Replace backend.get_option_for_target() with target.get_option()

That method had nothing specific to the backend, it's purely a Target
method. This allows to cache the OptionOverrideProxy object on the
Target instance instead of creating a new one for each option lookup.

5 files changed, 57 insertions, 67 deletions

diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index b15cfd0..8d3ba88 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -32,7 +32,7 @@ from .. import mesonlib
 from .. import mlog
 from ..compilers import LANGUAGES_USING_LDFLAGS, detect
 from ..mesonlib import (
-    File, MachineChoice, MesonException, OrderedSet, OptionOverrideProxy,
+    File, MachineChoice, MesonException, OrderedSet,
     classify_unity_sources, OptionKey, join_args
 )
 
@@ -310,19 +310,6 @@ class Backend:
     def get_target_filename_abs(self, target: T.Union[build.Target, build.CustomTargetIndex]) -> str:
         return os.path.join(self.environment.get_build_dir(), self.get_target_filename(target))
 
-    def get_options_for_target(self, target: build.BuildTarget) -> OptionOverrideProxy:
-        return OptionOverrideProxy(target.option_overrides,
-                                   self.environment.coredata.options,
-                                   target.subproject)
-
-    def get_option_for_target(self, key: 'OptionKey', target: build.BuildTarget) -> T.Union[str, int, bool, 'WrapMode']:
-        options = self.get_options_for_target(target)
-        # We don't actually have wrapmode here to do an assert, so just do a
-        # cast, we know what's in coredata anyway.
-        # TODO: if it's possible to annotate get_option or validate_option_value
-        # in the future we might be able to remove the cast here
-        return T.cast('T.Union[str, int, bool, WrapMode]', options[key].value)
-
     def get_source_dir_include_args(self, target: build.BuildTarget, compiler: 'Compiler', *, absolute_path: bool = False) -> T.List[str]:
         curdir = target.get_subdir()
         if absolute_path:
@@ -420,7 +407,7 @@ class Backend:
         abs_files: T.List[str] = []
         result: T.List[mesonlib.File] = []
         compsrcs = classify_unity_sources(target.compilers.values(), unity_src)
-        unity_size = self.get_option_for_target(OptionKey('unity_size'), target)
+        unity_size = target.get_option(OptionKey('unity_size'))
         assert isinstance(unity_size, int), 'for mypy'
 
         def init_language_file(suffix: str, unity_file_number: int) -> T.TextIO:
@@ -850,7 +837,7 @@ class Backend:
         if self.is_unity(extobj.target):
             compsrcs = classify_unity_sources(extobj.target.compilers.values(), sources)
             sources = []
-            unity_size = self.get_option_for_target(OptionKey('unity_size'), extobj.target)
+            unity_size = extobj.target.get_option(OptionKey('unity_size'))
             assert isinstance(unity_size, int), 'for mypy'
 
             for comp, srcs in compsrcs.items():
@@ -917,7 +904,7 @@ class Backend:
         # starting from hard-coded defaults followed by build options and so on.
         commands = compiler.compiler_args()
 
-        copt_proxy = self.get_options_for_target(target)
+        copt_proxy = target.get_options()
         # First, the trivial ones that are impossible to override.
         #
         # Add -nostdinc/-nostdinc++ if needed; can't be overridden
@@ -930,27 +917,27 @@ class Backend:
             commands += compiler.get_no_warn_args()
         else:
             # warning_level is a string, but mypy can't determine that
-            commands += compiler.get_warn_args(T.cast('str', self.get_option_for_target(OptionKey('warning_level'), target)))
+            commands += compiler.get_warn_args(T.cast('str', target.get_option(OptionKey('warning_level'))))
         # Add -Werror if werror=true is set in the build options set on the
         # command-line or default_options inside project(). This only sets the
         # action to be done for warnings if/when they are emitted, so it's ok
         # to set it after get_no_warn_args() or get_warn_args().
-        if self.get_option_for_target(OptionKey('werror'), target):
+        if target.get_option(OptionKey('werror')):
             commands += compiler.get_werror_args()
         # Add compile args for c_* or cpp_* build options set on the
         # command-line or default_options inside project().
         commands += compiler.get_option_compile_args(copt_proxy)
 
