Added "native" kwarg to add_XXX_args. Closes #3669.

10 files changed, 160 insertions, 40 deletions

diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index 3ae740d..6cf7552 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -13,13 +13,22 @@ afterwards](#returned-objects).
   void add_global_arguments(arg1, arg2, ...)
 ```
 
-Adds the positional arguments to the compiler command line for the
-language specified in `language` keyword argument. If a list of
-languages is given, the arguments are added to each of the
-corresponding compiler command lines. Note that there is no way to
-remove an argument set in this way. If you have an argument that is
-only used in a subset of targets, you have to specify it in per-target
-flags.
+Adds the positional arguments to the compiler command line. This
+function has two keyword arguments:
+
+- `language` specifies the language(s) that the arguments should be
+applied to. If a list of languages is given, the arguments are added
+to each of the corresponding compiler command lines. Note that there
+is no way to remove an argument set in this way. If you have an
+argument that is only used in a subset of targets, you have to specify
+it in per-target flags.
+
+- `native` is a boolean specifying whether the arguments should be
+  applied to the native or cross compilation. If `true` the arguments
+  will only be used for native compilations. If `false` the arguments
+  will only be used in cross compilations. If omitted, the flags are
+  added to native compilations if compiling natively and cross
+  compilations (only) when cross compiling. Available since 0.48.0
 
 The arguments are used in all compiler invocations with the exception
 of compile tests, because you might need to run a compile test with
@@ -60,8 +69,9 @@ endif
 Takes one keyword argument, `required`. It defaults to `true`, which
 means that if any of the languages specified is not found, Meson will
 halt. Returns true if all languages specified were found and false
-otherwise. Since *0.47.0*  the value of a [`feature`](Build-options.md#features)
-option can also be passed to the `required` keyword argument.
+otherwise. Since *0.47.0* the value of a
+[`feature`](Build-options.md#features) option can also be passed to
+the `required` keyword argument.
 
 ### add_project_arguments()
 
diff --git a/docs/markdown/snippets/native_args.md b/docs/markdown/snippets/native_args.md
new file mode 100644
index 0000000..54c6de2
--- /dev/null
+++ b/docs/markdown/snippets/native_args.md
@@ -0,0 +1,34 @@
+## Projects args can be set separately for cross and native builds (potentially breaking change)
+
+It has been a longstanding bug (or let's call it a "delayed bug fix")
+that if yo do this:
+
+```meson
+add_project_arguments('-DFOO', language : 'c')
+```
+
+Then the flag is used both in native and cross compilations. This is
+very confusing and almost never what you want. To fix this a new
+keyword `native` has been added to all functions that add arguments,
+namely `add_global_arguments`, `add_global_link_arguments`,
+`add_project_arguments` and `add_project_link_arguments` that behaves
+like the following:
+
+```
+## Added to native builds when compiling natively and to cross
+## compilations when doing cross compiles.
+add_project_arguments(...)
+
+## Added only to native compilations, not used in cross compilations.
+add_project_arguments(..., native : true)
+
+## Added only to cross compilations, not used in native compilations.
+add_project_arguments(..., native : false)
+```
+
+Also remember that cross compilation is a property of each
+target. There can be target that are compiled with the native compiler
+and some which are compiled with the cross compiler.
+
+Unfortunately this change is backwards incompatible and may cause some
+projects to fail building. However this should be very rare in practice.
diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index df72eff..bdc3fad 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -535,10 +535,10 @@ class Backend:
         commands += compiler.get_optimization_args(self.get_option_for_target('optimization', target))
         commands += compiler.get_debug_args(self.get_option_for_target('debug', target))
         # Add compile args added using add_project_arguments()
-        commands += self.build.get_project_args(compiler, target.subproject)
+        commands += self.build.get_project_args(compiler, target.subproject, target.is_cross)
         # Add compile args added using add_global_arguments()
         # These override per-project arguments
-        commands += self.build.get_global_args(compiler)
+        commands += self.build.get_global_args(compiler, target.is_cross)
         if not target.is_cross:
