python: Fix memleak in do_start_initialization

While playing with valgrind, I noticed that with Python 3, the progname
variable in do_start_initialization is not being freed (concat returns a
malloc'ed string).  This patch uses unique_xmalloc_ptr to manage it.
With Python 2, we pass progname it directly to Py_SetProgramName, so it
should not be freed.  We therefore release it before passing it.

gdb/ChangeLog:

	* python/python.c (do_start_initialization): Change progname
	type to gdb::unique_xmalloc_ptr.  Release the pointer when using
	Python 2.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a901409228b3f5c984a9f5ba0e61f8a5148e94ba..b3032ed7d88e4de73279cdbd927617296a7727c4 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-11-26  Simon Marchi  <simon.marchi@polymtl.ca>
+
+       * python/python.c (do_start_initialization): Change progname
+       type to gdb::unique_xmalloc_ptr.  Release the pointer when using
+       Python 2.
+
 2017-11-26  Tom Tromey  <tom@tromey.com>
 
        * common/format.h: Add include guards.

diff --git a/gdb/python/python.c b/gdb/python/python.c
index 5f152611e888c27d078fdda17983a621eee4bc8b..9ed9b6b1ca2f3c338c7fdd79de8453457e3c7198 100644 (file)
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1658,7 +1658,6 @@ finalize_python (void *ignore)
 static bool
 do_start_initialization ()
 {
-  char *progname;
 #ifdef IS_PY3K
   int i;
   size_t progsize, count;
@@ -1672,19 +1671,20 @@ do_start_initialization ()
      /foo/bin/python
      /foo/lib/pythonX.Y/...
      This must be done before calling Py_Initialize.  */
-  progname = concat (ldirname (python_libdir).c_str (), SLASH_STRING, "bin",
-                    SLASH_STRING, "python", (char *) NULL);
+  gdb::unique_xmalloc_ptr<char> progname
+    (concat (ldirname (python_libdir).c_str (), SLASH_STRING, "bin",
+             SLASH_STRING, "python", (char *) NULL));
 #ifdef IS_PY3K
   std::string oldloc = setlocale (LC_ALL, NULL);
   setlocale (LC_ALL, "");
-  progsize = strlen (progname);
+  progsize = strlen (progname.get ());
   progname_copy = (wchar_t *) PyMem_Malloc ((progsize + 1) * sizeof (wchar_t));
   if (!progname_copy)
     {
       fprintf (stderr, "out of memory\n");
       return false;
     }
-  count = mbstowcs (progname_copy, progname, progsize + 1);
+  count = mbstowcs (progname_copy, progname.get (), progsize + 1);
   if (count == (size_t) -1)
     {
       fprintf (stderr, "Could not convert python path to string\n");
@@ -1697,7 +1697,7 @@ do_start_initialization ()
      it is not freed after this call.  */
   Py_SetProgramName (progname_copy);
 #else
-  Py_SetProgramName (progname);
+  Py_SetProgramName (progname.release ());
 #endif
 #endif