Add clang tidy tooling (#7412)

3 files changed, 237 insertions, 0 deletions

diff --git a/.clang-tidy b/.clang-tidy
new file mode 100644
index 0000000000..19dad14435
--- /dev/null
+++ b/.clang-tidy
@@ -0,0 +1,40 @@
+---
+# NOTE: there must be no spaces before the '-', so put the comma first.
+Checks: '
+  *
+  ,modernize-*
+  ,clang-analyzer-*
+  ,-clang-diagnostic-*
+  ,-hicpp-no-array-decay
+  ,-fuchsia-*
+  ,-google-readability-namespace-comments
+  ,-llvm-namespace-comment
+  ,-google-readability-todo
+  ,-cppcoreguidelines-pro-bounds-array-to-pointer-decay
+  ,-cert-err60-cpp
+  ,-llvm-header-guard
+  ,-cppcoreguidelines-special-member-functions
+  ,-misc-unused-parameters
+  ,-hicpp-braces-around-statements
+  ,-hicpp-special-member-functions
+  ,-readability-braces-around-statements
+  ,-modernize-use-default-member-init
+  ,-google-runtime-references
+  ,-cppcoreguidelines-pro-type-vararg
+  ,-google-readability-braces-around-statements
+  ,-google-build-using-namespace
+  ,-hicpp-vararg
+  ,-hicpp-explicit-conversions
+  ,-performance-unnecessary-value-param
+  ,-google-runtime-references
+  ,-cppcoreguidelines-pro-type-static-cast-downcast
+  ,-cppcoreguidelines-pro-bounds-constant-array-index
+  ,-cert-err58-cpp
+  ,-modernize-make-unique
+  ,-cppcoreguidelines-owning-memory
+  '
+WarningsAsErrors: ''
+HeaderFilterRegex: 'torch/csrc/'
+AnalyzeTemporaryDtors: false
+CheckOptions:
+...
diff --git a/tools/clang_tidy.py b/tools/clang_tidy.py
new file mode 100644
index 0000000000..f8c0563633
--- /dev/null
+++ b/tools/clang_tidy.py
@@ -0,0 +1,196 @@
+#!/usr/bin/env python
+
+import argparse
+import json
+import os.path
+import re
+import subprocess
+import sys
+
+DEFAULT_FILE_PATTERN = r".*\.[ch](pp)?"
+
+# @@ -start,count +start,count @@
+CHUNK_PATTERN = r"^@@\s+-\d+,\d+\s+\+(\d+)(?:,(\d+))?\s+@@"
+
+
+def run_shell_command(arguments, process_name=None):
+    """Executes a shell command."""
+    assert len(arguments) > 0
+    try:
+        output = subprocess.check_output(arguments, stderr=subprocess.STDOUT)
+    except OSError:
+        _, e, _ = sys.exc_info()
+        process_name = process_name or arguments[0]
+        raise RuntimeError("Error executing {}: {}".format(process_name, e))
+    else:
+        return output.decode()
+
+
+def transform_globs_into_regexes(globs):
+    """Turns glob patterns into regular expressions."""
+    return [glob.replace("*", ".*").replace("?", ".") for glob in globs]
+
+
+def get_file_patterns(globs, regexes):
+    """Returns a list of compiled regex objects from globs and regex pattern strings."""
+    regexes += transform_globs_into_regexes(globs)
+    if not regexes:
+        regexes = [DEFAULT_FILE_PATTERN]
+    return [re.compile(regex + "$") for regex in regexes]
+
+
+def git_diff(args, verbose):
+    """Executes a git diff command in the shell and returns its output."""
+    # --no-pager gets us the plain output, without pagination.
+    # --no-color removes color codes.
+    command = ["git", "--no-pager", "diff", "--no-color"] + args
+    if verbose:
+        print(" ".join(command))
+    return run_shell_command(command, process_name="git diff")
+
+
+def filter_files(files, file_patterns):
+    """Returns all files that match any of the patterns."""
+    filtered = []
+    for file in files:
+        for pattern in file_patterns:
+            if pattern.match(file):
+                filtered.append(file)
+    return filtered
+
+
+def get_changed_files(revision, paths, verbose):
+    """Runs git diff to get the paths of all changed files."""
+    # --diff-filter AMU gets us files that are (A)dded, (M)odified or (U)nmerged (in the working copy).
+    # --name-only makes git diff return only the file paths, without any of the source changes.
