[clang-tidy] Implement alphabetical order test

clang-tools-extra/clang-tidy/tool/check-alphabetical-order.py

@@ -0,0 +1,378 @@
+#!/usr/bin/env python3
+#
+# ===-----------------------------------------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+# ===-----------------------------------------------------------------------===#
+
+"""
+
+Clang-Tidy Alphabetical Order Checker
+=====================================
+
+Normalize Clang-Tidy documentation with deterministic sorting for linting/tests.
+
+Behavior:
+- Sort entries in docs/clang-tidy/checks/list.rst csv-table.
+- Sort key sections in docs/ReleaseNotes.rst.
+- Detect duplicated entries in 'Changes in existing checks'.
+
+Flags:
+  -o/--output  Write normalized content to this path instead of updating docs.
+"""
+
+import argparse
+import io
+import os
+import re
+import sys
+from typing import Dict, List, Optional, Sequence, Tuple
+
+# Matches a :doc:`label <path>` or :doc:`label` reference anywhere in text and
+# captures the label. Used to sort bullet items alphabetically in ReleaseNotes
+# items by their label.
+DOC_LABEL_RN_RE = re.compile(r":doc:`(?P<label>[^`<]+)\s*(?:<[^>]+>)?`")
+
+# Matches a single csv-table row line in list.rst that begins with a :doc:
+# reference, capturing the label. Used to extract the sort key per row.
+DOC_LINE_RE = re.compile(r"^\s*:doc:`(?P<label>[^`<]+?)\s*<[^>]+>`.*$")
+
+
+def script_dir() -> str:
+    return os.path.dirname(os.path.abspath(__file__))
+
+
+def read_text(path: str) -> List[str]:
+    with io.open(path, "r", encoding="utf-8") as f:
+        return f.read().splitlines(True)
+
+
+def write_text(path: str, content: str) -> None:
+    with io.open(path, "w", encoding="utf-8", newline="") as f:
+        f.write(content)
+
+
+def normalize_list_rst(lines: Sequence[str]) -> str:
+    """Return normalized content of checks list.rst from given lines.
+
+    Input: full file content split into lines.
+    Output: single string with all csv-table rows sorted by :doc: label while
+            preserving non-table content and table options/headers.
+    """
+    out: List[str] = []
+    i = 0
+    n = len(lines)
+
+    def key_for(line: str):
+        m = DOC_LINE_RE.match(line)
+        if not m:
+            return (1, "")
+        return (0, m.group("label"))
+
+    while i < n:
+        line = lines[i]
+        if line.lstrip().startswith(".. csv-table::"):
+            out.append(line)
+            i += 1
+
+            while i < n and (lines[i].startswith(" ") or lines[i].strip() == ""):
+                if DOC_LINE_RE.match(lines[i]):
+                    break
+                out.append(lines[i])
+                i += 1
+
+            entries: List[str] = []
+            while i < n and lines[i].startswith(" "):
+                entries.append(lines[i])
+                i += 1
+
+            entries_sorted = sorted(entries, key=key_for)
+            out.extend(entries_sorted)
+            continue
+
+        out.append(line)
+        i += 1
+
+    return "".join(out)
+
+
+def find_heading(lines: Sequence[str], title: str) -> Optional[int]:
+    """Find heading start index for a section underlined with ^ characters.
+
+    The function looks for a line equal to `title` followed by a line that
+    consists solely of ^, which matches the ReleaseNotes style for subsection
+    headings used here.
+
+    Returns index of the title line, or None if not found.
