Introduce a class encapsulating arguments descriptor arrays.

runtime/vm/code_patcher_x64.cc

 // Copyright (c) 2012, 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_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
+#include "vm/dart_entry.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
 
 namespace dart {
 
 // The pattern of a Dart instance call is:
 //  00: 48 bb imm64  mov RBX, immediate 1
 //  10: 49 ba imm64  mov R10, immediate 2
 //  20: 49 bb imm64  mov R11, target_address
@@ skipping 22 matching lines @@
   uword target() const {
     return *reinterpret_cast<uword*>(start_ + 20 + 2);
   }
 
   void set_target(uword target) const {
     uword* target_addr = reinterpret_cast<uword*>(start_ + 20 + 2);
     *target_addr = target;
     CPU::FlushICache(start_ + 20, 2 + 8);
   }
 
-  uint64_t immediate_one() const {
-    return *reinterpret_cast<uint64_t*>(start_ + 0 + 2);
+  RawObject* immediate_one() const {
+    return *reinterpret_cast<RawObject**>(start_ + 0 + 2);
   }
 
   void set_immediate_one(uint64_t value) {
     uint64_t* target_addr = reinterpret_cast<uint64_t*>(start_ + 0 + 2);
     *target_addr = value;
     CPU::FlushICache(start_ + 0, 2 + 8);
   }
 
-  uint64_t immediate_two() const {
-    return *reinterpret_cast<uint64_t*>(start_ + 10 + 2);
+  RawObject* immediate_two() const {
+    return *reinterpret_cast<RawObject**>(start_ + 10 + 2);
   }
 
-  int argument_count() const {
-    Array& args_desc = Array::Handle();
-    args_desc ^= reinterpret_cast<RawObject*>(immediate_two());
-    Smi& num_args = Smi::Handle();
-    num_args ^= args_desc.At(0);
-    return num_args.Value();
+  intptr_t argument_count() const {
+    ArgumentsDescriptor args_desc(immediate_two());
+    return args_desc.Count();
   }
 
-  int named_argument_count() const {
-    Array& args_desc = Array::Handle();
-    args_desc ^= reinterpret_cast<RawObject*>(immediate_two());
-    Smi& num_args = Smi::Handle();
-    num_args ^= args_desc.At(0);
-    Smi& num_pos_args = Smi::Handle();
-    num_pos_args ^= args_desc.At(1);
-    return num_args.Value() - num_pos_args.Value();
+  intptr_t named_argument_count() const {
+    ArgumentsDescriptor args_desc(immediate_two());
+    return args_desc.NamedCount();
   }
 
   uword start_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(DartCallPattern);
 };
 
 
 // A Dart instance call passes the ic-data in RBX.
 // The expected pattern of a dart instance call:
 //  mov RBX, ic-data
-//  mov R10, argument_descriptor_array
+//  mov R10, arguments_descriptor_array
 //  mov R11, target_address
 //  call R11
 //  <- return address
 class InstanceCall : public DartCallPattern {
  public:
   explicit InstanceCall(uword return_address)
       : DartCallPattern(return_address) {}
 
   RawICData* ic_data() const {
     ICData& ic_data = ICData::Handle();
-    ic_data ^= reinterpret_cast<RawObject*>(immediate_one());
+    ic_data ^= immediate_one();
     return ic_data.raw();
   }
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(InstanceCall);
 };
 
 
 // The expected pattern of a dart static call:
-//  mov R10, argument_descriptor_array (10 bytes)
+//  mov R10, arguments_descriptor_array (10 bytes)
 //  mov R11, target_address (10 bytes)
 //  call R11  (3 bytes)
 //  <- return address
 class StaticCall : public ValueObject {
  public:
   explicit StaticCall(uword return_address)
       : start_(return_address - kCallPatternSize) {
     ASSERT(IsValid(return_address));
     ASSERT((kCallPatternSize - 10) == Assembler::kCallExternalLabelSize);
   }
@@ skipping 146 matching lines @@
   *reinterpret_cast<uint8_t*>(start) = 0xE8;
   ShortCallPattern call(start);
   call.SetTargetAddress(target);
   CPU::FlushICache(start, ShortCallPattern::InstructionLength());
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64