Don't report down-calls as unhandled exceptions.

Bug: 15310540
Also, narrow scope of catch/deoptimize stack visitors that are specific to
quick exception delivery.

Change-Id: Ib13a006ce1347acb93a36b0186550d4c3ec2034b

1 files changed, 174 insertions, 12 deletions

diff --git a/runtime/quick_exception_handler.cc b/runtime/quick_exception_handler.cc
index 243818c4a2..b9cec40ebf 100644
--- a/runtime/quick_exception_handler.cc
+++ b/runtime/quick_exception_handler.cc
@@ -16,25 +16,105 @@
 
 #include "quick_exception_handler.h"
 
-#include "catch_block_stack_visitor.h"
-#include "deoptimize_stack_visitor.h"
+#include "dex_instruction.h"
 #include "entrypoints/entrypoint_utils.h"
-#include "mirror/art_method-inl.h"
 #include "handle_scope-inl.h"
+#include "mirror/art_method-inl.h"
+#include "verifier/method_verifier.h"
 
 namespace art {
 
+static constexpr bool kDebugExceptionDelivery = false;
+static constexpr size_t kInvalidFrameId = 0xffffffff;
+
 QuickExceptionHandler::QuickExceptionHandler(Thread* self, bool is_deoptimization)
   : self_(self), context_(self->GetLongJumpContext()), is_deoptimization_(is_deoptimization),
     method_tracing_active_(is_deoptimization ||
                            Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()),
-    handler_quick_frame_(nullptr), handler_quick_frame_pc_(0), handler_dex_pc_(0),
-    clear_exception_(false), handler_frame_id_(kInvalidFrameId) {
+    handler_quick_frame_(nullptr), handler_quick_frame_pc_(0), handler_method_(nullptr),
+    handler_dex_pc_(0), clear_exception_(false), handler_frame_id_(kInvalidFrameId) {
 }
 
+// Finds catch handler or prepares for deoptimization.
+class CatchBlockStackVisitor FINAL : public StackVisitor {
+ public:
+  CatchBlockStackVisitor(Thread* self, Context* context, Handle<mirror::Throwable>* exception,
+                         QuickExceptionHandler* exception_handler)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
+      : StackVisitor(self, context), self_(self), exception_(exception),
+        exception_handler_(exception_handler) {
+  }
+
+  bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    mirror::ArtMethod* method = GetMethod();
+    exception_handler_->SetHandlerFrameId(GetFrameId());
+    if (method == nullptr) {
+      // This is the upcall, we remember the frame and last pc so that we may long jump to them.
+      exception_handler_->SetHandlerQuickFramePc(GetCurrentQuickFramePc());
+      exception_handler_->SetHandlerQuickFrame(GetCurrentQuickFrame());
+      uint32_t next_dex_pc;
+      mirror::ArtMethod* next_art_method;
+      bool has_next = GetNextMethodAndDexPc(&next_art_method, &next_dex_pc);
+      // Report the method that did the down call as the handler.
+      exception_handler_->SetHandlerDexPc(next_dex_pc);
+      exception_handler_->SetHandlerMethod(next_art_method);
+      if (!has_next) {
+        // No next method? Check exception handler is set up for the unhandled exception handler
+        // case.
+        DCHECK_EQ(0U, exception_handler_->GetHandlerDexPc());
+        DCHECK(nullptr == exception_handler_->GetHandlerMethod());
+      }
+      return false;  // End stack walk.
+    }
+    if (method->IsRuntimeMethod()) {
+      // Ignore callee save method.
+      DCHECK(method->IsCalleeSaveMethod());
+      return true;
+    }
+    return HandleTryItems(method);
+  }
+
+ private:
+  bool HandleTryItems(mirror::ArtMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    uint32_t dex_pc = DexFile::kDexNoIndex;
+    if (!method->IsNative()) {
+      dex_pc = GetDexPc();
+    }
+    if (dex_pc != DexFile::kDexNoIndex) {
+      bool clear_exception = false;
+      StackHandleScope<1> hs(Thread::Current());
+      Handle<mirror::Class> to_find(hs.NewHandle((*exception_)->GetClass()));
+      uint32_t found_dex_pc = method->FindCatchBlock(to_find, dex_pc, &clear_exception);
+      exception_handler_->SetClearException(clear_exception);
+      if (found_dex_pc != DexFile::kDexNoIndex) {
+        exception_handler_->SetHandlerMethod(method);
+        exception_handler_->SetHandlerDexPc(found_dex_pc);
+        exception_handler_->SetHandlerQuickFramePc(method->ToNativePc(found_dex_pc));
+        exception_handler_->SetHandlerQuickFrame(GetCurrentQuickFrame());
+        return false;  // End stack walk.
+      }
+    }
+    return true;  // Continue stack walk.
+  }
+
+  Thread* const self_;
+  // The exception we're looking for the catch block of.
+  Handle<mirror::Throwable>* exception_;
+  // The quick exception handler we're visiting for.
+  QuickExceptionHandler* const exception_handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(CatchBlockStackVisitor);
+};
+
 void QuickExceptionHandler::FindCatch(const ThrowLocation& throw_location,
                                       mirror::Throwable* exception) {
   DCHECK(!is_deoptimization_);
+  if (kDebugExceptionDelivery) {
+    mirror::String* msg = exception->GetDetailMessage();
+    std::string str_msg(msg != nullptr ? msg->ToModifiedUtf8() : "");
+    self_->DumpStack(LOG(INFO) << "Delivering exception: " << PrettyTypeOf(exception)
+                     << ": " << str_msg << "\n");
+  }
   StackHandleScope<1> hs(self_);
   Handle<mirror::Throwable> exception_ref(hs.NewHandle(exception));
 
