StubCallInterfaceDescriptor takes a context register.

src/code-stubs.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
@@ skipping 253 matching lines @@
 
  protected:
   // Generates the assembler code for the stub.
   virtual void Generate(MacroAssembler* masm) = 0;
 };
 
 
 enum StubFunctionMode { NOT_JS_FUNCTION_STUB_MODE, JS_FUNCTION_STUB_MODE };
 enum HandlerArgumentsMode { DONT_PASS_ARGUMENTS, PASS_ARGUMENTS };
 
-class CodeStubInterfaceDescriptor {
+class InterfaceDescriptor {

[danno, 2014/07/15 07:48:31]

In general, could more stuff in this class be private?

+ public:
+  static const Register ContextRegister();

[danno, 2014/07/15 07:48:31]

Can you make this a virtual register that returns either the register if needed
or no_reg. That would obviate the need for needs_context_register().

+
+  InterfaceDescriptor();
+  virtual ~InterfaceDescriptor() {}
+
+  bool initialized() const { return register_param_count_ >= 0; }
+
+  int environment_length() const {

[danno, 2014/07/15 07:48:31]

Since this is not an accessor with an indentical name, this should be
GetEnvironmentLength().

[mvstanton, 2014/07/16 09:43:26]

Done.

+    return register_param_count_;
+  }
+
+  int register_param_count() const { return register_param_count_; }
+
+  Register GetParameterRegister(int index) const {
+    return register_params_[index];
+  }
+
+  Representation GetParameterRepresentation(int index) const {
+    ASSERT(index < register_param_count_);
+    if (register_param_representations_.get() == NULL) {
+      return Representation::Tagged();
+    }
+
+    return register_param_representations_[index];
+  }
+
+  Representation* register_param_representations() const {

[danno, 2014/07/15 07:48:31]

Does this have to be public?

[mvstanton, 2014/07/16 09:43:26]

No, it is gone, good catch.

+    return register_param_representations_.get();
+  }
+
+  virtual bool needs_context_register() const { return true; }

[danno, 2014/07/15 07:48:31]

NeedsContextRegister

[mvstanton, 2014/07/16 09:43:26]

Done.

+
+ protected:
+  void Initialize(int register_parameter_count, Register* registers,
+                  Representation* register_param_representations);
+
+ private:
+  int register_param_count_;
+
+  // The Register params are allocated dynamically by the
+  // CodeStubInterfaceDescriptor, and freed on destruction. This is because
+  // static arrays of Registers cause creation of runtime static initializers
+  // which we don't want.
+  SmartArrayPointer<Register> register_params_;
+  // Specifies Representations for the stub's parameter. Points to an array of
+  // Representations of the same length of the numbers of parameters to the
+  // stub, or if NULL (the default value), Representation of each parameter
+  // assumed to be Tagged().
+  SmartArrayPointer<Representation> register_param_representations_;
+};
+
+
+class CodeStubInterfaceDescriptor: public InterfaceDescriptor {
  public:
   CodeStubInterfaceDescriptor();
 
   void Initialize(int register_parameter_count, Register* registers,
                   Address deoptimization_handler = NULL,
                   Representation* register_param_representations = NULL,
                   int hint_stack_parameter_count = -1,
                   StubFunctionMode function_mode = NOT_JS_FUNCTION_STUB_MODE);
   void Initialize(int register_parameter_count, Register* registers,
                   Register stack_parameter_count,
                   Address deoptimization_handler = NULL,
                   Representation* register_param_representations = NULL,
                   int hint_stack_parameter_count = -1,
                   StubFunctionMode function_mode = NOT_JS_FUNCTION_STUB_MODE,
                   HandlerArgumentsMode handler_mode = DONT_PASS_ARGUMENTS);
-  bool initialized() const { return register_param_count_ >= 0; }
-
-  int environment_length() const {
-    return register_param_count_;
-  }
 
   void SetMissHandler(ExternalReference handler) {
     miss_handler_ = handler;
     has_miss_handler_ = true;
     // Our miss handler infrastructure doesn't currently support
     // variable stack parameter counts.
     ASSERT(!stack_parameter_count_.is_valid());
   }
 
