perf annotate: Introduce strerror for handling symbol__disassemble() errors

We were just using pr_error() which makes it difficult for non stdio UIs
to provide errors using its widgets, as they need to somehow catch what
was passed to pr_error().

Fix it by introducing a __strerror() interface like the ones used
elsewhere, for instance target__strerror().

This is just the initial step, more work will be done, but first some
error handling bugs noticed while working on this need to be dealt with.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-dgd22zl2xg7x4vcnoa83jxfb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index f4d6a8a..2e2d100 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -1026,7 +1026,7 @@
 			.use_navkeypressed = true,
 		},
 	};
-	int ret = -1;
+	int ret = -1, err;
 	int nr_pcnt = 1;
 	size_t sizeof_bdl = sizeof(struct browser_disasm_line);
 
@@ -1050,8 +1050,11 @@
 		  (nr_pcnt - 1);
 	}
 
-	if (symbol__disassemble(sym, map, sizeof_bdl) < 0) {
-		ui__error("%s", ui_helpline__last_msg);
+	err = symbol__disassemble(sym, map, sizeof_bdl);
+	if (err) {
+		char msg[BUFSIZ];
+		symbol__strerror_disassemble(sym, map, err, msg, sizeof(msg));
+		ui__error("Couldn't annotate %s:\n%s", sym->name, msg);
 		goto out_free_offsets;
 	}
 
diff --git a/tools/perf/ui/gtk/annotate.c b/tools/perf/ui/gtk/annotate.c
index 35e4b9e..42d3199 100644
--- a/tools/perf/ui/gtk/annotate.c
+++ b/tools/perf/ui/gtk/annotate.c
@@ -162,12 +162,16 @@
 	GtkWidget *notebook;
 	GtkWidget *scrolled_window;
 	GtkWidget *tab_label;
+	int err;
 
 	if (map->dso->annotate_warned)
 		return -1;
 
-	if (symbol__disassemble(sym, map, 0) < 0) {
-		ui__error("%s", ui_helpline__current);
+	err = symbol__disassemble(sym, map, 0);
+	if (err) {
+		char msg[BUFSIZ];
+		symbol__strerror_disassemble(sym, map, err, msg, sizeof(msg));
+		ui__error("Couldn't annotate %s: %s\n", sym->name, msg);
 		return -1;
 	}