typing: fully annotate scripts

22 files changed, 182 insertions, 152 deletions

diff --git a/mesonbuild/scripts/__init__.py b/mesonbuild/scripts/__init__.py
index af6bedc..2edbe88 100644
--- a/mesonbuild/scripts/__init__.py
+++ b/mesonbuild/scripts/__init__.py
@@ -12,7 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-def destdir_join(d1, d2):
+# TODO: consider switching to pathlib for this
+def destdir_join(d1: str, d2: str) -> str:
     # c:\destdir + c:\prefix must produce c:\destdir\prefix
     if len(d1) > 1 and d1[1] == ':' \
             and len(d2) > 1 and d2[1] == ':':
diff --git a/mesonbuild/scripts/clangformat.py b/mesonbuild/scripts/clangformat.py
index 4b441de..19ea5ec 100644
--- a/mesonbuild/scripts/clangformat.py
+++ b/mesonbuild/scripts/clangformat.py
@@ -18,8 +18,9 @@ from concurrent.futures import ThreadPoolExecutor
 
 from ..environment import detect_clangformat
 from ..compilers import lang_suffixes
+import typing as T
 
-def clangformat(exelist, srcdir_name, builddir_name):
+def clangformat(exelist: T.List[str], srcdir_name: str, builddir_name: str) -> int:
     srcdir = pathlib.Path(srcdir_name)
     suffixes = set(lang_suffixes['c']).union(set(lang_suffixes['cpp']))
     suffixes.add('h')
@@ -33,7 +34,7 @@ def clangformat(exelist, srcdir_name, builddir_name):
         [x.result() for x in futures]
     return 0
 
-def run(args):
+def run(args: T.List[str]) -> int:
     srcdir_name = args[0]
     builddir_name = args[1]
 
diff --git a/mesonbuild/scripts/clangtidy.py b/mesonbuild/scripts/clangtidy.py
index 0452086..11174ea 100644
--- a/mesonbuild/scripts/clangtidy.py
+++ b/mesonbuild/scripts/clangtidy.py
@@ -16,10 +16,11 @@ import pathlib
 import subprocess
 import shutil
 from concurrent.futures import ThreadPoolExecutor
+import typing as T
 
 from ..compilers import lang_suffixes
 
-def manual_clangformat(srcdir_name, builddir_name):
+def manual_clangformat(srcdir_name: str, builddir_name: str) -> int:
     srcdir = pathlib.Path(srcdir_name)
     suffixes = set(lang_suffixes['c']).union(set(lang_suffixes['cpp']))
     suffixes.add('h')
@@ -34,7 +35,7 @@ def manual_clangformat(srcdir_name, builddir_name):
         [max(returncode, x.result().returncode) for x in futures]
     return returncode
 
-def clangformat(srcdir_name, builddir_name):
+def clangformat(srcdir_name: str, builddir_name: str) -> int:
     run_clang_tidy = None
     for rct in ('run-clang-tidy', 'run-clang-tidy.py'):
         if shutil.which(rct):
@@ -45,8 +46,9 @@ def clangformat(srcdir_name, builddir_name):
     else:
         print('Could not find run-clang-tidy, running checks manually.')
         manual_clangformat(srcdir_name, builddir_name)
+    return 0
 
-def run(args):
+def run(args: T.List[str]) -> int:
     srcdir_name = args[0]
     builddir_name = args[1]
     return clangformat(srcdir_name, builddir_name)
diff --git a/mesonbuild/scripts/cleantrees.py b/mesonbuild/scripts/cleantrees.py
index 0af8dd0..6feb9a7 100644
--- a/mesonbuild/scripts/cleantrees.py
+++ b/mesonbuild/scripts/cleantrees.py
@@ -16,8 +16,9 @@ import os
 import sys
 import shutil
 import pickle
+import typing as T
 
-def rmtrees(build_dir, trees):
+def rmtrees(build_dir: str, trees: T.List[str]) -> None:
     for t in trees:
         # Never delete trees outside of the builddir
         if os.path.isabs(t):
@@ -28,7 +29,7 @@ def rmtrees(build_dir, trees):
         if os.path.isdir(bt):
             shutil.rmtree(bt, ignore_errors=True)
 
-def run(args):
+def run(args: T.List[str]) -> int:
     if len(args) != 1:
         print('Cleaner script for Meson. Do not run on your own please.')
         print('cleantrees.py <data-file>')
diff --git a/mesonbuild/scripts/cmake_run_ctgt.py b/mesonbuild/scripts/cmake_run_ctgt.py
index 5c0b31f..2d9aeca 100755
--- a/mesonbuild/scripts/cmake_run_ctgt.py
+++ b/mesonbuild/scripts/cmake_run_ctgt.py
@@ -3,12 +3,12 @@
 import argparse
 import subprocess
 import shutil
-import os
 import sys
 from pathlib import Path
+import typing as T
 
-def run(argsv):
-    commands = [[]]
+def run(argsv: T.List[str]) -> int:
+    commands = [[]]  # type: T.List[T.List[str]]
     SEPARATOR = ';;;'
 
     # Generate CMD parameters
@@ -20,13 +20,14 @@ def run(argsv):
 
     # Parse
     args = parser.parse_args(argsv)
+    directory = Path(args.directory)
 
     dummy_target = None
     if len(args.outputs) == 1 and len(args.original_outputs) == 0:
-        dummy_target = args.outputs[0]
+        dummy_target = Path(args.outputs[0])
     elif len(args.outputs) != len(args.original_outputs):
         print('Length of output list and original output list differ')
-        sys.exit(1)
+        return 1
 
     for i in args.commands:
         if i == SEPARATOR:
@@ -62,39 +63,40 @@ def run(argsv):
                 cmd += [j]
 
         try:
-            os.makedirs(args.directory, exist_ok=True)
+            directory.mkdir(parents=True, exist_ok=True)
 
-            res = subprocess.run(cmd, stdout=stdout, stderr=stderr, cwd=args.directory, check=True)
+            res = subprocess.run(cmd, stdout=stdout, stderr=stderr, cwd=str(directory), check=True)
             if capture_file:
-                out_file = Path(args.directory) / capture_file
+                out_file = directory / capture_file
                 out_file.write_bytes(res.stdout)
         except subprocess.CalledProcessError:
-            sys.exit(1)
+            return 1
 
     if dummy_target:
-        with open(dummy_target, 'a'):
-            os.utime(dummy_target, None)
-        sys.exit(0)
+        dummy_target.touch()
+        return 0
 
