various low-hanging typing fruit

ninjabackend.py goes down from 322 type errors to 253, mainly by marking
functions as returning None.

1 files changed, 57 insertions, 55 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 65f6ea195..b43b8bbe4 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -45,6 +45,7 @@ if T.TYPE_CHECKING:
     from ..linkers.linkers import DynamicLinker, StaticLinker
     from ..compilers.cs import CsCompiler
     from ..compilers.fortran import FortranCompiler
+    from ..mesonlib import FileOrString
 
     CommandArgOrStr = T.List[T.Union['NinjaCommandArg', str]]
     RUST_EDITIONS = Literal['2015', '2018', '2021']
@@ -333,7 +334,7 @@ class NinjaBuildElement:
         else:
             self.deps.add(dep)
 
-    def add_orderdep(self, dep):
+    def add_orderdep(self, dep) -> None:
         if isinstance(dep, list):
             self.orderdeps.update(dep)
         else:
@@ -351,7 +352,7 @@ class NinjaBuildElement:
         if name == 'DEPFILE':
             self.elems.append((name + '_UNQUOTED', elems))
 
-    def _should_use_rspfile(self):
+    def _should_use_rspfile(self) -> bool:
         # 'phony' is a rule built-in to ninja
         if self.rulename == 'phony':
             return False
@@ -366,14 +367,14 @@ class NinjaBuildElement:
                                          outfilenames,
                                          self.elems) >= rsp_threshold
 
-    def count_rule_references(self):
+    def count_rule_references(self) -> None:
         if self.rulename != 'phony':
             if self._should_use_rspfile():
                 self.rule.rsprefcount += 1
             else:
                 self.rule.refcount += 1
 
-    def write(self, outfile):
+    def write(self, outfile: T.TextIO) -> None:
         if self.output_errors:
             raise MesonException(self.output_errors)
         ins = ' '.join([ninja_quote(i, True) for i in self.infilenames])
@@ -432,7 +433,7 @@ class NinjaBuildElement:
             outfile.write(line)
         outfile.write('\n')
 
-    def check_outputs(self):
+    def check_outputs(self) -> None:
         for n in self.outfilenames:
             if n in self.all_outputs:
                 self.output_errors = f'Multiple producers for Ninja target "{n}". Please rename your targets.'
@@ -713,7 +714,7 @@ class NinjaBackend(backends.Backend):
                 f, indent=4)
 
     # http://clang.llvm.org/docs/JSONCompilationDatabase.html
-    def generate_compdb(self):
+    def generate_compdb(self) -> None:
         rules = []
         # TODO: Rather than an explicit list here, rules could be marked in the
         # rule store as being wanted in compdb
@@ -735,10 +736,10 @@ class NinjaBackend(backends.Backend):
 
     # Get all generated headers. Any source file might need them so
     # we need to add an order dependency to them.
-    def get_generated_headers(self, target):
+    def get_generated_headers(self, target: build.BuildTarget) -> T.List[FileOrString]:
         if hasattr(target, 'cached_generated_headers'):
             return target.cached_generated_headers
-        header_deps = []
+        header_deps: T.List[FileOrString] = []
         # XXX: Why don't we add deps to CustomTarget headers here?
         for genlist in target.get_generated_sources():
             if isinstance(genlist, (build.CustomTarget, build.CustomTargetIndex)):
@@ -798,7 +799,7 @@ class NinjaBackend(backends.Backend):
         return True
 
     def create_target_source_introspection(self, target: build.Target, comp: compilers.Compiler, parameters, sources, generated_sources,
-                                           unity_sources: T.Optional[T.List[mesonlib.FileOrString]] = None):
+                                           unity_sources: T.Optional[T.List[FileOrString]] = None) -> None:
         '''
         Adds the source file introspection information for a language of a target
 
@@ -837,7 +838,7 @@ class NinjaBackend(backends.Backend):
             }
             tgt[id_hash] = src_block
 