         # Add buildtype args: optimization level, debugging, etc.
-        buildtype = self.get_option_for_target(OptionKey('buildtype'), target)
+        buildtype = target.get_option(OptionKey('buildtype'))
         assert isinstance(buildtype, str), 'for mypy'
         commands += compiler.get_buildtype_args(buildtype)
 
-        optimization = self.get_option_for_target(OptionKey('optimization'), target)
+        optimization = target.get_option(OptionKey('optimization'))
         assert isinstance(optimization, str), 'for mypy'
         commands += compiler.get_optimization_args(optimization)
 
-        debug = self.get_option_for_target(OptionKey('debug'), target)
+        debug = target.get_option(OptionKey('debug'))
         assert isinstance(debug, bool), 'for mypy'
         commands += compiler.get_debug_args(debug)
 
@@ -1290,7 +1277,7 @@ class Backend:
         return libs
 
     def is_unity(self, target: build.BuildTarget) -> bool:
-        optval = self.get_option_for_target(OptionKey('unity'), target)
+        optval = target.get_option(OptionKey('unity'))
         return optval == 'on' or (optval == 'subprojects' and target.subproject != '')
 
     def get_custom_target_sources(self, target: build.CustomTarget) -> T.List[str]:
@@ -1568,7 +1555,7 @@ class Backend:
                 # TODO: Create GNUStrip/AppleStrip/etc. hierarchy for more
                 #       fine-grained stripping of static archives.
                 can_strip = not isinstance(t, build.StaticLibrary)
-                should_strip = can_strip and self.get_option_for_target(OptionKey('strip'), t)
+                should_strip = can_strip and t.get_option(OptionKey('strip'))
                 assert isinstance(should_strip, bool), 'for mypy'
                 # Install primary build output (library/executable/jar, etc)
                 # Done separately because of strip/aliases/rpath
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 6f560fe..422f6bc 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -1311,7 +1311,7 @@ class NinjaBackend(backends.Backend):
         return args, deps
 
     def generate_cs_target(self, target: build.BuildTarget):
-        buildtype = self.get_option_for_target(OptionKey('buildtype'), target)
+        buildtype = target.get_option(OptionKey('buildtype'))
         fname = target.get_filename()
         outname_rel = os.path.join(self.get_target_dir(target), fname)
         src_list = target.get_sources()
@@ -1320,8 +1320,8 @@ class NinjaBackend(backends.Backend):
         deps = []
         commands = compiler.compiler_args(target.extra_args.get('cs', []))
         commands += compiler.get_buildtype_args(buildtype)
-        commands += compiler.get_optimization_args(self.get_option_for_target(OptionKey('optimization'), target))
-        commands += compiler.get_debug_args(self.get_option_for_target(OptionKey('debug'), target))
+        commands += compiler.get_optimization_args(target.get_option(OptionKey('optimization')))
+        commands += compiler.get_debug_args(target.get_option(OptionKey('debug')))
         if isinstance(target, build.Executable):
             commands.append('-target:exe')
         elif isinstance(target, build.SharedLibrary):
@@ -1362,7 +1362,7 @@ class NinjaBackend(backends.Backend):
 
     def determine_single_java_compile_args(self, target, compiler):
         args = []
-        args += compiler.get_buildtype_args(self.get_option_for_target(OptionKey('buildtype'), target))
+        args += compiler.get_buildtype_args(target.get_option(OptionKey('buildtype')))
         args += self.build.get_global_args(compiler, target.for_machine)
         args += self.build.get_project_args(compiler, target.subproject, target.for_machine)
         args += target.get_java_args()
@@ -1605,19 +1605,17 @@ class NinjaBackend(backends.Backend):
 
         cython = target.compilers['cython']
 
