fix a gcc warning with clang pragmas

README.md

@@ -86,9 +86,13 @@ Check the output of `meson setup` carefully and make sure it found everything
 you wanted it to find.  Add arguments to `meson setup` to change the build
 configuration.
 
-- Add flags like `-Dnsgif=false` to turn options on and off, see
+- Add flags like `-Dnsgif=false` to turn libvips options on and off, see
   `meson_options.txt` for a list of all the build options libvips supports.
 
+- Add flags like `-Dmagick=disable` to turn libvips dependencies on and off, 
+  see `meson_options.txt` and the list below for a summary of all the libvips
+  dependencies.
+
 - Meson will do a debug build by default. Add `--buildtype=release` for a 
   release (optimised) build.
 

libvips/conversion/composite.cpp

@@ -1785,8 +1785,10 @@ vips_composite2( VipsImage *base, VipsImage *overlay, VipsImage **out,
 	va_list ap;
 	int result;
 
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wvarargs"
+	/* Works for gcc and clang.
+	 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wvarargs"
 
 	/* Triggers a clang compiler warning because mode might not be an int.
 	 * I think the warning is harmless for all platforms we care about.
@@ -1795,7 +1797,7 @@ vips_composite2( VipsImage *base, VipsImage *overlay, VipsImage **out,
 
 	g_assert( sizeof( mode ) == sizeof( int ) );
 
-#pragma clang diagnostic pop
+#pragma GCC diagnostic pop
 
 	result = vips_call_split( "composite2", ap, base, overlay, out, mode );
 	va_end( ap );