Improve clang-format-diff help output

[serge-sans-paille]

It is quite common to symlink clang-format-diff.py to clang-format-diff, and in that case the help output still refers to the .py version. Compute it instead to work in both setup.

[llvmbot]

@llvm/pr-subscribers-clang-format

Author: None (serge-sans-paille)

Changes

It is quite common to symlink clang-format-diff.py to clang-format-diff, and in that case the help output still refers to the .py version. Compute it instead to work in both setup.

---

Full diff: https://github.com/llvm/llvm-project/pull/73491.diff

1 Files Affected:

• (modified) clang/tools/clang-format/clang-format-diff.py (+6-3)

diff --git a/clang/tools/clang-format/clang-format-diff.py b/clang/tools/clang-format/clang-format-diff.py
index 892c1e38a462ff4..facaaf96dd8f90a 100755
--- a/clang/tools/clang-format/clang-format-diff.py
+++ b/clang/tools/clang-format/clang-format-diff.py
@@ -13,8 +13,8 @@
 lines. This is useful to reformat all the lines touched by a specific patch.
 Example usage for git/svn users:
 
-  git diff -U0 --no-color --relative HEAD^ | clang-format-diff.py -p1 -i
-  svn diff --diff-cmd=diff -x-U0 | clang-format-diff.py -i
+  git diff -U0 --no-color --relative HEAD^ | {clang_format_diff} -p1 -i
+  svn diff --diff-cmd=diff -x-U0 | {clang_format_diff} -i
 
 It should be noted that the filename contained in the diff is used unmodified
 to determine the source file to update. Users calling this script directly
@@ -25,6 +25,7 @@
 
 import argparse
 import difflib
+import os
 import re
 import subprocess
 import sys
@@ -36,8 +37,10 @@
 
 
 def main():
+    basename = os.path.basename(sys.argv[0])
     parser = argparse.ArgumentParser(
-        description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter
+        description=__doc__.format(clang_format_diff=basename),
+        formatter_class=argparse.RawDescriptionHelpFormatter
     )
     parser.add_argument(
         "-i",

[github-actions]

✅ With the latest revision this PR passed the Python code formatter.

[owenca]

See below. Seems it's already working as expected without this patch.

$ clang-format -version
clang-format version 17.0.5
$ clang-format-diff.py foo
usage: clang-format-diff.py [-h] [-i] [-p NUM] [-regex PATTERN] [-iregex PATTERN]
                            [-sort-includes] [-v] [-style STYLE]
                            [-fallback-style FALLBACK_STYLE] [-binary BINARY]
clang-format-diff.py: error: unrecognized arguments: foo
$ ln -s clang-format-diff.py cfd
$ cfd foo
usage: cfd [-h] [-i] [-p NUM] [-regex PATTERN] [-iregex PATTERN] [-sort-includes] [-v]
           [-style STYLE] [-fallback-style FALLBACK_STYLE] [-binary BINARY]
cfd: error: unrecognized arguments: foo

[serge-sans-paille]

See below. Seems it's already working as expected without this patch.

$ clang-format -version
clang-format version 17.0.5
$ clang-format-diff.py foo
usage: clang-format-diff.py [-h] [-i] [-p NUM] [-regex PATTERN] [-iregex PATTERN]
                            [-sort-includes] [-v] [-style STYLE]
                            [-fallback-style FALLBACK_STYLE] [-binary BINARY]
clang-format-diff.py: error: unrecognized arguments: foo
$ ln -s clang-format-diff.py cfd
$ cfd foo
usage: cfd [-h] [-i] [-p NUM] [-regex PATTERN] [-iregex PATTERN] [-sort-includes] [-v]
           [-style STYLE] [-fallback-style FALLBACK_STYLE] [-binary BINARY]
cfd: error: unrecognized arguments: foo

try with clang-format-diff.py --help vs cfd --help ;-)

[owenca]

Please open a github issue to show us what you are trying to accomplish and reference the issue number here.

[serge-sans-paille]

@owenca bug opened as #73635 and commit message updated to link to it.