@@ -42,14 +122,14 @@ void QuickExceptionHandler::FindCatch(const ThrowLocation& throw_location,
   CatchBlockStackVisitor visitor(self_, context_, &exception_ref, this);
   visitor.WalkStack(true);
 
-  mirror::ArtMethod* catch_method = handler_quick_frame_->AsMirrorPtr();
   if (kDebugExceptionDelivery) {
-    if (catch_method == nullptr) {
+    if (handler_quick_frame_->AsMirrorPtr() == nullptr) {
       LOG(INFO) << "Handler is upcall";
-    } else {
-      const DexFile& dex_file = *catch_method->GetDeclaringClass()->GetDexCache()->GetDexFile();
-      int line_number = dex_file.GetLineNumFromPC(catch_method, handler_dex_pc_);
-      LOG(INFO) << "Handler: " << PrettyMethod(catch_method) << " (line: " << line_number << ")";
+    }
+    if (handler_method_ != nullptr) {
+      const DexFile& dex_file = *handler_method_->GetDeclaringClass()->GetDexCache()->GetDexFile();
+      int line_number = dex_file.GetLineNumFromPC(handler_method_, handler_dex_pc_);
+      LOG(INFO) << "Handler: " << PrettyMethod(handler_method_) << " (line: " << line_number << ")";
     }
   }
   if (clear_exception_) {
@@ -62,12 +142,94 @@ void QuickExceptionHandler::FindCatch(const ThrowLocation& throw_location,
   // The debugger may suspend this thread and walk its stack. Let's do this before popping
   // instrumentation frames.
   instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
-  instrumentation->ExceptionCaughtEvent(self_, throw_location, catch_method, handler_dex_pc_,
+  instrumentation->ExceptionCaughtEvent(self_, throw_location, handler_method_, handler_dex_pc_,
                                         exception_ref.Get());
 }
 
+// Prepares deoptimization.
+class DeoptimizeStackVisitor FINAL : public StackVisitor {
+ public:
+  DeoptimizeStackVisitor(Thread* self, Context* context, QuickExceptionHandler* exception_handler)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
+      : StackVisitor(self, context), self_(self), exception_handler_(exception_handler),
+        prev_shadow_frame_(nullptr) {
+    CHECK(!self_->HasDeoptimizationShadowFrame());
+  }
+
+  bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    exception_handler_->SetHandlerFrameId(GetFrameId());
+    mirror::ArtMethod* method = GetMethod();
+    if (method == nullptr) {
+      // This is the upcall, we remember the frame and last pc so that we may long jump to them.
+      exception_handler_->SetHandlerQuickFramePc(GetCurrentQuickFramePc());
+      exception_handler_->SetHandlerQuickFrame(GetCurrentQuickFrame());
+      return false;  // End stack walk.
+    } else if (method->IsRuntimeMethod()) {
+      // Ignore callee save method.
+      DCHECK(method->IsCalleeSaveMethod());
+      return true;
+    } else {
+      return HandleDeoptimization(method);
+    }
+  }
+
+ private:
+  bool HandleDeoptimization(mirror::ArtMethod* m) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    MethodHelper mh(m);
+    const DexFile::CodeItem* code_item = mh.GetCodeItem();
+    CHECK(code_item != nullptr);
+    uint16_t num_regs = code_item->registers_size_;
+    uint32_t dex_pc = GetDexPc();
+    const Instruction* inst = Instruction::At(code_item->insns_ + dex_pc);
+    uint32_t new_dex_pc = dex_pc + inst->SizeInCodeUnits();
+    ShadowFrame* new_frame = ShadowFrame::Create(num_regs, nullptr, m, new_dex_pc);
+    StackHandleScope<2> hs(self_);
+    Handle<mirror::DexCache> dex_cache(hs.NewHandle(mh.GetDexCache()));
+    Handle<mirror::ClassLoader> class_loader(hs.NewHandle(mh.GetClassLoader()));
+    verifier::MethodVerifier verifier(&mh.GetDexFile(), &dex_cache, &class_loader,
+                                      &mh.GetClassDef(), code_item, m->GetDexMethodIndex(), m,
+                                      m->GetAccessFlags(), false, true, true);
+    verifier.Verify();
+    std::vector<int32_t> kinds = verifier.DescribeVRegs(dex_pc);
+    for (uint16_t reg = 0; reg < num_regs; ++reg) {
+      VRegKind kind = static_cast<VRegKind>(kinds.at(reg * 2));
+      switch (kind) {
+        case kUndefined:
+          new_frame->SetVReg(reg, 0xEBADDE09);
+          break;
+        case kConstant:
+          new_frame->SetVReg(reg, kinds.at((reg * 2) + 1));
+          break;
+        case kReferenceVReg:
+          new_frame->SetVRegReference(reg,
+                                      reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kind)));
+          break;
+        default:
+          new_frame->SetVReg(reg, GetVReg(m, reg, kind));
+          break;
+      }
+    }
+    if (prev_shadow_frame_ != nullptr) {
+      prev_shadow_frame_->SetLink(new_frame);
+    } else {
+      self_->SetDeoptimizationShadowFrame(new_frame);
+    }
+    prev_shadow_frame_ = new_frame;
+    return true;
+  }
+
+  Thread* const self_;
+  QuickExceptionHandler* const exception_handler_;
+  ShadowFrame* prev_shadow_frame_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeoptimizeStackVisitor);
+};
+
 void QuickExceptionHandler::DeoptimizeStack() {
   DCHECK(is_deoptimization_);
+  if (kDebugExceptionDelivery) {
+    self_->DumpStack(LOG(INFO) << "Deoptimizing: ");
+  }
 
   DeoptimizeStackVisitor visitor(self_, context_, this);
   visitor.WalkStack(true);