     # Copy outputs
-    zipped_outputs = zip(args.outputs, args.original_outputs)
+    zipped_outputs = zip([Path(x) for x in args.outputs], [Path(x) for x in args.original_outputs])
     for expected, generated in zipped_outputs:
         do_copy = False
-        if not os.path.exists(expected):
-            if not os.path.exists(generated):
+        if not expected.exists():
+            if not generated.exists():
                 print('Unable to find generated file. This can cause the build to fail:')
                 print(generated)
                 do_copy = False
             else:
                 do_copy = True
-        elif os.path.exists(generated):
-            if os.path.getmtime(generated) > os.path.getmtime(expected):
+        elif generated.exists():
+            if generated.stat().st_mtime > expected.stat().st_mtime:
                 do_copy = True
 
         if do_copy:
-            if os.path.exists(expected):
-                os.remove(expected)
-            shutil.copyfile(generated, expected)
+            if expected.exists():
+                expected.unlink()
+            shutil.copyfile(str(generated), str(expected))
+
+    return 0
 
 if __name__ == '__main__':
-    sys.run(sys.argv[1:])
+    sys.exit(run(sys.argv[1:]))
diff --git a/mesonbuild/scripts/commandrunner.py b/mesonbuild/scripts/commandrunner.py
index 22da417..aeeaa3b 100644
--- a/mesonbuild/scripts/commandrunner.py
+++ b/mesonbuild/scripts/commandrunner.py
@@ -17,8 +17,9 @@ what to run, sets up the environment and executes the command."""
 
 import sys, os, subprocess, shutil, shlex
 import re
+import typing as T
 
-def run_command(source_dir, build_dir, subdir, meson_command, command, arguments):
+def run_command(source_dir: str, build_dir: str, subdir: str, meson_command: T.List[str], command: str, arguments: T.List[str]) -> subprocess.Popen:
     env = {'MESON_SOURCE_ROOT': source_dir,
            'MESON_BUILD_ROOT': build_dir,
            'MESON_SUBDIR': subdir,
@@ -50,24 +51,24 @@ def run_command(source_dir, build_dir, subdir, meson_command, command, arguments
         print('Could not execute command "{}": {}'.format(command, err))
         sys.exit(1)
 
-def is_python_command(cmdname):
+def is_python_command(cmdname: str) -> bool:
     end_py_regex = r'python(3|3\.\d+)?(\.exe)?$'
     return re.search(end_py_regex, cmdname) is not None
 
-def run(args):
+def run(args: T.List[str]) -> int:
     if len(args) < 4:
         print('commandrunner.py <source dir> <build dir> <subdir> <command> [arguments]')
         return 1
     src_dir = args[0]
     build_dir = args[1]
     subdir = args[2]
-    meson_command = args[3]
-    if is_python_command(meson_command):
-        meson_command = [meson_command, args[4]]
+    meson_bin = args[3]
+    if is_python_command(meson_bin):
+        meson_command = [meson_bin, args[4]]
         command = args[5]
         arguments = args[6:]
     else:
-        meson_command = [meson_command]
+        meson_command = [meson_bin]
         command = args[4]
         arguments = args[5:]
     pc = run_command(src_dir, build_dir, subdir, meson_command, command, arguments)
diff --git a/mesonbuild/scripts/coverage.py b/mesonbuild/scripts/coverage.py
index 7231972..80e9052 100644
--- a/mesonbuild/scripts/coverage.py
+++ b/mesonbuild/scripts/coverage.py
@@ -15,8 +15,9 @@
 from mesonbuild import environment, mesonlib
 
 import argparse, sys, os, subprocess, pathlib, stat
+import typing as T
 
-def coverage(outputs, source_root, subproject_root, build_root, log_dir, use_llvm_cov):
+def coverage(outputs: T.List[str], source_root: str, subproject_root: str, build_root: str, log_dir: str, use_llvm_cov: bool) -> int:
     outfiles = []
     exitcode = 0
 
@@ -146,7 +147,7 @@ def coverage(outputs, source_root, subproject_root, build_root, log_dir, use_llv
 
     return exitcode
 
-def run(args):
+def run(args: T.List[str]) -> int:
     if not os.path.isfile('build.ninja'):
         print('Coverage currently only works with the Ninja backend.')
         return 1
diff --git a/mesonbuild/scripts/delwithsuffix.py b/mesonbuild/scripts/delwithsuffix.py
index 0d410ae..873db0d 100644
--- a/mesonbuild/scripts/delwithsuffix.py
+++ b/mesonbuild/scripts/delwithsuffix.py
@@ -13,8 +13,9 @@
 # limitations under the License.
 
 import os, sys
+import typing as T
 
-def run(args):
+def run(args: T.List[str]) -> int:
     if len(args) != 2:
         print('delwithsuffix.py <root of subdir to process> <suffix to delete>')
         sys.exit(1)
diff --git a/mesonbuild/scripts/depfixer.py b/mesonbuild/scripts/depfixer.py
index f927693..a64caca 100644
--- a/mesonbuild/scripts/depfixer.py
+++ b/mesonbuild/scripts/depfixer.py
@@ -15,6 +15,7 @@
 
 import sys, struct
 import shutil, subprocess
+import typing as T
 
 from ..mesonlib import OrderedSet
 
@@ -30,7 +31,7 @@ DT_MIPS_RLD_MAP_REL = 1879048245
 INSTALL_NAME_TOOL = False
 
 class DataSizes:
-    def __init__(self, ptrsize, is_le):
+    def __init__(self, ptrsize: int, is_le: bool) -> None:
         if is_le:
             p = '<'
         else:
@@ -57,7 +58,7 @@ class DataSizes:
             self.OffSize = 4
 
 class DynamicEntry(DataSizes):
-    def __init__(self, ifile, ptrsize, is_le):
+    def __init__(self, ifile: T.BinaryIO, ptrsize: int, is_le: bool) -> None:
         super().__init__(ptrsize, is_le)
         self.ptrsize = ptrsize
         if ptrsize == 64:
@@ -67,7 +68,7 @@ class DynamicEntry(DataSizes):
             self.d_tag = struct.unpack(self.Sword, ifile.read(self.SwordSize))[0]
             self.val = struct.unpack(self.Word, ifile.read(self.WordSize))[0]
 
