Splitting debugger breakpoints into two parts

runtime/vm/debugger_x64.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/debugger.h"
 
 #include "vm/cpu.h"
@@ skipping 10 matching lines @@
 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() {
+void CodeBreakpoint::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() {
+void CodeBreakpoint::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