-        opt_proxy = self.get_options_for_target(target)
-
         args: T.List[str] = []
         args += cython.get_always_args()
-        args += cython.get_buildtype_args(self.get_option_for_target(OptionKey('buildtype'), target))
-        args += cython.get_debug_args(self.get_option_for_target(OptionKey('debug'), target))
-        args += cython.get_optimization_args(self.get_option_for_target(OptionKey('optimization'), target))
-        args += cython.get_option_compile_args(opt_proxy)
+        args += cython.get_buildtype_args(target.get_option(OptionKey('buildtype')))
+        args += cython.get_debug_args(target.get_option(OptionKey('debug')))
+        args += cython.get_optimization_args(target.get_option(OptionKey('optimization')))
+        args += cython.get_option_compile_args(target.get_options())
         args += self.build.get_global_args(cython, target.for_machine)
         args += self.build.get_project_args(cython, target.subproject, target.for_machine)
         args += target.get_extra_args('cython')
 
-        ext = opt_proxy[OptionKey('language', machine=target.for_machine, lang='cython')].value
+        ext = target.get_option(OptionKey('language', machine=target.for_machine, lang='cython'))
 
         for src in target.get_sources():
             if src.endswith('.pyx'):
@@ -1693,7 +1691,7 @@ class NinjaBackend(backends.Backend):
         # Rust compiler takes only the main file as input and
         # figures out what other files are needed via import
         # statements and magic.
-        base_proxy = self.get_options_for_target(target)
+        base_proxy = target.get_options()
         args = rustc.compiler_args()
         # Compiler args for compiling this target
         args += compilers.get_base_compile_args(base_proxy, rustc)
@@ -1935,8 +1933,8 @@ class NinjaBackend(backends.Backend):
                 raise InvalidArguments(f'Swift target {target.get_basename()} contains a non-swift source file.')
         os.makedirs(self.get_target_private_dir_abs(target), exist_ok=True)
         compile_args = swiftc.get_compile_only_args()
-        compile_args += swiftc.get_optimization_args(self.get_option_for_target(OptionKey('optimization'), target))
-        compile_args += swiftc.get_debug_args(self.get_option_for_target(OptionKey('debug'), target))
+        compile_args += swiftc.get_optimization_args(target.get_option(OptionKey('optimization')))
+        compile_args += swiftc.get_debug_args(target.get_option(OptionKey('debug')))
         compile_args += swiftc.get_module_args(module_name)
         compile_args += self.build.get_project_args(swiftc, target.subproject, target.for_machine)
         compile_args += self.build.get_global_args(swiftc, target.for_machine)
@@ -2464,7 +2462,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         return linker.get_link_debugfile_args(outname)
 
     def generate_llvm_ir_compile(self, target, src):
-        base_proxy = self.get_options_for_target(target)
+        base_proxy = target.get_options()
         compiler = get_compiler_for_source(target.compilers.values(), src)
         commands = compiler.compiler_args()
         # Compiler args for compiling this target
@@ -2524,7 +2522,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         return commands
 