-    def write(self, ofile):
+    def write(self, ofile: T.BinaryIO) -> None:
         if self.ptrsize == 64:
             ofile.write(struct.pack(self.Sxword, self.d_tag))
             ofile.write(struct.pack(self.XWord, self.val))
@@ -76,7 +77,7 @@ class DynamicEntry(DataSizes):
             ofile.write(struct.pack(self.Word, self.val))
 
 class SectionHeader(DataSizes):
-    def __init__(self, ifile, ptrsize, is_le):
+    def __init__(self, ifile: T.BinaryIO, ptrsize: int, is_le: bool) -> None:
         super().__init__(ptrsize, is_le)
         if ptrsize == 64:
             is_64 = True
@@ -116,10 +117,12 @@ class SectionHeader(DataSizes):
             self.sh_entsize = struct.unpack(self.Word, ifile.read(self.WordSize))[0]
 
 class Elf(DataSizes):
-    def __init__(self, bfile, verbose=True):
+    def __init__(self, bfile: str, verbose: bool = True) -> None:
         self.bfile = bfile
         self.verbose = verbose
         self.bf = open(bfile, 'r+b')
+        self.sections = []  # type: T.List[SectionHeader]
+        self.dynamic = []   # type: T.List[DynamicEntry]
         try:
             (self.ptrsize, self.is_le) = self.detect_elf_type()
             super().__init__(self.ptrsize, self.is_le)
@@ -130,18 +133,18 @@ class Elf(DataSizes):
             self.bf.close()
             raise
 
-    def __enter__(self):
+    def __enter__(self) -> 'Elf':
         return self
 
-    def __del__(self):
+    def __del__(self) -> None:
         if self.bf:
             self.bf.close()
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(self, exc_type: T.Any, exc_value: T.Any, traceback: T.Any) -> None:
         self.bf.close()
         self.bf = None
 
-    def detect_elf_type(self):
+    def detect_elf_type(self) -> T.Tuple[int, bool]:
         data = self.bf.read(6)
         if data[1:4] != b'ELF':
             # This script gets called to non-elf targets too
@@ -163,7 +166,7 @@ class Elf(DataSizes):
             sys.exit('File "%s" has unknown ELF endianness.' % self.bfile)
         return ptrsize, is_le
 
-    def parse_header(self):
+    def parse_header(self) -> None:
         self.bf.seek(0)
         self.e_ident = struct.unpack('16s', self.bf.read(16))[0]
         self.e_type = struct.unpack(self.Half, self.bf.read(self.HalfSize))[0]
@@ -180,13 +183,12 @@ class Elf(DataSizes):
         self.e_shnum = struct.unpack(self.Half, self.bf.read(self.HalfSize))[0]
         self.e_shstrndx = struct.unpack(self.Half, self.bf.read(self.HalfSize))[0]
 
-    def parse_sections(self):
+    def parse_sections(self) -> None:
         self.bf.seek(self.e_shoff)
-        self.sections = []
         for _ in range(self.e_shnum):
             self.sections.append(SectionHeader(self.bf, self.ptrsize, self.is_le))
 
-    def read_str(self):
+    def read_str(self) -> bytes:
         arr = []
         x = self.bf.read(1)
         while x != b'\0':
@@ -196,17 +198,17 @@ class Elf(DataSizes):
                 raise RuntimeError('Tried to read past the end of the file')
         return b''.join(arr)
 
-    def find_section(self, target_name):
+    def find_section(self, target_name: bytes) -> T.Optional[SectionHeader]:
         section_names = self.sections[self.e_shstrndx]
         for i in self.sections:
             self.bf.seek(section_names.sh_offset + i.sh_name)
             name = self.read_str()
             if name == target_name:
                 return i
+        return None
 
-    def parse_dynamic(self):
+    def parse_dynamic(self) -> None:
         sec = self.find_section(b'.dynamic')
-        self.dynamic = []
         if sec is None:
             return
         self.bf.seek(sec.sh_offset)
@@ -216,14 +218,14 @@ class Elf(DataSizes):
             if e.d_tag == 0:
                 break
 
-    def print_section_names(self):
+    def print_section_names(self) -> None:
         section_names = self.sections[self.e_shstrndx]
         for i in self.sections:
             self.bf.seek(section_names.sh_offset + i.sh_name)
             name = self.read_str()
             print(name.decode())
 
-    def print_soname(self):
+    def print_soname(self) -> None:
         soname = None
         strtab = None
         for i in self.dynamic:
@@ -237,14 +239,16 @@ class Elf(DataSizes):
         self.bf.seek(strtab.val + soname.val)
         print(self.read_str())
 
-    def get_entry_offset(self, entrynum):
+    def get_entry_offset(self, entrynum: int) -> T.Optional[int]:
         sec = self.find_section(b'.dynstr')
         for i in self.dynamic:
             if i.d_tag == entrynum:
-                return sec.sh_offset + i.val
+                res = sec.sh_offset + i.val
+                assert isinstance(res, int)
+                return res
         return None
 
-    def print_rpath(self):
+    def print_rpath(self) -> None:
         offset = self.get_entry_offset(DT_RPATH)
         if offset is None:
             print("This file does not have an rpath.")
@@ -252,7 +256,7 @@ class Elf(DataSizes):
             self.bf.seek(offset)
             print(self.read_str())
 
-    def print_runpath(self):
+    def print_runpath(self) -> None:
         offset = self.get_entry_offset(DT_RUNPATH)
         if offset is None:
             print("This file does not have a runpath.")
@@ -260,7 +264,7 @@ class Elf(DataSizes):
             self.bf.seek(offset)
             print(self.read_str())
 
-    def print_deps(self):
+    def print_deps(self) -> None:
         sec = self.find_section(b'.dynstr')
         deps = []
         for i in self.dynamic:
@@ -272,7 +276,7 @@ class Elf(DataSizes):
             name = self.read_str()
             print(name)
 
-    def fix_deps(self, prefix):
+    def fix_deps(self, prefix: bytes) -> None:
         sec = self.find_section(b'.dynstr')
         deps = []
         for i in self.dynamic:
@@ -290,15 +294,13 @@ class Elf(DataSizes):
                 self.bf.seek(offset)
                 self.bf.write(newname)
 
-    def fix_rpath(self, rpath_dirs_to_remove, new_rpath):
+    def fix_rpath(self, rpath_dirs_to_remove: T.List[bytes], new_rpath: bytes) -> None:
         # The path to search for can be either rpath or runpath.
         # Fix both of them to be sure.
         self.fix_rpathtype_entry(rpath_dirs_to_remove, new_rpath, DT_RPATH)
         self.fix_rpathtype_entry(rpath_dirs_to_remove, new_rpath, DT_RUNPATH)
 
