VM: Link native calls lazily.

runtime/vm/instructions_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/assembler.h"
 #include "vm/constants_arm64.h"
 #include "vm/cpu.h"
@@ skipping 16 matching lines @@
 
   Register reg;
   ic_data_load_end_ =
       InstructionPattern::DecodeLoadWordFromPool(end_ - Instr::kInstrSize,
                                                  &reg,
                                                  &target_address_pool_index_);
   ASSERT(reg == IP0);
 }
 
 
+NativeCallPattern::NativeCallPattern(uword pc, const Code& code)
+    : object_pool_(ObjectPool::Handle(code.GetObjectPool())),
+      end_(pc),
+      native_function_pool_index_(-1),
+      target_address_pool_index_(-1) {
+  ASSERT(code.ContainsInstructionAt(pc));
+  // Last instruction: blr ip0.
+  ASSERT(*(reinterpret_cast<uint32_t*>(end_) - 1) == 0xd63f0200);
+
+  Register reg;
+  uword native_function_load_end =
+      InstructionPattern::DecodeLoadWordFromPool(end_ - Instr::kInstrSize,
+                                                 &reg,
+                                                 &target_address_pool_index_);
+  ASSERT(reg == IP0);
+  InstructionPattern::DecodeLoadWordFromPool(native_function_load_end,
+                                             &reg,
+                                             &native_function_pool_index_);
+  ASSERT(reg == R5);
+}
+
+
+uword NativeCallPattern::target() const {
+  return object_pool_.RawValueAt(target_address_pool_index_);
+}
+
+
+void NativeCallPattern::set_target(uword target_address) const {
+  object_pool_.SetRawValueAt(target_address_pool_index_, target_address);
+  // No need to flush the instruction cache, since the code is not modified.
+}
+
+
+NativeFunction NativeCallPattern::native_function() const {
+  return reinterpret_cast<NativeFunction>(
+      object_pool_.RawValueAt(native_function_pool_index_));
+}
+
+
+void NativeCallPattern::set_native_function(NativeFunction func) const {
+  object_pool_.SetRawValueAt(native_function_pool_index_,
+      reinterpret_cast<uword>(func));
+}
+
+
 intptr_t InstructionPattern::OffsetFromPPIndex(intptr_t index) {
   return Array::element_offset(index);
 }
 
 
 // Decodes a load sequence ending at 'end' (the last instruction of the load
 // sequence is the instruction before the one at end).  Returns a pointer to
 // the first instruction in the sequence.  Returns the register being loaded
 // and the loaded object in the output parameters 'reg' and 'obj'
 // respectively.
@@ skipping 319 matching lines @@
 bool ReturnPattern::IsValid() const {
   Instr* bx_lr = Instr::At(pc_);
   const Register crn = ConcreteRegister(LR);
   const int32_t instruction = RET | (static_cast<int32_t>(crn) << kRnShift);
   return bx_lr->InstructionBits() == instruction;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64