-        def compute_path(file: mesonlib.FileOrString) -> str:
+        def compute_path(file: FileOrString) -> str:
             """ Make source files absolute """
             if isinstance(file, File):
                 return file.absolute_path(self.source_dir, self.build_dir)
@@ -848,7 +849,7 @@ class NinjaBackend(backends.Backend):
         if unity_sources:
             src_block['unity_sources'].extend(compute_path(x) for x in unity_sources)
 
-    def create_target_linker_introspection(self, target: build.Target, linker: T.Union[Compiler, StaticLinker], parameters):
+    def create_target_linker_introspection(self, target: build.Target, linker: T.Union[Compiler, StaticLinker], parameters) -> None:
         tid = target.get_id()
         tgt = self.introspection_data[tid]
         lnk_hash = tuple(parameters)
@@ -868,7 +869,7 @@ class NinjaBackend(backends.Backend):
             }
             tgt[lnk_hash] = lnk_block
 
-    def generate_target(self, target):
+    def generate_target(self, target) -> None:
         if isinstance(target, build.BuildTarget):
             os.makedirs(self.get_target_private_dir_abs(target), exist_ok=True)
         if isinstance(target, build.CustomTarget):
@@ -1108,7 +1109,7 @@ class NinjaBackend(backends.Backend):
                                         compiled_sources: T.List[str],
                                         source2object: T.Dict[str, str],
                                         generated_source_files: T.List[mesonlib.File],
-                                        object_deps: T.List['mesonlib.FileOrString']) -> None:
+                                        object_deps: T.List[FileOrString]) -> None:
         if not self.should_use_dyndeps_for_target(target):
             return
         self._uses_dyndeps = True
@@ -1152,12 +1153,12 @@ class NinjaBackend(backends.Backend):
             elif ext.lower() in compilers.lang_suffixes['fortran']:
                 yield source, 'fortran'
 
-    def process_target_dependencies(self, target):
+    def process_target_dependencies(self, target) -> None:
         for t in target.get_dependencies():
             if t.get_id() not in self.processed_targets:
                 self.generate_target(t)
 
-    def custom_target_generator_inputs(self, target):
+    def custom_target_generator_inputs(self, target) -> None:
         for s in target.sources:
             if isinstance(s, build.GeneratedList):
                 self.generate_genlist_for_target(s, target)
@@ -1173,7 +1174,7 @@ class NinjaBackend(backends.Backend):
                 deps.append(os.path.join(self.get_target_dir(i), output))
         return deps
 
-    def generate_custom_target(self, target: build.CustomTarget):
+    def generate_custom_target(self, target: build.CustomTarget) -> None:
         self.custom_target_generator_inputs(target)
         (srcs, ofilenames, cmd) = self.eval_custom_target_command(target)
         deps = self.unwrap_dep_list(target)
@@ -1215,14 +1216,14 @@ class NinjaBackend(backends.Backend):
         self.add_build(elem)
         self.processed_targets.add(target.get_id())
 
-    def build_run_target_name(self, target):
+    def build_run_target_name(self, target) -> str:
         if target.subproject != '':
             subproject_prefix = f'{target.subproject}@@'
         else:
             subproject_prefix = ''
         return f'{subproject_prefix}{target.name}'
 
-    def generate_run_target(self, target: build.RunTarget):
+    def generate_run_target(self, target: build.RunTarget) -> None:
         target_name = self.build_run_target_name(target)
         if not target.command:
             # This is an alias target, it has no command, it just depends on
@@ -1245,7 +1246,8 @@ class NinjaBackend(backends.Backend):
         self.add_build(elem)
         self.processed_targets.add(target.get_id())
 
