Re: PATCH: PR binutils/14526: c++filt is crashed on large files

[H.J. Lu]

On Tue, Aug 28, 2012 at 5:09 PM, Ian Lance Taylor <i...@google.com> wrote:
> On Tue, Aug 28, 2012 at 11:33 AM, H.J. Lu <hongjiu...@intel.com> wrote:
>>
>> buildargv uses alloca to allocate buffer, whose size may exceed stack
>> limit.  This patch replaces alloca with xmalloc/free.  OK to install?
>>
>> Thanks.
>>
>> H.J.
>> ---
>>         PR binutils/14526
>>         * argv.c (buildargv): Replace alloca with xmalloc/free.
>
> This is OK.
>
> Thanks.
>
> Consider also replacing strdup with xstrdup.  And there are other
> malloc calls that could become xmalloc.  I can't think of any way that
> this code would be used where it needs to degrade gracefully when
> short on memory.
>
> Ian

Here is a patch.  OK to install?

Thanks.

-- 
H.J.
---
        * argv.c (dupargv): Replace malloc with xmalloc.  Don't check
        xmalloc return.
        (buildargv): Likewise.
        (expandargv): Don't check dupargv return.

diff --git a/libiberty/argv.c b/libiberty/argv.c
index ca53f91..a5fe0af 100644
--- a/libiberty/argv.c
+++ b/libiberty/argv.c
@@ -1,5 +1,5 @@
 /* Create and destroy argument vectors (argv's)
-   Copyright (C) 1992, 2001, 2010 Free Software Foundation, Inc.
+   Copyright (C) 1992, 2001, 2010, 2012 Free Software Foundation, Inc.
    Written by Fred Fish @ Cygnus Support

 This file is part of the libiberty library.
@@ -72,20 +72,13 @@ dupargv (char **argv)

   /* the vector */
   for (argc = 0; argv[argc] != NULL; argc++);
-  copy = (char **) malloc ((argc + 1) * sizeof (char *));
-  if (copy == NULL)
-    return NULL;
-
+  copy = (char **) xmalloc ((argc + 1) * sizeof (char *));
+
   /* the strings */
   for (argc = 0; argv[argc] != NULL; argc++)
     {
       int len = strlen (argv[argc]);
-      copy[argc] = (char *) malloc (len + 1);
-      if (copy[argc] == NULL)
-       {
-         freeargv (copy);
-         return NULL;
-       }
+      copy[argc] = (char *) xmalloc (len + 1);
       strcpy (copy[argc], argv[argc]);
     }
   copy[argc] = NULL;
@@ -149,7 +142,7 @@ remains unchanged.  The last element of the vector
is followed by a
 @code{NULL} element.

 All of the memory for the pointer array and copies of the string
-is obtained from @code{malloc}.  All of the memory can be returned to the
+is obtained from @code{xmalloc}.  All of the memory can be returned to the
 system with the single function call @code{freeargv}, which takes the
 returned result of @code{buildargv}, as it's argument.

@@ -205,21 +198,12 @@ char **buildargv (const char *input)
              if (argv == NULL)
                {
                  maxargc = INITIAL_MAXARGC;
-                 nargv = (char **) malloc (maxargc * sizeof (char *));
+                 nargv = (char **) xmalloc (maxargc * sizeof (char *));
                }
              else
                {
                  maxargc *= 2;
-                 nargv = (char **) realloc (argv, maxargc * sizeof (char *));
-               }
-             if (nargv == NULL)
-               {
-                 if (argv != NULL)
-                   {
-                     freeargv (argv);
-                     argv = NULL;
-                   }
-                 break;
+                 nargv = (char **) xrealloc (argv, maxargc * sizeof (char *));
                }
              argv = nargv;
              argv[argc] = NULL;
@@ -284,13 +268,7 @@ char **buildargv (const char *input)
                }
            }
          *arg = EOS;
-         argv[argc] = strdup (copybuf);
-         if (argv[argc] == NULL)
-           {
-             freeargv (argv);
-             argv = NULL;
-             break;
-           }
+         argv[argc] = xstrdup (copybuf);
          argc++;
          argv[argc] = NULL;

@@ -455,14 +433,7 @@ expandargv (int *argcp, char ***argvp)
        file_argv = buildargv (buffer);
       /* If *ARGVP is not already dynamically allocated, copy it.  */
       if (!argv_dynamic)
-       {
-         *argvp = dupargv (*argvp);
-         if (!*argvp)
-           {
-             fputs ("\nout of memory\n", stderr);
-             xexit (1);
-           }
-       }
+       *argvp = dupargv (*argvp);
       /* Count the number of arguments.  */
       file_argc = 0;
       while (file_argv[file_argc])