Split ERROR_{C|CXX} flags into WARNING and ERROR flags

The WARNING flags now contain all warning flags, the ERROR flags contain
the flags related to making warnings fatal. For more explanation, see
the inline docs.

The rationale is that we want to turn on a lot more warning flags, but
generated and imported sources might not have the same quality. For
those, we want to use the WARNING_CFLAGS but not the ERROR_CFLAGS.

diff --git a/m4/gst-error.m4 b/m4/gst-error.m4
index 099f292..fdd7044 100644 (file)
--- a/m4/gst-error.m4
+++ b/m4/gst-error.m4
@@ -10,14 +10,18 @@ dnl AG_GST_SET_ERROR_CXXFLAGS([ADD-WERROR], [MORE_FLAGS])
 dnl AG_GST_SET_LEVEL_DEFAULT([IS-GIT-VERSION])
 
 
-dnl Sets ERROR_CFLAGS 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 Sets WARNING_CFLAGS and ERROR_CFLAGS to something the compiler 
+dnl will accept and AC_SUBST them so they are available in Makefile
+dnl
+dnl WARNING_CFLAGS will contain flags to make the compiler emit more
+dnl   warnings.
+dnl ERROR_CFLAGS will contain flags to make those warnings fatal,
+dnl   unless ADD-WERROR is set to "no"
+dnl 
 dnl If MORE_FLAGS is set, tries to add each of the given flags
-dnl as a compiler flag.
-
+dnl to WARNING_CFLAGS if the compiler supports them. Each flag is 
+dnl tested separately.
+dnl
 dnl These flags can be overridden at make time:
 dnl make ERROR_CFLAGS=
 AC_DEFUN([AG_GST_SET_ERROR_CFLAGS],
@@ -25,23 +29,24 @@ AC_DEFUN([AG_GST_SET_ERROR_CFLAGS],
   AC_REQUIRE([AC_PROG_CC])
   AC_REQUIRE([AS_COMPILER_FLAG])
 
+  WARNING_CFLAGS=""
+  ERROR_CFLAGS=""
 
   dnl if we support -Wall, set it unconditionally
   AS_COMPILER_FLAG(-Wall,
-                   ERROR_CFLAGS="-Wall",
-                   ERROR_CFLAGS="")
+                   WARNING_CFLAGS="$WARNING_CFLAGS -Wall")
 
   dnl Warn if declarations after statements are used (C99 extension)
   AS_COMPILER_FLAG(-Wdeclaration-after-statement,
-        ERROR_CFLAGS="$ERROR_CFLAGS -Wdeclaration-after-statement")
+        WARNING_CFLAGS="$WARNING_CFLAGS -Wdeclaration-after-statement")
 
   dnl Warn if variable length arrays are used (C99 extension)
   AS_COMPILER_FLAG(-Wvla,
-        ERROR_CFLAGS="$ERROR_CFLAGS -Wvla")
+        WARNING_CFLAGS="$WARNING_CFLAGS -Wvla")
 
   dnl Warn for invalid pointer arithmetic
   AS_COMPILER_FLAG(-Wpointer-arith,
-        ERROR_CFLAGS="$ERROR_CFLAGS -Wpointer-arith")
+        WARNING_CFLAGS="$WARNING_CFLAGS -Wpointer-arith")
 
   dnl if asked for, add -Werror if supported
   if test "x$1" != "xno"
@@ -86,25 +91,31 @@ AC_DEFUN([AG_GST_SET_ERROR_CFLAGS],
   for each in $2
   do
     AS_COMPILER_FLAG($each,
-        ERROR_CFLAGS="$ERROR_CFLAGS $each",
+        WARNING_CFLAGS="$WARNING_CFLAGS $each",
         UNSUPPORTED="$UNSUPPORTED $each")
   done
   if test "X$UNSUPPORTED" != X ; then
     AC_MSG_NOTICE([unsupported compiler flags: $UNSUPPORTED])
   fi
 