-    def fix_rpathtype_entry(self, rpath_dirs_to_remove, new_rpath, entrynum):
-        if isinstance(new_rpath, str):
-            new_rpath = new_rpath.encode('utf8')
+    def fix_rpathtype_entry(self, rpath_dirs_to_remove: T.List[bytes], new_rpath: bytes, entrynum: int) -> None:
         rp_off = self.get_entry_offset(entrynum)
         if rp_off is None:
             if self.verbose:
@@ -326,7 +328,7 @@ class Elf(DataSizes):
         new_rpath = b':'.join(new_rpaths)
 
         if len(old_rpath) < len(new_rpath):
-            msg = "New rpath must not be longer than the old one.\n Old: {}\n New: {}".format(old_rpath, new_rpath)
+            msg = "New rpath must not be longer than the old one.\n Old: {!r}\n New: {!r}".format(old_rpath, new_rpath)
             sys.exit(msg)
         # The linker does read-only string deduplication. If there is a
         # string that shares a suffix with the rpath, they might get
@@ -343,7 +345,7 @@ class Elf(DataSizes):
             self.bf.write(new_rpath)
             self.bf.write(b'\0')
 
-    def remove_rpath_entry(self, entrynum):
+    def remove_rpath_entry(self, entrynum: int) -> None:
         sec = self.find_section(b'.dynamic')
         if sec is None:
             return None
@@ -363,7 +365,7 @@ class Elf(DataSizes):
             entry.write(self.bf)
         return None
 
-def fix_elf(fname, rpath_dirs_to_remove, new_rpath, verbose=True):
+def fix_elf(fname: str, rpath_dirs_to_remove: T.List[bytes], new_rpath: T.Optional[bytes], verbose: bool = True) -> None:
     with Elf(fname, verbose) as e:
         if new_rpath is None:
             e.print_rpath()
@@ -371,7 +373,7 @@ def fix_elf(fname, rpath_dirs_to_remove, new_rpath, verbose=True):
         else:
             e.fix_rpath(rpath_dirs_to_remove, new_rpath)
 
-def get_darwin_rpaths_to_remove(fname):
+def get_darwin_rpaths_to_remove(fname: str) -> T.List[str]:
     out = subprocess.check_output(['otool', '-l', fname],
                                   universal_newlines=True,
                                   stderr=subprocess.DEVNULL)
@@ -389,7 +391,7 @@ def get_darwin_rpaths_to_remove(fname):
             result.append(rp)
     return result
 
-def fix_darwin(fname, new_rpath, final_path, install_name_mappings):
+def fix_darwin(fname: str, new_rpath: str, final_path: str, install_name_mappings: T.Dict[str, str]) -> None:
     try:
         rpaths = get_darwin_rpaths_to_remove(fname)
     except subprocess.CalledProcessError:
@@ -439,7 +441,7 @@ def fix_darwin(fname, new_rpath, final_path, install_name_mappings):
     except Exception as err:
         raise SystemExit(err)
 
-def fix_jar(fname):
+def fix_jar(fname: str) -> None:
     subprocess.check_call(['jar', 'xfv', fname, 'META-INF/MANIFEST.MF'])
     with open('META-INF/MANIFEST.MF', 'r+') as f:
         lines = f.readlines()
@@ -450,7 +452,7 @@ def fix_jar(fname):
         f.truncate()
     subprocess.check_call(['jar', 'ufm', fname, 'META-INF/MANIFEST.MF'])
 
-def fix_rpath(fname, rpath_dirs_to_remove, new_rpath, final_path, install_name_mappings, verbose=True):
+def fix_rpath(fname: str, rpath_dirs_to_remove: T.List[bytes], new_rpath: T.Union[str, bytes], final_path: str, install_name_mappings: T.Dict[str, str], verbose: bool = True) -> None:
     global INSTALL_NAME_TOOL
     # Static libraries, import libraries, debug information, headers, etc
     # never have rpaths
@@ -461,6 +463,8 @@ def fix_rpath(fname, rpath_dirs_to_remove, new_rpath, final_path, install_name_m
         if fname.endswith('.jar'):
             fix_jar(fname)
             return
+        if isinstance(new_rpath, str):
+            new_rpath = new_rpath.encode('utf8')
         fix_elf(fname, rpath_dirs_to_remove, new_rpath, verbose)
         return
     except SystemExit as e:
@@ -473,6 +477,8 @@ def fix_rpath(fname, rpath_dirs_to_remove, new_rpath, final_path, install_name_m
     # (upto 30ms), which is significant with --only-changed. For details, see:
     # https://github.com/mesonbuild/meson/pull/6612#discussion_r378581401
     if INSTALL_NAME_TOOL is False:
-        INSTALL_NAME_TOOL = shutil.which('install_name_tool')
+        INSTALL_NAME_TOOL = bool(shutil.which('install_name_tool'))
     if INSTALL_NAME_TOOL:
+        if isinstance(new_rpath, bytes):
+            new_rpath = new_rpath.decode('utf8')
         fix_darwin(fname, new_rpath, final_path, install_name_mappings)
diff --git a/mesonbuild/scripts/dirchanger.py b/mesonbuild/scripts/dirchanger.py
index 3d7f4e2..21632cd 100644
--- a/mesonbuild/scripts/dirchanger.py
+++ b/mesonbuild/scripts/dirchanger.py
@@ -16,8 +16,9 @@
 the command given in the rest of the arguments.'''
 
 import os, subprocess, sys
+import typing as T
 
-def run(args):
+def run(args: T.List[str]) -> int:
     dirname = args[0]
     command = args[1:]
 
diff --git a/mesonbuild/scripts/gettext.py b/mesonbuild/scripts/gettext.py
index 7042863..547d14f 100644
--- a/mesonbuild/scripts/gettext.py
+++ b/mesonbuild/scripts/gettext.py
@@ -17,6 +17,7 @@ import shutil
 import argparse
 import subprocess
 from . import destdir_join
+import typing as T
 
 parser = argparse.ArgumentParser()
 parser.add_argument('command')
@@ -27,7 +28,7 @@ parser.add_argument('--localedir', default='')
 parser.add_argument('--subdir', default='')
 parser.add_argument('--extra-args', default='')
 
-def read_linguas(src_sub):
+def read_linguas(src_sub: str) -> T.List[str]:
     # Syntax of this file is documented here:
     # https://www.gnu.org/software/gettext/manual/html_node/po_002fLINGUAS.html
     linguas = os.path.join(src_sub, 'LINGUAS')
@@ -43,7 +44,7 @@ def read_linguas(src_sub):
         print('Could not find file LINGUAS in {}'.format(src_sub))
         return []
 
-def run_potgen(src_sub, pkgname, datadirs, args):
+def run_potgen(src_sub: str, pkgname: str, datadirs: str, args: T.List[str]) -> int:
     listfile = os.path.join(src_sub, 'POTFILES.in')
     if not os.path.exists(listfile):
         listfile = os.path.join(src_sub, 'POTFILES')
@@ -60,13 +61,13 @@ def run_potgen(src_sub, pkgname, datadirs, args):
                             '-D', os.environ['MESON_SOURCE_ROOT'], '-k_', '-o', ofile] + args,
                            env=child_env)
 
