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-rw-r--r--gl/m4/00gnulib.m491
1 files changed, 73 insertions, 18 deletions
diff --git a/gl/m4/00gnulib.m4 b/gl/m4/00gnulib.m4
index d4ad759..7fe03e0 100644
--- a/gl/m4/00gnulib.m4
+++ b/gl/m4/00gnulib.m4
@@ -1,27 +1,82 @@
1# 00gnulib.m4 serial 2 1# 00gnulib.m4 serial 8
2dnl Copyright (C) 2009-2013 Free Software Foundation, Inc. 2dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation 3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it, 4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved. 5dnl with or without modifications, as long as this notice is preserved.
6 6
7dnl This file must be named something that sorts before all other 7dnl This file must be named something that sorts before all other
8dnl gnulib-provided .m4 files. It is needed until such time as we can 8dnl gnulib-provided .m4 files. It is needed until the clang fix has
9dnl assume Autoconf 2.64, with its improved AC_DEFUN_ONCE semantics. 9dnl been included in Autoconf.
10 10
11# AC_DEFUN_ONCE([NAME], VALUE) 11# The following definitions arrange to use a compiler option
12# ---------------------------- 12# -Werror=implicit-function-declaration in AC_CHECK_DECL, when the
13# Define NAME to expand to VALUE on the first use (whether by direct 13# compiler is clang. Without it, clang implicitly declares "known"
14# expansion, or by AC_REQUIRE), and to nothing on all subsequent uses. 14# library functions in C mode, but not in C++ mode, which would cause
15# Avoid bugs in AC_REQUIRE in Autoconf 2.63 and earlier. This 15# Gnulib to omit a declaration and thus later produce an error in C++
16# definition is slower than the version in Autoconf 2.64, because it 16# mode. As of clang 9.0, these "known" functions are identified through
17# can only use interfaces that existed since 2.59; but it achieves the 17# LIBBUILTIN invocations in the LLVM source file
18# same effect. Quoting is necessary to avoid confusing Automake. 18# llvm/tools/clang/include/clang/Basic/Builtins.def.
19m4_version_prereq([2.63.263], [], 19# It's not possible to AC_REQUIRE the extra tests from AC_CHECK_DECL,
20[m4_define([AC][_DEFUN_ONCE], 20# because AC_CHECK_DECL, like other Autoconf built-ins, is not supposed
21 [AC][_DEFUN([$1], 21# to AC_REQUIRE anything: some configure.ac files have their first
22 [AC_REQUIRE([_gl_DEFUN_ONCE([$1])], 22# AC_CHECK_DECL executed conditionally. Therefore append the extra tests
23 [m4_indir([_gl_DEFUN_ONCE([$1])])])])]dnl 23# to AC_PROG_CC.
24[AC][_DEFUN([_gl_DEFUN_ONCE([$1])], [$2])])]) 24AC_DEFUN([gl_COMPILER_CLANG],
25[
26dnl AC_REQUIRE([AC_PROG_CC])
27 AC_CACHE_CHECK([whether the compiler is clang],
28 [gl_cv_compiler_clang],
29 [dnl Use _AC_COMPILE_IFELSE instead of AC_EGREP_CPP, to avoid error
30 dnl "circular dependency of AC_LANG_COMPILER(C)" if AC_PROG_CC has
31 dnl not yet been invoked.
32 _AC_COMPILE_IFELSE(
33 [AC_LANG_PROGRAM([[
34 #ifdef __clang__
35 barfbarf
36 #endif
37 ]],[[]])
38 ],
39 [gl_cv_compiler_clang=no],
40 [gl_cv_compiler_clang=yes])
41 ])
42])
43AC_DEFUN([gl_COMPILER_PREPARE_CHECK_DECL],
44[
45dnl AC_REQUIRE([AC_PROG_CC])
46dnl AC_REQUIRE([gl_COMPILER_CLANG])
47 AC_CACHE_CHECK([for compiler option needed when checking for declarations],
48 [gl_cv_compiler_check_decl_option],
49 [if test $gl_cv_compiler_clang = yes; then
50 dnl Test whether the compiler supports the option
51 dnl '-Werror=implicit-function-declaration'.
52 save_ac_compile="$ac_compile"
53 ac_compile="$ac_compile -Werror=implicit-function-declaration"
54 dnl Use _AC_COMPILE_IFELSE instead of AC_COMPILE_IFELSE, to avoid a
55 dnl warning "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS".
56 _AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
57 [gl_cv_compiler_check_decl_option='-Werror=implicit-function-declaration'],
58 [gl_cv_compiler_check_decl_option=none])
59 ac_compile="$save_ac_compile"
60 else
61 gl_cv_compiler_check_decl_option=none
62 fi
63 ])
64 if test "x$gl_cv_compiler_check_decl_option" != xnone; then
65 ac_compile_for_check_decl="$ac_compile $gl_cv_compiler_check_decl_option"
66 else
67 ac_compile_for_check_decl="$ac_compile"
68 fi
69])
70dnl Redefine _AC_CHECK_DECL_BODY so that it references ac_compile_for_check_decl
71dnl instead of ac_compile. If, for whatever reason, the override of AC_PROG_CC
72dnl in zzgnulib.m4 is inactive, use the original ac_compile.
73m4_define([_AC_CHECK_DECL_BODY],
74[ ac_save_ac_compile="$ac_compile"
75 if test -n "$ac_compile_for_check_decl"; then
76 ac_compile="$ac_compile_for_check_decl"
77 fi]
78m4_defn([_AC_CHECK_DECL_BODY])[ ac_compile="$ac_save_ac_compile"
79])
25 80
26# gl_00GNULIB 81# gl_00GNULIB
27# ----------- 82# -----------