drm_hwcomposer: clang-tidy: enable cppcoreguidelines-* checks

Our code isn't ready for the following checks therefore keep disabled
-cppcoreguidelines-pro-bounds-array-to-pointer-decay
-cppcoreguidelines-pro-bounds-constant-array-index
-cppcoreguidelines-pro-bounds-pointer-arithmetic
-cppcoreguidelines-pro-type-cstyle-cast
-cppcoreguidelines-pro-type-vararg
-cppcoreguidelines-avoid-magic-numbers
-cppcoreguidelines-macro-usage
-cppcoreguidelines-avoid-c-arrays

+ fixed existing tidy warnings for these checks.

Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/compositor/DrmDisplayComposition.cpp b/compositor/DrmDisplayComposition.cpp
index a8dc0fc..ef151a1 100644
--- a/compositor/DrmDisplayComposition.cpp
+++ b/compositor/DrmDisplayComposition.cpp
@@ -103,7 +103,7 @@
   for (size_t i = 0; i < layers_.size(); ++i)
     to_composite.emplace(std::make_pair(i, &layers_[i]));
 
-  int ret;
+  int ret = 0;
   std::tie(ret,
            composition_planes_) = planner_->ProvisionPlanes(to_composite, crtc_,
                                                             primary_planes,
@@ -122,7 +122,7 @@
     // make sure that source layers are ordered based on zorder
     std::sort(i.source_layers().begin(), i.source_layers().end());
 
-    std::vector<DrmPlane *> *container;
+    std::vector<DrmPlane *> *container = nullptr;
     if (i.plane()->type() == DRM_PLANE_TYPE_PRIMARY)
       container = primary_planes;
     else
diff --git a/compositor/DrmDisplayCompositor.cpp b/compositor/DrmDisplayCompositor.cpp
index 5331b6d..8d96d0e 100644
--- a/compositor/DrmDisplayCompositor.cpp
+++ b/compositor/DrmDisplayCompositor.cpp
@@ -76,7 +76,7 @@
       writeback_fence_(-1),
       flattening_state_(FlatteningState::kNone),
       frames_flattened_(0) {
-  struct timespec ts;
+  struct timespec ts {};
   if (clock_gettime(CLOCK_MONOTONIC, &ts))
     return;
   dump_last_timestamp_ns_ = ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
@@ -189,7 +189,7 @@
     return -ENOMEM;
   }
 
-  int ret;
+  int ret = 0;
   std::vector<DrmCompositionPlane> &comp_planes = display_comp
                                                       ->composition_planes();
   for (DrmCompositionPlane &comp_plane : comp_planes) {
@@ -638,8 +638,7 @@
 
 std::tuple<int, uint32_t> DrmDisplayCompositor::CreateModeBlob(
     const DrmMode &mode) {
-  struct drm_mode_modeinfo drm_mode;
-  memset(&drm_mode, 0, sizeof(drm_mode));
+  struct drm_mode_modeinfo drm_mode {};
   mode.ToDrmModeModeInfo(&drm_mode);
 
   uint32_t id = 0;
@@ -1138,7 +1137,7 @@
   uint64_t num_frames = dump_frames_composited_;
   dump_frames_composited_ = 0;
 
-  struct timespec ts;
+  struct timespec ts {};
   ret = clock_gettime(CLOCK_MONOTONIC, &ts);
   if (ret) {
     pthread_mutex_unlock(&lock_);
diff --git a/compositor/DrmDisplayCompositor.h b/compositor/DrmDisplayCompositor.h
index ab3f867..92dadca 100644
--- a/compositor/DrmDisplayCompositor.h
+++ b/compositor/DrmDisplayCompositor.h
@@ -143,11 +143,11 @@
 
   ModeState mode_;
 
-  int framebuffer_index_;
+  int framebuffer_index_{};
   DrmFramebuffer framebuffers_[DRM_DISPLAY_BUFFERS];
 
   // mutable since we need to acquire in Dump()
-  mutable pthread_mutex_t lock_;
+  mutable pthread_mutex_t lock_{};
 
   // State tracking progress since our last Dump(). These are mutable since
   // we need to reset them on every Dump() call.
diff --git a/compositor/Planner.cpp b/compositor/Planner.cpp
index fb6a8c3..b6f10d2 100644
--- a/compositor/Planner.cpp
+++ b/compositor/Planner.cpp
@@ -45,7 +45,7 @@
 
 int Planner::PlanStage::ValidatePlane(DrmPlane *plane, DrmHwcLayer *layer) {
   int ret = 0;
-  uint64_t blend;
+  uint64_t blend = UINT64_MAX;
 
   if ((plane->rotation_property().id() == 0) &&
       layer->transform != DrmHwcTransform::kIdentity) {
@@ -122,7 +122,7 @@
     std::vector<DrmCompositionPlane> *composition,
     std::map<size_t, DrmHwcLayer *> &layers, DrmCrtc *crtc,
     std::vector<DrmPlane *> *planes) {
-  int ret;
+  int ret = 0;
   for (auto i = layers.begin(); i != layers.end();) {
     if (!i->second->protected_usage()) {
       ++i;