Added clang-tidy ban of qMin, qMax, qAbs and qBound.

tools/clangtidy/README.md

@@ -0,0 +1,13 @@
+# clang-tidy for tdesktop
+
+```bash
+python3 tools/clangtidy/compile_db.py               # after each configure
+git diff -U0 HEAD | clang-tidy-diff.py -p1 -path out/clang-tidy -j 10 -quiet
+run-clang-tidy -p out/clang-tidy -j 10 -quiet <files>
+```
+
+The second line is the gate: it reports only the lines a commit touches. Both
+runners ship with LLVM, under `share/clang` next to the binary.
+
+Needs clang-tidy 20 or newer -- an older one ignores `CustomFunctions`, which
+the bans in `.clang-tidy` are built on, without a word.

tools/clangtidy/compile_db.py

@@ -0,0 +1,137 @@
+#!/usr/bin/env python3
+"""Write the database clang-tidy reads: compile_db.py [build dir, "out"]."""
+import collections
+import json
+import os
+import shlex
+import shutil
+import subprocess
+import sys
+
+GCC_ONLY = frozenset(["-fhardened"])
+MSVC_NOISE = frozenset(["MP", "WX", "FS", "showIncludes"])
+MSVC_FILES = ("Yu", "Yc", "Fp", "Fo", "Fd")
+
+
+def tools_directory():
+    """Where clang-tidy sits, since its clang++ has to stand in for ours."""
+    tidy = (os.environ.get("CLANG_TIDY") or shutil.which("clang-tidy")
+        or shutil.which("clang-tidy", path="/opt/homebrew/opt/llvm/bin"))
+    if not tidy:
+        sys.exit("error: clang-tidy not found; set CLANG_TIDY")
+    return os.path.dirname(tidy)
+
+
+def compiler_for(original, directory):
+    """clang-cl stands in for MSVC, clang++ for every other compiler."""
+    msvc = os.path.basename(original).lower() in ("cl", "cl.exe")
+    name = "clang-cl" if msvc else "clang++"
+    name += ".exe" if os.name == "nt" else ""
+    beside = os.path.join(directory, name)
+    return beside if os.path.exists(beside) else name
+
+
+def split_command(command):
+    """Windows quotes by CommandLineToArgvW rules, which shlex cannot read."""
+    if os.name != "nt":
+        return shlex.split(command)
+    if not command.strip():
+        return []  # an empty line answers with the path of this very process
+    import ctypes
+    shell, kernel = ctypes.windll.shell32, ctypes.windll.kernel32
+    shell.CommandLineToArgvW.restype = ctypes.POINTER(ctypes.c_wchar_p)
+    count = ctypes.c_int()
+    parts = shell.CommandLineToArgvW(command, ctypes.byref(count))
+    try:
+        return [parts[index] for index in range(count.value)]
+    finally:
+        kernel.LocalFree(parts)
+
+
+def dropped(argument):
+    """An option clang rejects or cannot use; /FI stays, it force-includes."""
+    if argument in GCC_ONLY:
+        return True
+    if argument[:1] not in ("/", "-"):
+        return False
+    flag = argument[1:]
+    return flag.startswith(MSVC_FILES) or flag in MSVC_NOISE
+
+
+def platform_arguments(driver):
+    """What clang-tidy's clang needs and the build's own compiler did not."""
+    if sys.platform == "darwin":
+        sdk = subprocess.run(["xcrun", "--show-sdk-path"],
+            capture_output=True, text=True).stdout.strip()
+        if not sdk:
+            return []
+        # Its own libc++ is newer than ours and rejects some of our files.
+        return ["-isysroot", sdk, "-nostdinc++",
+            "-isystem" + os.path.join(sdk, "usr/include/c++/v1")]
+    if os.name == "nt":
+        # MSVC backs an enum of no fixed type by int, so mtpc_ cases narrow.
+        return ["-Wno-c++11-narrowing"]
+    if not os.path.basename(driver).startswith(("gcc", "g++")):
+        return []
+    found = shutil.which(driver) or driver
+    prefix = os.path.dirname(os.path.dirname(found))
+    if not os.path.isdir(prefix):
+        print(f"warning: {driver} not on PATH, so the standard library it "
+            f"carries stays hidden from clang", file=sys.stderr)
+        return []
+    return ["--gcc-toolchain=" + prefix]
+
+
+def rewrite(command):
+    """The command without what clang-tidy's clang cannot take."""
+    arguments, kept, index = split_command(command), [], 0
+    while index < len(arguments):
+        argument = arguments[index]
+        # Only clang's own form: GCC's -include of the header has to stay.
+        if (argument == "-Xclang"
+            and arguments[index + 1:index + 2] == ["-include-pch"]):
+            index += 4
+            continue
+        if index and dropped(argument):
+            index += 1
+            continue
+        kept.append(argument)
+        index += 1
+    if kept and os.path.basename(kept[0]) in ("ccache", "sccache"):
+        kept.pop(0)
+    return kept
+
+
+def main():
+    build = sys.argv[1] if len(sys.argv) > 1 else "out"
+    if not os.path.exists(os.path.join(build, "build.ninja")):
+        sys.exit(f"error: no ninja build in {build}")
+    raw = subprocess.run(["ninja", "-C", build, "-t", "compdb"], check=True,
+        capture_output=True, text=True).stdout
+    commands = []
+    for entry in json.loads(raw):
+        if not entry["file"].endswith((".cpp", ".mm", ".cxx")):
+            continue
+        if not entry["command"].strip() or not os.path.exists(entry["file"]):
+            continue
+        kept = rewrite(entry["command"])
+        if kept:
+            commands.append((entry, kept))
+    directory = tools_directory()
+    drivers = collections.Counter(kept[0] for _, kept in commands)
+    extra = platform_arguments(
+        drivers.most_common(1)[0][0] if drivers else "")
+    entries = [{
+        "directory": entry["directory"],
+        "file": entry["file"],
+        "arguments": [compiler_for(kept[0], directory)] + extra + kept[1:],
+    } for entry, kept in commands]
+    target = os.path.join(build, "clang-tidy")
+    os.makedirs(target, exist_ok=True)
+    with open(os.path.join(target, "compile_commands.json"), "w") as stream:
+        json.dump(entries, stream, indent=1)
+    print(f"{len(entries)} entries -> {target}/compile_commands.json")
+
+
+if __name__ == "__main__":
+    main()