Add tool to fix lines > 120 chars. (#18293)

### Description
<!-- Describe your changes. -->
Helper to run clang-format on lines that are > 120 chars.

We disable clang-format enforcing 120 chars by default because it's
formatting can negatively impact readability. If a developer has not
manually kept a line within the 120 char limit this tool will fix it. It
will leave all other lines alone to honor the formatting the developer
chose.

### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Help developers fix lint errors. 

Preferred is to use a vertical ruler/guideline in your editor when
actually writing the code.

tools/python/fix_long_lines.py

@@ -0,0 +1,134 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+import argparse
+import logging
+import os
+import pathlib
+import shutil
+import tempfile
+
+from util import logger, run
+
+_log = logger.get_logger("fix_long_lines", logging.INFO)
+
+
+# look for long lines in the file, and if found run clang-format on those lines
+def _process_files(filenames, clang_exe, tmpdir):
+    for path in filenames:
+        _log.debug(f"Checking {path}")
+        bad_lines = []
+
+        with open(path, encoding="UTF8") as f:
+            line_num = 0
+            for line in f:
+                line_num += 1  # clang-format line numbers start at 1
+                if len(line) > 120:
+                    bad_lines.append(line_num)
+
+        if bad_lines:
+            _log.info(f"Updating {path}")
+            filename = os.path.basename(path)
+            target = os.path.join(tmpdir, filename)
+            shutil.copy(path, target)
+
+            # run clang-format to update just the long lines in the file
+            cmd = [
+                clang_exe,
+                "-i",
+            ]
+            for line in bad_lines:
+                cmd.append(f"--lines={line}:{line}")
+
+            cmd.append(target)
+
+            run(*cmd, cwd=tmpdir, check=True, shell=True)
+
+            # copy updated file back to original location
+            shutil.copy(target, path)
+
+
+# file extensions we process
+_EXTENSIONS = [".cc", ".h"]
+
+
+def _get_branch_diffs(ort_root, branch):
+    command = ["git", "diff", branch, "--name-only"]
+    result = run(*command, capture_stdout=True, check=True)
+
+    # stdout is bytes. one filename per line. decode, split, and filter to the extensions we are looking at
+    for f in result.stdout.decode("utf-8").splitlines():
+        if os.path.splitext(f.lower())[-1] in _EXTENSIONS:
+            yield os.path.join(ort_root, f)
+
+
+def _get_file_list(path):
+    for root, _, files in os.walk(path):
+        for file in files:
+            if os.path.splitext(file.lower())[-1] in _EXTENSIONS:
+                yield os.path.join(root, file)
+
+
+def main():
+    argparser = argparse.ArgumentParser(
+        "Script to fix long lines in the source using clang-format. "
+        "Only lines that exceed the 120 character maximum are altered in order to minimize the impact. "
+        "Checks .cc and .h files",
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+    )
+
+    argparser.add_argument(
+        "--branch",
+        type=str,
+        default="origin/main",
+        help="Limit changes to files that differ from this branch. Use origin/main when preparing a PR.",
+    )
+
+    argparser.add_argument(
+        "--all_files",
+        action="store_true",
+        help="Process all files under /include/onnxruntime and /onnxruntime/core. Ignores --branch value.",
+    )
+
+    argparser.add_argument(
+        "--clang-format",
+        type=pathlib.Path,
+        required=False,
+        default="clang-format",
+        help="Path to clang-format executable",
+    )
+
+    argparser.add_argument("--debug", action="store_true", help="Set log level to DEBUG.")
+
+    args = argparser.parse_args()
+
+    if args.debug:
+        _log.setLevel(logging.DEBUG)
+
+    script_dir = os.path.dirname(os.path.realpath(__file__))
+    ort_root = os.path.abspath(os.path.join(script_dir, "..", ".."))
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        # create config in tmpdir
+        with open(os.path.join(tmpdir, ".clang-format"), "w") as f:
+            f.write(
+                """
+            BasedOnStyle: Google
+            ColumnLimit: 120
+            DerivePointerAlignment: false
+            """
+            )
+
+        clang_format = str(args.clang_format)
+
+        if args.all_files:
+            include_path = os.path.join(ort_root, "include", "onnxruntime")
+            src_path = os.path.join(ort_root, "onnxruntime", "core")
+            _process_files(_get_file_list(include_path), clang_format, tmpdir)
+            _process_files(_get_file_list(src_path), clang_format, tmpdir)
+        else:
+            _process_files(_get_branch_diffs(ort_root, args.branch), clang_format, tmpdir)
+
+
+if __name__ == "__main__":
+    main()

tools/python/util/logger.py

@@ -4,8 +4,8 @@
 import logging
 
 
-def get_logger(name):
+def get_logger(name, level=logging.DEBUG):
     logging.basicConfig(format="%(asctime)s %(name)s [%(levelname)s] - %(message)s")
     logger = logging.getLogger(name)
-    logger.setLevel(logging.DEBUG)
+    logger.setLevel(level)
     return logger