diff --git a/aclocal.m4 b/aclocal.m4 index a517e94..bfd34ec 100644 *** a/aclocal.m4 --- b/aclocal.m4 *************** m4_include([config/ax_prog_perl_modules. *** 4,9 **** --- 4,10 ---- m4_include([config/ax_pthread.m4]) m4_include([config/c-compiler.m4]) m4_include([config/c-library.m4]) + m4_include([config/check_decls.m4]) m4_include([config/docbook.m4]) m4_include([config/general.m4]) m4_include([config/libtool.m4]) diff --git a/config/check_decls.m4 b/config/check_decls.m4 index ...0dda18b . *** a/config/check_decls.m4 --- b/config/check_decls.m4 *************** *** 0 **** --- 1,116 ---- + # config/check_decls.m4 + + # This file redefines the standard Autoconf macro _AC_CHECK_DECL_BODY, + # and adds a supporting function _AC_UNDECLARED_WARNING, to make + # AC_CHECK_DECLS behave correctly when checking for built-in library + # functions with clang. + + # This is based on commit 82ef7805faffa151e724aa76c245ec590d174580 + # in the Autoconf git repository. We can drop it if they ever get + # around to releasing a new version of Autoconf. In the meantime, + # it's distributed under Autoconf's license: + + # This file is part of Autoconf. 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. + # + # Under Section 7 of GPL version 3, you are granted additional + # permissions described in the Autoconf Configure Script Exception, + # version 3.0, as published by the Free Software Foundation. + # + # You should have received a copy of the GNU General Public License + # and a copy of the Autoconf Configure Script Exception along with + # this program; see the files COPYINGv3 and COPYING.EXCEPTION + # respectively. If not, see . + + # Written by David MacKenzie, with help from + # Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor, + # Roland McGrath, Noah Friedman, david d zuhn, and many others. + + + # _AC_UNDECLARED_WARNING + # ---------------------- + # Set ac_[]_AC_LANG_ABBREV[]_decl_warn_flag=yes if the compiler uses a warning, + # not a more-customary error, to report some undeclared identifiers. Fail when + # an affected compiler warns also on valid input. _AC_PROG_PREPROC_WORKS_IFELSE + # solves a related problem. + AC_DEFUN([_AC_UNDECLARED_WARNING], + [# The Clang compiler raises a warning for an undeclared identifier that matches + # a compiler builtin function. All extant Clang versions are affected, as of + # Clang 3.6.0. Test a builtin known to every version. This problem affects the + # C and Objective C languages, but Clang does report an error under C++ and + # Objective C++. + # + # Passing -fno-builtin to the compiler would suppress this problem. That + # strategy would have the advantage of being insensitive to stray warnings, but + # it would make tests less realistic. + AC_CACHE_CHECK([how $[]_AC_CC[] reports undeclared, standard C functions], + [ac_cv_[]_AC_LANG_ABBREV[]_decl_report], + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [(void) strchr;])], + [AS_IF([test -s conftest.err], [dnl + # For AC_CHECK_DECL to react to warnings, the compiler must be silent on + # valid AC_CHECK_DECL input. No library function is consistently available + # on freestanding implementations, so test against a dummy declaration. + # Include always-available headers on the off chance that they somehow + # elicit warnings. + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([dnl + #include + #include + #include + #include + extern void ac_decl (int, char *);], + [@%:@ifdef __cplusplus + (void) ac_decl ((int) 0, (char *) 0); + (void) ac_decl; + @%:@else + (void) ac_decl; + @%:@endif + ])], + [AS_IF([test -s conftest.err], + [AC_MSG_FAILURE([cannot detect from compiler exit status or warnings])], + [ac_cv_[]_AC_LANG_ABBREV[]_decl_report=warning])], + [AC_MSG_FAILURE([cannot compile a simple declaration test])])], + [AC_MSG_FAILURE([compiler does not report undeclared identifiers])])], + [ac_cv_[]_AC_LANG_ABBREV[]_decl_report=error])]) + + case $ac_cv_[]_AC_LANG_ABBREV[]_decl_report in + warning) ac_[]_AC_LANG_ABBREV[]_decl_warn_flag=yes ;; + *) ac_[]_AC_LANG_ABBREV[]_decl_warn_flag= ;; + esac + ])# _AC_UNDECLARED_WARNING + + # _AC_CHECK_DECL_BODY + # ------------------- + # Shell function body for AC_CHECK_DECL. + m4_define([_AC_CHECK_DECL_BODY], + [ AS_LINENO_PUSH([$[]1]) + # Initialize each $ac_[]_AC_LANG_ABBREV[]_decl_warn_flag once. + AC_DEFUN([_AC_UNDECLARED_WARNING_]_AC_LANG_ABBREV, + [_AC_UNDECLARED_WARNING])dnl + AC_REQUIRE([_AC_UNDECLARED_WARNING_]_AC_LANG_ABBREV)dnl + [as_decl_name=`echo $][2|sed 's/ *(.