m4/as-compiler-flag.m4: Add AS_CXX_COMPILER_FLAG

Original commit message from CVS:
* m4/as-compiler-flag.m4:
Add AS_CXX_COMPILER_FLAG
* m4/gst-error.m4:
Add AG_GST_SET_ERROR_CXXFLAGS (Forte bits need testing)

3 files changed, 126 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index 2c731fa..2966805 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2008-02-22  Tim-Philipp Müller  <tim at centricular dot net>
 
+	* m4/as-compiler-flag.m4:
+	  Add AS_CXX_COMPILER_FLAG
+
+	* m4/gst-error.m4:
+	  Add AG_GST_SET_ERROR_CXXFLAGS (Forte bits need testing)
+
+2008-02-22  Tim-Philipp Müller  <tim at centricular dot net>
+
 	* gtk-doc-plugins.mak:
 	  Add 'check-inspected-versions' target; this helps identify
 	  files that should have been removed or where the version
diff --git a/m4/as-compiler-flag.m4 b/m4/as-compiler-flag.m4
index aba31b1..882a4c7 100644
--- a/m4/as-compiler-flag.m4
+++ b/m4/as-compiler-flag.m4
@@ -3,8 +3,7 @@ dnl as-compiler-flag.m4 0.1.0
 dnl autostars m4 macro for detection of compiler flags
 
 dnl David Schleef <ds@schleef.org>
-
-dnl $Id: as-compiler-flag.m4,v 1.1 2004/06/01 09:33:45 thomasvs Exp $
+dnl Tim-Philipp Müller <tim centricular net>
 
 dnl AS_COMPILER_FLAG(CFLAGS, ACTION-IF-ACCEPTED, [ACTION-IF-NOT-ACCEPTED])
 dnl Tries to compile with the given CFLAGS.
@@ -31,3 +30,35 @@ AC_DEFUN([AS_COMPILER_FLAG],
   AC_MSG_RESULT([$flag_ok])
 ])
 
+dnl AS_CXX_COMPILER_FLAG(CPPFLAGS, ACTION-IF-ACCEPTED, [ACTION-IF-NOT-ACCEPTED])
+dnl Tries to compile with the given CPPFLAGS.
+dnl Runs ACTION-IF-ACCEPTED if the compiler can compile with the flags,
+dnl and ACTION-IF-NOT-ACCEPTED otherwise.
+
+AC_DEFUN([AS_CXX_COMPILER_FLAG],
+[
+  AC_REQUIRE([AC_PROG_CXX])
+
+  AC_MSG_CHECKING([to see if c++ compiler understands $1])
+
+  save_CPPFLAGS="$CPPFLAGS"
+  CPPFLAGS="$CPPFLAGS $1"
+
+  AC_LANG_PUSH(C++)
+
+  AC_TRY_COMPILE([ ], [], [flag_ok=yes], [flag_ok=no])
+  CPPFLAGS="$save_CPPFLAGS"
+
+  if test "X$flag_ok" = Xyes ; then
+    $2
+    true
+  else
+    $3
+    true
+  fi
+
+  AC_LANG_POP(C++)
+
+  AC_MSG_RESULT([$flag_ok])
+])
+
diff --git a/m4/gst-error.m4 b/m4/gst-error.m4
index ad0622b..d9d9d82 100644
--- a/m4/gst-error.m4
+++ b/m4/gst-error.m4
@@ -1,10 +1,12 @@
 dnl handle various error-related things
 
 dnl Thomas Vander Stichele <thomas@apestaart.org>
+dnl Tim-Philipp Müller <tim centricular net>
 
-dnl Last modification: 2005-10-16
+dnl Last modification: 2008-02-18
 
 dnl AG_GST_SET_ERROR_CFLAGS([ADD-WERROR])
+dnl AG_GST_SET_ERROR_CXXFLAGS([ADD-WERROR])
 dnl AG_GST_SET_LEVEL_DEFAULT([IS-CVS-VERSION])
 
 
@@ -32,22 +34,28 @@ AC_DEFUN([AG_GST_SET_ERROR_CFLAGS],
   then
     AS_COMPILER_FLAG(-Werror, ERROR_CFLAGS="$ERROR_CFLAGS -Werror")
 
