[clang-tidy] Add ability to checkout clang-tidy.

This CL adds the DEPS entry to checkout `clang-tidy` if requested
in the `.gclient` config file. A doc is added which gives some
guidance on how to run `clang-tidy`.

Change-Id: I92eeaff33137158ffd17315649fb333c366fc91d
Bug: dawn:1414
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/89801
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

.clang-tidy

@@ -0,0 +1,179 @@
+FormatStyle: file
+Checks: "+*,\
+          -bugprone-argument-comment,\
+          -bugprone-branch-clone,\
+          -bugprone-copy-constructor-init,\
+          -bugprone-easily-swappable-parameters,\
+          -bugprone-exception-escape,\
+          -bugprone-fold-init-type,\
+          -bugprone-forward-declaration-namespace,\
+          -bugprone-forwarding-reference-overload,\
+          -bugprone-implicit-widening-of-multiplication-result,\
+          -bugprone-incorrect-roundings,\
+          -bugprone-infinite-loop,\
+          -bugprone-integer-division,\
+          -bugprone-lambda-function-name,\
+          -bugprone-macro-parentheses,\
+          -bugprone-misplaced-widening-cast,\
+          -bugprone-move-forwarding-reference,\
+          -bugprone-multiple-statement-macro,\
+          -bugprone-narrowing-conversions,\
+          -bugprone-not-null-terminated-result,\
+          -bugprone-parent-virtual-call,\
+          -bugprone-redundant-branch-condition,\
+          -bugprone-reserved-identifier,\
+          -bugprone-signed-char-misuse,\
+          -bugprone-sizeof-expression,\
+          -bugprone-string-constructor,\
+          -bugprone-suspicious-enum-usage,\
+          -bugprone-suspicious-include,\
+          -bugprone-suspicious-memory-comparison,\
+          -bugprone-suspicious-string-compare,\
+          -bugprone-terminating-continue,\
+          -bugprone-throw-keyword-missing,\
+          -bugprone-too-small-loop-variable,\
+          -bugprone-undefined-memory-manipulation,\
+          -bugprone-unhandled-self-assignment,\
+          -bugprone-unused-raii,\
+          -bugprone-unused-return-value,\
+          -bugprone-use-after-move,\
+          -bugprone-virtual-near-miss,\
+          -cert-dcl03-c,\
+          -cert-dcl16-c,\
+          -cert-dcl21-cpp,\
+          -cert-dcl50-cpp,\
+          -cert-dcl54-cpp,\
+          -cert-dcl58-cpp,\
+          -cert-dcl59-cpp,\
+          -cert-err09-cpp,\
+          -cert-err33-c,\
+          -cert-err34-c,\
+          -cert-err52-cpp,\
+          -cert-err58-cpp,\
+          -cert-msc30-c,\
+          -cert-msc32-c,\
+          -cert-oop11-cpp,\
+          -cert-oop54-cpp,\
+          -cert-oop57-cpp,\
+          -clang-analyzer-core.CallAndMessage,\
+          -clang-analyzer-core.DivideZero,\
+          -clang-analyzer-core.NonNullParamChecker,\
+          -clang-analyzer-core.NullDereference,\
+          -clang-analyzer-core.UndefinedBinaryOperatorResult,\
+          -clang-analyzer-core.uninitialized.Assign,\
+          -clang-analyzer-core.uninitialized.Branch,\
+          -clang-analyzer-core.uninitialized.UndefReturn,\
+          -clang-analyzer-cplusplus.Move,\
+          -clang-analyzer-cplusplus.NewDelete,\
+          -clang-analyzer-cplusplus.NewDeleteLeaks,\
+          -clang-analyzer-cplusplus.PlacementNew,\
+          -clang-analyzer-deadcode.DeadStores,\
+          -clang-analyzer-optin.cplusplus.UninitializedObject,\
+          -clang-analyzer-optin.cplusplus.VirtualCall,\
+          -clang-analyzer-optin.performance.Padding,\
+          -clang-analyzer-optin.portability.UnixAPI,\
+          -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,\
+          -clang-analyzer-security.insecureAPI.strcpy,\
+          -clang-analyzer-unix.Malloc,\
+          -clang-analyzer-valist.Unterminated,\
+          -concurrency-mt-unsafe,\
+          -google-build-using-namespace,\
+          -google-default-arguments,\
+          -google-explicit-constructor,\
+          -google-global-names-in-headers,\
+          -google-readability-avoid-underscore-in-googletest-name,\
+          -google-readability-braces-around-statements,\
+          -google-readability-casting,\
+          -google-readability-function-size,\
+          -google-readability-namespace-comments,\
+          -google-readability-todo,\
+          -google-runtime-int,\
+          -google-runtime-operator,\
+          -google-upgrade-googletest-case,\
+          -misc-definitions-in-headers,\
+          -misc-misplaced-const,\
+          -misc-non-private-member-variables-in-classes,\
+          -misc-no-recursion,\
+          -misc-redundant-expression,\
+          -misc-unconventional-assign-operator,\
+          -misc-uniqueptr-reset-release,\
+          -misc-unused-parameters,\
+          -misc-unused-using-decls,\
+          -modernize-avoid-bind,\
+          -modernize-avoid-c-arrays,\
+          -modernize-concat-nested-namespaces,\
+          -modernize-deprecated-headers,\
+          -modernize-loop-convert,\
+          -modernize-macro-to-enum,\
+          -modernize-make-shared,\
+          -modernize-make-unique,\
+          -modernize-pass-by-value,\
+          -modernize-raw-string-literal,\
+          -modernize-redundant-void-arg,\
+          -modernize-replace-disallow-copy-and-assign-macro,\
+          -modernize-return-braced-init-list,\
+          -modernize-unary-static-assert,\
+          -modernize-use-auto,\
+          -modernize-use-bool-literals,\
+          -modernize-use-default-member-init,\
+          -modernize-use-emplace,\
+          -modernize-use-equals-default,\
+          -modernize-use-equals-delete,\
+          -modernize-use-nodiscard,\
+          -modernize-use-noexcept,\
+          -modernize-use-nullptr,\
+          -modernize-use-override,\
+          -modernize-use-trailing-return-type,\
+          -modernize-use-transparent-functors,\
+          -modernize-use-using,\
+          -performance-faster-string-find,\
+          -performance-for-range-copy,\
+          -performance-inefficient-algorithm,\
+          -performance-inefficient-string-concatenation,\
+          -performance-inefficient-vector-operation,\
+          -performance-move-const-arg,\
+          -performance-no-automatic-move,\
+          -performance-noexcept-move-constructor,\
+          -performance-no-int-to-ptr,\
+          -performance-trivially-destructible,\
+          -performance-unnecessary-copy-initialization,\
+          -performance-unnecessary-value-param,\
+          -portability-std-allocator-const,\
+          -readability-avoid-const-params-in-decls,\
+          -readability-braces-around-statements,\
+          -readability-const-return-type,\
+          -readability-container-data-pointer,\
+          -readability-container-size-empty,\
+          -readability-convert-member-functions-to-static,\
+          -readability-delete-null-pointer,\
+          -readability-duplicate-include,\
+          -readability-else-after-return,\
+          -readability-function-cognitive-complexity,\
+          -readability-identifier-length,\
+          -readability-identifier-naming,\
+          -readability-implicit-bool-conversion,\
+          -readability-inconsistent-declaration-parameter-name,\
+          -readability-isolate-declaration,\
+          -readability-magic-numbers,\
+          -readability-make-member-function-const,\
+          -readability-misleading-indentation,\
+          -readability-named-parameter,\
+          -readability-non-const-parameter,\
+          -readability-qualified-auto,\
+          -readability-redundant-access-specifiers,\
+          -readability-redundant-control-flow,\
+          -readability-redundant-declaration,\
+          -readability-redundant-member-init,\
+          -readability-redundant-preprocessor,\
+          -readability-redundant-smartptr-get,\
+          -readability-redundant-string-cstr,\
+          -readability-redundant-string-init,\
+          -readability-simplify-boolean-expr,\
+          -readability-simplify-subscript-expr,\
+          -readability-static-accessed-through-instance,\
+          -readability-static-definition-in-anonymous-namespace,\
+          -readability-string-compare,\
+          -readability-suspicious-call-argument,\
+          -readability-uppercase-literal-suffix,\
+          -readability-use-anyofallof,\
+          "

