# Prefer GNU C11 and C++11 to earlier versions. -*- coding: utf-8 -*-
# This implementation is taken from GNU Autoconf lib/autoconf/c.m4
# commit 017d5ddd82854911f0119691d91ea8a1438824d6
# dated Sun Apr 3 13:57:17 2016 -0700
# This implementation will be obsolete once we can assume Autoconf 2.70
# or later is installed everywhere a Gnulib program might be developed.
# Copyright (C) 2001-2020 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
# Written by David MacKenzie, with help from
# Akim Demaille, Paul Eggert,
# François Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor,
# Roland McGrath, Noah Friedman, david d zuhn, and many others.
# AC_PROG_CC([COMPILER ...])
# --------------------------
# COMPILER ... is a space separated list of C compilers to search for.
# This just gives the user an opportunity to specify an alternative
# search list for the C compiler.
AC_DEFUN_ONCE([AC_PROG_CC],
[AC_LANG_PUSH(C)dnl
AC_ARG_VAR([CC], [C compiler command])dnl
AC_ARG_VAR([CFLAGS], [C compiler flags])dnl
_AC_ARG_VAR_LDFLAGS()dnl
_AC_ARG_VAR_LIBS()dnl
_AC_ARG_VAR_CPPFLAGS()dnl
m4_ifval([$1],
[AC_CHECK_TOOLS(CC, [$1])],
[AC_CHECK_TOOL(CC, gcc)
if test -z "$CC"; then
dnl Here we want:
dnl AC_CHECK_TOOL(CC, cc)
dnl but without the check for a tool without the prefix.
dnl Until the check is removed from there, copy the code:
if test -n "$ac_tool_prefix"; then
AC_CHECK_PROG(CC, [${ac_tool_prefix}cc], [${ac_tool_prefix}cc])
fi
fi
if test -z "$CC"; then
AC_CHECK_PROG(CC, cc, cc, , , /usr/ucb/cc)
fi
if test -z "$CC"; then
AC_CHECK_TOOLS(CC, cl.exe)
fi
if test -z "$CC"; then
AC_CHECK_TOOL(CC, clang)
fi
])
test -z "$CC" && AC_MSG_FAILURE([no acceptable C compiler found in \$PATH])
# Provide some information about the compiler.
_AS_ECHO_LOG([checking for _AC_LANG compiler version])
set X $ac_compile
ac_compiler=$[2]
for ac_option in --version -v -V -qversion -version; do
m4_ifdef([_AC_DO_LIMIT],[_AC_DO_LIMIT],[_AC_DO])([$ac_compiler $ac_option >&AS_MESSAGE_LOG_FD])
done
m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
_AC_LANG_COMPILER_GNU
if test $ac_compiler_gnu = yes; then
GCC=yes
else
GCC=
fi
_AC_PROG_CC_G
dnl
dnl Set ac_prog_cc_stdc to the supported C version.
dnl Also set the documented variable ac_cv_prog_cc_stdc;
dnl its name was chosen when it was cached, but it is no longer cached.
_AC_PROG_CC_C11([ac_prog_cc_stdc=c11
ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c11],
[_AC_PROG_CC_C99([ac_prog_cc_stdc=c99
ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c99],
[_AC_PROG_CC_C89([ac_prog_cc_stdc=c89
ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c89],
[ac_prog_cc_stdc=no
ac_cv_prog_cc_stdc=no])])])
