| // Copyright 2014 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. |
| |
| #include "src/runtime/runtime-utils.h" |
| |
| #include "src/arguments.h" |
| #include "src/factory.h" |
| #include "src/frames-inl.h" |
| #include "src/objects-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| RUNTIME_FUNCTION(Runtime_CreateJSGeneratorObject) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 0); |
| |
| JavaScriptFrameIterator it(isolate); |
| JavaScriptFrame* frame = it.frame(); |
| Handle<JSFunction> function(frame->function()); |
| RUNTIME_ASSERT(function->shared()->is_generator()); |
| |
| Handle<JSGeneratorObject> generator; |
| DCHECK(!frame->IsConstructor()); |
| generator = isolate->factory()->NewJSGeneratorObject(function); |
| generator->set_function(*function); |
| generator->set_context(Context::cast(frame->context())); |
| generator->set_receiver(frame->receiver()); |
| generator->set_continuation(0); |
| generator->set_operand_stack(isolate->heap()->empty_fixed_array()); |
| |
| return *generator; |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_SuspendJSGeneratorObject) { |
| HandleScope handle_scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator_object, 0); |
| |
| JavaScriptFrameIterator stack_iterator(isolate); |
| JavaScriptFrame* frame = stack_iterator.frame(); |
| RUNTIME_ASSERT(frame->function()->shared()->is_generator()); |
| DCHECK_EQ(frame->function(), generator_object->function()); |
| |
| // The caller should have saved the context and continuation already. |
| DCHECK_EQ(generator_object->context(), Context::cast(frame->context())); |
| DCHECK_LT(0, generator_object->continuation()); |
| |
| // We expect there to be at least two values on the operand stack: the return |
| // value of the yield expression, and the arguments to this runtime call. |
| // Neither of those should be saved. |
| int operands_count = frame->ComputeOperandsCount(); |
| DCHECK_GE(operands_count, 1 + args.length()); |
| operands_count -= 1 + args.length(); |
| |
| if (operands_count == 0) { |
| // Although it's semantically harmless to call this function with an |
| // operands_count of zero, it is also unnecessary. |
| DCHECK_EQ(generator_object->operand_stack(), |
| isolate->heap()->empty_fixed_array()); |
| } else { |
| Handle<FixedArray> operand_stack = |
| isolate->factory()->NewFixedArray(operands_count); |
| frame->SaveOperandStack(*operand_stack); |
| generator_object->set_operand_stack(*operand_stack); |
| } |
| |
| return isolate->heap()->undefined_value(); |
| } |
| |
| |
| // Note that this function is the slow path for resuming generators. It is only |
| // called if the suspended activation had operands on the stack, stack handlers |
| // needing rewinding, or if the resume should throw an exception. The fast path |
| // is handled directly in FullCodeGenerator::EmitGeneratorResume(), which is |
| // inlined into GeneratorNext, GeneratorReturn, and GeneratorThrow. |
| // EmitGeneratorResume is called in any case, as it needs to reconstruct the |
| // stack frame and make space for arguments and operands. |
| RUNTIME_FUNCTION(Runtime_ResumeJSGeneratorObject) { |
| SealHandleScope shs(isolate); |
| DCHECK(args.length() == 3); |
| CONVERT_ARG_CHECKED(JSGeneratorObject, generator_object, 0); |
| CONVERT_ARG_CHECKED(Object, value, 1); |
| CONVERT_SMI_ARG_CHECKED(resume_mode_int, 2); |
| JavaScriptFrameIterator stack_iterator(isolate); |
| JavaScriptFrame* frame = stack_iterator.frame(); |
| |
| DCHECK_EQ(frame->function(), generator_object->function()); |
| DCHECK(frame->function()->is_compiled()); |
| |
| STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting < 0); |
| STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed == 0); |
| |
| Address pc = generator_object->function()->code()->instruction_start(); |
| int offset = generator_object->continuation(); |
| DCHECK(offset > 0); |
| frame->set_pc(pc + offset); |
| if (FLAG_enable_embedded_constant_pool) { |
| frame->set_constant_pool( |
| generator_object->function()->code()->constant_pool()); |
| } |
| generator_object->set_continuation(JSGeneratorObject::kGeneratorExecuting); |
| |
| FixedArray* operand_stack = generator_object->operand_stack(); |
| int operands_count = operand_stack->length(); |
| if (operands_count != 0) { |
| frame->RestoreOperandStack(operand_stack); |
| generator_object->set_operand_stack(isolate->heap()->empty_fixed_array()); |
| } |
| |
| JSGeneratorObject::ResumeMode resume_mode = |
| static_cast<JSGeneratorObject::ResumeMode>(resume_mode_int); |
| switch (resume_mode) { |
| // Note: this looks like NEXT and RETURN are the same but RETURN receives |
| // special treatment in the generator code (to which we return here). |
| case JSGeneratorObject::NEXT: |
| case JSGeneratorObject::RETURN: |
| return value; |
| case JSGeneratorObject::THROW: |
| return isolate->Throw(value); |
| } |
| |
| UNREACHABLE(); |
| return isolate->ThrowIllegalOperation(); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_GeneratorClose) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| generator->set_continuation(JSGeneratorObject::kGeneratorClosed); |
| |
| return isolate->heap()->undefined_value(); |
| } |
| |
| |
| // Returns function of generator activation. |
| RUNTIME_FUNCTION(Runtime_GeneratorGetFunction) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| return generator->function(); |
| } |
| |
| |
| // Returns context of generator activation. |
| RUNTIME_FUNCTION(Runtime_GeneratorGetContext) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| return generator->context(); |
| } |
| |
| |
| // Returns receiver of generator activation. |
| RUNTIME_FUNCTION(Runtime_GeneratorGetReceiver) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| return generator->receiver(); |
| } |
| |
| |
| // Returns input of generator activation. |
| RUNTIME_FUNCTION(Runtime_GeneratorGetInput) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| return generator->input(); |
| } |
| |
| |
| // Returns generator continuation as a PC offset, or the magic -1 or 0 values. |
| RUNTIME_FUNCTION(Runtime_GeneratorGetContinuation) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| return Smi::FromInt(generator->continuation()); |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_GeneratorGetSourcePosition) { |
| HandleScope scope(isolate); |
| DCHECK(args.length() == 1); |
| CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0); |
| |
| if (generator->is_suspended()) { |
| Handle<Code> code(generator->function()->code(), isolate); |
| int offset = generator->continuation(); |
| RUNTIME_ASSERT(0 <= offset && offset < code->instruction_size()); |
| return Smi::FromInt(code->SourcePosition(offset)); |
| } |
| |
| return isolate->heap()->undefined_value(); |
| } |
| |
| |
| // Optimization for the following three functions is disabled in |
| // js/generator.js and compiler/ast-graph-builder.cc. |
| |
| |
| RUNTIME_FUNCTION(Runtime_GeneratorNext) { |
| UNREACHABLE(); |
| return nullptr; |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_GeneratorReturn) { |
| UNREACHABLE(); |
| return nullptr; |
| } |
| |
| |
| RUNTIME_FUNCTION(Runtime_GeneratorThrow) { |
| UNREACHABLE(); |
| return nullptr; |
| } |
| } // namespace internal |
| } // namespace v8 |