Re: [tip:perf/core] tools: Add err.h with ERR_PTR PTR_ERR interface

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Sep 29, 2015 at 09:14:10AM +0200, Jiri Olsa wrote:

SNIP

> > > $ gcc --version
> > > gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16)
> > > Copyright (C) 2010 Free Software Foundation, Inc.
> > > This is free software; see the source for copying conditions.  There is NO
> > > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> > >
> > > Cheers,
> > > Vinson
> > 
> > Hi.
> > 
> > This build error still occurs with next-20150929.
> 
> attached patch should fix it
> 
> FYI there's another instance of this bug in parse-events.c in
> Arnaldo's perf/core due to recent fixes, I'll send out fix shortly

and here it is..

He Kuang,
this might collide with your recent fixes..

jirka


---
The error variable breaks build on CentOS 6.7, due to
collision with global error symbol:

    CC       util/parse-events.o
  cc1: warnings being treated as errors
  util/parse-events.c:419: error: declaration of ‘error’ shadows a global
  declaration
  util/util.h:135: error: shadowed declaration is here
  util/parse-events.c: In function ‘add_tracepoint_multi_event’:
  ...

Using different argument names instead to fix it.

Reported-by: Vinson Lee <vlee@twopensource.com>
Link: http://lkml.kernel.org/n/tip-ujp5f63wvy70jlzeh3rt5f98@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/parse-events.c |   38 +++++++++++++++++++-------------------
 1 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 61c2bc2..626bf85 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -387,7 +387,7 @@ int parse_events_add_cache(struct list_head *list, int *idx,
 	return add_event(list, idx, &attr, name, NULL);
 }
 
-static void tracepoint_error(struct parse_events_error *error, int err,
+static void tracepoint_error(struct parse_events_error *e, int err,
 			     char *sys, char *name)
 {
 	char help[BUFSIZ];
@@ -400,29 +400,29 @@ static void tracepoint_error(struct parse_events_error *error, int err,
 
 	switch (err) {
 	case EACCES:
-		error->str = strdup("can't access trace events");
+		e->str = strdup("can't access trace events");
 		break;
 	case ENOENT:
-		error->str = strdup("unknown tracepoint");
+		e->str = strdup("unknown tracepoint");
 		break;
 	default:
-		error->str = strdup("failed to add tracepoint");
+		e->str = strdup("failed to add tracepoint");
 		break;
 	}
 
 	tracing_path__strerror_open_tp(err, help, sizeof(help), sys, name);
-	error->help = strdup(help);
+	e->help = strdup(help);
 }
 
 static int add_tracepoint(struct list_head *list, int *idx,
 			  char *sys_name, char *evt_name,
-			  struct parse_events_error *error __maybe_unused)
+			  struct parse_events_error *err __maybe_unused)
 {
 	struct perf_evsel *evsel;
 
 	evsel = perf_evsel__newtp_idx(sys_name, evt_name, (*idx)++);
 	if (IS_ERR(evsel)) {
-		tracepoint_error(error, PTR_ERR(evsel), sys_name, evt_name);
+		tracepoint_error(err, PTR_ERR(evsel), sys_name, evt_name);
 		return PTR_ERR(evsel);
 	}
 
@@ -432,7 +432,7 @@ static int add_tracepoint(struct list_head *list, int *idx,
 
 static int add_tracepoint_multi_event(struct list_head *list, int *idx,
 				      char *sys_name, char *evt_name,
-				      struct parse_events_error *error)
+				      struct parse_events_error *err)
 {
 	char evt_path[MAXPATHLEN];
 	struct dirent *evt_ent;
@@ -442,7 +442,7 @@ static int add_tracepoint_multi_event(struct list_head *list, int *idx,
 	snprintf(evt_path, MAXPATHLEN, "%s/%s", tracing_events_path, sys_name);
 	evt_dir = opendir(evt_path);
 	if (!evt_dir) {
-		tracepoint_error(error, errno, sys_name, evt_name);
+		tracepoint_error(err, errno, sys_name, evt_name);
 		return -1;
 	}
 
@@ -456,7 +456,7 @@ static int add_tracepoint_multi_event(struct list_head *list, int *idx,
 		if (!strglobmatch(evt_ent->d_name, evt_name))
 			continue;
 
-		ret = add_tracepoint(list, idx, sys_name, evt_ent->d_name, error);
+		ret = add_tracepoint(list, idx, sys_name, evt_ent->d_name, err);
 	}
 
 	closedir(evt_dir);
@@ -465,16 +465,16 @@ static int add_tracepoint_multi_event(struct list_head *list, int *idx,
 
 static int add_tracepoint_event(struct list_head *list, int *idx,
 				char *sys_name, char *evt_name,
-				struct parse_events_error *error)
+				struct parse_events_error *err)
 {
 	return strpbrk(evt_name, "*?") ?
-	       add_tracepoint_multi_event(list, idx, sys_name, evt_name, error) :
-	       add_tracepoint(list, idx, sys_name, evt_name, error);
+	       add_tracepoint_multi_event(list, idx, sys_name, evt_name, err) :
+	       add_tracepoint(list, idx, sys_name, evt_name, err);
 }
 
 static int add_tracepoint_multi_sys(struct list_head *list, int *idx,
 				    char *sys_name, char *evt_name,
-				    struct parse_events_error *error)
+				    struct parse_events_error *err)
 {
 	struct dirent *events_ent;
 	DIR *events_dir;
@@ -482,7 +482,7 @@ static int add_tracepoint_multi_sys(struct list_head *list, int *idx,
 
 	events_dir = opendir(tracing_events_path);
 	if (!events_dir) {
-		tracepoint_error(error, errno, sys_name, evt_name);
+		tracepoint_error(err, errno, sys_name, evt_name);
 		return -1;
 	}
 
@@ -498,7 +498,7 @@ static int add_tracepoint_multi_sys(struct list_head *list, int *idx,
 			continue;
 
 		ret = add_tracepoint_event(list, idx, events_ent->d_name,
-					   evt_name, error);
+					   evt_name, err);
 	}
 
 	closedir(events_dir);
@@ -507,12 +507,12 @@ static int add_tracepoint_multi_sys(struct list_head *list, int *idx,
 
 int parse_events_add_tracepoint(struct list_head *list, int *idx,
 				char *sys, char *event,
-				struct parse_events_error *error)
+				struct parse_events_error *err)
 {
 	if (strpbrk(sys, "*?"))
-		return add_tracepoint_multi_sys(list, idx, sys, event, error);
+		return add_tracepoint_multi_sys(list, idx, sys, event, err);
 	else
-		return add_tracepoint_event(list, idx, sys, event, error);
+		return add_tracepoint_event(list, idx, sys, event, err);
 }
 
 static int
-- 
1.7.1