Implement CFI for Optimizing.

CFI is necessary for stack unwinding in gdb, lldb, and libunwind.

Change-Id: I1a3480e3a4a99f48bf7e6e63c4e83a80cfee40a2

1 files changed, 28 insertions, 3 deletions

diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index cfc798a34e..a799a519c0 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -513,6 +513,14 @@ void CodeGeneratorARM::ComputeSpillMask() {
   }
 }
 
+static dwarf::Reg DWARFReg(Register reg) {
+    return dwarf::Reg::ArmCore(static_cast<int>(reg));
+}
+
+static dwarf::Reg DWARFReg(SRegister reg) {
+    return dwarf::Reg::ArmFp(static_cast<int>(reg));
+}
+
 void CodeGeneratorARM::GenerateFrameEntry() {
   bool skip_overflow_check =
       IsLeafMethod() && !FrameNeedsStackCheck(GetFrameSize(), InstructionSet::kArm);
@@ -531,12 +539,19 @@ void CodeGeneratorARM::GenerateFrameEntry() {
 
   // PC is in the list of callee-save to mimic Quick, but we need to push
   // LR at entry instead.
-  __ PushList((core_spill_mask_ & (~(1 << PC))) | 1 << LR);
+  uint32_t push_mask = (core_spill_mask_ & (~(1 << PC))) | 1 << LR;
+  __ PushList(push_mask);
+  __ cfi().AdjustCFAOffset(kArmWordSize * POPCOUNT(push_mask));
+  __ cfi().RelOffsetForMany(DWARFReg(Register(0)), 0, push_mask, kArmWordSize);
   if (fpu_spill_mask_ != 0) {
     SRegister start_register = SRegister(LeastSignificantBit(fpu_spill_mask_));
     __ vpushs(start_register, POPCOUNT(fpu_spill_mask_));
+    __ cfi().AdjustCFAOffset(kArmWordSize * POPCOUNT(fpu_spill_mask_));
+    __ cfi().RelOffsetForMany(DWARFReg(SRegister(0)), 0, fpu_spill_mask_, kArmWordSize);
   }
-  __ AddConstant(SP, -(GetFrameSize() - FrameEntrySpillSize()));
+  int adjust = GetFrameSize() - FrameEntrySpillSize();
+  __ AddConstant(SP, -adjust);
+  __ cfi().AdjustCFAOffset(adjust);
   __ StoreToOffset(kStoreWord, R0, SP, 0);
 }
 
@@ -545,10 +560,14 @@ void CodeGeneratorARM::GenerateFrameExit() {
     __ bx(LR);
     return;
   }
-  __ AddConstant(SP, GetFrameSize() - FrameEntrySpillSize());
+  int adjust = GetFrameSize() - FrameEntrySpillSize();
+  __ AddConstant(SP, adjust);
+  __ cfi().AdjustCFAOffset(-adjust);
   if (fpu_spill_mask_ != 0) {
     SRegister start_register = SRegister(LeastSignificantBit(fpu_spill_mask_));
     __ vpops(start_register, POPCOUNT(fpu_spill_mask_));
+    __ cfi().AdjustCFAOffset(-kArmPointerSize * POPCOUNT(fpu_spill_mask_));
+    __ cfi().RestoreMany(DWARFReg(SRegister(0)), fpu_spill_mask_);
   }
   __ PopList(core_spill_mask_);
 }
@@ -1190,7 +1209,10 @@ void LocationsBuilderARM::VisitReturnVoid(HReturnVoid* ret) {
 
 void InstructionCodeGeneratorARM::VisitReturnVoid(HReturnVoid* ret) {
   UNUSED(ret);
+  __ cfi().RememberState();
   codegen_->GenerateFrameExit();
+  __ cfi().RestoreState();
+  __ cfi().DefCFAOffset(codegen_->GetFrameSize());
 }
 
 void LocationsBuilderARM::VisitReturn(HReturn* ret) {
@@ -1201,7 +1223,10 @@ void LocationsBuilderARM::VisitReturn(HReturn* ret) {
 
 void InstructionCodeGeneratorARM::VisitReturn(HReturn* ret) {
   UNUSED(ret);
+  __ cfi().RememberState();
   codegen_->GenerateFrameExit();
+  __ cfi().RestoreState();
+  __ cfi().DefCFAOffset(codegen_->GetFrameSize());
 }
 
 void LocationsBuilderARM::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {