[clang-tidy] add option to avoid "no checks enabled" error

clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp

@@ -325,6 +325,14 @@ option is recognized.
 )"),
  cl::init(false), cl::cat(ClangTidyCategory));
 
+static cl::opt<bool> AllowNoChecks("allow-no-checks", desc(R"(
+Allow empty enabled checks. This suppresses
+the "no checks enabled" error when disabling
+all of the checks.
+)"),
+ cl::init(false),
+ cl::cat(ClangTidyCategory));
+
 namespace clang::tidy {
 
 static void printStats(const ClangTidyStats &Stats) {
@@ -598,7 +606,7 @@ int clangTidyMain(int argc, const char **argv) {
  }
 
  if (ListChecks) {
- if (EnabledChecks.empty()) {
+ if (EnabledChecks.empty() && !AllowNoChecks) {
  llvm::errs() << "No checks enabled.\n";
  return 1;
  }
@@ -652,6 +660,10 @@ int clangTidyMain(int argc, const char **argv) {
  }
 
  if (EnabledChecks.empty()) {
+ if (AllowNoChecks) {
+ llvm::outs() << "No checks enabled.\n";
+ return 0;
+ }
  llvm::errs() << "Error: no checks enabled.\n";
  llvm::cl::PrintHelpMessage(/*Hidden=*/false, /*Categorized=*/true);
  return 1;

clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py

@@ -229,6 +229,11 @@ def main():
  default=[],
  help="Load the specified plugin in clang-tidy.",
  )
+ parser.add_argument(
+ "-allow-no-checks",
+ action="store_true",
+ help="Allow empty enabled checks.",
+ )
 
  clang_tidy_args = []
  argv = sys.argv[1:]
@@ -327,6 +332,8 @@ def main():
  common_clang_tidy_args.append("-p=%s" % args.build_path)
  if args.use_color:
  common_clang_tidy_args.append("--use-color")
+ if args.allow_no_checks:
+ common_clang_tidy_args.append("--allow-no-checks")
  for arg in args.extra_arg:
  common_clang_tidy_args.append("-extra-arg=%s" % arg)
  for arg in args.extra_arg_before:

clang-tools-extra/clang-tidy/tool/run-clang-tidy.py

@@ -107,6 +107,7 @@ def get_tidy_invocation(
  plugins,
  warnings_as_errors,
  exclude_header_filter,
+ allow_no_checks,
 ):
  """Gets a command line for clang-tidy."""
  start = [clang_tidy_binary]
@@ -147,6 +148,8 @@ def get_tidy_invocation(
  start.append("-load=" + plugin)
  if warnings_as_errors:
  start.append("--warnings-as-errors=" + warnings_as_errors)
+ if allow_no_checks:
+ start.append("--allow-no-checks")
  start.append(f)
  return start
 
@@ -232,6 +235,7 @@ def run_tidy(args, clang_tidy_binary, tmpdir, build_path, queue, lock, failed_fi
  args.plugins,
  args.warnings_as_errors,
  args.exclude_header_filter,
+ args.allow_no_checks,
  )
 
  proc = subprocess.Popen(
@@ -402,6 +406,11 @@ def main():
  default=None,
  help="Upgrades warnings to errors. Same format as '-checks'",
  )
+ parser.add_argument(
+ "-allow-no-checks",
+ action="store_true",
+ help="Allow empty enabled checks.",
+ )
  args = parser.parse_args()
 
  db_path = "compile_commands.json"
@@ -463,6 +472,7 @@ def main():
  args.plugins,
  args.warnings_as_errors,
  args.exclude_header_filter,
+ args.allow_no_checks,
  )
  invocation.append("-list-checks")
  invocation.append("-")

clang-tools-extra/docs/ReleaseNotes.rst

@@ -125,6 +125,9 @@ Improvements to clang-tidy
 - Added argument `--exclude-header-filter` and config option `ExcludeHeaderFilterRegex`
  to exclude headers from analysis via a RegEx.
 
+- Added argument `--allow-no-checks` to suppress "no checks enabled" error
+ when disabling all of the checks by `--checks='-*'`.
+
 New checks
 ^^^^^^^^^^
 

clang-tools-extra/docs/clang-tidy/index.rst

@@ -240,6 +240,9 @@ An overview of all the command-line options:
  This option's value is appended to the value of
  the 'WarningsAsErrors' option in .clang-tidy
  file, if any.
+ --allow-no-checks - Allow empty enabled checks. This suppresses
+ the "no checks enabled" error when disabling
+ all of the checks.
 
  -p <build-path> is used to read a compile command database.
 

clang-tools-extra/test/clang-tidy/infrastructure/allow-no-checks.cpp

@@ -0,0 +1,4 @@
+// RUN: not clang-tidy %s -checks='-*'
+// RUN: clang-tidy %s -checks='-*' --allow-no-checks | FileCheck --match-full-lines %s
+
+// CHECK: No checks enabled.