diff options
Diffstat (limited to 'gnulib-m4/realloc.m4')
| -rw-r--r-- | gnulib-m4/realloc.m4 | 117 |
1 files changed, 66 insertions, 51 deletions
diff --git a/gnulib-m4/realloc.m4 b/gnulib-m4/realloc.m4 index cc911028..0242abdc 100644 --- a/gnulib-m4/realloc.m4 +++ b/gnulib-m4/realloc.m4 @@ -1,59 +1,22 @@ # realloc.m4 -# serial 32 -dnl Copyright (C) 2007, 2009-2024 Free Software Foundation, Inc. +# serial 39 +dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. +dnl This file is offered as-is, without any warranty. -# This is adapted with modifications from upstream Autoconf here: -# https://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/functions.m4?id=v2.70#n1455 -AC_DEFUN([_AC_FUNC_REALLOC_IF], +# An an experimental option, the user can request a sanitized realloc() +# implementation, i.e. one that aborts upon undefined behaviour, +# by setting +# gl_cv_func_realloc_sanitize=yes +# at configure time. +AC_DEFUN([gl_FUNC_REALLOC_SANITIZED], [ - AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles - AC_CACHE_CHECK([whether realloc (0, 0) returns nonnull], - [ac_cv_func_realloc_0_nonnull], - [AC_RUN_IFELSE( - [AC_LANG_PROGRAM( - [[#include <stdlib.h> - ]], - [[void *p = realloc (0, 0); - void * volatile vp = p; - int result = !vp; - free (p); - return result;]]) - ], - [ac_cv_func_realloc_0_nonnull=yes], - [ac_cv_func_realloc_0_nonnull=no], - [case "$host_os" in - # Guess yes on platforms where we know the result. - *-gnu* | freebsd* | netbsd* | openbsd* | bitrig* \ - | gnu* | *-musl* | midipix* | midnightbsd* \ - | hpux* | solaris* | cygwin* | mingw* | windows* | msys* ) - ac_cv_func_realloc_0_nonnull="guessing yes" ;; - # If we don't know, obey --enable-cross-guesses. - *) ac_cv_func_realloc_0_nonnull="$gl_cross_guess_normal" ;; - esac - ]) - ]) - AS_CASE([$ac_cv_func_realloc_0_nonnull], [*yes], [$1], [$2]) -])# AC_FUNC_REALLOC - -# gl_FUNC_REALLOC_GNU -# ------------------- -# Replace realloc if it is not compatible with GNU libc. -AC_DEFUN([gl_FUNC_REALLOC_GNU], -[ - AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) - AC_REQUIRE([gl_FUNC_REALLOC_POSIX]) - - dnl Through the dependency on module extensions-aix, _LINUX_SOURCE_COMPAT - dnl gets defined already before this macro gets invoked. This helps - dnl if !(__VEC__ || __AIXVEC), and doesn't hurt otherwise. - - if test $REPLACE_REALLOC_FOR_REALLOC_GNU = 0; then - _AC_FUNC_REALLOC_IF([], [REPLACE_REALLOC_FOR_REALLOC_GNU=1]) - fi -])# gl_FUNC_REALLOC_GNU + AC_CACHE_CHECK([whether realloc should abort upon undefined behaviour], + [gl_cv_func_realloc_sanitize], + [test -n "$gl_cv_func_realloc_sanitize" || gl_cv_func_realloc_sanitize=no]) +]) # gl_FUNC_REALLOC_POSIX # --------------------- @@ -64,7 +27,59 @@ AC_DEFUN([gl_FUNC_REALLOC_POSIX], [ AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) AC_REQUIRE([gl_FUNC_MALLOC_POSIX]) - if test $REPLACE_MALLOC_FOR_MALLOC_POSIX = 1; then + AC_REQUIRE([gl_FUNC_REALLOC_SANITIZED]) + if test "$gl_cv_func_realloc_sanitize" != no; then REPLACE_REALLOC_FOR_REALLOC_POSIX=1 + AC_DEFINE([NEED_SANITIZED_REALLOC], [1], + [Define to 1 if realloc should abort upon undefined behaviour.]) + else + REPLACE_REALLOC_FOR_REALLOC_POSIX=$REPLACE_MALLOC_FOR_MALLOC_POSIX fi ]) + +# gl_FUNC_REALLOC_0_NONNULL +# ------------------------- +# Replace realloc if realloc (..., 0) returns null. +# Modules that use this macro directly or indirectly should depend +# on extensions-aix, so that _LINUX_SOURCE_COMPAT gets defined +# before this macro gets invoked. This helps if !(__VEC__ || __AIXVEC), +# and doesn't hurt otherwise. +AC_DEFUN([gl_FUNC_REALLOC_0_NONNULL], +[ + AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles + AC_REQUIRE([gl_FUNC_REALLOC_POSIX]) + AC_CACHE_CHECK([whether realloc (..., 0) returns nonnull], + [gl_cv_func_realloc_0_nonnull], + [AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[#include <stdlib.h> + /* Use prealloc to test; "volatile" prevents the compiler + from optimizing the realloc call away. */ + void *(*volatile prealloc) (void *, size_t) = realloc;]], + [[void *p = prealloc (0, 0); + int result = !p; + p = prealloc (p, 0); + result |= !p; + free (p); + return result;]])], + [gl_cv_func_realloc_0_nonnull=yes], + [gl_cv_func_realloc_0_nonnull=no], + [AS_CASE([$host_os], + [# Guess yes on platforms where we know the result. + freebsd* | netbsd* | openbsd* | darwin* | bitrig* \ + | *-musl* | midipix* | midnightbsd* \ + | hpux* | solaris* | cygwin*], + [gl_cv_func_realloc_0_nonnull="guessing yes"], + [# Guess as follows if we don't know. + gl_cv_func_realloc_0_nonnull=$gl_cross_guess_normal])])]) + AS_CASE([$gl_cv_func_realloc_0_nonnull], + [*yes], + [AC_DEFINE([HAVE_REALLOC_0_NONNULL], [1], + [Define to 1 if realloc (..., 0) returns nonnull.])], + [AS_CASE([$gl_cv_func_realloc_sanitize,$gl_cv_malloc_ptrdiff,$gl_cv_func_malloc_posix,$host], + [yes,*,*,* | *,no,*,* | *,*,*no,* | *,*,*,aarch64c-*-freebsd*], + [REPLACE_REALLOC_FOR_REALLOC_POSIX=1], + [# Optimize for common case of glibc 2.1.1+ and compatibles. + REPLACE_REALLOC_FOR_REALLOC_POSIX=2])]) +]) |