-def gen_gmo(src_sub, bld_sub, langs):
+def gen_gmo(src_sub: str, bld_sub: str, langs: T.List[str]) -> int:
     for l in langs:
         subprocess.check_call(['msgfmt', os.path.join(src_sub, l + '.po'),
                                '-o', os.path.join(bld_sub, l + '.gmo')])
     return 0
 
-def update_po(src_sub, pkgname, langs):
+def update_po(src_sub: str, pkgname: str, langs: T.List[str]) -> int:
     potfile = os.path.join(src_sub, pkgname + '.pot')
     for l in langs:
         pofile = os.path.join(src_sub, l + '.po')
@@ -76,7 +77,7 @@ def update_po(src_sub, pkgname, langs):
             subprocess.check_call(['msginit', '--input', potfile, '--output-file', pofile, '--locale', l, '--no-translator'])
     return 0
 
-def do_install(src_sub, bld_sub, dest, pkgname, langs):
+def do_install(src_sub: str, bld_sub: str, dest: str, pkgname: str, langs: T.List[str]) -> int:
     for l in langs:
         srcfile = os.path.join(bld_sub, l + '.gmo')
         outfile = os.path.join(dest, l, 'LC_MESSAGES',
@@ -88,7 +89,7 @@ def do_install(src_sub, bld_sub, dest, pkgname, langs):
         print('Installing %s to %s' % (srcfile, outfile))
     return 0
 
-def run(args):
+def run(args: T.List[str]) -> int:
     options = parser.parse_args(args)
     subcmd = options.command
     langs = options.langs.split('@@') if options.langs else None
@@ -120,3 +121,4 @@ def run(args):
     else:
         print('Unknown subcommand.')
         return 1
+    return 0
diff --git a/mesonbuild/scripts/gtkdochelper.py b/mesonbuild/scripts/gtkdochelper.py
index 812604a..86949e5 100644
--- a/mesonbuild/scripts/gtkdochelper.py
+++ b/mesonbuild/scripts/gtkdochelper.py
@@ -18,6 +18,7 @@ import shutil
 import argparse
 from ..mesonlib import MesonException, Popen_safe, is_windows, is_cygwin, split_args
 from . import destdir_join
+import typing as T
 
 parser = argparse.ArgumentParser()
 
@@ -50,7 +51,7 @@ for tool in ['scan', 'scangobj', 'mkdb', 'mkhtml', 'fixxref']:
     program_name = 'gtkdoc-' + tool
     parser.add_argument('--' + program_name, dest=program_name.replace('-', '_'))
 
-def gtkdoc_run_check(cmd, cwd, library_paths=None):
+def gtkdoc_run_check(cmd: T.List[str], cwd: str, library_paths: T.Optional[T.List[str]] = None) -> None:
     if library_paths is None:
         library_paths = []
 
@@ -85,12 +86,12 @@ def gtkdoc_run_check(cmd, cwd, library_paths=None):
         except UnicodeEncodeError:
             pass
 
-def build_gtkdoc(source_root, build_root, doc_subdir, src_subdirs,
-                 main_file, module, module_version,
-                 html_args, scan_args, fixxref_args, mkdb_args,
-                 gobject_typesfile, scanobjs_args, run, ld, cc, ldflags, cflags,
-                 html_assets, content_files, ignore_headers, namespace,
-                 expand_content_files, mode, options):
+def build_gtkdoc(source_root: str, build_root: str, doc_subdir: str, src_subdirs: T.List[str],
+                 main_file: str, module: str, module_version: str,
+                 html_args: T.List[str], scan_args: T.List[str], fixxref_args: T.List[str], mkdb_args: T.List[str],
+                 gobject_typesfile: str, scanobjs_args: T.List[str], run: str, ld: str, cc: str, ldflags: str, cflags: str,
+                 html_assets: T.List[str], content_files: T.List[str], ignore_headers: T.List[str], namespace: str,
+                 expand_content_files: T.List[str], mode: str, options: argparse.Namespace) -> None:
     print("Building documentation for %s" % module)
 
     src_dir_args = []
@@ -217,13 +218,13 @@ def build_gtkdoc(source_root, build_root, doc_subdir, src_subdirs,
         shutil.move(os.path.join(htmldir, '{}.devhelp2'.format(module)),
                     os.path.join(htmldir, '{}-{}.devhelp2'.format(module, module_version)))
 
-def install_gtkdoc(build_root, doc_subdir, install_prefix, datadir, module):
+def install_gtkdoc(build_root: str, doc_subdir: str, install_prefix: str, datadir: str, module: str) -> None:
     source = os.path.join(build_root, doc_subdir, 'html')
     final_destination = os.path.join(install_prefix, datadir, module)
     shutil.rmtree(final_destination, ignore_errors=True)
     shutil.copytree(source, final_destination)
 
-def run(args):
+def run(args: T.List[str]) -> int:
     options = parser.parse_args(args)
     if options.htmlargs:
         htmlargs = options.htmlargs.split('@@')
diff --git a/mesonbuild/scripts/hotdochelper.py b/mesonbuild/scripts/hotdochelper.py
index 826745d..a96a34a 100644
--- a/mesonbuild/scripts/hotdochelper.py
+++ b/mesonbuild/scripts/hotdochelper.py
@@ -5,6 +5,7 @@ import subprocess
 from . import destdir_join
 
 import argparse
+import typing as T
 
 parser = argparse.ArgumentParser()
 parser.add_argument('--install')
@@ -14,7 +15,7 @@ parser.add_argument('--builddir')
 parser.add_argument('--project-version')
 
 
-def run(argv):
+def run(argv: T.List[str]) -> int:
     options, args = parser.parse_known_args(argv)
     subenv = os.environ.copy()
 
@@ -23,7 +24,7 @@ def run(argv):
 
     res = subprocess.call(args, cwd=options.builddir, env=subenv)
     if res != 0:
-        exit(res)
+        return res
 
     if options.install:
         source_dir = os.path.join(options.builddir, options.install)
@@ -34,3 +35,4 @@ def run(argv):
 
         shutil.rmtree(installdir, ignore_errors=True)
         shutil.copytree(source_dir, installdir)
+    return 0
diff --git a/mesonbuild/scripts/meson_exe.py b/mesonbuild/scripts/meson_exe.py
index f1b0299..68ba120 100644
--- a/mesonbuild/scripts/meson_exe.py
+++ b/mesonbuild/scripts/meson_exe.py
@@ -17,19 +17,20 @@ import sys
 import argparse
 import pickle
 import subprocess
+import typing as T
 
 from .. import mesonlib
 from ..backend.backends import ExecutableSerialisation
 
 options = None
 
-def buildparser():
+def buildparser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(description='Custom executable wrapper for Meson. Do not run on your own, mmm\'kay?')
     parser.add_argument('--unpickle')
     parser.add_argument('--capture')
     return parser
 
