Sync with the latest Gnulib code (1a268176f)

1 files changed, 31 insertions, 38 deletions

diff --git a/gl/malloca.h b/gl/malloca.h
index 6fbe45ea..7eb63d2a 100644
--- a/gl/malloca.h
+++ b/gl/malloca.h
@@ -1,19 +1,19 @@
 /* Safe automatic memory allocation.
-   Copyright (C) 2003-2007, 2009-2013 Free Software Foundation, Inc.
+   Copyright (C) 2003-2007, 2009-2021 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2003.
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3, or (at your option)
-   any later version.
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful,
+   This file is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
+   GNU Lesser General Public License for more details.
 
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef _MALLOCA_H
 #define _MALLOCA_H
@@ -21,6 +21,9 @@
 #include <alloca.h>
 #include <stddef.h>
 #include <stdlib.h>
+#include <stdint.h>
+
+#include "xalloc-oversized.h"
 
 
 #ifdef __cplusplus
@@ -48,40 +51,37 @@ extern "C" {
 # define safe_alloca(N) ((void) (N), NULL)
 #endif
 
+/* Free a block of memory allocated through malloca().  */
+#if HAVE_ALLOCA
+extern void freea (void *p);
+#else
+# define freea free
+#endif
+
 /* malloca(N) is a safe variant of alloca(N).  It allocates N bytes of
    memory allocated on the stack, that must be freed using freea() before
    the function returns.  Upon failure, it returns NULL.  */
 #if HAVE_ALLOCA
 # define malloca(N) \
-  ((N) < 4032 - sa_increment                                        \
-   ? (void *) ((char *) alloca ((N) + sa_increment) + sa_increment) \
+  ((N) < 4032 - (2 * sa_alignment_max - 1)                                   \
+   ? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \
+                + (2 * sa_alignment_max - 1))                                \
+               & ~(uintptr_t)(2 * sa_alignment_max - 1))                     \
    : mmalloca (N))
 #else
 # define malloca(N) \
   mmalloca (N)
 #endif
-extern void * mmalloca (size_t n);
-
-/* Free a block of memory allocated through malloca().  */
-#if HAVE_ALLOCA
-extern void freea (void *p);
-#else
-# define freea free
-#endif
+extern void *mmalloca (size_t n)
+  _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (freea, 1)
+  _GL_ATTRIBUTE_ALLOC_SIZE ((1));
 
 /* nmalloca(N,S) is an overflow-safe variant of malloca (N * S).
    It allocates an array of N objects, each with S bytes of memory,
-   on the stack.  S must be positive and N must be nonnegative.
+   on the stack.  N and S should be nonnegative and free of side effects.
    The array must be freed using freea() before the function returns.  */
-#if 1
-/* Cf. the definition of xalloc_oversized.  */
-# define nmalloca(n, s) \
-    ((n) > (size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) \
-     ? NULL \
-     : malloca ((n) * (s)))
-#else
-extern void * nmalloca (size_t n, size_t s);
-#endif
+#define nmalloca(n, s) \
+  (xalloc_oversized (n, s) ? NULL : malloca ((n) * (size_t) (s)))
 
 
 #ifdef __cplusplus
@@ -92,7 +92,7 @@ extern void * nmalloca (size_t n, size_t s);
 /* ------------------- Auxiliary, non-public definitions ------------------- */
 
 /* Determine the alignment of a type at compile time.  */
-#if defined __GNUC__ || defined __IBM__ALIGNOF__
+#if defined __GNUC__ || defined __clang__ || defined __IBM__ALIGNOF__
 # define sa_alignof __alignof__
 #elif defined __cplusplus
   template <class type> struct sa_alignof_helper { char __slot1; type __slot2; };
@@ -115,19 +115,12 @@ enum
    among all elementary types.  */
   sa_alignment_long = sa_alignof (long),
   sa_alignment_double = sa_alignof (double),
-#if HAVE_LONG_LONG_INT
   sa_alignment_longlong = sa_alignof (long long),
-#endif
   sa_alignment_longdouble = sa_alignof (long double),
   sa_alignment_max = ((sa_alignment_long - 1) | (sa_alignment_double - 1)
-#if HAVE_LONG_LONG_INT
                       | (sa_alignment_longlong - 1)
-#endif
                       | (sa_alignment_longdouble - 1)
-                     ) + 1,
-/* The increment that guarantees room for a magic word must be >= sizeof (int)
-   and a multiple of sa_alignment_max.  */
-  sa_increment = ((sizeof (int) + sa_alignment_max - 1) / sa_alignment_max) * sa_alignment_max
+                     ) + 1
 };
 
 #endif /* _MALLOCA_H */