             # Compile args added from the env: CFLAGS/CXXFLAGS, etc. We want these
             # to override all the defaults, but not the per-target compile args.
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 824145a..83bff8a 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -855,8 +855,8 @@ int dummy;
 
         for dep in target.get_external_deps():
             commands.extend_direct(dep.get_link_args())
-        commands += self.build.get_project_args(compiler, target.subproject)
-        commands += self.build.get_global_args(compiler)
+        commands += self.build.get_project_args(compiler, target.subproject, target.is_cross)
+        commands += self.build.get_global_args(compiler, target.is_cross)
 
         elem = NinjaBuildElement(self.all_outputs, outputs, 'cs_COMPILER', rel_srcs)
         elem.add_dep(deps)
@@ -869,8 +869,8 @@ int dummy;
         deps = [os.path.join(self.get_target_dir(l), l.get_filename()) for l in target.link_targets]
         args = []
         args += compiler.get_buildtype_args(self.get_option_for_target('buildtype', target))
-        args += self.build.get_global_args(compiler)
-        args += self.build.get_project_args(compiler, target.subproject)
+        args += self.build.get_global_args(compiler, target.is_cross)
+        args += self.build.get_project_args(compiler, target.subproject, target.is_cross)
         args += target.get_java_args()
         args += compiler.get_output_args(self.get_target_private_dir(target))
         args += target.get_classpath_args()
@@ -1247,8 +1247,8 @@ int dummy;
         compile_args += swiftc.get_optimization_args(self.get_option_for_target('optimization', target))
         compile_args += swiftc.get_debug_args(self.get_option_for_target('debug', target))
         compile_args += swiftc.get_module_args(module_name)
-        compile_args += self.build.get_project_args(swiftc, target.subproject)
-        compile_args += self.build.get_global_args(swiftc)
+        compile_args += self.build.get_project_args(swiftc, target.subproject, target.is_cross)
+        compile_args += self.build.get_global_args(swiftc, target.is_cross)
         for i in reversed(target.get_include_dirs()):
             basedir = i.get_curdir()
             for d in i.get_incdirs():
@@ -1260,8 +1260,8 @@ int dummy;
                 sargs = swiftc.get_include_args(srctreedir)
                 compile_args += sargs
         link_args = swiftc.get_output_args(os.path.join(self.environment.get_build_dir(), self.get_target_filename(target)))
-        link_args += self.build.get_project_link_args(swiftc, target.subproject)
-        link_args += self.build.get_global_link_args(swiftc)
+        link_args += self.build.get_project_link_args(swiftc, target.subproject, target.is_cross)
+        link_args += self.build.get_global_link_args(swiftc, target.is_cross)
         rundir = self.get_target_private_dir(target)
         out_module_name = self.swift_module_file_name(target)
         in_module_files = self.determine_swift_dep_modules(target)
@@ -2395,10 +2395,10 @@ rule FORTRAN_DEP_HACK%s
 
         if not isinstance(target, build.StaticLibrary):
             # Add link args added using add_project_link_arguments()
-            commands += self.build.get_project_link_args(linker, target.subproject)
+            commands += self.build.get_project_link_args(linker, target.subproject, target.is_cross)
             # Add link args added using add_global_link_arguments()
             # These override per-project link arguments
-            commands += self.build.get_global_link_args(linker)
+            commands += self.build.get_global_link_args(linker, target.is_cross)
             if not target.is_cross:
                 # Link args added from the env: LDFLAGS. We want these to
                 # override all the defaults but not the per-target link args.
diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index 4c799d0..2e86ca9 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -998,10 +998,10 @@ class Vs2010Backend(backends.Backend):
                 options = self.environment.coredata.base_options
                 extra_link_args += compiler.get_std_shared_module_link_args(options)
             # Add link args added using add_project_link_arguments()
-            extra_link_args += self.build.get_project_link_args(compiler, target.subproject)
+            extra_link_args += self.build.get_project_link_args(compiler, target.subproject, target.is_cross)
             # Add link args added using add_global_link_arguments()
             # These override per-project link arguments
-            extra_link_args += self.build.get_global_link_args(compiler)
+            extra_link_args += self.build.get_global_link_args(compiler, target.is_cross)
             if not target.is_cross:
