StepOver, StepInto, StepOut

runtime/vm/debugger_x64.cc

Index: runtime/vm/debugger_x64.cc
===================================================================
--- runtime/vm/debugger_x64.cc	(revision 4638)
+++ runtime/vm/debugger_x64.cc	(working copy)
@@ -7,6 +7,9 @@
 
 #include "vm/debugger.h"
 
+#include "vm/cpu.h"
+#include "vm/stub_code.h"
+
 namespace dart {
 
 RawInstance* ActivationFrame::GetLocalVarValue(intptr_t slot_index) {
@@ -14,6 +17,59 @@
   return NULL;
 }
 
+
+RawInstance* ActivationFrame::GetInstanceCallReceiver(
+                 intptr_t num_actual_args) {
+  ASSERT(num_actual_args > 0);  // At minimum we have a receiver on the stack.
+  // Stack pointer points to last argument that was pushed on the stack.
+  uword receiver_addr = sp() + ((num_actual_args - 1) * kWordSize);
+  return reinterpret_cast<RawInstance*>(
+             *reinterpret_cast<uword*>(receiver_addr));
+}
+
+
+void Breakpoint::PatchFunctionReturn() {
+  uint8_t* code = reinterpret_cast<uint8_t*>(pc_ - 13);
+  // movq %rbp,%rsp
+  ASSERT((code[0] == 0x48) && (code[1] == 0x8b) && (code[2] == 0xe5));
+  ASSERT(code[3] == 0x5d);  // popq %rbp
+  ASSERT(code[4] == 0xc3);  // ret
+  // Next 8 bytes are nop instructions
+  ASSERT((code[5] == 0x90) && (code[6] == 0x90) &&
+         (code[7] == 0x90) && (code[8] == 0x90) &&
+         (code[9] == 0x90) && (code[10] == 0x90) &&
+         (code[11] == 0x90) && (code[12] == 0x90));
+         // Smash code with call instruction and relative target address.
+  uword stub_addr = StubCode::BreakpointReturnEntryPoint();
+  code[0] = 0x49;
+  code[1] = 0xbb;
+  *reinterpret_cast<uword*>(&code[2]) = stub_addr;
+  code[10] = 0x41;
+  code[11] = 0xff;
+  code[12] = 0xd3;
+  CPU::FlushICache(pc_, 5);
+}
+
+
+void Breakpoint::RestoreFunctionReturn() {
+  uint8_t* code = reinterpret_cast<uint8_t*>(pc_ - 13);
+  ASSERT((code[0] == 0x49) && (code[1] == 0xbb));
+  code[0] = 0x48;  // movq %rbp,%rsp
+  code[1] = 0x8b;
+  code[2] = 0xe5;
+  code[3] = 0x5d;  // popq %rbp
+  code[4] = 0xc3;  // ret
+  code[5] = 0x90;  // nop
+  code[6] = 0x90;  // nop
+  code[7] = 0x90;  // nop
+  code[8] = 0x90;  // nop
+  code[9] = 0x90;  // nop
+  code[10] = 0x90;  // nop
+  code[11] = 0x90;  // nop
+  code[12] = 0x90;  // nop
+  CPU::FlushICache(pc_, 5);
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64