-    def generate_coverage_command(self, elem: NinjaBuildElement, outputs: T.List[str], gcovr_exe: T.Optional[str], llvm_cov_exe: T.Optional[str]):
+    def generate_coverage_command(self, elem: NinjaBuildElement, outputs: T.List[str],
+                                  gcovr_exe: T.Optional[str], llvm_cov_exe: T.Optional[str]) -> None:
         targets = self.build.get_targets().values()
         use_llvm_cov = False
         exe_args = []
@@ -1272,14 +1274,14 @@ class NinjaBackend(backends.Backend):
                       exe_args +
                       (['--use-llvm-cov'] if use_llvm_cov else []))
 
-    def generate_coverage_rules(self, gcovr_exe: T.Optional[str], gcovr_version: T.Optional[str], llvm_cov_exe: T.Optional[str]):
+    def generate_coverage_rules(self, gcovr_exe: T.Optional[str], gcovr_version: T.Optional[str], llvm_cov_exe: T.Optional[str]) -> None:
         e = self.create_phony_target('coverage', 'CUSTOM_COMMAND', 'PHONY')
         self.generate_coverage_command(e, [], gcovr_exe, llvm_cov_exe)
         e.add_item('description', 'Generates coverage reports')
         self.add_build(e)
         self.generate_coverage_legacy_rules(gcovr_exe, gcovr_version, llvm_cov_exe)
 
-    def generate_coverage_legacy_rules(self, gcovr_exe: T.Optional[str], gcovr_version: T.Optional[str], llvm_cov_exe: T.Optional[str]):
+    def generate_coverage_legacy_rules(self, gcovr_exe: T.Optional[str], gcovr_version: T.Optional[str], llvm_cov_exe: T.Optional[str]) -> None:
         e = self.create_phony_target('coverage-html', 'CUSTOM_COMMAND', 'PHONY')
         self.generate_coverage_command(e, ['--html'], gcovr_exe, llvm_cov_exe)
         e.add_item('description', 'Generates HTML coverage report')
@@ -1302,7 +1304,7 @@ class NinjaBackend(backends.Backend):
                 e.add_item('description', 'Generates Sonarqube XML coverage report')
                 self.add_build(e)
 
-    def generate_install(self):
+    def generate_install(self) -> None:
         self.create_install_data_files()
         elem = self.create_phony_target('install', 'CUSTOM_COMMAND', 'PHONY')
         elem.add_dep('all')
@@ -1311,7 +1313,7 @@ class NinjaBackend(backends.Backend):
         elem.add_item('pool', 'console')
         self.add_build(elem)
 
-    def generate_tests(self):
+    def generate_tests(self) -> None:
         self.serialize_tests()
         cmd = self.environment.get_build_command(True) + ['test', '--no-rebuild']
         if not self.environment.coredata.get_option(OptionKey('stdsplit')):
@@ -1334,7 +1336,7 @@ class NinjaBackend(backends.Backend):
         elem.add_item('pool', 'console')
         self.add_build(elem)
 
-    def generate_rules(self):
+    def generate_rules(self) -> None:
         self.rules = []
         self.ruledict = {}
 
@@ -1409,7 +1411,7 @@ class NinjaBackend(backends.Backend):
         elem = NinjaBuildElement(self.all_outputs, 'PHONY', 'phony', '')
         self.add_build(elem)
 
-    def generate_jar_target(self, target: build.Jar):
+    def generate_jar_target(self, target: build.Jar) -> None:
         fname = target.get_filename()
         outname_rel = os.path.join(self.get_target_dir(target), fname)
         src_list = target.get_sources()
@@ -1463,7 +1465,7 @@ class NinjaBackend(backends.Backend):
         # Create introspection information
         self.create_target_source_introspection(target, compiler, compile_args, src_list, gen_src_list)
 
-    def generate_cs_resource_tasks(self, target):
+    def generate_cs_resource_tasks(self, target) -> T.Tuple[T.List[str], T.List[str]]:
         args = []
         deps = []
         for r in target.resources:
@@ -1484,7 +1486,7 @@ class NinjaBackend(backends.Backend):
             args.append(a)
         return args, deps
 
