Check if we can link against libatomic if needed

Also move the OS detection to the top (cherry picked from commit 03571f7)
PowerDNS · Feb 14, 2017 · 6484f26 · 6484f26
1 parent a08b422
commit 6484f26
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Showing 5 changed files with 83 additions and 2 deletions.
diff --git a/configure.ac b/configure.ac
@@ -41,6 +41,8 @@ AC_DEFINE([_GNU_SOURCE], [1],
 # Warn when pkg.m4 is missing
 m4_pattern_forbid([^_?PKG_[A-Z_]+$], [*** pkg.m4 missing, please install pkg-config])
 
+PDNS_CHECK_OS
+
 PDNS_WITH_LUAJIT
 AS_IF([test "x$with_luajit" = "xno"], [
   PDNS_WITH_LUA
@@ -131,7 +133,6 @@ AS_IF([test "x$lt_cv_dlopen" = "xno"],
 
 AC_SUBST([LIBDL], [$lt_cv_dlopen_libs])
 
-PDNS_CHECK_OS
 PDNS_ENABLE_VERBOSE_LOGGING
 PDNS_ENABLE_PKCS11
 PDNS_ENABLE_GSS_TSIG

diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
@@ -0,0 +1,74 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+#   Check whether the given FLAG works with the linker or gives an error.
+#   (Warnings, however, are ignored)
+#
+#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+#   success/failure.
+#
+#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
+#   when the check is done.  The check is thus made with the flags: "LDFLAGS
+#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
+#   issue an error when a bad flag is given.
+#
+#   INPUT gives an alternative input source to AC_LINK_IFELSE.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+#   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   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 <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 4
+
+AC_DEFUN([AX_CHECK_LINK_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $4 $1"
+  AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+    [AS_VAR_SET(CACHEVAR,[yes])],
+    [AS_VAR_SET(CACHEVAR,[no])])
+  LDFLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+  [m4_default([$2], :)],
+  [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_LINK_FLAGS
diff --git a/m4/pdns_check_os.m4 b/m4/pdns_check_os.m4
@@ -36,7 +36,11 @@ AC_DEFUN([PDNS_CHECK_OS],[
   AM_CONDITIONAL([HAVE_SOLARIS], [test "x$have_solaris" = "xyes"])
 
   case "$host" in
-  mips*)
+  mips* | powerpc* )
+    AX_CHECK_LINK_FLAG([-latomic],
+      [ : ],
+      AC_MSG_ERROR([Unable to link against libatomic, cannot continue])
+    )
     LDFLAGS="-latomic $LDFLAGS"
     ;;
   esac

diff --git a/pdns/dnsdistdist/m4/ax_check_link_flag.m4 b/pdns/dnsdistdist/m4/ax_check_link_flag.m4
@@ -0,0 +1 @@
+../../../m4/ax_check_link_flag.m4
diff --git a/pdns/recursordist/m4/ax_check_link_flag.m4 b/pdns/recursordist/m4/ax_check_link_flag.m4
@@ -0,0 +1 @@
+../../../m4/ax_check_link_flag.m4