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| author | Bruno Haible <bruno@clisp.org> | 2020-05-23 23:46:43 +0200 |
|---|---|---|
| committer | Bruno Haible <bruno@clisp.org> | 2020-05-23 23:47:27 +0200 |
| commit | d5ea809c3c7063d0dd5f7b70de7430f5bd4b991a (patch) | |
| tree | 04ca1f0961ae829f3dad00113d66e8154b1406a8 /m4/calloc.m4 | |
| parent | 3d29ad5500aca06b0f56bbe979b09c32017f6c1d (diff) | |
| download | gnulib-d5ea809c3c7063d0dd5f7b70de7430f5bd4b991a.tar.gz | |
calloc-gnu: Make the test work in non-flat address spaces.
Uses code by Paul Eggert.
* m4/calloc.m4 (_AC_FUNC_CALLOC_IF): Allow a calloc() implementation
to return more than SIZE_MAX bytes, but only without wrap-around bugs.
Diffstat (limited to 'm4/calloc.m4')
| -rw-r--r-- | m4/calloc.m4 | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/m4/calloc.m4 b/m4/calloc.m4 index a93439e8c8..f179a8a112 100644 --- a/m4/calloc.m4 +++ b/m4/calloc.m4 @@ -1,4 +1,4 @@ -# calloc.m4 serial 22 +# calloc.m4 serial 23 # Copyright (C) 2004-2020 Free Software Foundation, Inc. # This file is free software; the Free Software Foundation @@ -38,16 +38,27 @@ AC_DEFUN([_AC_FUNC_CALLOC_IF], AC_RUN_IFELSE( [AC_LANG_PROGRAM( [AC_INCLUDES_DEFAULT], - [[int result = 0; - char * volatile p = calloc ((size_t) -1 / 8 + 1, 8); - if (!p) - result |= 2; - free (p); + [[int result; + typedef struct { char c[8]; } S8; + size_t n = (size_t) -1 / sizeof (S8) + 2; + S8 * volatile s = calloc (n, sizeof (S8)); + if (s) + { + s[0].c[0] = 1; + if (s[n - 1].c[0]) + result = 0; + else + result = 2; + } + else + result = 3; + free (s); return result; ]])], - dnl The exit code of this program is 0 if calloc() succeeded (which - dnl it shouldn't), 2 if calloc() failed, or 1 if some leak sanitizer - dnl terminated the program as a result of the calloc() call. + dnl The exit code of this program is 0 if calloc() succeeded with a + dnl wrap-around bug (which it shouldn't), 2 if calloc() succeeded in + dnl a non-flat address space, 3 if calloc() failed, or 1 if some leak + dnl sanitizer terminated the program as a result of the calloc() call. [ac_cv_func_calloc_0_nonnull=no], []) else |