+    """
+    for i in range(len(lines) - 1):
+        if lines[i].rstrip("\n") == title:
+            underline = lines[i + 1].rstrip("\n")
+            if underline and set(underline) == {"^"} and len(underline) >= len(title):
+                return i
+    return None
+
+
+def extract_label(text: str) -> str:
+    m = DOC_LABEL_RN_RE.search(text)
+    return m.group("label") if m else text
+
+
+def is_bullet_start(line: str) -> bool:
+    return line.startswith("- ")
+
+
+def collect_bullet_blocks(
+    lines: Sequence[str], start: int, end: int
+) -> Tuple[List[str], List[Tuple[str, List[str]]], List[str]]:
+    i = start
+    n = end
+    first_bullet = i
+    while first_bullet < n and not is_bullet_start(lines[first_bullet]):
+        first_bullet += 1
+    prefix = list(lines[i:first_bullet])
+
+    blocks: List[Tuple[str, List[str]]] = []
+    i = first_bullet
+    while i < n:
+        if not is_bullet_start(lines[i]):
+            break
+        bstart = i
+        i += 1
+        while i < n and not is_bullet_start(lines[i]):
+            if (
+                i + 1 < n
+                and set(lines[i + 1].rstrip("\n")) == {"^"}
+                and lines[i].strip()
+            ):
+                break
+            i += 1
+        block = list(lines[bstart:i])
+        key = extract_label(block[0])
+        blocks.append((key, block))
+
+    suffix = list(lines[i:n])
+    return prefix, blocks, suffix
+
+
+def sort_blocks(blocks: List[Tuple[str, List[str]]]) -> List[List[str]]:
+    """Return blocks sorted deterministically by their extracted label.
+
+    Duplicates are preserved; merging is left to authors to handle manually.
+    """
+    return [b for _, b in sorted(blocks, key=lambda kb: kb[0])]
+
+
+def find_duplicate_block_details(
+    lines: Sequence[str], title: str
+) -> List[Tuple[str, List[Tuple[int, List[str]]]]]:
+    """Return detailed duplicate info as (key, [(start_idx, block_lines), ...]).
+
+    start_idx is the 0-based index of the first line of the bullet block in
+    the original lines list. Only keys with more than one occurrence are
+    returned, and occurrences are listed in the order they appear.
+    """
+    bounds = _find_section_bounds(lines, title, None)
+    if bounds is None:
+        return []
+    _, sec_start, sec_end = bounds
+
+    i = sec_start
+    n = sec_end
+
+    while i < n and not is_bullet_start(lines[i]):
+        i += 1
+
+    blocks_with_pos: List[Tuple[str, int, List[str]]] = []
+    while i < n:
+        if not is_bullet_start(lines[i]):
+            break
+        bstart = i
+        i += 1
+        while i < n and not is_bullet_start(lines[i]):
+            if (
+                i + 1 < n
+                and set(lines[i + 1].rstrip("\n")) == {"^"}
+                and lines[i].strip()
+            ):
+                break
+            i += 1
+        block = list(lines[bstart:i])
+        key = extract_label(block[0])
+        blocks_with_pos.append((key, bstart, block))
+
+    grouped: Dict[str, List[Tuple[int, List[str]]]] = {}
+    for key, start, block in blocks_with_pos:
+        grouped.setdefault(key, []).append((start, block))
+
+    result: List[Tuple[str, List[Tuple[int, List[str]]]]] = []
+    for key, occs in grouped.items():
+        if len(occs) > 1:
+            result.append((key, occs))
+
+    result.sort(key=lambda kv: kv[0])
+    return result
+
+
+def _find_section_bounds(
+    lines: Sequence[str], title: str, next_title: Optional[str]
+) -> Optional[Tuple[int, int, int]]:
+    """Return (h_start, sec_start, sec_end) for section `title`.
+
+    - h_start: index of the section title line
+    - sec_start: index of the first content line after underline
+    - sec_end: index of the first line of the next section title (or end)
+    """
+    h_start = find_heading(lines, title)
+    if h_start is None:
+        return None
+
+    sec_start = h_start + 2
+
+    # Determine end of section either from next_title or by scanning.
+    if next_title is not None:
+        h_end = find_heading(lines, next_title)
+        if h_end is None:
+            # Scan forward to the next heading-like underline.
+            h_end = sec_start
+            while h_end + 1 < len(lines):
+                if lines[h_end].strip() and set(lines[h_end + 1].rstrip("\n")) == {"^"}:
+                    break
+                h_end += 1
+        sec_end = h_end
+    else:
+        # Scan to end or until a heading underline is found.
+        h_end = sec_start
+        while h_end + 1 < len(lines):
+            if lines[h_end].strip() and set(lines[h_end + 1].rstrip("\n")) == {"^"}:
+                break
+            h_end += 1
+        sec_end = h_end
+
+    return h_start, sec_start, sec_end
+
+
+def _normalize_release_notes_section(
+    lines: Sequence[str], title: str, next_title: Optional[str]
+) -> List[str]:
+    """Normalize a single release-notes section and return updated lines."""
