Imported Upstream version 0.9.6+really0.9.6upstream/0.9.6+really0.9.6

1 files changed, 28 insertions, 16 deletions

diff --git a/lib/malloca.c b/lib/malloca.c
index 39baa5e2..ef07acd7 100644
--- a/lib/malloca.c
+++ b/lib/malloca.c
@@ -1,5 +1,5 @@
 /* Safe automatic memory allocation.
-   Copyright (C) 2003, 2006-2007, 2009-2010 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2006-2007, 2009-2015 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2003.
 
    This program is free software; you can redistribute it and/or modify
@@ -13,14 +13,18 @@
    GNU Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
+#define _GL_USE_STDLIB_ALLOC 1
 #include <config.h>
 
 /* Specification.  */
 #include "malloca.h"
 
+#include <stdint.h>
+
+#include "verify.h"
+
 /* The speed critical point in this file is freea() applied to an alloca()
    result: it must be fast, to match the speed of alloca().  The speed of
    mmalloca() and freea() in the other case are not critical, because they
@@ -45,13 +49,18 @@
 #define MAGIC_SIZE sizeof (int)
 /* This is how the header info would look like without any alignment
    considerations.  */
-struct preliminary_header { void *next; char room[MAGIC_SIZE]; };
+struct preliminary_header { void *next; int magic; };
 /* But the header's size must be a multiple of sa_alignment_max.  */
 #define HEADER_SIZE \
   (((sizeof (struct preliminary_header) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max)
-struct header { void *next; char room[HEADER_SIZE - sizeof (struct preliminary_header) + MAGIC_SIZE]; };
-/* Verify that HEADER_SIZE == sizeof (struct header).  */
-typedef int verify1[2 * (HEADER_SIZE == sizeof (struct header)) - 1];
+union header {
+  void *next;
+  struct {
+    char room[HEADER_SIZE - MAGIC_SIZE];
+    int word;
+  } magic;
+};
+verify (HEADER_SIZE == sizeof (union header));
 /* We make the hash table quite big, so that during lookups the probability
    of empty hash buckets is quite high.  There is no need to make the hash
    table resizable, because when the hash table gets filled so much that the
@@ -71,20 +80,21 @@ mmalloca (size_t n)
 
   if (nplus >= n)
     {
-      char *p = (char *) malloc (nplus);
+      void *p = malloc (nplus);
 
       if (p != NULL)
         {
           size_t slot;
+          union header *h = p;
 
-          p += HEADER_SIZE;
+          p = h + 1;
 
           /* Put a magic number into the indicator word.  */
-          ((int *) p)[-1] = MAGIC_NUMBER;
+          h->magic.word = MAGIC_NUMBER;
 
           /* Enter p into the hash table.  */
-          slot = (unsigned long) p % HASH_TABLE_SIZE;
-          ((struct header *) (p - HEADER_SIZE))->next = mmalloca_results[slot];
+          slot = (uintptr_t) p % HASH_TABLE_SIZE;
+          h->next = mmalloca_results[slot];
           mmalloca_results[slot] = p;
 
           return p;
@@ -116,19 +126,21 @@ freea (void *p)
         {
           /* Looks like a mmalloca() result.  To see whether it really is one,
              perform a lookup in the hash table.  */
-          size_t slot = (unsigned long) p % HASH_TABLE_SIZE;
+          size_t slot = (uintptr_t) p % HASH_TABLE_SIZE;
           void **chain = &mmalloca_results[slot];
           for (; *chain != NULL;)
             {
+              union header *h = p;
               if (*chain == p)
                 {
                   /* Found it.  Remove it from the hash table and free it.  */
-                  char *p_begin = (char *) p - HEADER_SIZE;
-                  *chain = ((struct header *) p_begin)->next;
+                  union header *p_begin = h - 1;
+                  *chain = p_begin->next;
                   free (p_begin);
                   return;
                 }
-              chain = &((struct header *) ((char *) *chain - HEADER_SIZE))->next;
+              h = *chain;
+              chain = &h[-1].next;
             }
         }
       /* At this point, we know it was not a mmalloca() result.  */