build: add warnings and compiler flags to meson

this moves meson and autotools closer to each other. The flags are
selected in order to keep the amount of warnings low.

Differential Revision: https://phab.enlightenment.org/D7429

meson.build

@@ -77,6 +77,22 @@ local_benchmark = join_paths('src', 'benchmarks')
 local_examples = join_paths('src', 'examples')
 local_scripts = join_paths('src', 'scripts')
 
+dev_cflags = []
+dev_cflags_try = [
+  '-fvisibility=hidden',
+  '-Wall',
+  '-Wsign-compare',
+  '-Wno-missing-field-initializers',
+]
+
+foreach cf: dev_cflags_try
+  if cc.has_argument(cf) == true
+    dev_cflags += cf
+  endif
+endforeach
+add_global_arguments(dev_cflags, language: 'c')
+
+
 foreach lang : ['c', 'objc', 'cpp']
   add_global_arguments('-DHAVE_CONFIG_H=1', language: lang)
   add_global_arguments('-D_GNU_SOURCE=1', language: lang)