+  AC_SUBST(WARNING_CFLAGS)
   AC_SUBST(ERROR_CFLAGS)
+  AC_MSG_NOTICE([set WARNING_CFLAGS to $WARNING_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 Sets WARNING_CXXFLAGS and ERROR_CXXFLAGS to something the compiler 
+dnl will accept and AC_SUBST them so they are available in Makefile
+dnl
+dnl WARNING_CXXFLAGS will contain flags to make the compiler emit more
+dnl   warnings.
+dnl ERROR_CXXFLAGS will contain flags to make those warnings fatal,
+dnl   unless ADD-WERROR is set to "no"
+dnl 
 dnl If MORE_FLAGS is set, tries to add each of the given flags
-dnl as a compiler flag.
-
+dnl to WARNING_CFLAGS if the compiler supports them. Each flag is 
+dnl tested separately.
+dnl
 dnl These flags can be overridden at make time:
 dnl make ERROR_CXXFLAGS=
 AC_DEFUN([AG_GST_SET_ERROR_CXXFLAGS],
@@ -112,22 +123,18 @@ AC_DEFUN([AG_GST_SET_ERROR_CXXFLAGS],
   AC_REQUIRE([AC_PROG_CXX])
   AC_REQUIRE([AS_CXX_COMPILER_FLAG])
 
+  ERROR_CXXFLAGS=""
+  WARNING_CXXFLAGS=""
 
   dnl if we support -Wall, set it unconditionally
-  AS_CXX_COMPILER_FLAG(-Wall, [
-      ERROR_CXXFLAGS="-Wall"
-  ], [
-      ERROR_CXXFLAGS=""
-  ])
+  AS_CXX_COMPILER_FLAG(-Wall, WARNING_CXXFLAGS="$WARNING_CXXFLAGS -Wall")
 
   dnl if asked for, add -Werror if supported
   if test "x$1" != "xno"
   then
-    AS_CXX_COMPILER_FLAG(-Werror, werror_supported=yes, werror_supported=no)
-
-    if test "x$werror_supported" = "xyes"; then
-        ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror"
+    AS_CXX_COMPILER_FLAG(-Werror, "ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror"
 
+    if test "xERROR_CXXFLAGS" != "x"; then
         dnl add exceptions
         AS_CXX_COMPILER_FLAG([-Wno-non-virtual-dtor], ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Wno-non-virtual-dtor")
 
@@ -140,9 +147,8 @@ AC_DEFUN([AG_GST_SET_ERROR_CXXFLAGS],
          ])
     else
       dnl if -Werror isn't suported, try -errwarn=%all
-      AS_CXX_COMPILER_FLAG([-errwarn=%all], errwarnall=yes, errwarnall=no)
-      if test "x$errwarnall" = "xyes"; then
-        ERROR_CXXFLAGS="-errwarn=%all"
+      AS_CXX_COMPILER_FLAG([-errwarn=%all], "ERROR_CXXFLAGS="$ERROR_CXXFLAGS -errwarn=%all")
+      if test "x$ERROR_CXXFLAGS" != "x"; then
         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)
@@ -170,14 +176,16 @@ AC_DEFUN([AG_GST_SET_ERROR_CXXFLAGS],
   for each in $2
   do
     AS_CXX_COMPILER_FLAG($each,
-        ERROR_CXXFLAGS="$ERROR_CXXFLAGS $each",
+        WARNING_CXXFLAGS="$WARNING_CXXFLAGS $each",
         UNSUPPORTED="$UNSUPPORTED $each")
   done
   if test "X$UNSUPPORTED" != X ; then
     AC_MSG_NOTICE([unsupported compiler flags: $UNSUPPORTED])
   fi
 
+  AC_SUBST(WARNING_CXXFLAGS)
   AC_SUBST(ERROR_CXXFLAGS)
+  AC_MSG_NOTICE([set WARNING_CXXFLAGS to $WARNING_CXXFLAGS])
   AC_MSG_NOTICE([set ERROR_CXXFLAGS to $ERROR_CXXFLAGS])
 ])