   ExternalReference miss_handler() const {
     ASSERT(has_miss_handler_);
     return miss_handler_;
   }
 
   bool has_miss_handler() const {
     return has_miss_handler_;
   }
 
-  Register GetParameterRegister(int index) const {
-    return register_params_[index];
-  }
-
-  Representation GetRegisterParameterRepresentation(int index) const {
-    ASSERT(index < register_param_count_);
-    if (register_param_representations_.get() == NULL) {
-      return Representation::Tagged();
-    }
-
-    return register_param_representations_[index];
-  }
-
   bool IsParameterCountRegister(int index) const {
     return GetParameterRegister(index).is(stack_parameter_count_);
   }
 
   int GetHandlerParameterCount() const {
     int params = environment_length();
     if (handler_arguments_mode_ == PASS_ARGUMENTS) {
       params += 1;
     }
     return params;
   }
 
-  int register_param_count() const { return register_param_count_; }
   int hint_stack_parameter_count() const { return hint_stack_parameter_count_; }
   Register stack_parameter_count() const { return stack_parameter_count_; }
   StubFunctionMode function_mode() const { return function_mode_; }
   Address deoptimization_handler() const { return deoptimization_handler_; }
-  Representation* register_param_representations() const {
-    return register_param_representations_.get();
-  }
 
  private:
-  int register_param_count_;
-
   Register stack_parameter_count_;
   // If hint_stack_parameter_count_ > 0, the code stub can optimize the
   // return sequence. Default value is -1, which means it is ignored.
   int hint_stack_parameter_count_;
   StubFunctionMode function_mode_;
-  // The Register params are allocated dynamically by the
-  // CodeStubInterfaceDescriptor, and freed on destruction. This is because
-  // static arrays of Registers cause creation of runtime static initializers
-  // which we don't want.
-  SmartArrayPointer<Register> register_params_;
-  // Specifies Representations for the stub's parameter. Points to an array of
-  // Representations of the same length of the numbers of parameters to the
-  // stub, or if NULL (the default value), Representation of each parameter
-  // assumed to be Tagged().
-  SmartArrayPointer<Representation> register_param_representations_;
 
   Address deoptimization_handler_;
   HandlerArgumentsMode handler_arguments_mode_;
 
   ExternalReference miss_handler_;
   bool has_miss_handler_;
   DISALLOW_COPY_AND_ASSIGN(CodeStubInterfaceDescriptor);
 };
 
 
 class PlatformCallInterfaceDescriptor;
 
 
-class CallInterfaceDescriptor {
+class CallInterfaceDescriptor: public InterfaceDescriptor {
  public:
   CallInterfaceDescriptor()
-      : register_param_count_(-1),
-        register_params_(NULL),
-        param_representations_(NULL),
-        platform_specific_descriptor_(NULL) { }
+      : platform_specific_descriptor_(NULL) { }
 
   // A copy of the passed in registers and param_representations is made
   // and owned by the CallInterfaceDescriptor.
 
   // TODO(mvstanton): Instead of taking parallel arrays register and
   // param_representations, how about a struct that puts the representation
   // and register side by side (eg, RegRep(r1, Representation::Tagged()).
   // The same should go for the CodeStubInterfaceDescriptor class.
   void Initialize(int register_parameter_count, Register* registers,
                   Representation* param_representations,
                   PlatformCallInterfaceDescriptor* platform_descriptor = NULL);
 
-  bool initialized() const { return register_param_count_ >= 0; }
-
-  int environment_length() const {
-    return register_param_count_;
-  }
-
-  Representation GetParameterRepresentation(int index) const {
-    return param_representations_[index];
-  }
-
-  Register GetParameterRegister(int index) const {
-    return register_params_[index];
-  }
-
   PlatformCallInterfaceDescriptor* platform_specific_descriptor() const {
     return platform_specific_descriptor_;
   }
 
  private:
   int register_param_count_;
-  SmartArrayPointer<Register> register_params_;
-  SmartArrayPointer<Representation> param_representations_;
   PlatformCallInterfaceDescriptor* platform_specific_descriptor_;
 };
 
 
 class HydrogenCodeStub : public CodeStub {
  public:
   enum InitializationState {
     UNINITIALIZED,
     INITIALIZED
   };
@@ skipping 2111 matching lines @@
 
 
 class CallDescriptors {
  public:
   static void InitializeForIsolate(Isolate* isolate);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_