                 # Link args added from the env: LDFLAGS. We want these to
                 # override all the defaults but not the per-target link args.
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index c1cb8a8..caaadd8 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -108,6 +108,10 @@ class Build:
         self.projects_args = {}
         self.global_link_args = {}
         self.projects_link_args = {}
+        self.cross_global_args = {}
+        self.cross_projects_args = {}
+        self.cross_global_link_args = {}
+        self.cross_projects_link_args = {}
         self.tests = []
         self.benchmarks = []
         self.headers = []
@@ -168,20 +172,25 @@ class Build:
     def get_install_subdirs(self):
         return self.install_dirs
 
-    def get_global_args(self, compiler):
-        return self.global_args.get(compiler.get_language(), [])
+    def get_global_args(self, compiler, for_cross):
+        d = self.cross_global_args if for_cross else self.global_args
+        return d.get(compiler.get_language(), [])
 
-    def get_project_args(self, compiler, project):
-        args = self.projects_args.get(project)
+    def get_project_args(self, compiler, project, for_cross):
+        d = self.cross_projects_args if for_cross else self.projects_args
+        args = d.get(project)
         if not args:
             return []
         return args.get(compiler.get_language(), [])
 
-    def get_global_link_args(self, compiler):
-        return self.global_link_args.get(compiler.get_language(), [])
+    def get_global_link_args(self, compiler, for_cross):
+        d = self.cross_global_link_args if for_cross else self.global_link_args
+        return d.get(compiler.get_language(), [])
 
-    def get_project_link_args(self, compiler, project):
-        link_args = self.projects_link_args.get(project)
+    def get_project_link_args(self, compiler, project, for_cross):
+        d = self.cross_projects_link_args if for_cross else self.projects_link_args
+
+        link_args = d.get(project)
         if not link_args:
             return []
 
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index 707cf9e..0b4cbce 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -1808,11 +1808,11 @@ known_build_target_kwargs = (
     {'target_type'}
 )
 
-permitted_kwargs = {'add_global_arguments': {'language'},
-                    'add_global_link_arguments': {'language'},
-                    'add_project_link_arguments': {'language'},
+permitted_kwargs = {'add_global_arguments': {'language', 'native'},
+                    'add_global_link_arguments': {'language', 'native'},
                     'add_languages': {'required'},
-                    'add_project_arguments': {'language'},
+                    'add_project_link_arguments': {'language', 'native'},
+                    'add_project_arguments': {'language', 'native'},
                     'add_test_setup': {'exe_wrapper', 'gdb', 'timeout_multiplier', 'env'},
                     'benchmark': {'args', 'env', 'should_fail', 'timeout', 'workdir', 'suite'},
                     'build_target': known_build_target_kwargs,
@@ -3653,25 +3653,45 @@ different subdirectory.
                                                              timeout_multiplier=timeout_multiplier,
                                                              env=env)
 
+    def get_argdict_on_crossness(self, native_dict, cross_dict, kwargs):
+        for_native = kwargs.get('native', not self.environment.is_cross_build())
+        if not isinstance(for_native, bool):
+            raise InterpreterException('Keyword native must be a boolean.')