     def _generate_single_compile_base_args(self, target: build.BuildTarget, compiler: 'Compiler') -> 'CompilerArgs':
-        base_proxy = self.get_options_for_target(target)
+        base_proxy = target.get_options()
         # Create an empty commands list, and start adding arguments from
         # various sources in the order in which they must override each other
         commands = compiler.compiler_args()
@@ -3026,9 +3024,9 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         # options passed on the command-line, in default_options, etc.
         # These have the lowest priority.
         if isinstance(target, build.StaticLibrary):
-            commands += linker.get_base_link_args(self.get_options_for_target(target))
+            commands += linker.get_base_link_args(target.get_options())
         else:
-            commands += compilers.get_base_link_args(self.get_options_for_target(target),
+            commands += compilers.get_base_link_args(target.get_options(),
                                                      linker,
                                                      isinstance(target, build.SharedModule))
         # Add -nostdlib if needed; can't be overridden
@@ -3036,9 +3034,9 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         # Add things like /NOLOGO; usually can't be overridden
         commands += linker.get_linker_always_args()
         # Add buildtype linker args: optimization level, etc.
-        commands += linker.get_buildtype_linker_args(self.get_option_for_target(OptionKey('buildtype'), target))
+        commands += linker.get_buildtype_linker_args(target.get_option(OptionKey('buildtype')))
         # Add /DEBUG and the pdb filename when using MSVC
-        if self.get_option_for_target(OptionKey('debug'), target):
+        if target.get_option(OptionKey('debug')):
             commands += self.get_link_debugfile_args(linker, target, outname)
             debugfile = self.get_link_debugfile_name(linker, target, outname)
             if debugfile is not None:
diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index 3190630..b2ece1c 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -990,7 +990,7 @@ class Vs2010Backend(backends.Backend):
         for l, comp in target.compilers.items():
             if l in file_args:
                 file_args[l] += compilers.get_base_compile_args(
-                    self.get_options_for_target(target), comp)
+                    target.get_options(), comp)
                 file_args[l] += comp.get_option_compile_args(
                     self.environment.coredata.options)
 
@@ -1114,9 +1114,9 @@ class Vs2010Backend(backends.Backend):
         ET.SubElement(clconf, 'PreprocessorDefinitions').text = ';'.join(target_defines)
         ET.SubElement(clconf, 'FunctionLevelLinking').text = 'true'
         # Warning level
-        warning_level = self.get_option_for_target(OptionKey('warning_level'), target)
+        warning_level = target.get_option(OptionKey('warning_level'))
         ET.SubElement(clconf, 'WarningLevel').text = 'Level' + str(1 + int(warning_level))
-        if self.get_option_for_target(OptionKey('werror'), target):
+        if target.get_option(OptionKey('werror')):
             ET.SubElement(clconf, 'TreatWarningAsError').text = 'true'
         # Optimization flags
         o_flags = split_o_flags_args(build_args)
diff --git a/mesonbuild/backend/xcodebackend.py b/mesonbuild/backend/xcodebackend.py
index 1cf1765..72667d7 100644
--- a/mesonbuild/backend/xcodebackend.py
+++ b/mesonbuild/backend/xcodebackend.py
@@ -1503,8 +1503,8 @@ class XCodeBackend(backends.Backend):
                 if compiler is None:
                     continue
                 # Start with warning args
-                warn_args = compiler.get_warn_args(self.get_option_for_target(OptionKey('warning_level'), target))
-                copt_proxy = self.get_options_for_target(target)
+                warn_args = compiler.get_warn_args(target.get_option(OptionKey('warning_level')))
+                copt_proxy = target.get_options()
                 std_args = compiler.get_option_compile_args(copt_proxy)
                 # Add compile args added using add_project_arguments()
                 pargs = self.build.projects_args[target.for_machine].get(target.subproject, {}).get(lang, [])
@@ -1556,9 +1556,9 @@ class XCodeBackend(backends.Backend):
             if target.suffix:
                 suffix = '.' + target.suffix
                 settings_dict.add_item('EXECUTABLE_SUFFIX', suffix)
-            settings_dict.add_item('GCC_GENERATE_DEBUGGING_SYMBOLS', BOOL2XCODEBOOL[self.get_option_for_target(OptionKey('debug'), target)])
+            settings_dict.add_item('GCC_GENERATE_DEBUGGING_SYMBOLS', BOOL2XCODEBOOL[target.get_option(OptionKey('debug'))])
             settings_dict.add_item('GCC_INLINES_ARE_PRIVATE_EXTERN', 'NO')
-            settings_dict.add_item('GCC_OPTIMIZATION_LEVEL', OPT2XCODEOPT[self.get_option_for_target(OptionKey('optimization'), target)])
+            settings_dict.add_item('GCC_OPTIMIZATION_LEVEL', OPT2XCODEOPT[target.get_option(OptionKey('optimization'))])
             if target.has_pch:
                 # Xcode uses GCC_PREFIX_HEADER which only allows one file per target/executable. Precompiling various header files and
                 # applying a particular pch to each source file will require custom scripts (as a build phase) and build flags per each
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 24eeb08..72f5950 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -35,7 +35,7 @@ from .mesonlib import (
     File, MesonException, MachineChoice, PerMachine, OrderedSet, listify,
     extract_as_list, typeslistify, stringlistify, classify_unity_sources,
     get_filenames_templates_dict, substitute_values, has_path_sep,
-    OptionKey, PerMachineDefaultable,
+    OptionKey, PerMachineDefaultable, OptionOverrideProxy,
     MesonBugException
 )
 from .compilers import (
@@ -578,7 +578,7 @@ class Target(HoldableObject):
             '''))
         self.install = False
         self.build_always_stale = False
-        self.option_overrides: T.Dict[OptionKey, str] = {}
+        self.options = OptionOverrideProxy({}, self.environment.coredata.options, self.subproject)
         self.extra_files = []  # type: T.List[File]
         if not hasattr(self, 'typename'):
             raise RuntimeError(f'Target type is not set for target class "{type(self).__name__}". This is a bug')
@@ -682,13 +682,25 @@ class Target(HoldableObject):
             # set, use the value of 'install' if it's enabled.
             self.build_by_default = True
 