dnl
AC_LANG_POP(C)dnl
])# AC_PROG_CC
# AC_PROG_CXX([LIST-OF-COMPILERS])
# --------------------------------
# LIST-OF-COMPILERS is a space separated list of C++ compilers to search
# for (if not specified, a default list is used). This just gives the
# user an opportunity to specify an alternative search list for the C++
# compiler.
# aCC HP-UX C++ compiler much better than `CC', so test before.
# FCC Fujitsu C++ compiler
# KCC KAI C++ compiler
# RCC Rational C++
# xlC_r AIX C Set++ (with support for reentrant code)
# xlC AIX C Set++
AC_DEFUN([AC_PROG_CXX],
[AC_LANG_PUSH(C++)dnl
AC_ARG_VAR([CXX], [C++ compiler command])dnl
AC_ARG_VAR([CXXFLAGS], [C++ compiler flags])dnl
_AC_ARG_VAR_LDFLAGS()dnl
_AC_ARG_VAR_LIBS()dnl
_AC_ARG_VAR_CPPFLAGS()dnl
_AC_ARG_VAR_PRECIOUS([CCC])dnl
if test -z "$CXX"; then
if test -n "$CCC"; then
CXX=$CCC
else
AC_CHECK_TOOLS(CXX,
[m4_default([$1],
[g++ c++ gpp aCC CC cxx cc++ cl.exe FCC KCC RCC xlC_r xlC clang++])],
g++)
fi
fi
# Provide some information about the compiler.
_AS_ECHO_LOG([checking for _AC_LANG compiler version])
set X $ac_compile
ac_compiler=$[2]
for ac_option in --version -v -V -qversion; do
m4_ifdef([_AC_DO_LIMIT],[_AC_DO_LIMIT],[_AC_DO])([$ac_compiler $ac_option >&AS_MESSAGE_LOG_FD])
done
m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
_AC_LANG_COMPILER_GNU
if test $ac_compiler_gnu = yes; then
GXX=yes
else
GXX=
fi
_AC_PROG_CXX_G
_AC_PROG_CXX_CXX11([ac_prog_cxx_stdcxx=cxx11
ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx11
ac_cv_prog_cxx_cxx98=$ac_cv_prog_cxx_cxx11],
[_AC_PROG_CXX_CXX98([ac_prog_cxx_stdcxx=cxx98
ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx98],
[ac_prog_cxx_stdcxx=no
ac_cv_prog_cxx_stdcxx=no])])
AC_LANG_POP(C++)dnl
])# AC_PROG_CXX
# _AC_C_STD_TRY(STANDARD, TEST-PROLOGUE, TEST-BODY, OPTION-LIST,
# ACTION-IF-AVAILABLE, ACTION-IF-UNAVAILABLE)
# --------------------------------------------------------------
# Check whether the C compiler accepts features of STANDARD (e.g `c89', `c99')
# by trying to compile a program of TEST-PROLOGUE and TEST-BODY. If this fails,
# try again with each compiler option in the space-separated OPTION-LIST; if one
# helps, append it to CC. If eventually successful, run ACTION-IF-AVAILABLE,
# else ACTION-IF-UNAVAILABLE.
AC_DEFUN([_AC_C_STD_TRY],
[AC_MSG_CHECKING([for $CC option to enable ]m4_translit($1, [c], [C])[ features])
AC_CACHE_VAL(ac_cv_prog_cc_$1,
[ac_cv_prog_cc_$1=no
ac_save_CC=$CC
AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])])
for ac_arg in '' $4
do
CC="$ac_save_CC $ac_arg"
_AC_COMPILE_IFELSE([], [ac_cv_prog_cc_$1=$ac_arg])
test "x$ac_cv_prog_cc_$1" != "xno" && break
done
rm -f conftest.$ac_ext
CC=$ac_save_CC
])# AC_CACHE_VAL
ac_prog_cc_stdc_options=
case "x$ac_cv_prog_cc_$1" in
x)
AC_MSG_RESULT([none needed]) ;;
xno)
AC_MSG_RESULT([unsupported]) ;;
*)
ac_prog_cc_stdc_options=" $ac_cv_prog_cc_$1"
CC=$CC$ac_prog_cc_stdc_options
AC_MSG_RESULT([$ac_cv_prog_cc_$1]) ;;
esac
AS_IF([test "x$ac_cv_prog_cc_$1" != xno], [$5], [$6])
])# _AC_C_STD_TRY
# _AC_C_C99_TEST_HEADER
# ---------------------
# A C header suitable for testing for C99.
AC_DEFUN([_AC_C_C99_TEST_HEADER],
[[#include
#include
#include
#include
#include
#include
// Check varargs macros. These examples are taken from C99 6.10.3.5.