+        if for_native:
+            return native_dict
+        else:
+            return cross_dict
+
     @permittedKwargs(permitted_kwargs['add_global_arguments'])
     @stringArgs
     def func_add_global_arguments(self, node, args, kwargs):
-        self.add_global_arguments(node, self.build.global_args, args, kwargs)
+        argdict = self.get_argdict_on_crossness(self.build.global_args,
+                                                self.build.cross_global_args,
+                                                kwargs)
+        self.add_global_arguments(node, argdict, args, kwargs)
 
     @permittedKwargs(permitted_kwargs['add_global_link_arguments'])
     @stringArgs
     def func_add_global_link_arguments(self, node, args, kwargs):
-        self.add_global_arguments(node, self.build.global_link_args, args, kwargs)
+        argdict = self.get_argdict_on_crossness(self.build.global_link_args,
+                                                self.build.cross_global_link_args,
+                                                kwargs)
+        self.add_global_arguments(node, argdict, args, kwargs)
 
     @permittedKwargs(permitted_kwargs['add_project_arguments'])
     @stringArgs
     def func_add_project_arguments(self, node, args, kwargs):
-        self.add_project_arguments(node, self.build.projects_args, args, kwargs)
+        argdict = self.get_argdict_on_crossness(self.build.projects_args,
+                                                self.build.cross_projects_args,
+                                                kwargs)
+        self.add_project_arguments(node, argdict, args, kwargs)
 
     @permittedKwargs(permitted_kwargs['add_project_link_arguments'])
     @stringArgs
     def func_add_project_link_arguments(self, node, args, kwargs):
-        self.add_project_arguments(node, self.build.projects_link_args, args, kwargs)
+        argdict = self.get_argdict_on_crossness(self.build.projects_link_args,
+                                                self.build.cross_projects_link_args, kwargs)
+        self.add_project_arguments(node, argdict, args, kwargs)
 
     def add_global_arguments(self, node, argsdict, args, kwargs):
         if self.is_subproject():
diff --git a/run_unittests.py b/run_unittests.py
index 513a11f..f4c50a5 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -664,6 +664,8 @@ class DataTests(unittest.TestCase):
         self.assertTrue(snippet_dir.is_dir())
         for f in snippet_dir.glob('*'):
             self.assertTrue(f.is_file())
+            if f.parts[-1].endswith('~'):
+                continue
             if f.suffix == '.md':
                 with f.open() as snippet:
                     for line in snippet:
diff --git a/test cases/common/21 global arg/meson.build b/test cases/common/21 global arg/meson.build
index d7fd428..699dae6 100644
--- a/test cases/common/21 global arg/meson.build
+++ b/test cases/common/21 global arg/meson.build
@@ -3,9 +3,18 @@ project('global arg test', 'cpp', 'c')
 add_global_arguments('-DMYTHING', language : 'c')
 add_global_arguments('-DMYCPPTHING', language : 'cpp')
 
+add_global_arguments('-DGLOBAL_NATIVE', language : 'c', native : true)
+add_global_arguments('-DGLOBAL_CROSS', language : 'c', native : false)
+
+if meson.is_cross_build()
+  c_args = ['-DARG_CROSS']
+else
+  c_args = ['-DARG_NATIVE']
+endif
+
 add_global_arguments('-DMYCANDCPPTHING', language: ['c', 'cpp'])
 
-exe1 = executable('prog', 'prog.c')
+exe1 = executable('prog', 'prog.c', c_args : c_args)
 exe2 = executable('prog2', 'prog.cc')
 
 test('prog1', exe1)
diff --git a/test cases/common/21 global arg/prog.c b/test cases/common/21 global arg/prog.c
index ace5a0a..fb014c7 100644
--- a/test cases/common/21 global arg/prog.c
+++ b/test cases/common/21 global arg/prog.c
@@ -10,6 +10,42 @@
 #error "Global argument not set"
 #endif
 
+#ifdef GLOBAL_NATIVE
+  #ifndef ARG_NATIVE
+    #error "Global is native but arg_native is not set."
+  #endif
+
+  #ifdef GLOBAL_CROSS
+    #error "Both global native and global cross set."
+  #endif
+#else
+  #ifndef GLOBAL_CROSS
+    #error "Neither global_cross nor glogal_native is set."
+  #endif
+
+  #ifndef ARG_CROSS
+    #error "Global is cross but arg_cross is not set."
+  #endif
+
+  #ifdef ARG_NATIVE
+    #error "Global is cross but arg_native is set."
+  #endif
+#endif
+
+#ifdef GLOBAL_CROSS
+  #ifndef ARG_CROSS
+    #error "Global is cross but arg_cross is not set."
+  #endif
+#else
+  #ifdef ARG_CROSS
+    #error "Global is cross but arg_native is set."
+  #endif
+
+  #ifdef ARG_CROSS
+    #error "Global is native but arg cross is set."
+  #endif
+#endif
+
 int main(int argc, char **argv) {
     return 0;
 }