-        option_overrides = self.parse_overrides(kwargs)
+        self.set_option_overrides(self.parse_overrides(kwargs))
 
+    def set_option_overrides(self, option_overrides: T.Dict[OptionKey, str]) -> None:
+        self.options.overrides = {}
         for k, v in option_overrides.items():
             if k.lang:
-                self.option_overrides[k.evolve(machine=self.for_machine)] = v
-                continue
-            self.option_overrides[k] = v
+                self.options.overrides[k.evolve(machine=self.for_machine)] = v
+            else:
+                self.options.overrides[k] = v
+
+    def get_options(self) -> OptionOverrideProxy:
+        return self.options
+
+    def get_option(self, key: 'OptionKey') -> T.Union[str, int, bool, 'WrapMode']:
+        # We don't actually have wrapmode here to do an assert, so just do a
+        # cast, we know what's in coredata anyway.
+        # TODO: if it's possible to annotate get_option or validate_option_value
+        # in the future we might be able to remove the cast here
+        return T.cast('T.Union[str, int, bool, WrapMode]', self.options[key].value)
 
     @staticmethod
     def parse_overrides(kwargs: T.Dict[str, T.Any]) -> T.Dict[OptionKey, str]:
@@ -959,10 +971,8 @@ class BuildTarget(Target):
             self.compilers['c'] = self.all_compilers['c']
         if 'cython' in self.compilers:
             key = OptionKey('language', machine=self.for_machine, lang='cython')
-            if key in self.option_overrides:
-                value = self.option_overrides[key]
-            else:
-                value = self.environment.coredata.options[key].value
+            value = self.get_option(key)
+
             try:
                 self.compilers[value] = self.all_compilers[value]
             except KeyError:
@@ -2450,12 +2460,7 @@ class CustomTarget(Target, CommandBase):
         self.install_tag = _install_tag
         self.name = name if name else self.outputs[0]
 
-        if override_options:
-            for k, v in override_options.items():
-                if k.lang:
-                    self.option_overrides_compiler[k.evolve(machine=self.for_machine)] = v
-                else:
-                    self.option_overrides_base[k] = v
+        self.set_option_overrides(override_options or {})
 
         # Whether to use absolute paths for all files on the commandline
         self.absolute_paths = absolute_paths