From 84d38abbc982db405cfe7a45ed53c64745da5511 Mon Sep 17 00:00:00 2001 From: Janne Blomqvist Date: Fri, 14 Jun 2019 19:05:54 +0300 Subject: [PATCH] Use __builtin_mul_overflow in xmallocarray As GCC now provides builtins for doing integer overflow checking, lets use it when checking for overflow in xmallocarray. Regtested on x86_64-pc-linux-gnu. libgfortran/ChangeLog: 2019-06-14 Janne Blomqvist * runtime/memory.c (SIZE_MAX):Remove macro definition. (xmallocarray): Use __builtin_mul_overflow. From-SVN: r272295 --- libgfortran/ChangeLog | 5 +++++ libgfortran/runtime/memory.c | 13 ++++--------- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog index 19c297efa32..013a03eff11 100644 --- a/libgfortran/ChangeLog +++ b/libgfortran/ChangeLog @@ -1,3 +1,8 @@ +2019-06-14 Janne Blomqvist + + * runtime/memory.c (SIZE_MAX):Remove macro definition. + (xmallocarray): Use __builtin_mul_overflow. + 2019-05-22 Jeff Law PR fortran/89100 diff --git a/libgfortran/runtime/memory.c b/libgfortran/runtime/memory.c index 1a3d33b59dd..09a4ff8733f 100644 --- a/libgfortran/runtime/memory.c +++ b/libgfortran/runtime/memory.c @@ -26,10 +26,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #include "libgfortran.h" #include -#ifndef SIZE_MAX -#define SIZE_MAX ((size_t)-1) -#endif - void * xmalloc (size_t n) @@ -52,18 +48,17 @@ void * xmallocarray (size_t nmemb, size_t size) { void *p; + size_t prod; if (!nmemb || !size) - size = nmemb = 1; -#define HALF_SIZE_T (((size_t) 1) << (__CHAR_BIT__ * sizeof (size_t) / 2)) - else if (__builtin_expect ((nmemb | size) >= HALF_SIZE_T, 0) - && nmemb > SIZE_MAX / size) + prod = 1; + else if (__builtin_mul_overflow (nmemb, size, &prod)) { errno = ENOMEM; os_error ("Integer overflow in xmallocarray"); } - p = malloc (nmemb * size); + p = malloc (prod); if (!p) os_error ("Memory allocation failed in xmallocarray");