Can tag include directories as system dirs to reduce compiler warning noise. Closes #345.

backends.py

@@ -201,7 +201,7 @@ class Backend():
     def get_pch_include_args(self, compiler, target):
         args = []
         pchpath = self.get_target_private_dir(target)
-        includeargs = compiler.get_include_args(pchpath)
+        includeargs = compiler.get_include_args(pchpath, False)
         for lang in ['c', 'cpp']:
             p = target.get_pch(lang)
             if len(p) == 0:
@@ -238,7 +238,7 @@ class Backend():
         if compiler.language == 'fortran':
             for lt in target.link_targets:
                 priv_dir = os.path.join(self.get_target_dir(lt), lt.get_basename() + lt.type_suffix())
-                incflag = compiler.get_include_args(priv_dir)
+                incflag = compiler.get_include_args(priv_dir, False)
                 commands += incflag
         return commands
 

build.py

@@ -148,9 +148,10 @@ class Build:
         return self.global_args.get(compiler.get_language(), [])
 
 class IncludeDirs():
-    def __init__(self, curdir, dirs, extra_build_dirs=None):
+    def __init__(self, curdir, dirs, is_system, extra_build_dirs=None):
         self.curdir = curdir
         self.incdirs = dirs
+        self.is_system = is_system
         # Interpreter has validated that all given directories
         # actually exist.
         if extra_build_dirs is None:

compilers.py

@@ -264,9 +264,11 @@ class CCompiler(Compiler):
     def get_std_exe_link_args(self):
         return []
 
-    def get_include_args(self, path):
+    def get_include_args(self, path, is_system):
         if path == '':
             path = '.'
+        if is_system:
+            return ['-isystem', path]
         return ['-I' + path]
 
     def get_std_shared_lib_link_args(self):
@@ -1174,6 +1176,12 @@ class VisualStudioCCompiler(CCompiler):
             result.append(i)
         return result
 
+    def get_include_args(self, path, is_system):
+        if path == '':
+            path = '.'
+        # msvc does not have a concept of system header dirs.
+        return ['-I' + path]
+
 class VisualStudioCPPCompiler(VisualStudioCCompiler):
     def __init__(self, exelist, version, is_cross, exe_wrap):
         VisualStudioCCompiler.__init__(self, exelist, version, is_cross, exe_wrap)
@@ -1588,7 +1596,7 @@ end program prog
             return True
         return False
 
-    def get_include_args(self, path):
+    def get_include_args(self, path, is_system):
         return ['-I' + path]
 
     def get_module_outdir_args(self, path):

interpreter.py

@@ -475,7 +475,7 @@ class BuildTargetHolder(InterpreterObject):
         return self.held_object.is_cross()
 
     def private_dir_include_method(self, args, kwargs):
-        return IncludeDirsHolder(build.IncludeDirs('', [],
+        return IncludeDirsHolder(build.IncludeDirs('', [], False,
                     [self.interpreter.backend.get_target_private_dir(self.held_object)]))
 
     def outdir_method(self, args, kwargs):
@@ -1821,14 +1821,16 @@ class Interpreter():
         return mesonlib.File.from_built_file(self.subdir, output)
 
     @stringArgs
-    @noKwargs
     def func_include_directories(self, node, args, kwargs):
         absbase = os.path.join(self.environment.get_source_dir(), self.subdir)
         for a in args:
             absdir = os.path.join(absbase, a)
             if not os.path.isdir(absdir):
                 raise InvalidArguments('Include dir %s does not exist.' % a)
-        i = IncludeDirsHolder(build.IncludeDirs(self.subdir, args))
+        is_system = kwargs.get('is_system', False)
+        if not isinstance(is_system, bool):
+            raise InvalidArguments('Is_system must be boolean.')
+        i = IncludeDirsHolder(build.IncludeDirs(self.subdir, args, is_system))
         return i
 
     @stringArgs

ninjabackend.py

@@ -1429,13 +1429,13 @@ rule FORTRAN_DEP_HACK
         extra_orderdeps = []
         compiler = self.get_compiler_for_source(src)
         commands = self.generate_basic_compiler_args(target, compiler)
-        commands += compiler.get_include_args(self.get_target_private_dir(target))
+        commands += compiler.get_include_args(self.get_target_private_dir(target), False)
         curdir = target.get_subdir()
         tmppath = os.path.normpath(os.path.join(self.build_to_src, curdir))
-        commands += compiler.get_include_args(tmppath)
+        commands += compiler.get_include_args(tmppath, False)
         if curdir ==  '':
             curdir = '.'
-        commands += compiler.get_include_args(curdir)
+        commands += compiler.get_include_args(curdir, False)
         for d in target.external_deps:
             if d.need_threads():
                 commands += compiler.thread_flags()
@@ -1482,12 +1482,12 @@ rule FORTRAN_DEP_HACK
             for d in i.get_incdirs():
                 expdir =  os.path.join(basedir, d)
                 srctreedir = os.path.join(self.build_to_src, expdir)
-                bargs = compiler.get_include_args(expdir)
-                sargs = compiler.get_include_args(srctreedir)
+                bargs = compiler.get_include_args(expdir, i.is_system)
+                sargs = compiler.get_include_args(srctreedir, i.is_system)
                 commands += bargs
                 commands += sargs
             for d in i.get_extra_build_dirs():
-                commands += compiler.get_include_args(d)
+                commands += compiler.get_include_args(d, i.is_system)
         custom_target_include_dirs = []
         for i in target.generated:
             if isinstance(i, build.CustomTarget):
@@ -1495,7 +1495,7 @@ rule FORTRAN_DEP_HACK
                 if idir not in custom_target_include_dirs:
                     custom_target_include_dirs.append(idir)
         for i in custom_target_include_dirs:
-            commands+= compiler.get_include_args(i)
+            commands+= compiler.get_include_args(i, False)
         if self.environment.coredata.get_builtin_option('use_pch'):
             commands += self.get_pch_include_args(compiler, target)
         crstr = ''