-    dnl if -Werror isn't suported
+    dnl if -Werror isn't suported, try -errwarn=%all (Sun Forte case)
     if test "x$ERROR_CFLAGS" == "x"
     then
-      dnl try -errwarn=%all,no%E_EMPTY_DECLARATION,no%E_STATEMENT_NOT_REACHED,no%E_ARGUEMENT_MISMATCH,no%E_MACRO_REDEFINED (Sun Forte case)
-      dnl For Forte we need disable "empty declaration" warning produced by un-needed semicolon 
-      dnl "statement not reached" disabled because there is g_assert_not_reached () in some places
-      dnl "macro redefined" because of gst/gettext.h
-      AS_COMPILER_FLAG([-errwarn=%all,no%E_EMPTY_DECLARATION,no%E_STATEMENT_NOT_REACHED,no%E_ARGUEMENT_MISMATCH,no%E_MACRO_REDEFINED],
-                       [ERROR_CFLAGS="-errwarn=%all,no%E_EMPTY_DECLARATION,no%E_STATEMENT_NOT_REACHED,no%E_ARGUEMENT_MISMATCH,no%E_MACRO_REDEFINED"])
-
-      dnl if this also isn't suported, try only for -errwarn=%all
-      if test "x$ERROR_CFLAGS" == "x"
-      then
-        AS_COMPILER_FLAG(-errwarn=%all,
-                         ERROR_CFLAGS="-errwarn=%all")
-      fi
+      AS_COMPILER_FLAG([-errwarn=%all], [
+          ERROR_CFLAGS="-errwarn=%all"
+          dnl try -errwarn=%all,no%E_EMPTY_DECLARATION,
+          dnl no%E_STATEMENT_NOT_REACHED,no%E_ARGUEMENT_MISMATCH,
+          dnl no%E_MACRO_REDEFINED (Sun Forte case)
+          dnl For Forte we need disable "empty declaration" warning produced by un-needed semicolon 
+          dnl "statement not reached" disabled because there is g_assert_not_reached () in some places
+          dnl "macro redefined" because of gst/gettext.h
+          dnl FIXME: is it really supposed to be 'ARGUEMENT' and not 'ARGUMENT'?
+          for f in 'no%E_EMPTY_DECLARATION' \
+                   'no%E_STATEMENT_NOT_REACHED' \
+                   'no%E_ARGUEMENT_MISMATCH' \
+                   'no%E_MACRO_REDEFINED'
+          do
+            AS_CXX_COMPILER_FLAG([-errwarn=%all,$f], [
+              ERROR_CXXFLAGS="$ERROR_CXXFLAGS,$f"
+            ])
+          done
+      ])
     fi
   fi
 
@@ -55,6 +63,68 @@ AC_DEFUN([AG_GST_SET_ERROR_CFLAGS],
   AC_MSG_NOTICE([set ERROR_CFLAGS to $ERROR_CFLAGS])
 ])
 
+dnl Sets ERROR_CXXFLAGS to something the compiler will accept.
+dnl AC_SUBST them so they are available in Makefile
+
+dnl -Wall is added if it is supported
+dnl -Werror is added if ADD-WERROR is not "no"
+
+dnl These flags can be overridden at make time:
+dnl make ERROR_CXXFLAGS=
+AC_DEFUN([AG_GST_SET_ERROR_CXXFLAGS],
+[
+  AC_REQUIRE([AC_PROG_CXX])
+  AC_REQUIRE([AS_CXX_COMPILER_FLAG])
+
+  
+  dnl if we support -Wall, set it unconditionally
+  AS_CXX_COMPILER_FLAG(-Wall, [
+      ERROR_CXXFLAGS="-Wall"
+  ], [
+      ERROR_CXXFLAGS=""
+  ])
+  
+  dnl if asked for, add -Werror if supported
+  if test "x$1" != "xno"
+  then
+    AS_CXX_COMPILER_FLAG([-Werror], [
+        ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror"
+
+        dnl add exceptions
+        for f in '-Wno-non-virtual-dtor'
+        do
+          AS_CXX_COMPILER_FLAG([$f], ERROR_CXXFLAGS="$ERROR_CXXFLAGS $f")
+        done
+    ], [
+      dnl if -Werror isn't suported, try -errwarn=%all
+      AS_CXX_COMPILER_FLAG([-errwarn=%all], [
+          ERROR_CXXFLAGS="-errwarn=%all"
+          dnl try -errwarn=%all,no%E_EMPTY_DECLARATION,
+          dnl no%E_STATEMENT_NOT_REACHED,no%E_ARGUEMENT_MISMATCH,
+          dnl no%E_MACRO_REDEFINED (Sun Forte case)
+          dnl For Forte we need disable "empty declaration" warning produced by un-needed semicolon 
+          dnl "statement not reached" disabled because there is g_assert_not_reached () in some places
+          dnl "macro redefined" because of gst/gettext.h
+          dnl FIXME: is it really supposed to be 'ARGUEMENT' and not 'ARGUMENT'?
+          dnl FIXME: do any of these work with the c++ compiler? if not, why
+          dnl do we check at all?
+          for f in 'no%E_EMPTY_DECLARATION' \
+                   'no%E_STATEMENT_NOT_REACHED' \
+                   'no%E_ARGUEMENT_MISMATCH' \
+                   'no%E_MACRO_REDEFINED'
+          do
+            AS_CXX_COMPILER_FLAG([-errwarn=%all,$f], [
+              ERROR_CXXFLAGS="$ERROR_CXXFLAGS,$f"
+            ])
+          done
+      ])
+    ])
+  fi
+
+  AC_SUBST(ERROR_CXXFLAGS)
+  AC_MSG_NOTICE([set ERROR_CXXFLAGS to $ERROR_CXXFLAGS])
+])
+
 dnl Sets the default error level for debugging messages
 AC_DEFUN([AG_GST_SET_LEVEL_DEFAULT],
 [