#define debug(...) fprintf (stderr, __VA_ARGS__)
#define showlist(...) puts (#__VA_ARGS__)
#define report(test,...) ((test) ? puts (#test) : printf (__VA_ARGS__))
static void
test_varargs_macros (void)
{
int x = 1234;
int y = 5678;
debug ("Flag");
debug ("X = %d\n", x);
showlist (The first, second, and third items.);
report (x>y, "x is %d but y is %d", x, y);
}
// Check long long types.
#define BIG64 18446744073709551615ull
#define BIG32 4294967295ul
#define BIG_OK (BIG64 / BIG32 == 4294967297ull && BIG64 % BIG32 == 0)
#if !BIG_OK
your preprocessor is broken;
#endif
#if BIG_OK
#else
your preprocessor is broken;
#endif
static long long int bignum = -9223372036854775807LL;
static unsigned long long int ubignum = BIG64;
struct incomplete_array
{
int datasize;
double data[];
};
struct named_init {
int number;
const wchar_t *name;
double average;
};
typedef const char *ccp;
static inline int
test_restrict (ccp restrict text)
{
// See if C++-style comments work.
// Iterate through items via the restricted pointer.
// Also check for declarations in for loops.
for (unsigned int i = 0; *(text+i) != '\0'; ++i)
continue;
return 0;
}
// Check varargs and va_copy.
static bool
test_varargs (const char *format, ...)
{
va_list args;
va_start (args, format);
va_list args_copy;
va_copy (args_copy, args);
const char *str = "";
int number = 0;
float fnumber = 0;
while (*format)
{
switch (*format++)
{
case 's': // string
str = va_arg (args_copy, const char *);
break;
case 'd': // int
number = va_arg (args_copy, int);
break;
case 'f': // float
fnumber = va_arg (args_copy, double);
break;
default:
break;
}
}
va_end (args_copy);
va_end (args);
return *str && number && fnumber;
}]])# _AC_C_C99_TEST_HEADER
# _AC_C_C99_TEST_BODY
# -------------------
# A C body suitable for testing for C99, assuming the corresponding header.
AC_DEFUN([_AC_C_C99_TEST_BODY],
[[
// Check bool.
_Bool success = false;
// Check restrict.
if (test_restrict ("String literal") == 0)
success = true;
char *restrict newvar = "Another string";
// Check varargs.
success &= test_varargs ("s, d' f .", "string", 65, 34.234);
test_varargs_macros ();
// Check flexible array members.
struct incomplete_array *ia =
malloc (sizeof (struct incomplete_array) + (sizeof (double) * 10));
ia->datasize = 10;
for (int i = 0; i < ia->datasize; ++i)
ia->data[i] = i * 1.234;
// Check named initializers.
struct named_init ni = {
.number = 34,
.name = L"Test wide string",
.average = 543.34343,
};
ni.number = 58;
int dynamic_array[ni.number];
dynamic_array[ni.number - 1] = 543;
// work around unused variable warnings
return (!success || bignum == 0LL || ubignum == 0uLL || newvar[0] == 'x'
|| dynamic_array[ni.number - 1] != 543);
]])
