[gtk-vnc] meson: only set extra warning flags when warninglevel==2

[Daniel P. Berrange <dberrange src gnome org>]

commit 731146cfefd9de998b3d50cde6a589bb82418ca1
Author: Daniel P. Berrangé <dan berrange com>
Date:   Wed Mar 31 14:24:49 2021 +0100

    meson: only set extra warning flags when warninglevel==2
    
    This makes us respect the meson warning level and avoids warnings from
    meson about reinventing its warninglevel feature.
    
    Signed-off-by: Daniel P. Berrangé <berrange redhat com>

 meson.build | 48 +++++++++++++++++++++++-------------------------
 1 file changed, 23 insertions(+), 25 deletions(-)
---
diff --git a/meson.build b/meson.build
index ef8bc66..b3fd98b 100644
--- a/meson.build
+++ b/meson.build
@@ -5,7 +5,7 @@ project(
   default_options: [
     'buildtype=debugoptimized',
     'c_std=gnu99',
-    'warning_level=1',
+    'warning_level=2',
   ],
   meson_version: '>= 0.49.0'
 )
@@ -124,10 +124,8 @@ gnome = import('gnome')
 i18n = import('i18n')
 
 check_cflags = [
-  '-W',
   '-Waddress',
   '-Waggressive-loop-optimizations',
-  '-Wall',
   '-Warray-bounds',
   '-Wattributes',
   '-Wbuiltin-macro-redefined',
@@ -145,7 +143,6 @@ check_cflags = [
   '-Wempty-body',
   '-Wendif-labels',
   '-Wenum-compare',
-  '-Wextra',
   '-Wformat-contains-nul',
   '-Wformat-extra-args',
   '-Wformat-security',
@@ -241,31 +238,32 @@ check_cflags = [
   '-Wno-suggest-attribute=const',
 ]
 
-cflags = []
-foreach cflag: check_cflags
-  if cc.has_argument(cflag)
-    cflags += [cflag]
+if get_option('warning_level') == '2'
+  cflags = []
+  foreach cflag: check_cflags
+    if cc.has_argument(cflag)
+      cflags += [cflag]
+    endif
+  endforeach
+
+  if host_machine.system() in [ 'linux', 'freebsd', 'windows' ]
+    # we prefer -fstack-protector-strong but fallback to -fstack-protector-all
+    fstack_cflags = cc.first_supported_argument([
+      '-fstack-protector-strong',
+      '-fstack-protector-all',
+    ])
+    cflags += fstack_cflags
+
+    # When building with mingw using -fstack-protector requires libssp library
+    # which is included by using -fstack-protector with linker.
+    if fstack_cflags.length() == 1 and host_machine.system() == 'windows'
+      add_project_link_arguments(fstack_cflags, language: 'c')
+    endif
   endif
-endforeach
-
 
-if host_machine.system() in [ 'linux', 'freebsd', 'windows' ]
-  # we prefer -fstack-protector-strong but fallback to -fstack-protector-all
-  fstack_cflags = cc.first_supported_argument([
-    '-fstack-protector-strong',
-    '-fstack-protector-all',
-  ])
-  cflags += fstack_cflags
-
-  # When building with mingw using -fstack-protector requires libssp library
-  # which is included by using -fstack-protector with linker.
-  if fstack_cflags.length() == 1 and host_machine.system() == 'windows'
-    add_project_link_arguments(fstack_cflags, language: 'c')
-  endif
+  add_project_arguments(cflags, language: 'c')
 endif
 
-add_project_arguments(cflags, language: 'c')
-
 gtk_vnc_prefix = get_option('prefix')
 gtk_vnc_bindir = join_paths(gtk_vnc_prefix, get_option('bindir'))
 gtk_vnc_libdir = join_paths(gtk_vnc_prefix, get_option('libdir'))