Adds debugger patching to arm64.

runtime/vm/code_patcher_arm64.cc

 // Copyright (c) 2014, 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"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/code_patcher.h"
-
+#include "vm/cpu.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
 
 namespace dart {
 
 RawArray* CodePatcher::GetClosureArgDescAt(uword return_address,
                                            const Code& code) {
   ASSERT(code.ContainsInstructionAt(return_address));
   CallPattern call(return_address, code);
   return call.ClosureArgumentsDescriptor();
@@ skipping 19 matching lines @@
 
 void CodePatcher::PatchInstanceCallAt(uword return_address,
                                       const Code& code,
                                       uword new_target) {
   ASSERT(code.ContainsInstructionAt(return_address));
   CallPattern call(return_address, code);
   call.SetTargetAddress(new_target);
 }
 
 
+class PoolPointerCall : public ValueObject {
+ public:
+  explicit PoolPointerCall(uword pc) : end_(pc) {
+    // Last instruction: blr ip0.
+    ASSERT(*(reinterpret_cast<uint32_t*>(end_) - 1) == 0xd63f0200);
+    InstructionPattern::DecodeLoadWordFromPool(
+        end_ - Instr::kInstrSize, &reg_, &index_);
+  }
+
+  int32_t pp_offset() const {
+    return InstructionPattern::OffsetFromPPIndex(index_);
+  }
+
+  void set_pp_offset(int32_t offset) const {
+    InstructionPattern::EncodeLoadWordFromPoolFixed(
+      end_ - Instr::kInstrSize, offset);
+    CPU::FlushICache(end_ - kCallPatternSize, kCallPatternSize);
+  }
+
+ private:
+  static const int kCallPatternSize = 3 * Instr::kInstrSize;
+  uword end_;
+  Register reg_;
+  intptr_t index_;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PoolPointerCall);
+};
+
+
 int32_t CodePatcher::GetPoolOffsetAt(uword return_address) {
-  // TODO(zra): Needed for debugger.
-  UNIMPLEMENTED();
-  return 0;
+  PoolPointerCall call(return_address);
+  return call.pp_offset();
 }
 
 
 void CodePatcher::SetPoolOffsetAt(uword return_address, int32_t offset) {
-  // TODO(zra): Needed for debugger.
-  UNIMPLEMENTED();
+  PoolPointerCall call(return_address);
+  call.set_pp_offset(offset);
 }
 
 
 void CodePatcher::InsertCallAt(uword start, uword target) {
   // The inserted call should not overlap the lazy deopt jump code.
   ASSERT(start + CallPattern::kLengthInBytes <= target);
   CallPattern::InsertAt(start, target);
 }
 
 
@@ skipping 65 matching lines @@
 
 RawObject* CodePatcher::GetEdgeCounterAt(uword pc, const Code& code) {
   ASSERT(code.ContainsInstructionAt(pc));
   EdgeCounter counter(pc, code);
   return counter.edge_counter();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64