+    args = ["--diff-filter", "AMU", "--ignore-all-space", "--name-only", revision]
+    output = git_diff(args + paths, verbose)
+    return output.split("\n")
+
+
+def get_all_files(paths):
+    """Yields all files in any of the given paths"""
+    for path in paths:
+        for root, _, files in os.walk(path):
+            for file in files:
+                yield os.path.join(root, file)
+
+
+def get_changed_lines(revision, filename, verbose):
+    """Runs git diff to get the line ranges of all file changes."""
+    output = git_diff(["--unified=0", revision, filename], verbose)
+    changed_lines = []
+    for chunk in re.finditer(CHUNK_PATTERN, output, re.MULTILINE):
+        start = int(chunk.group(1))
+        count = int(chunk.group(2) or 1)
+        changed_lines.append([start, start + count])
+
+    return {"name": filename, "lines": changed_lines}
+
+
+def run_clang_tidy(options, line_filters, files):
+    """Executes the actual clang-tidy command in the shell."""
+    command = [options.clang_tidy_exe, "-p", options.compile_commands_dir]
+    if not options.config_file and os.path.exists(".clang-tidy"):
+        options.config_file = ".clang-tidy"
+    if options.config_file:
+        import yaml
+
+        with open(options.config_file) as config:
+            # Here we convert the YAML config file to a JSON blob.
+            command += ["-config", json.dumps(yaml.load(config))]
+    if options.checks:
+        command += ["-checks", options.checks]
+    if line_filters:
+        command += ["-line-filter", json.dumps(line_filters)]
+    command += ["-{}".format(arg) for arg in options.extra_args]
+    command += files
+
+    if options.verbose:
+        print(" ".join(command))
+    if options.show_command_only:
+        command = [re.sub(r"^([{[].*[]}])$", r"'\1'", arg) for arg in command]
+        return " ".join(command)
+
+    return run_shell_command(command)
+
+
+def parse_options():
+    parser = argparse.ArgumentParser(description="Run Clang-Tidy (on your Git changes)")
+    parser.add_argument(
+        "-c",
+        "--clang-tidy-exe",
+        default="clang-tidy",
+        help="{ath to clang-tidy executable",
+    )
+    parser.add_argument(
+        "-e",
+        "--extra-args",
+        nargs="+",
+        default=[],
+        help="Extra arguments to forward to clang-tidy",
+    )
+    parser.add_argument(
+        "-g",
+        "--glob",
+        nargs="+",
+        default=[],
+        help="File patterns as UNIX globs (no **)",
+    )
+    parser.add_argument(
+        "-x", "--regex", nargs="+", default=[], help="File patterns as regexes"
+    )
+    parser.add_argument(
+        "-d",
+        "--compile-commands-dir",
+        default=".",
+        help="Path to the folder containing compile_commands.json",
+    )
+    parser.add_argument("-r", "--revision", help="Git revision to get changes from")
+    parser.add_argument(
+        "-p", "--paths", nargs="+", default=["."], help="Lint only the given paths"
+    )
+    parser.add_argument(
+        "-s",
+        "--show-command-only",
+        action="store_true",
+        help="Only show the command to be executed, without running it",
+    )
+    parser.add_argument("-v", "--verbose", action="store_true", help="Verbose output")
+    parser.add_argument(
+        "--config-file",
+        help="Path to a clang-tidy config file. Defaults to '.clang-tidy'.",
+    )
+    parser.add_argument(
+        "--checks", help="Appends checks to those from the config file (if any)"
+    )
+    return parser.parse_args()
+
+
+def main():
+    options = parse_options()
+    if options.revision:
+        files = get_changed_files(options.revision, options.paths, options.verbose)
+    else:
+        files = get_all_files(options.paths)
+    file_patterns = get_file_patterns(options.glob, options.regex)
+    files = filter_files(files, file_patterns)
+
+    # clang-tidy error's when it does not get input files.
+    if not files:
+        print("No files detected.")
+        sys.exit()
+
+    line_filters = []
+    if options.revision:
+        for filename in files:
+            changed_lines = get_changed_lines(
+                options.revision, filename, options.verbose
+            )
+            line_filters.append(changed_lines)
+
+    print(run_clang_tidy(options, line_filters, files))
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tools/cpp_build/libtorch/CMakeLists.txt b/tools/cpp_build/libtorch/CMakeLists.txt
index 6f30a879ce..e546529aab 100644
--- a/tools/cpp_build/libtorch/CMakeLists.txt
+++ b/tools/cpp_build/libtorch/CMakeLists.txt
@@ -4,6 +4,7 @@ cmake_policy(VERSION 3.0)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 if (VERBOSE)
   message(STATUS "ATEN_PATH is ${ATEN_PATH}")