Adjust in response to jan.h.d's comments.

See, for example <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=9196#26>.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/lisp.h b/src/lisp.h
index 267bfe1b21f..83cc680b7e2 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3574,6 +3574,9 @@ extern int immediate_quit;	    /* Nonzero means ^G can quit instantly */
 extern POINTER_TYPE *xmalloc (size_t);
 extern POINTER_TYPE *xrealloc (POINTER_TYPE *, size_t);
 extern void xfree (POINTER_TYPE *);
+extern void *xnmalloc (ptrdiff_t, ptrdiff_t);
+extern void *xnrealloc (void *, ptrdiff_t, ptrdiff_t);
+extern void *xpalloc (void *, ptrdiff_t *, ptrdiff_t, ptrdiff_t, ptrdiff_t);
 
 extern char *xstrdup (const char *);
 
@@ -3691,6 +3694,23 @@ extern Lisp_Object safe_alloca_unwind (Lisp_Object);
       }                                                   \
   } while (0)
 
+/* SAFE_NALLOCA sets BUF to a newly allocated array of MULTIPLIER *
+   NITEMS items, each of the same type as *BUF.  MULTIPLIER must
+   positive.  The code is tuned for MULTIPLIER being a constant.  */
+
+#define SAFE_NALLOCA(buf, multiplier, nitems)                   \
+  do {                                                          \
+    if ((nitems) <= MAX_ALLOCA / sizeof *(buf) / (multiplier))  \
+      (buf) = alloca (sizeof *(buf) * (multiplier) * (nitems)); \
+    else                                                        \
+      {                                                          \
+        (buf) = xnmalloc (nitems, sizeof *(buf) * (multiplier)); \
+        sa_must_free = 1;                                        \
+        record_unwind_protect (safe_alloca_unwind,               \
+                               make_save_value (buf, 0));        \
+      }                                                          \
+  } while (0)
+
 /* SAFE_FREE frees xmalloced memory and enables GC as needed.  */
 
 #define SAFE_FREE()                     \