-    def generate_cs_target(self, target: build.BuildTarget):
+    def generate_cs_target(self, target: build.BuildTarget) -> None:
         fname = target.get_filename()
         outname_rel = os.path.join(self.get_target_dir(target), fname)
         src_list = target.get_sources()
@@ -1529,7 +1531,7 @@ class NinjaBackend(backends.Backend):
         self.generate_generator_list_rules(target)
         self.create_target_source_introspection(target, compiler, commands, rel_srcs, generated_rel_srcs)
 
-    def determine_java_compile_args(self, target, compiler):
+    def determine_java_compile_args(self, target, compiler) -> T.List[str]:
         args = []
         args = self.generate_basic_compiler_args(target, compiler)
         args += target.get_java_args()
@@ -1569,13 +1571,13 @@ class NinjaBackend(backends.Backend):
         self.add_build(element)
         return plain_class_paths
 
-    def generate_java_link(self):
+    def generate_java_link(self) -> None:
         rule = 'java_LINKER'
         command = ['jar', '$ARGS']
         description = 'Creating JAR $out'
         self.add_rule(NinjaRule(rule, command, [], description))
 
-    def determine_dep_vapis(self, target):
+    def determine_dep_vapis(self, target) -> T.List[str]:
         """
         Peek into the sources of BuildTargets we're linking with, and if any of
         them was built with Vala, assume that it also generated a .vapi file of
@@ -1838,7 +1840,7 @@ class NinjaBackend(backends.Backend):
 
         return static_sources, generated_sources, cython_sources
 
-    def _generate_copy_target(self, src: 'mesonlib.FileOrString', output: Path) -> None:
+    def _generate_copy_target(self, src: FileOrString, output: Path) -> None:
         """Create a target to copy a source file from one location to another."""
         if isinstance(src, File):
             instr = src.absolute_path(self.environment.source_dir, self.environment.build_dir)
@@ -2191,7 +2193,7 @@ class NinjaBackend(backends.Backend):
                 others.append(i)
         return srcs, others
 
-    def generate_swift_target(self, target):
+    def generate_swift_target(self, target) -> None:
         module_name = self.target_swift_modulename(target)
         swiftc = target.compilers['swift']
         abssrc = []
@@ -2296,7 +2298,7 @@ class NinjaBackend(backends.Backend):
             options['rspfile_quote_style'] = tool.rsp_file_syntax()
         return options
 
-    def generate_static_link_rules(self):
+    def generate_static_link_rules(self) -> None:
         num_pools = self.environment.coredata.optstore.get_value('backend_max_links')
         if 'java' in self.environment.coredata.compilers.host:
             self.generate_java_link()
@@ -2344,7 +2346,7 @@ class NinjaBackend(backends.Backend):
             options = self._rsp_options(static_linker)
             self.add_rule(NinjaRule(rule, cmdlist, args, description, **options, extra=pool))
 
-    def generate_dynamic_link_rules(self):
+    def generate_dynamic_link_rules(self) -> None:
         num_pools = self.environment.coredata.optstore.get_value('backend_max_links')
         for for_machine in MachineChoice:
             complist = self.environment.coredata.compilers[for_machine]
@@ -2383,7 +2385,7 @@ class NinjaBackend(backends.Backend):
         synstat = 'restat = 1'
         self.add_rule(NinjaRule(symrule, symcmd, [], syndesc, extra=synstat))
 
-    def generate_java_compile_rule(self, compiler):
+    def generate_java_compile_rule(self, compiler) -> None:
         rule = self.compiler_to_rule_name(compiler)
         command = compiler.get_exelist() + ['$ARGS', '$in']
         description = 'Compiling Java sources for $FOR_JAR'
@@ -2398,7 +2400,7 @@ class NinjaBackend(backends.Backend):
                                 rspable=mesonlib.is_windows(),
                                 rspfile_quote_style=compiler.rsp_file_syntax()))
 
