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Member "pacemaker-Pacemaker-2.1.2/m4/00gnulib.m4" (24 Nov 2021, 3593 Bytes) of package /linux/misc/pacemaker-Pacemaker-2.1.2.tar.gz:


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    1 # 00gnulib.m4 serial 8
    2 dnl Copyright (C) 2009-2020 Free Software Foundation, Inc.
    3 dnl This file is free software; the Free Software Foundation
    4 dnl gives unlimited permission to copy and/or distribute it,
    5 dnl with or without modifications, as long as this notice is preserved.
    6 
    7 dnl This file must be named something that sorts before all other
    8 dnl gnulib-provided .m4 files.  It is needed until the clang fix has
    9 dnl been included in Autoconf.
   10 
   11 # The following definitions arrange to use a compiler option
   12 # -Werror=implicit-function-declaration in AC_CHECK_DECL, when the
   13 # compiler is clang.  Without it, clang implicitly declares "known"
   14 # library functions in C mode, but not in C++ mode, which would cause
   15 # Gnulib to omit a declaration and thus later produce an error in C++
   16 # mode.  As of clang 9.0, these "known" functions are identified through
   17 # LIBBUILTIN invocations in the LLVM source file
   18 # llvm/tools/clang/include/clang/Basic/Builtins.def.
   19 # It's not possible to AC_REQUIRE the extra tests from AC_CHECK_DECL,
   20 # because AC_CHECK_DECL, like other Autoconf built-ins, is not supposed
   21 # to AC_REQUIRE anything: some configure.ac files have their first
   22 # AC_CHECK_DECL executed conditionally.  Therefore append the extra tests
   23 # to AC_PROG_CC.
   24 AC_DEFUN([gl_COMPILER_CLANG],
   25 [
   26 dnl 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 ])
   43 AC_DEFUN([gl_COMPILER_PREPARE_CHECK_DECL],
   44 [
   45 dnl AC_REQUIRE([AC_PROG_CC])
   46 dnl 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 ])
   70 dnl Redefine _AC_CHECK_DECL_BODY so that it references ac_compile_for_check_decl
   71 dnl instead of ac_compile.  If, for whatever reason, the override of AC_PROG_CC
   72 dnl in zzgnulib.m4 is inactive, use the original ac_compile.
   73 m4_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="$ac_compile_for_check_decl"
   77   fi]
   78 m4_defn([_AC_CHECK_DECL_BODY])[  ac_compile="$ac_save_ac_compile"
   79 ])
   80 
   81 # gl_00GNULIB
   82 # -----------
   83 # Witness macro that this file has been included.  Needed to force
   84 # Automake to include this file prior to all other gnulib .m4 files.
   85 AC_DEFUN([gl_00GNULIB])