Emit unwinding information for TurboFan code.

src/compiler/arm/code-generator-arm.cc

Index: src/compiler/arm/code-generator-arm.cc
diff --git a/src/compiler/arm/code-generator-arm.cc b/src/compiler/arm/code-generator-arm.cc
index d959a5d34d6e188a9da6ba448b779d622b1e11b1..692a1ebc53a2f42a58a00eee294eb369cd4a7909 100644
--- a/src/compiler/arm/code-generator-arm.cc
+++ b/src/compiler/arm/code-generator-arm.cc
@@ -188,7 +188,8 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
  public:
   OutOfLineRecordWrite(CodeGenerator* gen, Register object, Register index,
                        Register value, Register scratch0, Register scratch1,
-                       RecordWriteMode mode)
+                       RecordWriteMode mode,
+                       UnwindingInfoWriter* unwinding_info_writer)
       : OutOfLineCode(gen),
         object_(object),
         index_(index),
@@ -197,11 +198,13 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
         scratch0_(scratch0),
         scratch1_(scratch1),
         mode_(mode),
-        must_save_lr_(!gen->frame_access_state()->has_frame()) {}
+        must_save_lr_(!gen->frame_access_state()->has_frame()),
+        unwinding_info_writer_(unwinding_info_writer) {}
 
   OutOfLineRecordWrite(CodeGenerator* gen, Register object, int32_t index,
                        Register value, Register scratch0, Register scratch1,
-                       RecordWriteMode mode)
+                       RecordWriteMode mode,
+                       UnwindingInfoWriter* unwinding_info_writer)
       : OutOfLineCode(gen),
         object_(object),
         index_(no_reg),
@@ -210,7 +213,8 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
         scratch0_(scratch0),
         scratch1_(scratch1),
         mode_(mode),
-        must_save_lr_(!gen->frame_access_state()->has_frame()) {}
+        must_save_lr_(!gen->frame_access_state()->has_frame()),
+        unwinding_info_writer_(unwinding_info_writer) {}
 
   void Generate() final {
     if (mode_ > RecordWriteMode::kValueIsPointer) {
@@ -227,6 +231,9 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
     if (must_save_lr_) {
       // We need to save and restore lr if the frame was elided.
       __ Push(lr);
+      if (unwinding_info_writer_) {
+        unwinding_info_writer_->MarkLinkRegisterOnTopOfStack(__ pc_offset());
+      }
     }
     RecordWriteStub stub(isolate(), object_, scratch0_, scratch1_,
                          remembered_set_action, save_fp_mode);
@@ -239,6 +246,10 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
     __ CallStub(&stub);
     if (must_save_lr_) {
       __ Pop(lr);
+      if (unwinding_info_writer_) {
+        unwinding_info_writer_->MarkPopLinkRegisterFromTopOfStack(
+            __ pc_offset());
+      }
     }
   }
 
@@ -251,6 +262,7 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   Register const scratch1_;
   RecordWriteMode const mode_;
   bool must_save_lr_;
+  UnwindingInfoWriter* const unwinding_info_writer_;
 };
 
 
@@ -413,6 +425,10 @@ Condition FlagsConditionToCondition(FlagsCondition condition) {
 
 void CodeGenerator::AssembleDeconstructFrame() {
   __ LeaveFrame(StackFrame::MANUAL);
+
+  if (!unwinding_info_writer_.is_empty()) {

[Jarin, 2016/07/06 07:09:42]

I am wondering whether you do not want to fold this is_empty logic into
UnwindingInforWriter - the writer would internally know whether it is active,
and it would only do its thing if it is active. That way, you could embed the
writer into the code generator, so here you would just say

unwinding_info_writer_.MarkFrameDeconstructed(__ pc_offset());

without the is_empty check. WDYT?

[rmcilroy, 2016/07/07 09:55:17]

+1, I think this would make things clearer in the code generators.

+    unwinding_info_writer_->MarkFrameDeconstructed(__ pc_offset());
+  }
 }
 
 void CodeGenerator::AssemblePrepareTailCall() {
@@ -600,6 +616,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ Jump(ip);
       }
       DCHECK_EQ(LeaveCC, i.OutputSBit());
+      if (!unwinding_info_writer_.is_empty()) {
+        unwinding_info_writer_->MarkBlockWillExit();
+      }
       frame_access_state()->ClearSPDelta();
       frame_access_state()->SetFrameAccessToDefault();
       break;
@@ -607,6 +626,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchTailCallAddress: {
       CHECK(!instr->InputAt(0)->IsImmediate());
       __ Jump(i.InputRegister(0));
+      if (!unwinding_info_writer_.is_empty()) {
+        unwinding_info_writer_->MarkBlockWillExit();
+      }
       frame_access_state()->ClearSPDelta();
       frame_access_state()->SetFrameAccessToDefault();
       break;
@@ -742,14 +764,16 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
           AddressingModeField::decode(instr->opcode());
       if (addressing_mode == kMode_Offset_RI) {
         int32_t index = i.InputInt32(1);
-        ool = new (zone()) OutOfLineRecordWrite(this, object, index, value,
-                                                scratch0, scratch1, mode);
+        ool = new (zone())
+            OutOfLineRecordWrite(this, object, index, value, scratch0, scratch1,
+                                 mode, unwinding_info_writer_.get());
         __ str(value, MemOperand(object, index));
       } else {
         DCHECK_EQ(kMode_Offset_RR, addressing_mode);
         Register index(i.InputRegister(1));
-        ool = new (zone()) OutOfLineRecordWrite(this, object, index, value,
-                                                scratch0, scratch1, mode);
+        ool = new (zone())
+            OutOfLineRecordWrite(this, object, index, value, scratch0, scratch1,
+                                 mode, unwinding_info_writer_.get());
         __ str(value, MemOperand(object, index));
       }
       __ CheckPageFlag(object, scratch0,
@@ -1600,6 +1624,11 @@ void CodeGenerator::AssembleConstructFrame() {
     }
   }
 
+  if (!unwinding_info_writer_.is_empty() &&
+      !info()->GeneratePreagedPrologue()) {
+    unwinding_info_writer_->MarkFrameConstructed(__ pc_offset());
+  }
+
   int shrink_slots = frame()->GetSpillSlotCount();
 
   if (info()->is_osr()) {
@@ -1661,6 +1690,10 @@ void CodeGenerator::AssembleReturn() {
             DwVfpRegister::from_code(last));
   }
 
+  if (!unwinding_info_writer_.is_empty()) {
+    unwinding_info_writer_->MarkBlockWillExit();
+  }
+
   if (descriptor->IsCFunctionCall()) {
     AssembleDeconstructFrame();
   } else if (frame_access_state()->has_frame()) {