[lint] Merge impeller .clang-tidy into main config (#33692)

Merges most (but not all) of the impeller .clang-tidy rules into the
main .clang-tidy config. Merges:

readability-identifier-naming.PrivateMemberSuffix (_)
readability-identifier-naming.EnumConstantPrefix (k)
modernize-use-default-member-init.UseAssignment
Does not merge:

readability-identifier-naming.PublicMethodCase (CamelCase)
readability-identifier-naming.PrivateMethodCase (CamelCase)
These last two are not merged due to the non-trivial number of existing
field accessors that use field_name() methods to directly return
field_name_. While these are permitted by the C++ style guide, we may
want to move to a single, simple rule and name everything in CamelCase.
These can be enabled in a followup patch.

No new tests added, since this change is style-only.

Author: cbracken

.clang-tidy

@@ -2,6 +2,7 @@
 Checks: "google-*,\
 clang-analyzer-*,\
 clang-diagnostic-*,\
+modernize-use-default-member-init,\
 readability-identifier-naming,\
 -google-objc-global-variable-declaration,\
 -google-objc-avoid-throwing-exception,\
@@ -22,5 +23,15 @@ google-objc-*,\
 google-explicit-constructor"
 
 CheckOptions:
-  - key: readability-identifier-naming.GlobalConstantPrefix
-    value: k
+  - key:    modernize-use-default-member-init.UseAssignment
+    value:  true
+  - key:    readability-identifier-naming.EnumConstantCase
+    value:  'CamelCase'
+  - key:    readability-identifier-naming.EnumConstantPrefix
+    value:  'k'
+  - key:    readability-identifier-naming.GlobalConstantPrefix
+    value:  'k'
+  - key:    readability-identifier-naming.PrivateMemberCase
+    value:  'lower_case'
+  - key:    readability-identifier-naming.PrivateMemberSuffix
+    value:  '_'

ci/licenses_golden/licenses_flutter

@@ -397,7 +397,6 @@ FILE: ../../../flutter/fml/unique_fd.cc
 FILE: ../../../flutter/fml/unique_fd.h
 FILE: ../../../flutter/fml/unique_object.h
 FILE: ../../../flutter/fml/wakeable.h
-FILE: ../../../flutter/impeller/.clang-tidy
 FILE: ../../../flutter/impeller/aiks/aiks_context.cc
 FILE: ../../../flutter/impeller/aiks/aiks_context.h
 FILE: ../../../flutter/impeller/aiks/aiks_playground.cc

display_list/display_list_unittests.cc

@@ -1360,15 +1360,15 @@ TEST(DisplayList, DisplayListBlenderRefHandling) {
   class BlenderRefTester : public virtual AttributeRefTester {
    public:
     void setRefToPaint(SkPaint& paint) const override {
-      paint.setBlender(blender);
+      paint.setBlender(blender_);
     }
     void setRefToDisplayList(DisplayListBuilder& builder) const override {
-      builder.setBlender(blender);
+      builder.setBlender(blender_);
     }
-    bool ref_is_unique() const override { return blender->unique(); }
+    bool ref_is_unique() const override { return blender_->unique(); }
 
    private:
-    sk_sp<SkBlender> blender =
+    sk_sp<SkBlender> blender_ =
         SkBlenders::Arithmetic(0.25, 0.25, 0.25, 0.25, true);
   };
 

flow/surface_frame.cc

@@ -17,8 +17,7 @@ SurfaceFrame::SurfaceFrame(sk_sp<SkSurface> surface,
                            const SubmitCallback& submit_callback,
                            std::unique_ptr<GLContextResult> context_result,
                            bool display_list_fallback)
-    : submitted_(false),
-      surface_(surface),
+    : surface_(surface),
       framebuffer_info_(std::move(framebuffer_info)),
       submit_callback_(submit_callback),
       context_result_(std::move(context_result)) {

fml/platform/posix/mapping_posix.cc

@@ -51,8 +51,7 @@ Mapping::Mapping() = default;
 Mapping::~Mapping() = default;
 
