binutils-gdb/gnulib/import/m4/builtin-expect.m4
Simon Marchi 5df4cba632 gdb: update gnulib import
This is mostly to get this commit from gnulib:

    e22cd2677a4b7beacbf30b93bb0559f7b89f96ce
    Add ‘extern "C"’ to count-one-bits.h etc.

... which fixes this compilation problem I observed with clang++:

      CXXLD  gdb
    arch/arm-get-next-pcs.o:arm-get-next-pcs.c:function thumb_get_next_pcs_raw(arm_get_next_pcs*): error: undefined reference to 'count_one_bits(unsigned int)'
    <more such undefined references>

I built-tested on GNU/Linux x86-64 (gcc-9 and clang-9) as well as with the
x86_64-w64-mingw32-gcc cross-compiler.

gnulib/ChangeLog:

	* update-gnulib.sh (GNULIB_COMMIT_SHA1): Bump to
	e22cd2677a4b7beacbf30b93bb0559f7b89f96ce.
	* Makefile.in, config.in, configure, import/*: Re-generate.
2020-02-22 20:37:18 -05:00

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dnl Check for __builtin_expect.
dnl Copyright 2016-2020 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 Written by Paul Eggert.
AC_DEFUN([gl___BUILTIN_EXPECT],
[
AC_CACHE_CHECK([for __builtin_expect],
[gl_cv___builtin_expect],
[AC_LINK_IFELSE(
[AC_LANG_SOURCE([[
int
main (int argc, char **argv)
{
argc = __builtin_expect (argc, 100);
return argv[argc != 100][0];
}]])],
[gl_cv___builtin_expect=yes],
[AC_LINK_IFELSE(
[AC_LANG_SOURCE([[
#include <builtins.h>
int
main (int argc, char **argv)
{
argc = __builtin_expect (argc, 100);
return argv[argc != 100][0];
}]])],
[gl_cv___builtin_expect="in <builtins.h>"],
[gl_cv___builtin_expect=no])])])
if test "$gl_cv___builtin_expect" = yes; then
AC_DEFINE([HAVE___BUILTIN_EXPECT], [1])
elif test "$gl_cv___builtin_expect" = "in <builtins.h>"; then
AC_DEFINE([HAVE___BUILTIN_EXPECT], [2])
fi
AH_VERBATIM([HAVE___BUILTIN_EXPECT],
[/* Define to 1 if the compiler supports __builtin_expect,
and to 2 if <builtins.h> does. */
#undef HAVE___BUILTIN_EXPECT
#ifndef HAVE___BUILTIN_EXPECT
# define __builtin_expect(e, c) (e)
#elif HAVE___BUILTIN_EXPECT == 2
# include <builtins.h>
#endif
])
])