# _AC_PROG_CC_C99 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
# ----------------------------------------------------------------
# If the C compiler is not in ISO C99 mode by default, try to add an
# option to output variable CC to make it so. This macro tries
# various options that select ISO C99 on some system or another. It
# considers the compiler to be in ISO C99 mode if it handles _Bool,
# // comments, flexible array members, inline, long long int, mixed
# code and declarations, named initialization of structs, restrict,
# va_copy, varargs macros, variable declarations in for loops and
# variable length arrays.
AC_DEFUN([_AC_PROG_CC_C99],
[_AC_C_STD_TRY([c99],
[_AC_C_C99_TEST_HEADER],
[_AC_C_C99_TEST_BODY],
dnl Try
dnl GCC -std=gnu99 (unused restrictive modes: -std=c99 -std=iso9899:1999)
dnl IBM XL C -qlanglvl=extc1x (V12.1; does not pass C11 test)
dnl IBM XL C -qlanglvl=extc99
dnl (pre-V12.1; unused restrictive mode: -qlanglvl=stdc99)
dnl HP cc -AC99
dnl Intel ICC -std=c99, -c99 (deprecated)
dnl IRIX -c99
dnl Solaris -D_STDC_C99=
dnl cc's -xc99 option uses linker magic to define the external
dnl symbol __xpg4 as if by "int __xpg4 = 1;", which enables C99
dnl behavior for C library functions. This is not wanted here,
dnl because it means that a single module compiled with -xc99
dnl alters C runtime behavior for the entire program, not for
dnl just the module. Instead, define the (private) symbol
dnl _STDC_C99, which suppresses a bogus failure in .
dnl The resulting compiler passes the test case here, and that's
dnl good enough. For more, please see the thread starting at:
dnl https://lists.gnu.org/r/autoconf/2010-12/msg00059.html
dnl Tru64 -c99
dnl with extended modes being tried first.
[[-std=gnu99 -std=c99 -c99 -AC99 -D_STDC_C99= -qlanglvl=extc1x -qlanglvl=extc99]], [$1], [$2])[]dnl
])# _AC_PROG_CC_C99
# _AC_PROG_CC_C11 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
# ----------------------------------------------------------------
# If the C compiler is not in ISO C11 mode by default, try to add an
# option to output variable CC to make it so. This macro tries
# various options that select ISO C11 on some system or another. It
# considers the compiler to be in ISO C11 mode if it handles _Alignas,
# _Alignof, _Noreturn, _Static_assert, UTF-8 string literals,
# duplicate typedefs, and anonymous structures and unions.
AC_DEFUN([_AC_PROG_CC_C11],
[_AC_C_STD_TRY([c11],
[_AC_C_C99_TEST_HEADER[
// Check _Alignas.
char _Alignas (double) aligned_as_double;
char _Alignas (0) no_special_alignment;
extern char aligned_as_int;
char _Alignas (0) _Alignas (int) aligned_as_int;
// Check _Alignof.
enum
{
int_alignment = _Alignof (int),
int_array_alignment = _Alignof (int[100]),
char_alignment = _Alignof (char)
};
_Static_assert (0 < -_Alignof (int), "_Alignof is signed");
// Check _Noreturn.
int _Noreturn does_not_return (void) { for (;;) continue; }
// Check _Static_assert.
struct test_static_assert
{
int x;
_Static_assert (sizeof (int) <= sizeof (long int),
"_Static_assert does not work in struct");
long int y;
};
// Check UTF-8 literals.
#define u8 syntax error!
char const utf8_literal[] = u8"happens to be ASCII" "another string";
// Check duplicate typedefs.
typedef long *long_ptr;
typedef long int *long_ptr;
typedef long_ptr long_ptr;
// Anonymous structures and unions -- taken from C11 6.7.2.1 Example 1.
struct anonymous
{
union {
struct { int i; int j; };
struct { int k; long int l; } w;
};
int m;
} v1;
]],
[_AC_C_C99_TEST_BODY[
v1.i = 2;
v1.w.k = 5;
_Static_assert ((offsetof (struct anonymous, i)
== offsetof (struct anonymous, w.k)),
"Anonymous union alignment botch");
]],
dnl Try
dnl GCC -std=gnu11 (unused restrictive mode: -std=c11)
dnl with extended modes being tried first.
dnl
dnl Do not try -qlanglvl=extc1x, because IBM XL C V12.1 (the latest version as
dnl of September 2012) does not pass the C11 test. For now, try extc1x when
dnl compiling the C99 test instead, since it enables _Static_assert and
dnl _Noreturn, which is a win. If -qlanglvl=extc11 or -qlanglvl=extc1x passes
dnl the C11 test in some future version of IBM XL C, we'll add it here,
dnl preferably extc11.
