scripts/build: add a python script for checking style rules

.github/workflows/style.yml

@@ -0,0 +1,55 @@
+name: Style Check
+
+on:
+  pull_request:
+    paths:
+    - '.github/workflows/**'
+    - 'src/**.cpp'
+    - 'src/**.h'
+
+jobs:
+  stylecheck:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 2
+
+      - name: Get changed files
+        id: changed-files
+        run: echo "changed_files=$(git diff --name-only --diff-filter=ACMRT ${{ github.event.pull_request.base.sha }}...HEAD | xargs)" >> $GITHUB_OUTPUT
+
+      - name: Run style check
+        id: style-check
+        run: echo "reviews=$(python3 scripts/build/style.py ${{ steps.changed-files.outputs.changed_files }} | jq -s -c .)" >> $GITHUB_OUTPUT
+
+      - name: Post review comments
+        uses: actions/github-script@v7
+        id: post-comments
+        env:
+          REVIEWS: ${{ steps.style-check.outputs.reviews }}
+        with:
+          script: |
+            const reviews = JSON.parse(process.env.REVIEWS || "[]");
+
+            const comments = reviews.map(r => ({
+              body: r.body,
+              path: r.path,
+              line: r.line,
+              side: "RIGHT",
+            }));
+
+            if (comments.length > 0) {
+              console.debug("Reviews: ", reviews);
+              await github.rest.pulls.createReview({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                pull_number: context.payload.pull_request.number,
+                event: "COMMENT",
+                comments,
+              });
+            } else {
+              console.info("Review list empty.");
+            }

