Fix handling of Dependency's include_type in few places

docs/yaml/objects/dep.yaml

@@ -90,7 +90,7 @@ methods:
     description: |
       Returns a copy of the dependency object, which has changed the value of `include_type`
       to `value`. The `value` argument is optional and
-      defaults to `'preserve'`.
+      defaults to `'system'`.
 
     optargs:
       value:

mesonbuild/build.py

@@ -1348,7 +1348,7 @@ def add_deps(self, deps):
                 # Those parts that are internal.
                 self.process_sourcelist(dep.sources)
                 self.extra_files.extend(f for f in dep.extra_files if f not in self.extra_files)
-                self.add_include_dirs(dep.include_directories, dep.get_include_type())
+                self.add_include_dirs(dep.get_include_dirs())
                 self.objects.extend(dep.objects)
                 self.link_targets.extend(dep.libraries)
                 self.link_whole_targets.extend(dep.whole_libraries)
@@ -1530,17 +1530,12 @@ def add_pch(self, language: str, pchlist: T.List[str]) -> None:
                 raise MesonException(f'File {f} does not exist.')
         self.pch[language] = pchlist
 
-    def add_include_dirs(self, args: T.Sequence['IncludeDirs'], set_is_system: T.Optional[str] = None) -> None:
+    def add_include_dirs(self, args: T.Sequence['IncludeDirs']) -> None:
         ids: T.List['IncludeDirs'] = []
         for a in args:
             if not isinstance(a, IncludeDirs):
                 raise InvalidArguments('Include directory to be added is not an include directory object.')
             ids.append(a)
-        if set_is_system is None:
-            set_is_system = 'preserve'
-        if set_is_system != 'preserve':
-            is_system = set_is_system == 'system'
-            ids = [IncludeDirs(x.get_curdir(), x.get_incdirs(), is_system, x.get_extra_build_dirs()) for x in ids]
         self.include_dirs += ids
 
     def get_aliases(self) -> T.List[T.Tuple[str, str, str]]:

mesonbuild/compilers/mixins/clike.py

@@ -430,10 +430,9 @@ def build_wrapper_args(self, env: 'Environment',
         for d in dependencies:
             # Add compile flags needed by dependencies
             cargs += d.get_compile_args()
-            system_incdir = d.get_include_type() == 'system'
             for i in d.get_include_dirs():
                 for idir in i.to_string_list(env.get_source_dir(), env.get_build_dir()):
-                    cargs.extend(self.get_include_args(idir, system_incdir))
+                    cargs.extend(self.get_include_args(idir, i.is_system))
             if mode is CompileCheckMode.LINK:
                 # Add link flags needed to find dependencies
                 largs += d.get_link_args()

mesonbuild/dependencies/base.py

@@ -304,6 +304,8 @@ def __deepcopy__(self, memo: T.Dict[int, 'InternalDependency']) -> 'InternalDepe
         for k, v in self.__dict__.items():
             if k in {'libraries', 'whole_libraries'}:
                 setattr(result, k, copy.copy(v))
+            elif k == 'include_directories':
+                setattr(result, k, copy.copy(self.get_include_dirs()))
             else:
                 setattr(result, k, copy.deepcopy(v, memo))
         return result
@@ -328,7 +330,7 @@ def get_partial_dependency(self, *, compile_args: bool = False,
         final_whole_libraries = self.whole_libraries.copy() if links else []
         final_sources = self.sources.copy() if sources else []
         final_extra_files = self.extra_files.copy() if extra_files else []
-        final_includes = self.include_directories.copy() if includes else []
+        final_includes = self.get_include_dirs().copy() if includes else []
         final_deps = [d.get_partial_dependency(
             compile_args=compile_args, link_args=link_args, links=links,
             includes=includes, sources=sources) for d in self.ext_deps]
@@ -338,7 +340,12 @@ def get_partial_dependency(self, *, compile_args: bool = False,
             final_sources, final_extra_files, final_deps, self.variables, [], [], [])
 
     def get_include_dirs(self) -> T.List['IncludeDirs']:
-        return self.include_directories
+        from ..build import IncludeDirs
+        ids = self.include_directories
+        if self.include_type != 'preserve':
+            is_system = self.include_type == 'system'
+            ids = [IncludeDirs(x.get_curdir(), x.get_incdirs(), is_system, x.get_extra_build_dirs()) for x in ids]
+        return ids
 
     def get_variable(self, *, cmake: T.Optional[str] = None, pkgconfig: T.Optional[str] = None,
                      configtool: T.Optional[str] = None, internal: T.Optional[str] = None,

mesonbuild/interpreter/interpreter.py

@@ -2958,12 +2958,11 @@ def func_add_project_dependencies(self, node: mparser.FunctionNode, args: T.Tupl
 
         for d in dependencies.get_leaf_external_dependencies(args[0]):
             compile_args = list(d.get_compile_args())
-            system_incdir = d.get_include_type() == 'system'
             for i in d.get_include_dirs():
                 for lang in kwargs['language']:
                     comp = self.coredata.compilers[for_machine][lang]
                     for idir in i.to_string_list(self.environment.get_source_dir(), self.environment.get_build_dir()):
-                        compile_args.extend(comp.get_include_args(idir, system_incdir))
+                        compile_args.extend(comp.get_include_args(idir, i.is_system))
 
             self._add_project_arguments(node, self.build.projects_args[for_machine], compile_args, kwargs)
             self._add_project_arguments(node, self.build.projects_link_args[for_machine], d.get_link_args(), kwargs)

test cases/linuxlike/16 isystem includes/global_include/my_global_lib/my_global.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stdbool.h>
+
+/* Attempt to trigger -Wsizeof-array-div */
+extern int arr1[10];
+const int C0 = sizeof(arr1) / sizeof(short);

test cases/linuxlike/16 isystem includes/local_include1/my_local1_lib/my_local1.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stdbool.h>
+
+/* Attempt to trigger -Wsizeof-array-div */
+extern int arr1[10];
+const int C1 = sizeof(arr1) / sizeof(short);

test cases/linuxlike/16 isystem includes/main.c

@@ -0,0 +1,6 @@
+#include <my_global_lib/my_global.h>
+#include <my_local1_lib/my_local1.h>
+
+int main() {
+    return C0 + C1;
+}

test cases/linuxlike/16 isystem includes/meson.build

@@ -0,0 +1,23 @@
+project('isystem includes', 'c', default_options : 'werror=true')
+
+cc = meson.get_compiler('c')
+
+# Canary warning to check suppression in system headers. Chosen randomly from GCC docs.
+incwarg = '-Wsizeof-array-div'
+
+add_project_dependencies(
+  declare_dependency(
+    include_directories: include_directories('global_include', is_system: true),
+  ),
+  language: ['c'],
+)
+
+local_inc_dep1 = declare_dependency(
+  include_directories: 'local_include1',
+).as_system().partial_dependency(includes : true)
+
+if cc.has_argument(incwarg)
+  executable('main', 'main.c', c_args: incwarg, dependencies: local_inc_dep1)
+else
+  error('MESON_SKIP_TEST compiler does not support emitting canary warning.')
+endif