llvm/utils/relative_lines.py

   1 #!/usr/bin/env python3
   2
   3 """Replaces absolute line numbers in lit-tests with relative line numbers.
   4
   5 Writing line numbers like 152 in 'RUN: or CHECK:' makes tests hard to maintain:
   6 inserting lines in the middle of the test means updating all the line numbers.
   7
   8 Encoding them relative to the current line helps, and tools support it:
   9     Lit will substitute %(line+2) with the actual line number
  10     FileCheck supports [[@LINE+2]]
  11
  12 This tool takes a regex which captures a line number, and a list of test files.
  13 It searches for line numbers in the files and replaces them with a relative
  14 line number reference.
  15 """
  16
  17 USAGE = """Example usage:
  18     find -type f clang/test/CodeCompletion | grep -v /Inputs/ | \\
  19     xargs relative_lines.py --dry-run --verbose --near=100 \\
  20     --pattern='-code-completion-at[ =]%s:(\d+)' \\
  21     --pattern='requires fix-it: {(\d+):\d+-(\d+):\d+}'
  22 """
  23
  24 import argparse
  25 import re
  26 import sys
  27
  28
  29 def b(x):
  30     return bytes(x, encoding="utf-8")
  31
  32
  33 parser = argparse.ArgumentParser(
  34     prog="relative_lines",
  35     description=__doc__,
  36     epilog=USAGE,
  37     formatter_class=argparse.RawTextHelpFormatter,
  38 )
  39 parser.add_argument(
  40     "--near", type=int, default=20, help="maximum line distance to make relative"
  41 )
  42 parser.add_argument(
  43     "--partial",
  44     action="store_true",
  45     default=False,
  46     help="apply replacements to files even if others failed",
  47 )
  48 parser.add_argument(
  49     "--pattern",
  50     default=[],
  51     action="append",
  52     type=lambda x: re.compile(b(x)),
  53     help="regex to match, with line numbers captured in ().",
  54 )
  55 parser.add_argument(
  56     "--verbose", action="store_true", default=False, help="print matches applied"
  57 )
  58 parser.add_argument(
  59     "--dry-run",
  60     action="store_true",
  61     default=False,
  62     help="don't apply replacements. Best with --verbose.",
  63 )
  64 parser.add_argument("files", nargs="+")
  65 args = parser.parse_args()
  66
  67 for file in args.files:
  68     try:
  69         contents = open(file, "rb").read()
  70     except UnicodeDecodeError as e:
  71         print(f"{file}: not valid UTF-8 - {e}", file=sys.stderr)
  72     failures = 0
  73
  74     def line_number(offset):
  75         return 1 + contents[:offset].count(b"\n")
  76
  77     def replace_one(capture, line, offset):
  78         """Text to replace a capture group, e.g. 42 => %(line+1)"""
  79         try:
  80             target = int(capture)
  81         except ValueError:
  82             print(f"{file}:{line}: matched non-number '{capture}'", file=sys.stderr)
  83             return capture
  84
  85         if args.near > 0 and abs(target - line) > args.near:
  86             print(
  87                 f"{file}:{line}: target line {target} is farther than {args.near}",
  88                 file=sys.stderr,
  89             )
  90             return capture
  91         if target > line:
  92             delta = "+" + str(target - line)
  93         elif target < line:
  94             delta = "-" + str(line - target)
  95         else:
  96             delta = ""
  97
  98         prefix = contents[:offset].rsplit(b"\n")[-1]
  99         is_lit = b"RUN" in prefix or b"DEFINE" in prefix
 100         text = ("%(line{0})" if is_lit else "[[@LINE{0}]]").format(delta)
 101         if args.verbose:
 102             print(f"{file}:{line}: {0} ==> {text}")
 103         return b(text)
 104
 105     def replace_match(m):
 106         """Text to replace a whole match, e.g. --at=42:3 => --at=%(line+2):3"""
 107         line = 1 + contents[: m.start()].count(b"\n")
 108         result = b""
 109         pos = m.start()
 110         for index, capture in enumerate(m.groups()):
 111             index += 1  # re groups are conventionally 1-indexed
 112             result += contents[pos : m.start(index)]
 113             replacement = replace_one(capture, line, m.start(index))
 114             result += replacement
 115             if replacement == capture:
 116                 global failures
 117                 failures += 1
 118             pos = m.end(index)
 119         result += contents[pos : m.end()]
 120         return result
 121
 122     for pattern in args.pattern:
 123         contents = re.sub(pattern, replace_match, contents)
 124     if failures > 0 and not args.partial:
 125         print(f"{file}: leaving unchanged (some failed, --partial not given)")
 126         continue
 127     if not args.dry_run:
 128         open(file, "wb").write(contents)