configure.ac: factor out a TP_COMPILER_WARNINGS macro

3 files changed, 59 insertions, 50 deletions

diff --git a/configure.ac b/configure.ac
index 4636da1a8..59717d9d9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,58 +70,26 @@ COMPILER_COVERAGE
 LINKER_OPTIMISATIONS
 LINKER_VERSION_SCRIPT
 
-dnl decide error flags
-AS_COMPILER_FLAG(-Wall, ERROR_CFLAGS="-Wall", ERROR_CFLAGS="")
-AS_COMPILER_FLAG(-Werror, werror=yes, werror=no)
-# never enable -Werror unless -Wno-error=foo also works
-AS_COMPILER_FLAG([-Wno-error=missing-field-initializers], [], [werror=no])
-AS_COMPILER_FLAG([-Wno-error=unused-parameter], [], [werror=no])
-
-AC_ARG_ENABLE(Werror,
-  AC_HELP_STRING([--disable-Werror],[compile without -Werror (normally enabled in development builds)]),
-    werror=$enableval, :)
-
-AS_COMPILER_FLAG(-Wextra, wextra=yes, wextra=no)
-AS_COMPILER_FLAG(-Wno-missing-field-initializers,
-        wno_missing_field_initializers=yes,
-        wno_missing_field_initializers=no)
-AS_COMPILER_FLAG(-Wno-unused-parameter,
-        wno_unused_parameter=yes,
-        wno_unused_parameter=no)
-
 ifelse(tp_glib_nano_version, 0,
     [ official_release=yes ],
-    [
-        official_release=no
-        if test x$werror = xyes; then
-            ERROR_CFLAGS="$ERROR_CFLAGS -Werror"
-            # We never want missing field initializers or unused parameters
-            # to be an error. We try to turn the warnings off, but CDBS has a
-            # tendency to turn them back on again...
-            ERROR_CFLAGS="$ERROR_CFLAGS -Wno-error=missing-field-initializers"
-            ERROR_CFLAGS="$ERROR_CFLAGS -Wno-error=unused-parameter"
-        fi
-        if test x$wextra = xyes -a \
-            x$wno_missing_field_initializers = xyes -a \
-            x$wno_unused_parameter = xyes; then
-            ERROR_CFLAGS="$ERROR_CFLAGS -Wextra"
-            ERROR_CFLAGS="$ERROR_CFLAGS -Wno-missing-field-initializers"
-            ERROR_CFLAGS="$ERROR_CFLAGS -Wno-unused-parameter"
-        fi
-    ])
+    [ official_release=no ])
+
+TP_COMPILER_WARNINGS([ERROR_CFLAGS], [test "x$official_release" = xno],
+  [all \
+   extra \
+   declaration-after-statement \
+   shadow \
+   strict-prototypes \
+   missing-prototypes \
+   sign-compare \
+   nested-externs \
+   pointer-arith \
+   format-security \
+   init-self],
+  [missing-field-initializers \
+   unused-parameter])
+AC_SUBST([ERROR_CFLAGS])
 
-AS_COMPILER_FLAG(-Wdeclaration-after-statement, ERROR_CFLAGS="$ERROR_CFLAGS -Wdeclaration-after-statement")
-AS_COMPILER_FLAG(-Wshadow, ERROR_CFLAGS="$ERROR_CFLAGS -Wshadow")
-AS_COMPILER_FLAG(-Wstrict-prototypes, ERROR_CFLAGS="$ERROR_CFLAGS -Wstrict-prototypes")
-AS_COMPILER_FLAG(-Wmissing-prototypes, ERROR_CFLAGS="$ERROR_CFLAGS -Wmissing-prototypes")
-AS_COMPILER_FLAG(-Wmissing-declarations, ERROR_CFLAGS="$ERROR_CFLAGS -Wmissing-declarations")
-AS_COMPILER_FLAG(-Wsign-compare, ERROR_CFLAGS="$ERROR_CFLAGS -Wsign-compare")
-AS_COMPILER_FLAG(-Wnested-externs, ERROR_CFLAGS="$ERROR_CFLAGS -Wnested-externs")
-AS_COMPILER_FLAG(-Wpointer-arith, ERROR_CFLAGS="$ERROR_CFLAGS -Wpointer-arith")
-AS_COMPILER_FLAG(-Wformat-security, ERROR_CFLAGS="$ERROR_CFLAGS -Wformat-security")
-AS_COMPILER_FLAG(-Winit-self, ERROR_CFLAGS="$ERROR_CFLAGS -Winit-self")
-
-AC_SUBST(ERROR_CFLAGS)
 AM_CONDITIONAL([OFFICIAL_RELEASE], [test "x$official_release" = xyes])
 
 AC_ARG_ENABLE(debug,
diff --git a/m4/Makefile.am b/m4/Makefile.am
index 06007e740..e2267e0da 100644
--- a/m4/Makefile.am
+++ b/m4/Makefile.am
@@ -2,4 +2,5 @@ EXTRA_DIST = \
 as-compiler-flag.m4 \
 compiler.m4 \
 gtk-doc.m4 \
-linker.m4
+linker.m4 \
+tp-compiler-warnings.m4
diff --git a/m4/tp-compiler-warnings.m4 b/m4/tp-compiler-warnings.m4
new file mode 100644
index 000000000..dbc4ebbe2
--- /dev/null
+++ b/m4/tp-compiler-warnings.m4
@@ -0,0 +1,40 @@
+dnl TP_COMPILER_WARNINGS(VARIABLE, WERROR_BY_DEFAULT, DESIRABLE, UNDESIRABLE)
+dnl $1 (VARIABLE): the variable to put flags into
+dnl $2 (WERROR_BY_DEFAULT): a command returning true if -Werror should be the
+dnl     default
+dnl $3 (DESIRABLE): warning flags we want (e.g. all extra shadow)
+dnl $4 (UNDESIRABLE): warning flags we don't want (e.g.
+dnl   missing-field-initializers unused-parameter)
+AC_DEFUN([TP_COMPILER_WARNINGS],
+[
+  AC_REQUIRE([AC_ARG_ENABLE])dnl
+  AC_REQUIRE([AC_HELP_STRING])dnl
+  AC_REQUIRE([AS_COMPILER_FLAG])dnl
+
+  tp_warnings=""
+  for tp_flag in $3; do
+    AS_COMPILER_FLAG([-W$tp_flag], [tp_warnings="$tp_warnings -W$tp_flag"])
+  done
+
+  tp_error_flags="-Werror"
+  AS_COMPILER_FLAG([-Werror], [tp_werror=yes], [tp_werror=no])
+
+  for tp_flag in $4; do
+    AS_COMPILER_FLAG([-Wno-$tp_flag],
+      [tp_warnings="$tp_warnings -Wno-$tp_flag"])
+    AS_COMPILER_FLAG([-Wno-error=$tp_flag],
+      [tp_error_flags="$tp_error_flags -Wno-error=$tp_flag"], [tp_werror=no])
+  done
+
+  AC_ARG_ENABLE([Werror],
+    AC_HELP_STRING([--disable-Werror],
+      [compile without -Werror (normally enabled in development builds)]),
+    tp_werror=$enableval, :)
+
+  if test "x$tp_werror" = xyes && $2; then
+    $1="$tp_warnings $tp_error_flags"
+  else
+    $1="$tp_warnings"
+  fi
+
+])