VM: Link native calls lazily.

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"
@@ skipping 100 matching lines @@
   CallPattern static_call(return_address, code);
   ICData& ic_data = ICData::Handle();
   ic_data ^= static_call.IcData();
   if (ic_data_result != NULL) {
     *ic_data_result = ic_data.raw();
   }
   return ic_data.GetTargetAt(0);
 }
 
 
+void CodePatcher::PatchNativeCallAt(uword return_address,
+                                    const Code& code,
+                                    NativeFunction target,
+                                    const Code& trampoline) {
+  ASSERT(code.ContainsInstructionAt(return_address));
+  NativeCallPattern call(return_address, code);
+  call.set_target(trampoline.EntryPoint());
+  call.set_native_function(target);
+}
+
+
+uword CodePatcher::GetNativeCallAt(uword return_address,
+                                   const Code& code,
+                                   NativeFunction* target) {
+  ASSERT(code.ContainsInstructionAt(return_address));
+  NativeCallPattern call(return_address, code);
+  *target = call.native_function();
+  return call.target();
+}
+
+
 // This class pattern matches on a load from the object pool.  Loading on
 // ARM64 is complicated because it can take more than one form.  We
 // match backwards from the end of the sequence so we can reuse the code for
 // matching object pool loads at calls.
 class EdgeCounter : public ValueObject {
  public:
   EdgeCounter(uword pc, const Code& code)
       : end_(pc - kAdjust),
         object_pool_(ObjectPool::Handle(code.GetObjectPool())) {
     // An IsValid predicate is complicated and duplicates the code in the
@@ skipping 24 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