-    def generate_vala_compile_rules(self, compiler):
+    def generate_vala_compile_rules(self, compiler) -> None:
         rule = self.compiler_to_rule_name(compiler)
         command = compiler.get_exelist() + ['$ARGS', '$in']
         description = 'Compiling Vala source $in'
@@ -2419,7 +2421,7 @@ class NinjaBackend(backends.Backend):
                                 depfile=depfile,
                                 extra='restat = 1'))
 
-    def generate_rust_compile_rules(self, compiler):
+    def generate_rust_compile_rules(self, compiler) -> None:
         rule = self.compiler_to_rule_name(compiler)
         command = compiler.get_exelist() + ['$ARGS', '$in']
         description = 'Compiling Rust source $in'
@@ -2428,7 +2430,7 @@ class NinjaBackend(backends.Backend):
         self.add_rule(NinjaRule(rule, command, [], description, deps=depstyle,
                                 depfile=depfile))
 
-    def generate_swift_compile_rules(self, compiler):
+    def generate_swift_compile_rules(self, compiler) -> None:
         rule = self.compiler_to_rule_name(compiler)
         full_exe = self.environment.get_build_command() + [
             '--internal',
@@ -2459,7 +2461,7 @@ https://groups.google.com/forum/#!topic/ninja-build/j-2RfBIOd_8
 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         self.add_rule(NinjaRule(rule, cmd, [], 'Dep hack', extra='restat = 1'))
 
-    def generate_llvm_ir_compile_rule(self, compiler):
+    def generate_llvm_ir_compile_rule(self, compiler) -> None:
         if self.created_llvm_ir_rule[compiler.for_machine]:
             return
         rule = self.get_compiler_rule_name('llvm_ir', compiler.for_machine)
@@ -2472,7 +2474,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         self.add_rule(NinjaRule(rule, command, args, description, **options))
         self.created_llvm_ir_rule[compiler.for_machine] = True
 
-    def generate_compile_rule_for(self, langname, compiler):
+    def generate_compile_rule_for(self, langname: str, compiler: Compiler) -> None:
         if langname == 'java':
             self.generate_java_compile_rule(compiler)
             return
@@ -2518,7 +2520,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         self.add_rule(NinjaRule(rule, command, args, description, **options,
                                 deps=deps, depfile=depfile))
 
-    def generate_pch_rule_for(self, langname, compiler):
+    def generate_pch_rule_for(self, langname: str, compiler: Compiler) -> None:
         if langname not in {'c', 'cpp'}:
             return
         rule = self.compiler_to_pch_rule_name(compiler)
@@ -2544,7 +2546,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         self.add_rule(NinjaRule(rule, command, [], description, deps=deps,
                                 depfile=depfile))
 
-    def generate_scanner_rules(self):
+    def generate_scanner_rules(self) -> None:
         rulename = 'depscan'
         if rulename in self.ruledict:
             # Scanning command is the same for native and cross compilation.
@@ -2556,7 +2558,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         rule = NinjaRule(rulename, command, args, description)
         self.add_rule(rule)
 
-    def generate_compile_rules(self):
+    def generate_compile_rules(self) -> None:
         for for_machine in MachineChoice:
             clist = self.environment.coredata.compilers[for_machine]
             for langname, compiler in clist.items():
@@ -2567,7 +2569,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
                 for mode in compiler.get_modes():
                     self.generate_compile_rule_for(langname, mode)
 
-    def generate_generator_list_rules(self, target):
+    def generate_generator_list_rules(self, target) -> None:
         # CustomTargets have already written their rules and
         # CustomTargetIndexes don't actually get generated, so write rules for
         # GeneratedLists here
@@ -2652,7 +2654,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
             elem.add_item('COMMAND', cmdlist)
             self.add_build(elem)
 
-    def scan_fortran_module_outputs(self, target):
+    def scan_fortran_module_outputs(self, target) -> None:
         """
         Find all module and submodule made available in a Fortran code file.
         """
@@ -2794,7 +2796,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
             return linker.get_link_debugfile_args(filename)
         return []
 