-def run_exe(exe):
+def run_exe(exe: ExecutableSerialisation) -> int:
     if exe.exe_runner:
         if not exe.exe_runner.found():
             raise AssertionError('BUG: Can\'t run cross-compiled exe {!r} with not-found '
@@ -74,7 +75,7 @@ def run_exe(exe):
         sys.stderr.buffer.write(stderr)
     return p.returncode
 
-def run(args):
+def run(args: T.List[str]) -> int:
     global options
     parser = buildparser()
     options, cmd_args = parser.parse_known_args(args)
diff --git a/mesonbuild/scripts/msgfmthelper.py b/mesonbuild/scripts/msgfmthelper.py
index 737f1bc..3ddc9e6 100644
--- a/mesonbuild/scripts/msgfmthelper.py
+++ b/mesonbuild/scripts/msgfmthelper.py
@@ -15,6 +15,7 @@
 import argparse
 import subprocess
 import os
+import typing as T
 
 parser = argparse.ArgumentParser()
 parser.add_argument('input')
@@ -25,7 +26,7 @@ parser.add_argument('--datadirs', default='')
 parser.add_argument('args', default=[], metavar='extra msgfmt argument', nargs='*')
 
 
-def run(args):
+def run(args: T.List[str]) -> int:
     options = parser.parse_args(args)
     env = None
     if options.datadirs:
diff --git a/mesonbuild/scripts/regen_checker.py b/mesonbuild/scripts/regen_checker.py
index 80d9242..84f7d77 100644
--- a/mesonbuild/scripts/regen_checker.py
+++ b/mesonbuild/scripts/regen_checker.py
@@ -14,10 +14,14 @@
 
 import sys, os
 import pickle, subprocess
+import typing as T
+
+if T.TYPE_CHECKING:
+    from ..backend.vs2010backend import RegenInfo
 
 # This could also be used for XCode.
 
-def need_regen(regeninfo, regen_timestamp):
+def need_regen(regeninfo: 'RegenInfo', regen_timestamp: float) -> bool:
     for i in regeninfo.depfiles:
         curfile = os.path.join(regeninfo.build_dir, i)
         curtime = os.stat(curfile).st_mtime
@@ -31,7 +35,7 @@ def need_regen(regeninfo, regen_timestamp):
     Vs2010Backend.touch_regen_timestamp(regeninfo.build_dir)
     return False
 
-def regen(regeninfo, meson_command, backend):
+def regen(regeninfo: 'RegenInfo', meson_command: T.List[str], backend: str) -> None:
     cmd = meson_command + ['--internal',
                            'regenerate',
                            regeninfo.build_dir,
@@ -39,19 +43,19 @@ def regen(regeninfo, meson_command, backend):
                            '--backend=' + backend]
     subprocess.check_call(cmd)
 
-def run(args):
+def run(args: T.List[str]) -> int:
     private_dir = args[0]
     dumpfile = os.path.join(private_dir, 'regeninfo.dump')
-    coredata = os.path.join(private_dir, 'coredata.dat')
+    coredata_file = os.path.join(private_dir, 'coredata.dat')
     with open(dumpfile, 'rb') as f:
-        regeninfo = pickle.load(f)
-    with open(coredata, 'rb') as f:
+        regeninfo = T.cast('RegenInfo', pickle.load(f))
+    with open(coredata_file, 'rb') as f:
         coredata = pickle.load(f)
     backend = coredata.get_builtin_option('backend')
     regen_timestamp = os.stat(dumpfile).st_mtime
     if need_regen(regeninfo, regen_timestamp):
         regen(regeninfo, coredata.meson_command, backend)
-    sys.exit(0)
+    return 0
 
 if __name__ == '__main__':
-    run(sys.argv[1:])
+    sys.exit(run(sys.argv[1:]))
diff --git a/mesonbuild/scripts/scanbuild.py b/mesonbuild/scripts/scanbuild.py
index 0190067..3e5b30f 100644
--- a/mesonbuild/scripts/scanbuild.py
+++ b/mesonbuild/scripts/scanbuild.py
@@ -12,30 +12,31 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
 import subprocess
 import shutil
 import tempfile
 from ..environment import detect_ninja, detect_scanbuild
+from pathlib import Path
+import typing as T
 
 
-def scanbuild(exelist, srcdir, blddir, privdir, logdir, args):
-    with tempfile.TemporaryDirectory(dir=privdir) as scandir:
+def scanbuild(exelist: T.List[str], srcdir: Path, blddir: Path, privdir: Path, logdir: Path, args: T.List[str]) -> int:
+    with tempfile.TemporaryDirectory(dir=str(privdir)) as scandir:
         meson_cmd = exelist + args
-        build_cmd = exelist + ['-o', logdir] + detect_ninja() + ['-C', scandir]
-        rc = subprocess.call(meson_cmd + [srcdir, scandir])
+        build_cmd = exelist + ['-o', str(logdir)] + detect_ninja() + ['-C', scandir]
+        rc = subprocess.call(meson_cmd + [str(srcdir), scandir])
         if rc != 0:
             return rc
         return subprocess.call(build_cmd)
 
 
-def run(args):
-    srcdir = args[0]
-    blddir = args[1]
+def run(args: T.List[str]) -> int:
+    srcdir = Path(args[0])
+    blddir = Path(args[1])
     meson_cmd = args[2:]
-    privdir = os.path.join(blddir, 'meson-private')
-    logdir = os.path.join(blddir, 'meson-logs/scanbuild')
-    shutil.rmtree(logdir, ignore_errors=True)
+    privdir = blddir / 'meson-private'
+    logdir = blddir / 'meson-logs' / 'scanbuild'
+    shutil.rmtree(str(logdir), ignore_errors=True)
 
     exelist = detect_scanbuild()
     if not exelist:
diff --git a/mesonbuild/scripts/symbolextractor.py b/mesonbuild/scripts/symbolextractor.py
index cf486af..e607315 100644
--- a/mesonbuild/scripts/symbolextractor.py
+++ b/mesonbuild/scripts/symbolextractor.py
@@ -36,12 +36,12 @@ parser.add_argument('args', nargs='+')
 TOOL_WARNING_FILE = None
 RELINKING_WARNING = 'Relinking will always happen on source changes.'
 
