build: move warning flag selection to meson

Meson already knows to test with the positive form of the flag, which
simplifies the test.  Warnings are now tested explicitly for the C++
compiler, instead of hardcoding those that are only available for
the C language.

At this point all compiler flags in QEMU_CFLAGS are global and only
depend on the OS.  No feature tests are performed in configure.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 47 insertions, 21 deletions

diff --git a/meson.build b/meson.build
index 252082c..515e319 100644
--- a/meson.build
+++ b/meson.build
@@ -190,16 +190,8 @@ endif
 # Compiler flags #
 ##################
 
-qemu_common_flags = []
+qemu_common_flags = config_host['QEMU_CFLAGS'].split()
 qemu_cflags = []
-foreach arg : config_host['QEMU_CFLAGS'].split()
-  if arg.startswith('-W')
-    qemu_cflags += arg
-  else
-    qemu_common_flags += arg
-  endif
-endforeach
-qemu_objcflags = config_host['QEMU_OBJCFLAGS'].split()
 qemu_ldflags = []
 
 if get_option('gprof')
@@ -369,20 +361,47 @@ endif
 add_global_arguments(qemu_common_flags, native: false, language: all_languages)
 add_global_link_arguments(qemu_ldflags, native: false, language: all_languages)
 
+# Collect warnings that we want to enable
+
+warn_flags = [
+  '-Wundef',
+  '-Wwrite-strings',
+  '-Wmissing-prototypes',
+  '-Wstrict-prototypes',
+  '-Wredundant-decls',
+  '-Wold-style-declaration',
+  '-Wold-style-definition',
+  '-Wtype-limits',
+  '-Wformat-security',
+  '-Wformat-y2k',
+  '-Winit-self',
+  '-Wignored-qualifiers',
+  '-Wempty-body',
+  '-Wnested-externs',
+  '-Wendif-labels',
+  '-Wexpansion-to-defined',
+  '-Wimplicit-fallthrough=2',
+  '-Wmissing-format-attribute',
+  '-Wno-initializer-overrides',
+  '-Wno-missing-include-dirs',
+  '-Wno-shift-negative-value',
+  '-Wno-string-plus-int',
+  '-Wno-typedef-redefinition',
+  '-Wno-tautological-type-limit-compare',
+  '-Wno-psabi',
+  '-Wno-gnu-variable-sized-type-not-at-end',
+]
+
+if targetos != 'darwin'
+  warn_flags += ['-Wthread-safety']
+endif
+
 # Check that the C++ compiler exists and works with the C compiler.
 link_language = 'c'
 linker = cc
 qemu_cxxflags = []
 if 'cpp' in all_languages
-  add_global_arguments(['-D__STDC_LIMIT_MACROS', '-D__STDC_CONSTANT_MACROS', '-D__STDC_FORMAT_MACROS'],
-                       native: false, language: 'cpp')
-  foreach k: qemu_cflags
-    if k not in ['-Wstrict-prototypes', '-Wmissing-prototypes', '-Wnested-externs',
-                 '-Wold-style-declaration', '-Wold-style-definition', '-Wredundant-decls']
-      qemu_cxxflags += [k]
-    endif
-  endforeach
-
+  qemu_cxxflags = ['-D__STDC_LIMIT_MACROS', '-D__STDC_CONSTANT_MACROS', '-D__STDC_FORMAT_MACROS'] + qemu_cflags
   if cxx.links(files('scripts/main.c'), args: qemu_cflags)
     link_language = 'cpp'
     linker = cxx
@@ -403,8 +422,15 @@ if get_option('optimization') != '0' and targetos == 'linux'
 endif
 
 add_project_arguments(qemu_cflags, native: false, language: 'c')
-add_project_arguments(qemu_cxxflags, native: false, language: 'cpp')
-add_project_arguments(qemu_objcflags, native: false, language: 'objc')
+add_project_arguments(cc.get_supported_arguments(warn_flags), native: false, language: 'c')
+if 'cpp' in all_languages
+  add_project_arguments(qemu_cxxflags, native: false, language: 'cpp')
+  add_project_arguments(cxx.get_supported_arguments(warn_flags), native: false, language: 'cpp')
+endif
+if 'objc' in all_languages
+  # Note sanitizer flags are not applied to Objective-C sources!
+  add_project_arguments(objc.get_supported_arguments(warn_flags), native: false, language: 'objc')
+endif
 if targetos == 'linux'
   add_project_arguments('-isystem', meson.current_source_dir() / 'linux-headers',
                         '-isystem', 'linux-headers',
@@ -4007,7 +4033,7 @@ if 'cpp' in all_languages
   summary_info += {'QEMU_CXXFLAGS':     ' '.join(qemu_common_flags + qemu_cxxflags)}
 endif
 if 'objc' in all_languages
-  summary_info += {'QEMU_OBJCFLAGS':    ' '.join(qemu_common_flags + qemu_objcflags)}
+  summary_info += {'QEMU_OBJCFLAGS':    ' '.join(qemu_common_flags)}
 endif
 summary_info += {'QEMU_LDFLAGS':      ' '.join(qemu_ldflags)}
 summary_info += {'profiler':          get_option('profiler')}