From 3cf2dc197941c8a162c338de008450a95a5bcc38 Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Sat, 23 May 2020 20:41:51 +0200 Subject: [PATCH] calloc-gnu: Avoid wrong configure results with clang. * m4/calloc.m4 (_AC_FUNC_CALLOC_IF): Mark the pointer variable as 'volatile', to defeat compiler optimizations. --- ChangeLog | 6 ++++++ m4/calloc.m4 | 4 ++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index af8062c562..e5a1f13f45 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2020-05-23 Bruno Haible + + calloc-gnu: Avoid wrong configure results with clang. + * m4/calloc.m4 (_AC_FUNC_CALLOC_IF): Mark the pointer variable as + 'volatile', to defeat compiler optimizations. + 2020-05-23 Bruno Haible isnanl, isnanl-nolibm: Make a test work better with "gcc -O2" on x86_64. diff --git a/m4/calloc.m4 b/m4/calloc.m4 index 2e0d8ff03a..3361cba7a6 100644 --- a/m4/calloc.m4 +++ b/m4/calloc.m4 @@ -1,4 +1,4 @@ -# calloc.m4 serial 20 +# calloc.m4 serial 21 # Copyright (C) 2004-2020 Free Software Foundation, Inc. # This file is free software; the Free Software Foundation @@ -25,7 +25,7 @@ AC_DEFUN([_AC_FUNC_CALLOC_IF], [AC_LANG_PROGRAM( [AC_INCLUDES_DEFAULT], [[int result = 0; - char *p = calloc (0, 0); + char * volatile p = calloc (0, 0); if (!p) result |= 1; free (p); -- 2.39.5