+    bounds = _find_section_bounds(lines, title, next_title)
+    if bounds is None:
+        return list(lines)
+    _, sec_start, sec_end = bounds
+
+    prefix, blocks, suffix = collect_bullet_blocks(lines, sec_start, sec_end)
+    sorted_blocks = sort_blocks(blocks)
+
+    new_section: List[str] = []
+    new_section.extend(prefix)
+    for i_b, b in enumerate(sorted_blocks):
+        if i_b > 0 and (
+            not new_section or (new_section and new_section[-1].strip() != "")
+        ):
+            new_section.append("\n")
+        new_section.extend(b)
+    new_section.extend(suffix)
+
+    return list(lines[:sec_start]) + new_section + list(lines[sec_end:])
+
+
+def normalize_release_notes(lines: Sequence[str]) -> str:
+    sections = ["New checks", "New check aliases", "Changes in existing checks"]
+
+    out = list(lines)
+
+    for idx in range(len(sections) - 1, -1, -1):
+        title = sections[idx]
+        next_title = sections[idx + 1] if idx + 1 < len(sections) else None
+        out = _normalize_release_notes_section(out, title, next_title)
+
+    return "".join(out)
+
+
+def _default_paths() -> Tuple[str, str]:
+    base = os.path.normpath(os.path.join(script_dir(), "..", ".."))
+    list_doc = os.path.join(base, "docs", "clang-tidy", "checks", "list.rst")
+    rn_doc = os.path.join(base, "docs", "ReleaseNotes.rst")
+    return list_doc, rn_doc
+
+
+def _emit_duplicate_report(lines: Sequence[str], title: str) -> Optional[str]:
+    dups_detail = find_duplicate_block_details(lines, title)
+    if not dups_detail:
+        return None
+    out: List[str] = []
+    out.append(f"Error: Duplicate entries in '{title}':\n")
+    for key, occs in dups_detail:
+        out.append(f"\n-- Duplicate: {key}\n")
+        for start_idx, block in occs:
+            out.append(f"- At line {start_idx + 1}:\n")
+            out.append("".join(block))
+            if not (block and block[-1].endswith("\n")):
+                out.append("\n")
+    return "".join(out)
+
+
+def _handle_release_notes_out(out_path: str, rn_doc: str) -> int:
+    lines = read_text(rn_doc)
+    normalized = normalize_release_notes(lines)
+    write_text(out_path, normalized)
+
+    # Prefer reporting ordering issues first; let diff fail the test.
+    if "".join(lines) != normalized:
+        sys.stderr.write(
+            "Note: 'ReleaseNotes.rst' section is not normalized; Please fix ordering first.\n"
+        )
+        return 0
+
+    # Ordering is clean then enforce duplicates.
+    report = _emit_duplicate_report(lines, "Changes in existing checks")
+    if report:
+        sys.stderr.write(report)
+        return 3
+    return 0
+
+
+def _handle_checks_list_out(out_path: str, list_doc: str) -> int:
+    lines = read_text(list_doc)
+    normalized = normalize_list_rst(lines)
+    write_text(out_path, normalized)
+    return 0
+
+
+def main(argv: List[str]) -> int:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("-o", "--output", dest="out", default=None)
+    args = ap.parse_args(argv)
+
+    list_doc, rn_doc = _default_paths()
+
+    if args.out:
+        out_path = args.out
+        out_lower = os.path.basename(out_path).lower()
+        if "release" in out_lower:
+            return _handle_release_notes_out(out_path, rn_doc)
+        else:
+            return _handle_checks_list_out(out_path, list_doc)
+
+    list_lines = read_text(list_doc)
+    rn_lines = read_text(rn_doc)
+    list_norm = normalize_list_rst(list_lines)
+    rn_norm = normalize_release_notes(rn_lines)
+    if "".join(list_lines) != list_norm:
+        write_text(list_doc, list_norm)
+    if "".join(rn_lines) != rn_norm:
+        write_text(rn_doc, rn_norm)
+
+    report = _emit_duplicate_report(rn_lines, "Changes in existing checks")
+    if report:
+        sys.stderr.write(report)
+        return 3
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))