Merge patch-bm from emacs20 (prevent gcc from optimizing out __malloc_hook)

to fix one source of SIGSEGVs during build.

1 files changed, 48 insertions, 0 deletions

diff --git a/editors/emacs21/patches/patch-src_alloc_c b/editors/emacs21/patches/patch-src_alloc_c
new file mode 100644
index 00000000000..3ad1ffe3eae
--- /dev/null
+++ b/editors/emacs21/patches/patch-src_alloc_c
@@ -0,0 +1,48 @@
+$NetBSD: patch-src_alloc_c,v 1.1 2011/12/31 11:40:27 dholland Exp $
+
+- use standard headers
+- add an empty asm() destroying memory that prevents gcc from
+  optimizing out __malloc_hook and friends (which leads to
+  SIGSEGV in temacs during build)
+
+--- src/alloc.c.orig	2003-01-17 13:45:13.000000000 +0000
++++ src/alloc.c
+@@ -57,6 +57,8 @@ Boston, MA 02111-1307, USA.  */
+ extern POINTER_TYPE *sbrk ();
+ #endif
+ 
++#include <stdlib.h>
++
+ #ifdef DOUG_LEA_MALLOC
+ 
+ #include <malloc.h>
+@@ -685,6 +687,9 @@ emacs_blocked_free (ptr)
+ #endif /* GC_MALLOC_CHECK */
+   
+   __free_hook = old_free_hook;
++#ifdef __GNUC__
++  __asm __volatile("":::"memory");
++#endif
+   free (ptr);
+   
+   /* If we released our reserve (due to running out of memory),
+@@ -728,6 +733,9 @@ emacs_blocked_malloc (size)
+ 
+   BLOCK_INPUT;
+   __malloc_hook = old_malloc_hook;
++#ifdef __GNUC__
++  __asm __volatile("":::"memory");
++#endif
+ #ifdef DOUG_LEA_MALLOC
+     mallopt (M_TOP_PAD, malloc_hysteresis * 4096);
+ #else
+@@ -776,6 +784,9 @@ emacs_blocked_realloc (ptr, size)
+ 
+   BLOCK_INPUT;
+   __realloc_hook = old_realloc_hook;
++#ifdef __GNUC__
++  __asm __volatile("":::"memory");
++#endif
+ 
+ #ifdef GC_MALLOC_CHECK
+   if (ptr)