diff options
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 |