 FileMapping::FileMapping(const fml::UniqueFD& handle,
-                         std::initializer_list<Protection> protection)
-    : size_(0), mapping_(nullptr) {
+                         std::initializer_list<Protection> protection) {
   if (!handle.is_valid()) {
     return;
   }

fml/synchronization/semaphore.cc

@@ -15,44 +15,44 @@ namespace fml {
 class PlatformSemaphore {
  public:
   explicit PlatformSemaphore(uint32_t count)
-      : _sem(dispatch_semaphore_create(count)), _initial(count) {}
+      : sem_(dispatch_semaphore_create(count)), initial_(count) {}
 
   ~PlatformSemaphore() {
-    for (uint32_t i = 0; i < _initial; ++i) {
+    for (uint32_t i = 0; i < initial_; ++i) {
       Signal();
     }
-    if (_sem != nullptr) {
-      dispatch_release(reinterpret_cast<dispatch_object_t>(_sem));
-      _sem = nullptr;
+    if (sem_ != nullptr) {
+      dispatch_release(reinterpret_cast<dispatch_object_t>(sem_));
+      sem_ = nullptr;
     }
   }
 
-  bool IsValid() const { return _sem != nullptr; }
+  bool IsValid() const { return sem_ != nullptr; }
 
   bool Wait() {
-    if (_sem == nullptr) {
+    if (sem_ == nullptr) {
       return false;
     }
-    return dispatch_semaphore_wait(_sem, DISPATCH_TIME_FOREVER) == 0;
+    return dispatch_semaphore_wait(sem_, DISPATCH_TIME_FOREVER) == 0;
   }
 
   bool TryWait() {
-    if (_sem == nullptr) {
+    if (sem_ == nullptr) {
       return false;
     }
 
-    return dispatch_semaphore_wait(_sem, DISPATCH_TIME_NOW) == 0;
+    return dispatch_semaphore_wait(sem_, DISPATCH_TIME_NOW) == 0;
   }
 
   void Signal() {
-    if (_sem != nullptr) {
-      dispatch_semaphore_signal(_sem);
+    if (sem_ != nullptr) {
+      dispatch_semaphore_signal(sem_);
     }
   }
 
  private:
-  dispatch_semaphore_t _sem;
-  const uint32_t _initial;
+  dispatch_semaphore_t sem_;
+  const uint32_t initial_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(PlatformSemaphore);
 };

impeller/.clang-tidy

@@ -17,7 +17,7 @@
 namespace impeller {
 
 struct ArchiveDatabase::Handle {
-  Handle(const std::string& filename) {
+  explicit Handle(const std::string& filename) {
     if (::sqlite3_initialize() != SQLITE_OK) {
       VALIDATION_LOG << "Could not initialize sqlite.";
       return;

impeller/archivist/archive_database.cc

@@ -18,7 +18,7 @@ static int64_t LastSample = 0;
 
 class Sample : public Archivable {
  public:
-  Sample(uint64_t count = 42) : some_data_(count) {}
+  explicit Sample(uint64_t count = 42) : some_data_(count) {}
 
   Sample(Sample&&) = default;
 

impeller/archivist/archivist_unittests.cc

@@ -44,7 +44,7 @@ TEST(ThreadTest, CanCreateRWMutex) {
   f.mtx.UnlockWriter();
   // int b = f.a; <--- Static analysis error.
   f.mtx.LockReader();
-  int b = f.a;
+  int b = f.a;  // NOLINT(clang-analyzer-deadcode.DeadStores)
   FML_ALLOW_UNUSED_LOCAL(b);
   f.mtx.UnlockReader();
 }
@@ -61,7 +61,7 @@ TEST(ThreadTest, CanCreateRWMutexLock) {
   // int b = f.a; <--- Static analysis error.
   {
     auto read_lock = ReaderLock(f.mtx);
-    int b = f.a;
+    int b = f.a;  // NOLINT(clang-analyzer-deadcode.DeadStores)
     FML_ALLOW_UNUSED_LOCAL(b);
   }