[[-std=gnu11]], [$1], [$2])[]dnl
])# _AC_PROG_CC_C11
# AC_PROG_CC_C89
# --------------
# Do not use AU_ALIAS here and in AC_PROG_CC_C99 and AC_PROG_CC_STDC,
# as that'd be incompatible with how Automake redefines AC_PROG_CC. See
# .
AU_DEFUN([AC_PROG_CC_C89],
[AC_REQUIRE([AC_PROG_CC])],
[$0 is obsolete; use AC_PROG_CC]
)
# AC_PROG_CC_C99
# --------------
AU_DEFUN([AC_PROG_CC_C99],
[AC_REQUIRE([AC_PROG_CC])],
[$0 is obsolete; use AC_PROG_CC]
)
# AC_PROG_CC_STDC
# ---------------
AU_DEFUN([AC_PROG_CC_STDC],
[AC_REQUIRE([AC_PROG_CC])],
[$0 is obsolete; use AC_PROG_CC]
)
# AC_C_PROTOTYPES
# ---------------
# Check if the C compiler supports prototypes, included if it needs
# options.
AC_DEFUN([AC_C_PROTOTYPES],
[AC_REQUIRE([AC_PROG_CC])dnl
if test "$ac_prog_cc_stdc" != no; then
AC_DEFINE(PROTOTYPES, 1,
[Define to 1 if the C compiler supports function prototypes.])
AC_DEFINE(__PROTOTYPES, 1,
[Define like PROTOTYPES; this can be used by system headers.])
fi
])# AC_C_PROTOTYPES
# _AC_CXX_STD_TRY(STANDARD, TEST-PROLOGUE, TEST-BODY, OPTION-LIST,
# ACTION-IF-AVAILABLE, ACTION-IF-UNAVAILABLE)
# ----------------------------------------------------------------
# Check whether the C++ compiler accepts features of STANDARD (e.g
# `cxx98', `cxx11') by trying to compile a program of TEST-PROLOGUE
# and TEST-BODY. If this fails, try again with each compiler option
# in the space-separated OPTION-LIST; if one helps, append it to CXX.
# If eventually successful, run ACTION-IF-AVAILABLE, else
# ACTION-IF-UNAVAILABLE.
AC_DEFUN([_AC_CXX_STD_TRY],
[AC_MSG_CHECKING([for $CXX option to enable ]m4_translit(m4_translit($1, [x], [+]), [a-z], [A-Z])[ features])
AC_LANG_PUSH(C++)dnl
AC_CACHE_VAL(ac_cv_prog_cxx_$1,
[ac_cv_prog_cxx_$1=no
ac_save_CXX=$CXX
AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])])
for ac_arg in '' $4
do
CXX="$ac_save_CXX $ac_arg"
_AC_COMPILE_IFELSE([], [ac_cv_prog_cxx_$1=$ac_arg])
test "x$ac_cv_prog_cxx_$1" != "xno" && break
done
rm -f conftest.$ac_ext
CXX=$ac_save_CXX
])# AC_CACHE_VAL
ac_prog_cxx_stdcxx_options=
case "x$ac_cv_prog_cxx_$1" in
x)
AC_MSG_RESULT([none needed]) ;;
xno)
AC_MSG_RESULT([unsupported]) ;;
*)
ac_prog_cxx_stdcxx_options=" $ac_cv_prog_cxx_$1"
CXX=$CXX$ac_prog_cxx_stdcxx_options
AC_MSG_RESULT([$ac_cv_prog_cxx_$1]) ;;
esac
AC_LANG_POP(C++)dnl
AS_IF([test "x$ac_cv_prog_cxx_$1" != xno], [$5], [$6])
])# _AC_CXX_STD_TRY
# _AC_CXX_CXX98_TEST_HEADER
# -------------------------
# A C++ header suitable for testing for CXX98.
AC_DEFUN([_AC_CXX_CXX98_TEST_HEADER],
[[
#include
#include
#include
#include
#include
#include
#include