-def dummy_syms(outfilename: str):
+def dummy_syms(outfilename: str) -> None:
     """Just touch it so relinking happens always."""
     with open(outfilename, 'w'):
         pass
 
-def write_if_changed(text: str, outfilename: str):
+def write_if_changed(text: str, outfilename: str) -> None:
     try:
         with open(outfilename, 'r') as f:
             oldtext = f.read()
@@ -52,13 +52,11 @@ def write_if_changed(text: str, outfilename: str):
     with open(outfilename, 'w') as f:
         f.write(text)
 
-def print_tool_warning(tool: list, msg: str, stderr: str = None):
+def print_tool_warning(tools: T.List[str], msg: str, stderr: T.Optional[str] = None) -> None:
     global TOOL_WARNING_FILE
     if os.path.exists(TOOL_WARNING_FILE):
         return
-    if len(tool) == 1:
-        tool = tool[0]
-    m = '{!r} {}. {}'.format(tool, msg, RELINKING_WARNING)
+    m = '{!r} {}. {}'.format(tools, msg, RELINKING_WARNING)
     if stderr:
         m += '\n' + stderr
     mlog.warning(m)
@@ -73,7 +71,7 @@ def get_tool(name: str) -> T.List[str]:
         return shlex.split(os.environ[evar])
     return [name]
 
-def call_tool(name: str, args: T.List[str], **kwargs) -> str:
+def call_tool(name: str, args: T.List[str], **kwargs: T.Any) -> str:
     tool = get_tool(name)
     try:
         p, output, e = Popen_safe(tool + args, **kwargs)
@@ -88,7 +86,7 @@ def call_tool(name: str, args: T.List[str], **kwargs) -> str:
         return None
     return output
 
-def call_tool_nowarn(tool: T.List[str], **kwargs) -> T.Tuple[str, str]:
+def call_tool_nowarn(tool: T.List[str], **kwargs: T.Any) -> T.Tuple[str, str]:
     try:
         p, output, e = Popen_safe(tool, **kwargs)
     except FileNotFoundError:
@@ -99,7 +97,7 @@ def call_tool_nowarn(tool: T.List[str], **kwargs) -> T.Tuple[str, str]:
         return None, e
     return output, None
 
-def gnu_syms(libfilename: str, outfilename: str):
+def gnu_syms(libfilename: str, outfilename: str) -> None:
     # Get the name of the library
     output = call_tool('readelf', ['-d', libfilename])
     if not output:
@@ -126,7 +124,7 @@ def gnu_syms(libfilename: str, outfilename: str):
         result += [' '.join(entry)]
     write_if_changed('\n'.join(result) + '\n', outfilename)
 
-def solaris_syms(libfilename: str, outfilename: str):
+def solaris_syms(libfilename: str, outfilename: str) -> None:
     # gnu_syms() works with GNU nm & readelf, not Solaris nm & elfdump
     origpath = os.environ['PATH']
     try:
@@ -135,7 +133,7 @@ def solaris_syms(libfilename: str, outfilename: str):
     finally:
         os.environ['PATH'] = origpath
 
-def osx_syms(libfilename: str, outfilename: str):
+def osx_syms(libfilename: str, outfilename: str) -> None:
     # Get the name of the library
     output = call_tool('otool', ['-l', libfilename])
     if not output:
@@ -156,7 +154,7 @@ def osx_syms(libfilename: str, outfilename: str):
     result += [' '.join(x.split()[0:2]) for x in output.split('\n')]
     write_if_changed('\n'.join(result) + '\n', outfilename)
 
-def openbsd_syms(libfilename: str, outfilename: str):
+def openbsd_syms(libfilename: str, outfilename: str) -> None:
     # Get the name of the library
     output = call_tool('readelf', ['-d', libfilename])
     if not output:
@@ -173,7 +171,7 @@ def openbsd_syms(libfilename: str, outfilename: str):
     result += [' '.join(x.split()[0:2]) for x in output.split('\n') if x and not x.endswith('U ')]
     write_if_changed('\n'.join(result) + '\n', outfilename)
 
-def cygwin_syms(impfilename: str, outfilename: str):
+def cygwin_syms(impfilename: str, outfilename: str) -> None:
     # Get the name of the library
     output = call_tool('dlltool', ['-I', impfilename])
     if not output:
@@ -242,23 +240,23 @@ def _get_implib_exports(impfilename: str) -> T.Tuple[T.List[str], str]:
         all_stderr += e
     return ([], all_stderr)
 
-def windows_syms(impfilename: str, outfilename: str):
+def windows_syms(impfilename: str, outfilename: str) -> None:
     # Get the name of the library
     result, e = _get_implib_dllname(impfilename)
     if not result:
-        print_tool_warning('lib, llvm-lib, dlltool', 'do not work or were not found', e)
+        print_tool_warning(['lib', 'llvm-lib', 'dlltool'], 'do not work or were not found', e)
         dummy_syms(outfilename)
         return
     # Get a list of all symbols exported
     symbols, e = _get_implib_exports(impfilename)
     if not symbols:
-        print_tool_warning('dumpbin, llvm-nm, nm', 'do not work or were not found', e)
+        print_tool_warning(['dumpbin', 'llvm-nm', 'nm'], 'do not work or were not found', e)
         dummy_syms(outfilename)
         return
     result += symbols
     write_if_changed('\n'.join(result) + '\n', outfilename)
 
-def gen_symbols(libfilename: str, impfilename: str, outfilename: str, cross_host: str):
+def gen_symbols(libfilename: str, impfilename: str, outfilename: str, cross_host: str) -> None:
     if cross_host is not None:
         # In case of cross builds just always relink. In theory we could
         # determine the correct toolset, but we would need to use the correct
@@ -295,7 +293,7 @@ def gen_symbols(libfilename: str, impfilename: str, outfilename: str, cross_host
                 pass
         dummy_syms(outfilename)
 
-def run(args):
+def run(args: T.List[str]) -> int:
     global TOOL_WARNING_FILE
     options = parser.parse_args(args)
     if len(options.args) != 4:
diff --git a/mesonbuild/scripts/tags.py b/mesonbuild/scripts/tags.py
index 431bb5f..bb85831 100644
--- a/mesonbuild/scripts/tags.py
+++ b/mesonbuild/scripts/tags.py
@@ -15,9 +15,9 @@
 import os
 import subprocess
 from pathlib import Path
+import typing as T
 
