add is_system kwarg to dependency

Also adds the is_system and as_system methods to
the dependency holder.

mesonbuild/dependencies/base.py

@@ -104,6 +104,14 @@ class Dependency:
 
         return methods
 
+    @classmethod
+    def  _process_is_system_kw(cls, kwargs):
+        if 'is_system' not in kwargs:
+            return False
+        if not isinstance(kwargs['is_system'], bool):
+            raise DependencyException('The is_system kwarg must be a boolean type')
+        return kwargs['is_system']
+
     def __init__(self, type_name, kwargs):
         self.name = "null"
         self.version = None
@@ -117,6 +125,7 @@ class Dependency:
         self.raw_link_args = None
         self.sources = []
         self.methods = self._process_method_kw(kwargs)
+        self.is_system = self._process_is_system_kw(kwargs)
         self.ext_deps = []  # type: List[Dependency]
 
     def __repr__(self):
@@ -124,7 +133,21 @@ class Dependency:
         return s.format(self.__class__.__name__, self.name, self.is_found)
 
     def get_compile_args(self):
-        return self.compile_args
+        if not self.is_system:
+            return self.compile_args
+
+        system_args = []
+        for i in self.compile_args:
+            if i.startswith('-I') or i.startswith('/I'):
+                # -isystem and -idirafter, both mark directories as system
+                # directories. However, both affect the search oder, which
+                # can lead to nasty bugs with -isystem:
+                # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70129
+                system_args += ['-idirafter' + i[2:]]
+            else:
+                system_args += [i]
+
+        return system_args
 
     def get_link_args(self, raw=False):
         if raw and self.raw_link_args is not None:
@@ -152,6 +175,9 @@ class Dependency:
         else:
             return 'unknown'
 
+    def get_is_system(self) -> bool:
+        return self.is_system
+
     def get_exe_args(self, compiler):
         return []
 

mesonbuild/interpreter.py

@@ -34,13 +34,12 @@ from .interpreterbase import ObjectHolder
 from .modules import ModuleReturnValue
 from .cmake import CMakeInterpreter
 
-from pathlib import Path
+from pathlib import Path, PurePath
 import os, shutil, uuid
-import re, shlex
+import re, shlex, copy
 import subprocess
 from collections import namedtuple
 from itertools import chain
-from pathlib import PurePath
 import functools
 from typing import Sequence, List, Union, Optional, Dict, Any
 
@@ -413,6 +412,8 @@ class DependencyHolder(InterpreterObject, ObjectHolder):
                              'get_configtool_variable': self.configtool_method,
                              'get_variable': self.variable_method,
                              'partial_dependency': self.partial_dependency_method,
+                             'is_system': self.is_system_method,
+                             'as_system': self.as_system_method,
                              })
 
     def found(self):
@@ -474,6 +475,27 @@ class DependencyHolder(InterpreterObject, ObjectHolder):
     def variable_method(self, args, kwargs):
         return self.held_object.get_variable(**kwargs)
 
+    @FeatureNew('dep.is_system', '0.52.0')
+    @noPosargs
+    @permittedKwargs({})
+    def is_system_method(self, args, kwargs):
+        return self.held_object.get_is_system()
+
+    @FeatureNew('dep.as_system', '0.52.0')
+    @permittedKwargs({})
+    def as_system_method(self, args, kwargs):
+        args = listify(args)
+        new_is_system = True
+        if len(args) > 1:
+            raise InterpreterException('as_system takes only one optional value')
+        if len(args) == 1:
+            if not isinstance(args[0], bool):
+                raise InterpreterException('as_system takes only a boolean value')
+            new_is_system = args[0]
+        new_dep = copy.deepcopy(self.held_object)
+        new_dep.is_system = new_is_system
+        return DependencyHolder(new_dep, self.subproject)
+
 class ExternalProgramHolder(InterpreterObject, ObjectHolder):
     def __init__(self, ep):
         InterpreterObject.__init__(self)
@@ -1998,6 +2020,7 @@ permitted_kwargs = {'add_global_arguments': {'language', 'native'},
                                    'version',
                                    'private_headers',
                                    'cmake_args',
+                                   'is_system',
                                    },
                     'declare_dependency': {'include_directories',
                                            'link_with',
@@ -3049,6 +3072,7 @@ external dependencies (including libraries) must go to "dependencies".''')
         elif name == 'openmp':
             FeatureNew('OpenMP Dependency', '0.46.0').use(self.subproject)
 
+    @FeatureNewKwargs('dependency', '0.52.0', ['is_system'])
     @FeatureNewKwargs('dependency', '0.50.0', ['not_found_message', 'cmake_module_path', 'cmake_args'])
     @FeatureNewKwargs('dependency', '0.49.0', ['disabler'])
     @FeatureNewKwargs('dependency', '0.40.0', ['method'])