +639,7 @@ bool find_process(const char *name)
 
 	dir = opendir(procfs__mountpoint());
 	if (!dir)
-		return -1;
+		return false;
 
 	/* Walk through the directory. */
 	while (ret && (d = readdir(dir)) != NULL) {
-- 
2.1.0

Re: [PATCH] tools-perf: Change -1 by false

[Arnaldo Carvalho de Melo]

Em Thu, Sep 17, 2015 at 12:08:53PM +0200, Peter Senna Tschudin escreveu:
> Returning a negative value for a boolean function seem to have the
> undesired effect of returning true. Replace -1 by false in a
> bool-returning function.
> 
> The diff of the .s file before and after the change (for x86_64):
> 3907c3907
> < 	movl	$1, %ebx
> ---

Please avoid adding a --- at the start of any changeset comment line, it
breaks scripts.

Thanks, applied.

- Arnaldo

> > 	xorl	%ebx, %ebx
> 
> while if -1 is replaced by true, the diff is empty.
> 
> This issue was found by the following Coccinelle semantic patch:
> <smpl>
> @@
> identifier f;
> constant C;
> typedef bool;
> @@
> bool f (...){
> <+...
> * return -C;
> ...+>
> }
> </smpl>
> 
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
> ---
>  tools/perf/util/util.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> index 49a5c6a..ce465b2 100644
> --- a/tools/perf/util/util.c
> +++ b/tools/perf/util/util.c
> @@ -639,7 +639,7 @@ bool find_process(const char *name)
>  
>  	dir = opendir(procfs__mountpoint());
>  	if (!dir)
> -		return -1;
> +		return false;
>  
>  	/* Walk through the directory. */
>  	while (ret && (d = readdir(dir)) != NULL) {
> -- 
> 2.1.0

[tip:perf/urgent] perf tools: Bool functions shouldn't return -1

[tip-bot for Peter Senna Tschudin]

Commit-ID:  bf6445631c6f00882b25516a174d5073ce0c6f81
Gitweb:     http://git.kernel.org/tip/bf6445631c6f00882b25516a174d5073ce0c6f81
Author:     Peter Senna Tschudin <peter.senna@gmail.com>
AuthorDate: Thu, 17 Sep 2015 12:08:53 +0200
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 17 Sep 2015 15:31:52 -0300

perf tools: Bool functions shouldn't return -1

Returning a negative value for a boolean function seem to have the
undesired effect of returning true. Replace -1 by false in a
bool-returning function.

The diff of the .s file before and after the change (for x86_64):

  3907c3907
  < 	movl	$1, %ebx
  ---
  > 	xorl	%ebx, %ebx

while if -1 is replaced by true, the diff is empty.

This issue was found by the following Coccinelle semantic patch:

  <smpl>
  @@
  identifier f;
  constant C;
  typedef bool;
  @@
  bool f (...){
  <+...
  * return -C;
  ...+>
  }
  </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Milos Vyletel <milos@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1442484533-19742-1-git-send-email-peter.senna@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 7acafb3..c2cd9bf2 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -709,7 +709,7 @@ bool find_process(const char *name)
 
 	dir = opendir(procfs__mountpoint());
 	if (!dir)
-		return -1;
+		return false;
 
 	/* Walk through the directory. */
 	while (ret && (d = readdir(dir)) != NULL) {