perf symbols: Return the first entry with a given name in find_by_name method

When a dso contains multiple symbols which have same name, current
dso__find_symbol_by_name() only finds an one of them and there's no way
to get the all symbols without going through the rbtree.

So make symbols__find_by_name() return the first entry with the given
name and the next patch in this series will provide a way to iterate
from there, by the name ordered rb_tree, till a suitable symbol is
found.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1421234288-22758-2-git-send-email-namhyung@kernel.org
[ Yanked this independent hunk, without changes, from a larger patch  ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index c24c5b83156c..3cb928e51a99 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -396,6 +396,7 @@ static struct symbol *symbols__find_by_name(struct rb_root *symbols,
                                             const char *name)
 {
         struct rb_node *n;
+        struct symbol_name_rb_node *s;
 
         if (symbols == NULL)
                 return NULL;
@@ -403,7 +404,6 @@ static struct symbol *symbols__find_by_name(struct rb_root *symbols,
         n = symbols->rb_node;
 
         while (n) {
-                struct symbol_name_rb_node *s;
                 int cmp;
 
                 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
@@ -414,10 +414,24 @@ static struct symbol *symbols__find_by_name(struct rb_root *symbols,
                 else if (cmp > 0)
                         n = n->rb_right;
                 else
-                        return &s->sym;
+                        break;
         }
 
-        return NULL;
+        if (n == NULL)
+                return NULL;
+
+        /* return first symbol that has same name (if any) */
+        for (n = rb_prev(n); n; n = rb_prev(n)) {
+                struct symbol_name_rb_node *tmp;
+
+                tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
+                if (strcmp(tmp->sym.name, s->sym.name))
+                        break;
+
+                s = tmp;
+        }
+
+        return &s->sym;
 }
 
 struct symbol *dso__find_symbol(struct dso *dso,