-    def generate_llvm_ir_compile(self, target, src: mesonlib.FileOrString):
+    def generate_llvm_ir_compile(self, target, src: FileOrString):
         base_proxy = target.get_options()
         compiler = get_compiler_for_source(target.compilers.values(), src)
         commands = compiler.compiler_args()
@@ -2954,9 +2956,9 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
 
     def generate_single_compile(self, target: build.BuildTarget, src,
                                 is_generated: bool = False, header_deps=None,
-                                order_deps: T.Optional[T.List['mesonlib.FileOrString']] = None,
+                                order_deps: T.Optional[T.List[FileOrString]] = None,
                                 extra_args: T.Optional[T.List[str]] = None,
-                                unity_sources: T.Optional[T.List[mesonlib.FileOrString]] = None,
+                                unity_sources: T.Optional[T.List[FileOrString]] = None,
                                 ) -> T.Tuple[str, str]:
         """
         Compiles C/C++, ObjC/ObjC++, Fortran, and D sources
@@ -3098,7 +3100,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         assert isinstance(rel_src, str)
         return (rel_obj, rel_src.replace('\\', '/'))
 
-    def add_dependency_scanner_entries_to_element(self, target: build.BuildTarget, compiler, element, src):
+    def add_dependency_scanner_entries_to_element(self, target: build.BuildTarget, compiler, element, src) -> None:
         if not self.should_use_dyndeps_for_target(target):
             return
         if isinstance(target, build.CompileTarget):
@@ -3123,7 +3125,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
                 d = os.path.join(self.get_target_private_dir(target), d)
             ninja_element.add_dep(d)
 
-    def has_dir_part(self, fname: mesonlib.FileOrString) -> bool:
+    def has_dir_part(self, fname: FileOrString) -> bool:
         # FIXME FIXME: The usage of this is a terrible and unreliable hack
         if isinstance(fname, File):
             return fname.subdir != ''
@@ -3230,7 +3232,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         targetdir = self.get_target_private_dir(target)
         return os.path.join(targetdir, target.get_filename() + '.symbols')
 
-    def generate_shsym(self, target):
+    def generate_shsym(self, target) -> None:
         target_file = self.get_target_filename(target)
         symname = self.get_target_shsym_filename(target)
         elem = NinjaBuildElement(self.all_outputs, symname, 'SHSYM', target_file)
@@ -3240,7 +3242,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
             elem.add_item('CROSS', '--cross-host=' + self.environment.machines[target.for_machine].system)
         self.add_build(elem)
 
-    def get_import_filename(self, target):
+    def get_import_filename(self, target) -> str:
         return os.path.join(self.get_target_dir(target), target.import_filename)
 
     def get_target_type_link_args(self, target, linker):
@@ -3295,7 +3297,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
                 commands += linker.get_win_subsystem_args(target.win_subsystem)
         return commands
 
-    def get_link_whole_args(self, linker, target):
+    def get_link_whole_args(self, linker: DynamicLinker, target):
         use_custom = False
         if linker.id == 'msvc':
             # Expand our object lists manually if we are on pre-Visual Studio 2015 Update 2
@@ -3565,7 +3567,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
                                        self.environment.get_build_dir())
         return self.get_target_filename(t)
 
-    def generate_shlib_aliases(self, target, outdir):
+    def generate_shlib_aliases(self, target, outdir) -> None:
         for alias, to, tag in target.get_aliases():
             aliasfile = os.path.join(outdir, alias)
             abs_aliasfile = os.path.join(self.environment.get_build_dir(), outdir, alias)
@@ -3605,7 +3607,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         gcda_elem.add_item('description', 'Deleting gcda files')
         self.add_build(gcda_elem)
 
-    def get_user_option_args(self):
+    def get_user_option_args(self) -> T.List[str]:
         cmds = []
         for k, v in self.environment.coredata.optstore.items():
             if self.environment.coredata.optstore.is_project_option(k):