howto: update m4 files to match latest master

1 files changed, 20 insertions, 27 deletions

diff --git a/gr-howto-write-a-block/config/lf_warnings.m4 b/gr-howto-write-a-block/config/lf_warnings.m4
index 4e2ca9111..d40c77f14 100644
--- a/gr-howto-write-a-block/config/lf_warnings.m4
+++ b/gr-howto-write-a-block/config/lf_warnings.m4
@@ -1,4 +1,5 @@
 dnl Copyright (C) 1988 Eleftherios Gkioulekas <lf@amath.washington.edu>
+dnl Copyright (C) 2009 Free Software Foundation, Inc.
 dnl  
 dnl This program is free software; you can redistribute it and/or modify
 dnl it under the terms of the GNU General Public License as published by
@@ -21,7 +22,7 @@ dnl distribution terms that you use for the rest of that program.
 
 # --------------------------------------------------------------------------
 # Check whether the C++ compiler accepts a certain flag
-# If it does it adds the flag to CXXFLAGS
+# If it does it adds the flag to lf_CXXFLAGS
 # If it does not then it returns an error to lf_ok
 # Usage:
 #   LF_CHECK_CXX_FLAG(-flag1 -flag2 -flag3 ...)
@@ -34,18 +35,19 @@ AC_DEFUN([LF_CHECK_CXX_FLAG],[
     AC_MSG_CHECKING([whether $CXX accepts $i])
     if test -z "`${CXX} $i -c conftest.cc 2>&1`"
     then
-      CXXFLAGS="${CXXFLAGS} $i"
+      lf_CXXFLAGS="${lf_CXXFLAGS} $i"
       AC_MSG_RESULT(yes)
     else
       AC_MSG_RESULT(no)
     fi
   done
   rm -f conftest.cc conftest.o
+  AC_SUBST(lf_CXXFLAGS)
 ])
 
 # --------------------------------------------------------------------------
 # Check whether the C compiler accepts a certain flag
-# If it does it adds the flag to CFLAGS
+# If it does it adds the flag to lf_CFLAGS
 # If it does not then it returns an error to lf_ok
 # Usage:
 #  LF_CHECK_CC_FLAG(-flag1 -flag2 -flag3 ...)
@@ -58,18 +60,19 @@ AC_DEFUN([LF_CHECK_CC_FLAG],[
     AC_MSG_CHECKING([whether $CC accepts $i])
     if test -z "`${CC} $i -c conftest.c 2>&1`"
     then
-      CFLAGS="${CFLAGS} $i"
+      lf_CFLAGS="${lf_CFLAGS} $i"
       AC_MSG_RESULT(yes)
     else
       AC_MSG_RESULT(no)
     fi
   done
   rm -f conftest.c conftest.o
+  AC_SUBST(lf_CFLAGS)
 ])
 
 # --------------------------------------------------------------------------
 # Check whether the Fortran compiler accepts a certain flag
-# If it does it adds the flag to FFLAGS
+# If it does it adds the flag to lf_FFLAGS
 # If it does not then it returns an error to lf_ok
 # Usage:
 #  LF_CHECK_F77_FLAG(-flag1 -flag2 -flag3 ...)
@@ -87,42 +90,32 @@ EOF
     AC_MSG_CHECKING([whether $F77 accepts $i])
     if test -z "`${F77} $i -c conftest.f 2>&1`"
     then
-      FFLAGS="${FFLAGS} $i"
+      lf_FFLAGS="${lf_FFLAGS} $i"
       AC_MSG_RESULT(yes)  
     else
       AC_MSG_RESULT(no)
     fi
   done
   rm -f conftest.f conftest.o
+  AC_SUBST(lf_FFLAGS)
 ])
 
 # ----------------------------------------------------------------------
-# Provide the configure script with an --with-warnings option that
-# turns on warnings. Call this command AFTER you have configured ALL your
-# compilers. 
+# Enable compiler warnings. 
+# 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)
-  
   dnl Warnings for the two main compilers
-  cc_warning_flags="-Wall"
+  dnl add -Wextra when you're got time to fix a bunch of them ;-)
+  cc_warning_flags="-Wall -Werror-implicit-function-declaration"
   cxx_warning_flags="-Wall -Woverloaded-virtual"
-  if test $lf_warnings = yes
+  if test -n "${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
 ])