config: enable comma warnings

Clang (3.9 or later) has a -Wcomma that emits warnings for questionable
uses of the comma operator.

Don't enable it for drivers since many drivers still use
comma operator unnecessarily.

Signed-off-by: Stephen Hemminger <[email protected]>
Acked-by: Konstantin Ananyev <[email protected]>
Acked-by: Chengwen Feng <[email protected]>
Acked-by: Morten Brørup <[email protected]>
Acked-by: Bruce Richardson <[email protected]>

Author: shemminger

config/meson.build

@@ -319,6 +319,7 @@ endif
 global_cflags = [
         # additional warnings in alphabetical order
         '-Wcast-qual',
+        '-Wcomma',
         '-Wdeprecated',
         '-Wformat',
         '-Wformat-nonliteral',

drivers/meson.build

@@ -86,7 +86,7 @@ default_cflags = machine_args
 default_cflags += ['-DALLOW_EXPERIMENTAL_API']
 default_cflags += ['-DALLOW_INTERNAL_API']
 
-warning_disable_cflags = ['-Wno-format-truncation', '-Wno-address-of-packed-member']
+warning_disable_cflags = ['-Wno-format-truncation', '-Wno-address-of-packed-member', '-Wno-comma']
 foreach cflag:warning_disable_cflags
     if cc.has_argument(cflag)
         default_cflags += cflag