From ae3d670a6d7d01e513b2431bde68e15870a9bae9 Mon Sep 17 00:00:00 2001
From: eb <eb@221aa14e-8319-0410-a670-987f0aec2ac5>
Date: Sun, 31 Aug 2008 23:00:30 +0000
Subject: [PATCH] fixed --enable-warnings-as-errors

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9474 221aa14e-8319-0410-a670-987f0aec2ac5
---
 config/lf_warnings.m4 | 42 +++++++++++++++++++++---------------------
 configure.ac          | 18 +++++++-----------
 2 files changed, 28 insertions(+), 32 deletions(-)

diff --git a/config/lf_warnings.m4 b/config/lf_warnings.m4
index 4e2ca911..e1828801 100644
--- a/config/lf_warnings.m4
+++ b/config/lf_warnings.m4
@@ -97,32 +97,32 @@ EOF
 ])
 
 # ----------------------------------------------------------------------
-# Provide the configure script with an --with-warnings option that
-# turns on warnings. Call this command AFTER you have configured ALL your
+# Enable compiler warnings.  Conditionally enable -Werror.
+# Call this command AFTER you have configured ALL your
 # compilers. 
 # ----------------------------------------------------------------------
 
 AC_DEFUN([LF_SET_WARNINGS],[
-  dnl Check for --with-warnings
-  AC_MSG_CHECKING([whether user wants warnings])
-  AC_ARG_WITH(warnings,
-              [  --with-warnings         Turn on warnings],
-              [ lf_warnings=yes ], [ lf_warnings=no ])
-  lf_warnings=yes # hard code for now -eb
-  AC_MSG_RESULT($lf_warnings)
-  
+  lf_warnings_as_errors=""
+  AC_ARG_ENABLE([warnings-as-errors],
+    AC_HELP_STRING([--enable-warnings-as-errors], [Treat compiler warnings as errors (no)]),
+    [case "$enableval" in 
+      (no) ;;
+      (yes) lf_warnings_as_errors="-Werror" ;;
+      (*) AC_MSG_ERROR([Invalid argument ($enableval) to --enable-warnings-as-errors]) ;;
+     esac],
+    [])
+     
   dnl Warnings for the two main compilers
-  cc_warning_flags="-Wall"
-  cxx_warning_flags="-Wall -Woverloaded-virtual"
-  if test $lf_warnings = yes
+  dnl add -Wextra when you're got time to fix a bunch of them ;-)
+  cc_warning_flags="-Wall $lf_warnings_as_errors"
+  cxx_warning_flags="-Wall -Woverloaded-virtual $lf_warnings_as_errors"
+  if test -n "${CC}"
   then
-    if test -n "${CC}"
-    then
-      LF_CHECK_CC_FLAG($cc_warning_flags)
-    fi
-    if test -n "${CXX}" 
-    then
-      LF_CHECK_CXX_FLAG($cxx_warning_flags)
-    fi
+    LF_CHECK_CC_FLAG($cc_warning_flags)
+  fi
+  if test -n "${CXX}" 
+  then
+    LF_CHECK_CXX_FLAG($cxx_warning_flags)
   fi
 ])
diff --git a/configure.ac b/configure.ac
index 003e6e3a..bae9f344 100644
--- a/configure.ac
+++ b/configure.ac
@@ -40,13 +40,6 @@ LF_CONFIGURE_CC
 LF_CONFIGURE_CXX
 GR_LIB64		dnl check for lib64 suffix after choosing compilers
 
-cxx_warnings_as_errors=""
-AC_ARG_ENABLE(
-    [warnings-as-errors],
-    [--enable-warnings-as-errors Treat compiler warnings as errors],
-    [cxx_warnings_as_errors="-Werror"]    
-)
-
 dnl The three macros above are known to override CXXFLAGS if the user
 dnl didn't specify them.  Though I'm sure somebody thought this was
 dnl a good idea, it makes it hard to use other than -g -O2 when compiling
@@ -57,16 +50,15 @@ dnl the output of swig use use -O1 if we're using g++.
 dnl See Makefile.common for the rest of the magic.
 if test "$user_set_cxxflags" != yes; then
   autoconf_default_CXXFLAGS="$CXXFLAGS"
-  CXXFLAGS=$cxx_warnings_as_errors
   if test "$GXX" = yes; then
     case "$host_cpu" in
     	powerpc*)
 	   dnl "-O1" is broken on the PPC for some reason
 	   dnl (at least as of g++ 4.1.1)
-	   swig_CXXFLAGS="-g1 -O2 -Wno-strict-aliasing"
+	   swig_CXXFLAGS="-g1 -O2 -Wno-strict-aliasing -Wno-parentheses"
 	;;
     	*) 
-	swig_CXXFLAGS="-g -O1 -Wno-strict-aliasing"
+	swig_CXXFLAGS="-g -O1 -Wno-strict-aliasing -Wno-parentheses"
 	;;
     esac
   fi
@@ -84,7 +76,6 @@ fi
 export PKG_CONFIG_PATH
 
 
-LF_SET_WARNINGS
 GR_SET_GPROF
 GR_SET_PROF
 AM_PROG_AS
@@ -336,6 +327,11 @@ AC_CONFIG_FILES([\
 dnl run_tests.sh is created from run_tests.sh.in .  Make it executable.
 AC_CONFIG_COMMANDS([run_tests_build], [chmod +x run_tests.sh])
 
+dnl Enable warnings as the last thing before generating output, since
+dnl this may add -Werror to CFLAGS which can cause various configure
+dnl checks to fail.
+LF_SET_WARNINGS
+
 AC_OUTPUT
 
 echo
-- 
2.30.2