.gitignore

@@ -122,3 +122,7 @@ default.profraw
 lcov.info
 /cmake-build-*/
 /testing
+
+### Clang-Tidy files
+all_findings.json
+

DEPS

@@ -26,6 +26,9 @@ vars = {
 
   # GN variable required by //testing that will be output in the gclient_args.gni
   'generate_location_tags': False,
+
+  # Fetch clang-tidy into the same bin/ directory as our clang binary.
+  'checkout_clang_tidy': False,
 }
 
 deps = {
@@ -242,6 +245,15 @@ hooks = [
     'action': ['python3', 'tools/clang/scripts/update.py'],
     'condition': 'dawn_standalone',
   },
+  {
+    # This is also supposed to support the same set of platforms as 'clang'
+    # above. LLVM ToT support isn't provided at the moment.
+    'name': 'clang_tidy',
+    'pattern': '.',
+    'condition': 'checkout_clang_tidy',
+    'action': ['python3', 'tools/clang/scripts/update.py',
+               '--package=clang-tidy'],
+  },
   {
     # Pull rc binaries using checked-in hashes.
     'name': 'rc_win',

docs/clang-tidy.md

@@ -0,0 +1,37 @@
+# Running clang-tidy
+
+* Add `"checkout_clang_tidy": True` to `.gclient` file in the `custom_vars`.
+  ```
+  {
+    "custom_vars": {
+      "checkout_clang_tidy": True,
+    }
+  }
+  ```
+* `gclient sync`
+
+There should now be `third_party/llvm-build/Release+Asserts/bin/clang-tidy`
+
+* `cd out`
+* `git clone https://chromium.googlesource.com/chromium/tools/build`
+
+The Chromium build folder contains the `tricium` files used to run `clang-tidy`
+
+Running clang-tidy over all the source can be done with:
+
+```
+cd ..
+out/build/recipes/recipe_modules/tricium_clang_tidy/resources/tricium_clang_tidy_script.py \
+--base_path $PWD \
+--out_dir out/Debug \
+--findings_file all_findings.json \
+--clang_tidy_binary $PWD/third_party/llvm-build/Release+Asserts/bin/clang-tidy \
+--all
+```
+
+`--all` can be replaced by specific files if desired to run on individual source
+files.
+
+
+## References
+* https://chromium.googlesource.com/chromium/src.git/+/HEAD/docs/clang_tidy.md