scripts/build/style.py

@@ -0,0 +1,173 @@
+#!/usr/bin/env python3
+##
+## license:BSD-3-Clause
+## copyright-holders:stonedDiscord
+
+import json
+import re
+import sys
+from pathlib import Path
+
+def is_screaming_snake(name: str):
+    return re.fullmatch(r"[A-Z][A-Z0-9_]*", name) is not None
+
+def is_snake_case(name: str):
+    return re.fullmatch(r"[a-z][a-z0-9_]*(_[a-z0-9]+)*", name) is not None
+
+def check_file(path: Path, fix: bool = False):
+    errors = []
+    try:
+        raw_bytes = path.read_bytes()
+        try:
+            text = raw_bytes.decode("utf-8", errors="strict")
+        except UnicodeDecodeError as e:
+            errors.append((1, f"Invalid UTF-8 sequence at byte {e.start}-{e.end}"))
+            return errors
+    except Exception:
+        return errors
+
+    if sys.platform != "win32" and b"\r\n" in raw_bytes:
+        errors.append((1, "File contains Windows (CRLF) line endings on a non-Windows system"))
+    elif sys.platform == "win32" and b"\n" in raw_bytes and b"\r\n" not in raw_bytes:
+        errors.append((1, "File contains Unix (LF) line endings on Windows"))
+
+    lines = text.splitlines()
+
+    if not text.endswith("\n"):
+        if fix:
+            path.write_text(text + "\n")
+        errors.append((len(lines) or 1, "File should end with a newline"))
+
+    for i, line in enumerate(lines, 1):
+        if line.rstrip() != line:
+            errors.append((i, "Lines should not have trailing whitespaces"))
+
+    return errors
+
+def check_cpp_file(path: Path, fix: bool = False):
+    errors = check_file(path, fix)
+    try:
+        text = path.read_text()
+    except Exception:
+        return errors
+
+    lines = text.splitlines()
+
+    for i, line in enumerate(lines, 1):
+        hex_pattern = re.compile(r"0x[A-F]+")
+        if hex_pattern.search(line):
+            errors.append((i, "Hex literals should be lowercase (0x1a not 0x1A)"))
+
+        comment_pattern = re.compile(r"/\*.*\*/")
+        if comment_pattern.search(line.strip()):
+            errors.append((i, "/* Single-line block comments */ should use // instead"))
+
+        macro_pattern = re.compile(r"^\s*#define\s+([A-Za-z0-9_]+)")
+        m = macro_pattern.match(line)
+        if m and not is_screaming_snake(m.group(1)):
+            errors.append((i, f"Macro '{m.group(1)}' should use SCREAMING_SNAKE_CASE"))
+
+        const_pattern = re.compile(r"\bconstexpr\b[^;=()]*\b([A-Za-z_][A-Za-z0-9_]*)\b\s*(?:=|;)")
+        c = const_pattern.search(line)
+        if c and not is_screaming_snake(c.group(1)):
+            errors.append((i, f"Constant expression '{c.group(1)}' should use SCREAMING_SNAKE_CASE"))
+
+        function_pattern = re.compile(r"\b([a-z][a-z0-9_]*)\s*\(")
+        f = function_pattern.search(line)
+        if f and not is_snake_case(f.group(1)):
+            errors.append((i, f"Function '{f.group(1)}' should use snake_case"))
+
+        class_pattern = re.compile(r"\bclass\s+([A-Za-z0-9_]+)")
+        cl = class_pattern.search(line)
+        if cl and not is_snake_case(cl.group(1)):
+            errors.append((i, f"Class '{cl.group(1)}' should use snake_case"))
+
+        enum_pattern = re.compile(r"\benum\s+(class\s+)?([A-Za-z0-9_]+)")
+        en = enum_pattern.search(line)
+        if en and not is_snake_case(en.group(2)):
+            errors.append((i, f"Enum '{en.group(2)}' should use snake_case"))
+
+    return errors
+
+def check_lst_block(block, changed_cpp_files, start_line, src_file):
+    if not src_file or src_file not in changed_cpp_files:
+        return []
+    sorted_block = sorted(block, key=lambda s: s.lower())
+    errors_local = []
+    for offset, (expected, actual) in enumerate(zip(sorted_block, block)):
+        if expected != actual:
+            line_no = start_line + offset + 1
+            errors_local.append(
+                (line_no, f"Entry '{actual}' is out of order, expected '{expected}'")
+            )
+    return errors_local
+
+def check_mame_lst(changed_cpp_files: set[str]):
+    path = Path("src/mame/mame.lst")
+    errors = check_file(path, False)
+    try:
+        lines = path.read_text().splitlines()
+    except Exception:
+        return errors
+
+    current_block = []
+    block_start_line = 0
+    current_source = None
+
+    for i, line in enumerate(lines):
+        if line.startswith("@source:"):
+            if current_block:
+                errors.extend(check_lst_block(current_block, changed_cpp_files, block_start_line, current_source))
+            current_source = "src/mame/" + line[len("@source:"):].strip()
+
+            current_block = []
+            block_start_line = i + 1
+        elif line.strip():
+            current_block.append(line.strip())
+
+    if current_block:
+        errors.extend(check_lst_block(current_block, changed_cpp_files, block_start_line, current_source))
+
+    return errors
+
+def print_review(path, lineno, msg):
+    review = {"body": str(msg), "path": str(path), "line": int(lineno)}
+    print(json.dumps(review))
+
+def main():
+    fix = "-f" in sys.argv
+    args = [f for f in sys.argv[1:] if f != "-f"]
+
+    cpp_files = {f for f in args if f.endswith(".c") or f.endswith(".cpp")}
+    h_files = {f for f in args if f.endswith(".h") or f.endswith(".hpp") or f.endswith(".hxx") or f.endswith(".ipp")}
+    other_files = {f for f in args if f.endswith(".lua") or f.endswith(".lay") or f.endswith(".lst") or f.endswith(".mm") or f.endswith(".py") or f.endswith(".yml")}
+
+    for file in cpp_files:
+        path = Path(file)
+        errors = check_cpp_file(path, fix=fix)
+
+        for lineno, msg in errors:
+            print_review(path,lineno,msg)
+
+    for file in h_files:
+        path = Path(file)
+        errors = check_cpp_file(path, fix=fix)
+
+        for lineno, msg in errors:
+            print_review(path,lineno,msg)
+
+    for file in other_files:
+        path = Path(file)
+        errors = check_file(path, fix=fix)
+
+        for lineno, msg in errors:
+            print_review(path,lineno,msg)
+
+    errors = check_mame_lst(cpp_files)
+    for lineno, msg in errors:
+            print_review("src/mame/mame.lst",lineno,msg)
+
+    sys.exit(0)
+
+if __name__ == "__main__":
+    main()