perf tool: Fix gcc 4.6.0 issues

GCC 4.6.0 in Fedora rawhide turned up some compile errors in tools/perf
due to the -Werror=unused-but-set-variable flag.

I've gone through and annotated some of the assignments that had side
effects (ie: return value from a function) with the __used annotation,
and in some cases, just removed unused code.

In a few cases, we were assigning something useful, but not using it in
later parts of the function.

kyle@dreadnought:~/src% gcc --version
gcc (GCC) 4.6.0 20110122 (Red Hat 4.6.0-0.3)

Cc: Ingo Molnar <mingo@redhat.com>
LKML-Reference: <20110124161304.GK27353@bombadil.infradead.org>
Signed-off-by: Kyle McMartin <kyle@redhat.com>
[ committer note: Fixed up the annotation fixes, as that code moved recently ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

6 files changed, 6 insertions, 10 deletions

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 2973376..1012841 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -236,7 +236,6 @@ int symbol__annotate(struct symbol *sym, struct map *map,
 	char command[PATH_MAX * 2];
 	FILE *file;
 	int err = 0;
-	u64 len;
 	char symfs_filename[PATH_MAX];
 
 	if (filename) {
@@ -281,8 +280,6 @@ fallback:
 		 filename, sym->name, map->unmap_ip(map, sym->start),
 		 map->unmap_ip(map, sym->end));
 
-	len = sym->end - sym->start;
-
 	pr_debug("annotating [%p] %30s : [%p] %30s\n",
 		 dso, dso->long_name, sym, sym->name);
 
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index c0de5ec..72c124d 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1145,7 +1145,7 @@ int perf_event__synthesize_tracing_data(int fd, struct perf_evlist *evlist,
 {
 	union perf_event ev;
 	ssize_t size = 0, aligned_size = 0, padding;
-	int err = 0;
+	int err __used = 0;
 
 	memset(&ev, 0, sizeof(ev));
 
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index c6d9933..2040b85 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -248,8 +248,7 @@ static void python_process_event(int cpu, void *data,
 	context = PyCObject_FromVoidPtr(scripting_context, NULL);
 
 	PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
-	PyTuple_SetItem(t, n++,
-			PyCObject_FromVoidPtr(scripting_context, NULL));
+	PyTuple_SetItem(t, n++, context);
 
 	if (handler) {
 		PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 7821d0e..3e193f8 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1525,8 +1525,8 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
 			     symbol_conf.symfs, self->long_name);
 			break;
 		case DSO__ORIG_GUEST_KMODULE:
-			if (map->groups && map->groups->machine)
-				root_dir = map->groups->machine->root_dir;
+			if (map->groups && machine)
+				root_dir = machine->root_dir;
 			else
 				root_dir = "";
 			snprintf(name, size, "%s%s%s", symbol_conf.symfs,
diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 73a0222..d8e622d 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -153,7 +153,7 @@ void parse_proc_kallsyms(char *file, unsigned int size __unused)
 	char *next = NULL;
 	char *addr_str;
 	char ch;
-	int ret;
+	int ret __used;
 	int i;
 
 	line = strtok_r(file, "\n", &next);
diff --git a/tools/perf/util/ui/browsers/map.c b/tools/perf/util/ui/browsers/map.c
index e515836..8462bff 100644
--- a/tools/perf/util/ui/browsers/map.c
+++ b/tools/perf/util/ui/browsers/map.c
@@ -41,7 +41,7 @@ static int ui_entry__read(const char *title, char *bf, size_t size, int width)
 out_free_form:
 	newtPopWindow();
 	newtFormDestroy(form);
-	return 0;
+	return err;
 }
 
 struct map_browser {