commit c6b4dd8980350aaf250f0185f73e9c42ec17cd57
author David Srbecky <dsrbecky@google.com> Tue Apr 07 20:32:43 2015 +0100
committer David Srbecky <dsrbecky@google.com> Thu Apr 09 16:47:50 2015 +0100
tree ef8d73e37abc04aecb430072a8bc463c73398fee
parent dd97393aca1a3ff2abec4dc4f78d7724300971bc

Implement CFI for Optimizing.

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

Change-Id: I1a3480e3a4a99f48bf7e6e63c4e83a80cfee40a2

compiler/optimizing/code_generator_x86.cc

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 92b62e2..8fbc64e 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -459,7 +459,12 @@
         assembler_(codegen->GetAssembler()),
         codegen_(codegen) {}
 
+static dwarf::Reg DWARFReg(Register reg) {
+    return dwarf::Reg::X86Core(static_cast<int>(reg));
+}
+
 void CodeGeneratorX86::GenerateFrameEntry() {
+  __ cfi().SetCurrentCFAOffset(kX86WordSize);  // return address
   __ Bind(&frame_entry_label_);
   bool skip_overflow_check =
       IsLeafMethod() && !FrameNeedsStackCheck(GetFrameSize(), InstructionSet::kX86);
@@ -478,10 +483,14 @@
     Register reg = kCoreCalleeSaves[i];
     if (allocated_registers_.ContainsCoreRegister(reg)) {
       __ pushl(reg);
+      __ cfi().AdjustCFAOffset(kX86WordSize);
+      __ cfi().RelOffset(DWARFReg(reg), 0);
     }
   }
 
-  __ subl(ESP, Immediate(GetFrameSize() - FrameEntrySpillSize()));
+  int adjust = GetFrameSize() - FrameEntrySpillSize();
+  __ subl(ESP, Immediate(adjust));
+  __ cfi().AdjustCFAOffset(adjust);
   __ movl(Address(ESP, kCurrentMethodStackOffset), EAX);
 }
 
@@ -490,12 +499,16 @@
     return;
   }
 
-  __ addl(ESP, Immediate(GetFrameSize() - FrameEntrySpillSize()));
+  int adjust = GetFrameSize() - FrameEntrySpillSize();
+  __ addl(ESP, Immediate(adjust));
+  __ cfi().AdjustCFAOffset(-adjust);
 
   for (size_t i = 0; i < arraysize(kCoreCalleeSaves); ++i) {
     Register reg = kCoreCalleeSaves[i];
     if (allocated_registers_.ContainsCoreRegister(reg)) {
       __ popl(reg);
+      __ cfi().AdjustCFAOffset(-static_cast<int>(kX86WordSize));
+      __ cfi().Restore(DWARFReg(reg));
     }
   }
 }
@@ -1102,8 +1115,11 @@
 
 void InstructionCodeGeneratorX86::VisitReturnVoid(HReturnVoid* ret) {
   UNUSED(ret);
+  __ cfi().RememberState();
   codegen_->GenerateFrameExit();
   __ ret();
+  __ cfi().RestoreState();
+  __ cfi().DefCFAOffset(codegen_->GetFrameSize());
 }
 
 void LocationsBuilderX86::VisitReturn(HReturn* ret) {
@@ -1161,8 +1177,11 @@
         LOG(FATAL) << "Unknown return type " << ret->InputAt(0)->GetType();
     }
   }
+  __ cfi().RememberState();
   codegen_->GenerateFrameExit();
   __ ret();
+  __ cfi().RestoreState();
+  __ cfi().DefCFAOffset(codegen_->GetFrameSize());
 }
 
 void LocationsBuilderX86::VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) {