*//'`] + [as_decl_use=`echo $][2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`] + AC_CACHE_CHECK([whether $as_decl_name is declared], [$[]3], + [ac_save_werror_flag=$ac_[]_AC_LANG_ABBREV[]_werror_flag + ac_[]_AC_LANG_ABBREV[]_werror_flag="$ac_[]_AC_LANG_ABBREV[]_decl_warn_flag$ac_[]_AC_LANG_ABBREV[]_werror_flag" + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$[]4], + [@%:@ifndef $[]as_decl_name + @%:@ifdef __cplusplus + (void) $[]as_decl_use; + @%:@else + (void) $[]as_decl_name; + @%:@endif + @%:@endif + ])], + [AS_VAR_SET([$[]3], [yes])], + [AS_VAR_SET([$[]3], [no])])]) + ac_[]_AC_LANG_ABBREV[]_werror_flag=$ac_save_werror_flag + AS_LINENO_POP + ])# _AC_CHECK_DECL_BODY diff --git a/configure b/configure index 67b7700..cf4954f 100755 *** a/configure --- b/configure *************** fi *** 1756,1768 **** ac_fn_c_check_decl () { as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack ! as_decl_name=`echo $2|sed 's/ *(.*//'` as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'` { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5 $as_echo_n "checking whether $as_decl_name is declared... " >&6; } if eval \${$3+:} false; then : $as_echo_n "(cached) " >&6 else cat confdefs.h - <<_ACEOF >conftest.$ac_ext /* end confdefs.h. */ $4 --- 1756,1771 ---- ac_fn_c_check_decl () { as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack ! # Initialize each $ac_[]_AC_LANG_ABBREV[]_decl_warn_flag once. ! as_decl_name=`echo $2|sed 's/ *(.*//'` as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'` { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5 $as_echo_n "checking whether $as_decl_name is declared... " >&6; } if eval \${$3+:} false; then : $as_echo_n "(cached) " >&6 else + ac_save_werror_flag=$ac_c_werror_flag + ac_c_werror_flag="$ac_c_decl_warn_flag$ac_c_werror_flag" cat confdefs.h - <<_ACEOF >conftest.$ac_ext /* end confdefs.h. */ $4 *************** fi *** 1791,1796 **** --- 1794,1800 ---- eval ac_res=\$$3 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 $as_echo "$ac_res" >&6; } + ac_c_werror_flag=$ac_save_werror_flag eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno } # ac_fn_c_check_decl *************** fi *** 4990,4995 **** --- 4994,5087 ---- test -n "$AWK" && break done + # The Clang compiler raises a warning for an undeclared identifier that matches + # a compiler builtin function. All extant Clang versions are affected, as of + # Clang 3.6.0. Test a builtin known to every version. This problem affects the + # C and Objective C languages, but Clang does report an error under C++ and + # Objective C++. + # + # Passing -fno-builtin to the compiler would suppress this problem. That + # strategy would have the advantage of being insensitive to stray warnings, but + # it would make tests less realistic. + { $as_echo "$as_me:${as_lineno-$LINENO}: checking how $CC reports undeclared, standard C functions" >&5 + $as_echo_n "checking how $CC reports undeclared, standard C functions... " >&6; } + if ${ac_cv_c_decl_report+:} false; then : + $as_echo_n "(cached) " >&6 + else + cat confdefs.h - <<_ACEOF >conftest.$ac_ext + /* end confdefs.h. */ + + int + main () + { + (void) strchr; + ; + return 0; + } + _ACEOF + if ac_fn_c_try_compile "$LINENO"; then : + if test -s conftest.err; then : + # For AC_CHECK_DECL to react to warnings, the compiler must be silent on + # valid AC_CHECK_DECL input. No library function is consistently available + # on freestanding implementations, so test against a dummy declaration. + # Include always-available headers on the off chance that they somehow + # elicit warnings. + cat confdefs.h - <<_ACEOF >conftest.$ac_ext + /* end confdefs.h. */ + #include + #include + #include + #include + extern void ac_decl (int, char *); + int + main () + { + #ifdef __cplusplus + (void) ac_decl ((int) 0, (char *) 0); + (void) ac_decl; + #else + (void) ac_decl; + #endif + + ; + return 0; + } + _ACEOF + if ac_fn_c_try_compile "$LINENO"; then : + if test -s conftest.err; then : + { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5 + $as_echo "$as_me: error: in \`$ac_pwd':" >&2;} + as_fn_error $? "cannot detect from compiler exit status or warnings + See \`config.log' for more details" "$LINENO" 5; } + else + ac_cv_c_decl_report=warning + fi + else + { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5 + $as_echo "$as_me: error: in \`$ac_pwd':" >&2;} + as_fn_error $? "cannot compile a simple declaration test + See \`config.log' for more details" "$LINENO" 5; } + fi + rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + else + { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5 + $as_echo "$as_me: error: in \`$ac_pwd':" >&2;} + as_fn_error $? "compiler does not report undeclared identifiers + See \`config.log' for more details" "$LINENO" 5; } + fi + else + ac_cv_c_decl_report=error + fi + rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + fi + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_decl_report" >&5 + $as_echo "$ac_cv_c_decl_report" >&6; } + + case $ac_cv_c_decl_report in + warning) ac_c_decl_warn_flag=yes ;; + *) ac_c_decl_warn_flag= ;; + esac + if test "$with_llvm" = yes; then :