-
-def ls_as_bytestream():
+def ls_as_bytestream() -> bytes:
     if os.path.exists('.git'):
         return subprocess.run(['git', 'ls-tree', '-r', '--name-only', 'HEAD'],
                               stdout=subprocess.PIPE).stdout
@@ -28,24 +28,24 @@ def ls_as_bytestream():
     return '\n'.join(files).encode()
 
 
-def cscope():
+def cscope() -> int:
     ls = b'\n'.join([b'"%s"' % f for f in ls_as_bytestream().split()])
     return subprocess.run(['cscope', '-v', '-b', '-i-'], input=ls).returncode
 
 
-def ctags():
+def ctags() -> int:
     ls = ls_as_bytestream()
     return subprocess.run(['ctags', '-L-'], input=ls).returncode
 
 
-def etags():
+def etags() -> int:
     ls = ls_as_bytestream()
     return subprocess.run(['etags', '-'], input=ls).returncode
 
 
-def run(args):
+def run(args: T.List[str]) -> int:
     tool_name = args[0]
     srcdir_name = args[1]
     os.chdir(srcdir_name)
     assert tool_name in ['cscope', 'ctags', 'etags']
-    return globals()[tool_name]()
+    return T.cast(int, globals()[tool_name]())
diff --git a/mesonbuild/scripts/uninstall.py b/mesonbuild/scripts/uninstall.py
index bdc036b..b648de4 100644
--- a/mesonbuild/scripts/uninstall.py
+++ b/mesonbuild/scripts/uninstall.py
@@ -13,10 +13,11 @@
 # limitations under the License.
 
 import os
+import typing as T
 
 logfile = 'meson-logs/install-log.txt'
 
-def do_uninstall(log):
+def do_uninstall(log: str) -> None:
     failures = 0
     successes = 0
     for line in open(log):
@@ -38,7 +39,7 @@ def do_uninstall(log):
     print('Failed:', failures)
     print('\nRemember that files created by custom scripts have not been removed.')
 
-def run(args):
+def run(args: T.List[str]) -> int:
     if args:
         print('Weird error.')
         return 1
diff --git a/mesonbuild/scripts/vcstagger.py b/mesonbuild/scripts/vcstagger.py
index 16dd4d1..64985f6 100644
--- a/mesonbuild/scripts/vcstagger.py
+++ b/mesonbuild/scripts/vcstagger.py
@@ -13,9 +13,9 @@
 # limitations under the License.
 
 import sys, os, subprocess, re
+import typing as T
 
-
-def config_vcs_tag(infile, outfile, fallback, source_dir, replace_string, regex_selector, cmd):
+def config_vcs_tag(infile: str, outfile: str, fallback: str, source_dir: str, replace_string: str, regex_selector: str, cmd: T.List[str]) -> None:
     try:
         output = subprocess.check_output(cmd, cwd=source_dir)
         new_string = re.search(regex_selector, output.decode()).group(1).strip()
@@ -34,7 +34,7 @@ def config_vcs_tag(infile, outfile, fallback, source_dir, replace_string, regex_
             f.write(new_data)
 
 
-def run(args):
+def run(args: T.List[str]) -> int:
     infile, outfile, fallback, source_dir, replace_string, regex_selector = args[0:6]
     command = args[6:]
     config_vcs_tag(infile, outfile, fallback, source_dir, replace_string, regex_selector, command)
diff --git a/mesonbuild/scripts/yelphelper.py b/mesonbuild/scripts/yelphelper.py
index 6bf0673..0355d9f 100644
--- a/mesonbuild/scripts/yelphelper.py
+++ b/mesonbuild/scripts/yelphelper.py
@@ -20,6 +20,7 @@ from .. import mlog
 from ..mesonlib import has_path_sep
 from . import destdir_join
 from .gettext import read_linguas
+import typing as T
 
 parser = argparse.ArgumentParser()
 parser.add_argument('command')
@@ -31,19 +32,19 @@ parser.add_argument('--media', dest='media', default='')
 parser.add_argument('--langs', dest='langs', default='')
 parser.add_argument('--symlinks', type=bool, dest='symlinks', default=False)
 
-def build_pot(srcdir, project_id, sources):
+def build_pot(srcdir: str, project_id: str, sources: T.List[str]) -> None:
     # Must be relative paths
     sources = [os.path.join('C', source) for source in sources]
     outfile = os.path.join(srcdir, project_id + '.pot')
     subprocess.call(['itstool', '-o', outfile] + sources)
 
-def update_po(srcdir, project_id, langs):
+def update_po(srcdir: str, project_id: str, langs: T.List[str]) -> None:
     potfile = os.path.join(srcdir, project_id + '.pot')
     for lang in langs:
         pofile = os.path.join(srcdir, lang, lang + '.po')
         subprocess.call(['msgmerge', '-q', '-o', pofile, pofile, potfile])
 
-def build_translations(srcdir, blddir, langs):
+def build_translations(srcdir: str, blddir: str, langs: T.List[str]) -> None:
     for lang in langs:
         outdir = os.path.join(blddir, lang)
         os.makedirs(outdir, exist_ok=True)
@@ -52,14 +53,14 @@ def build_translations(srcdir, blddir, langs):
             '-o', os.path.join(outdir, lang + '.gmo')
         ])
 
-def merge_translations(blddir, sources, langs):
+def merge_translations(blddir: str, sources: T.List[str], langs: T.List[str]) -> None:
     for lang in langs:
         subprocess.call([
             'itstool', '-m', os.path.join(blddir, lang, lang + '.gmo'),
             '-o', os.path.join(blddir, lang)
         ] + sources)
 
-def install_help(srcdir, blddir, sources, media, langs, install_dir, destdir, project_id, symlinks):
+def install_help(srcdir: str, blddir: str, sources: T.List[str], media: T.List[str], langs: T.List[str], install_dir: str, destdir: str, project_id: str, symlinks: bool) -> None:
     c_install_dir = os.path.join(install_dir, 'C', project_id)
     for lang in langs + ['C']:
         indir = destdir_join(destdir, os.path.join(install_dir, lang, project_id))
@@ -101,7 +102,7 @@ def install_help(srcdir, blddir, sources, media, langs, install_dir, destdir, pr
             shutil.copyfile(infile, outfile)
             shutil.copystat(infile, outfile)
 
-def run(args):
+def run(args: T.List[str]) -> int:
     options = parser.parse_args(args)
     langs = options.langs.split('@@') if options.langs else []
     media = options.media.split('@@') if options.media else []
@@ -129,3 +130,4 @@ def run(args):
             merge_translations(build_subdir, abs_sources, langs)
         install_help(src_subdir, build_subdir, sources, media, langs, install_dir,
                      destdir, options.project_id, options.symlinks)
+    return 0