RE: [RFA] Avoid memory leaks in set_language function.

["Pierre Muller" <pierre.muller@ics-cnrs.unistra.fr>]

> -----Message d'origine-----
> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Tom Tromey
> Envoyé : mercredi 5 décembre 2012 19:19
> À : Pierre Muller
> Cc : gdb-patches@sourceware.org
> Objet : Re: [RFA] Avoid memory leaks in set_language function.
> 
> >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr>
writes:
> 
> Pierre> This also revealed a few memory leaks
> Pierre> related to repeated add_language function calls.
> 
> Wow, add_language is gross.  I had no idea.
> 
> Pierre> +         if (iter->doc && iter->flags & DOC_ALLOCATED)
> 
> I think parens around the second clause here.
> Actually I tend to prefer the wordier
> 
>     (iter->flags & DOC_ALLOCATED) != 0
> 
> Pierre>  #define MALLOCED_REPLACEMENT      0x4
> Pierre> -
> Pierre> +#define DOC_ALLOCATED             0x8
> Pierre>  struct cmd_list_element
> 
> Please preserve the blank line after the block of #defines.
> 
> Ok with those changes.
> 
> Tom

Patch committed with your changes, see below.

Thanks for the approval.

Pierre


2012-12-05  Pierre Muller  <muller@sourceware.org>

        Avoid memory leaks on struct cmd_list_element.doc field.
        * cli/cli-decode.c (add_alias_cmd): Make a copy of doc field
        if flags contains DOC_ALLOCATED.
        (add_setshow_cmd_full): Add DOC_ALLOCATED to set and show
        flags.
        (delete_cmd): Handle DOC_ALLOCATED flag.
        * cli/cli-decode.h (DOC_ALLOCATED): New macro for use
        in flags filed of struct cmd_list_element.
        (struct cmd_list_element): Document new flag item.


Index: cli/cli-decode.c
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-decode.c,v
retrieving revision 1.110
diff -u -p -r1.110 cli-decode.c
--- cli/cli-decode.c    20 Nov 2012 21:02:35 -0000      1.110
+++ cli/cli-decode.c    5 Dec 2012 23:21:11 -0000
@@ -306,6 +306,13 @@ add_alias_cmd (char *name, char *oldname
     }

   c = add_cmd (name, class, NULL, old->doc, list);
+
+  /* If OLD->DOC can be freed, we should make another copy.  */
+  if ((old->flags & DOC_ALLOCATED) != 0)
+    {
+      c->doc = xstrdup (old->doc);
+      c->flags |= DOC_ALLOCATED;
+    }
   /* NOTE: Both FUNC and all the FUNCTIONs need to be copied.  */
   c->func = old->func;
   c->function = old->function;
@@ -451,6 +458,8 @@ add_setshow_cmd_full (char *name,
     }
   set = add_set_or_show_cmd (name, set_cmd, class, var_type, var,
                             full_set_doc, set_list);
+  set->flags |= DOC_ALLOCATED;
+
   if (set_func != NULL)
     set_cmd_sfunc (set, set_func);

@@ -458,6 +467,7 @@ add_setshow_cmd_full (char *name,

   show = add_set_or_show_cmd (name, show_cmd, class, var_type, var,
                              full_show_doc, show_list);
+  show->flags |= DOC_ALLOCATED;
   show->show_value_func = show_func;

   if (set_result != NULL)
@@ -769,6 +779,8 @@ delete_cmd (char *name, struct cmd_list_
          *prehookee = iter->hookee_pre;
          if (iter->hookee_post)
            iter->hookee_post->hook_post = 0;
+         if (iter->doc && (iter->flags & DOC_ALLOCATED) != 0)
+           xfree (iter->doc);
          *posthook = iter->hook_post;
          *posthookee = iter->hookee_post;

Index: cli/cli-decode.h
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-decode.h,v
retrieving revision 1.43
diff -u -p -r1.43 cli-decode.h
--- cli/cli-decode.h    9 Aug 2012 12:53:43 -0000       1.43
+++ cli/cli-decode.h    5 Dec 2012 23:21:11 -0000
@@ -51,6 +51,7 @@ cmd_types;
 #define CMD_DEPRECATED            0x1
 #define DEPRECATED_WARN_USER      0x2
 #define MALLOCED_REPLACEMENT      0x4
+#define DOC_ALLOCATED             0x8

 struct cmd_list_element
   {
@@ -112,7 +113,9 @@ struct cmd_list_element
        memory for replacement is malloc'ed.  When a command is
        undeprecated or re-deprecated at runtime we don't want to risk
        calling free on statically allocated memory, so we check this
-       flag.  */
+       flag.
+
+       bit 3: DOC_ALLOCATED, set if the doc field should be xfree'd.  */

     int flags;