Avoid potential memory leak in find_frame_funname

The PR 18565 thread pointed out that, if cp_remove_params can throw
(we aren't quite sure), then find_frame_funname could leak some
memory.  This patch avoids any potential issue by rearranging some
code in find_frame_funname.

Built and regtested on x86-64 Fedora 24.

2016-08-03  Tom Tromey  <tom@tromey.com>

	* stack.c (find_frame_funname): Avoid any possible leak in case
	cp_remove_params can throw.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 6b2fb9c..48ecd67 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2016-08-03  Tom Tromey  <tom@tromey.com>
 
+       * stack.c (find_frame_funname): Avoid any possible leak in case
+       cp_remove_params can throw.
+
+2016-08-03  Tom Tromey  <tom@tromey.com>
+
        * NEWS: Mention new Python breakpoint events.
 
 2016-08-02  Tom Tromey  <tom@tromey.com>

diff --git a/gdb/stack.c b/gdb/stack.c
index b9e74df..e890949 100644 (file)
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -1101,7 +1101,8 @@ find_frame_funname (struct frame_info *frame, char **funname,
        }
       else
        {
-         *funname = xstrdup (SYMBOL_PRINT_NAME (func));
+         const char *print_name = SYMBOL_PRINT_NAME (func);
+
          *funlang = SYMBOL_LANGUAGE (func);
          if (funcp)
            *funcp = func;
@@ -1112,14 +1113,17 @@ find_frame_funname (struct frame_info *frame, char **funname,
                 stored in the symbol table, but we stored a version
                 with DMGL_PARAMS turned on, and here we don't want to
                 display parameters.  So remove the parameters.  */
-             char *func_only = cp_remove_params (*funname);
+             char *func_only = cp_remove_params (print_name);
 
              if (func_only)
-               {
-                 xfree (*funname);
-                 *funname = func_only;
-               }
+               *funname = func_only;
            }
+
+         /* If we didn't hit the C++ case above, set *funname here.
+            This approach is taken to avoid having to install a
+            cleanup in case cp_remove_params can throw.  */
+         if (*funname == NULL)
+           *funname = xstrdup (print_name);
        }
     }
   else