Implement function proxies (except for their use as constructors).

src/x64/builtins-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 637 matching lines @@
     __ j(not_zero, &done);
     __ pop(rbx);
     __ Push(FACTORY->undefined_value());
     __ push(rbx);
     __ incq(rax);
     __ bind(&done);
   }
 
   // 2. Get the function to call (passed as receiver) from the stack, check
   //    if it is a function.
-  Label non_function;
+  Label slow, non_function;
   // The function to call is at position n+1 on the stack.
   __ movq(rdi, Operand(rsp, rax, times_pointer_size, 1 * kPointerSize));
   __ JumpIfSmi(rdi, &non_function);
   __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
-  __ j(not_equal, &non_function);
+  __ j(not_equal, &slow);
 
   // 3a. Patch the first argument if necessary when calling a function.
   Label shift_arguments;
+  __ Set(rdx, 0);  // indicate regular JS_FUNCTION
   { Label convert_to_object, use_global_receiver, patch_receiver;
     // Change context eagerly in case we need the global receiver.
     __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
     // Do not transform the receiver for strict mode functions.
     __ movq(rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
     __ testb(FieldOperand(rbx, SharedFunctionInfo::kStrictModeByteOffset),
              Immediate(1 << SharedFunctionInfo::kStrictModeBitWithinByte));
     __ j(not_equal, &shift_arguments);
 
@@ skipping 17 matching lines @@
     __ j(above_equal, &shift_arguments);
 
     __ bind(&convert_to_object);
     __ EnterInternalFrame();  // In order to preserve argument count.
     __ Integer32ToSmi(rax, rax);
     __ push(rax);
 
     __ push(rbx);
     __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
     __ movq(rbx, rax);
+    __ Set(rdx, 0);  // indicate regular JS_FUNCTION
 
     __ pop(rax);
     __ SmiToInteger32(rax, rax);
     __ LeaveInternalFrame();
     // Restore the function to rdi.
     __ movq(rdi, Operand(rsp, rax, times_pointer_size, 1 * kPointerSize));
     __ jmp(&patch_receiver, Label::kNear);
 
     // Use the global receiver object from the called function as the
     // receiver.
     __ bind(&use_global_receiver);
     const int kGlobalIndex =
         Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
     __ movq(rbx, FieldOperand(rsi, kGlobalIndex));
     __ movq(rbx, FieldOperand(rbx, GlobalObject::kGlobalContextOffset));
     __ movq(rbx, FieldOperand(rbx, kGlobalIndex));
     __ movq(rbx, FieldOperand(rbx, GlobalObject::kGlobalReceiverOffset));
 
     __ bind(&patch_receiver);
     __ movq(Operand(rsp, rax, times_pointer_size, 0), rbx);
 
     __ jmp(&shift_arguments);
   }
 
+  // 3b. Check for function proxy.
+  __ bind(&slow);
+  __ Set(rdx, 1);  // indicate function proxy
+  __ CmpInstanceType(rcx, JS_FUNCTION_PROXY_TYPE);
+  __ j(equal, &shift_arguments);
+  __ bind(&non_function);
+  __ Set(rdx, 2);  // indicate non-function
 
-  // 3b. Patch the first argument when calling a non-function.  The
+  // 3c. Patch the first argument when calling a non-function.  The
   //     CALL_NON_FUNCTION builtin expects the non-function callee as
   //     receiver, so overwrite the first argument which will ultimately
   //     become the receiver.
-  __ bind(&non_function);
   __ movq(Operand(rsp, rax, times_pointer_size, 0), rdi);
-  __ Set(rdi, 0);
 
   // 4. Shift arguments and return address one slot down on the stack
   //    (overwriting the original receiver).  Adjust argument count to make
   //    the original first argument the new receiver.
   __ bind(&shift_arguments);
   { Label loop;
     __ movq(rcx, rax);
     __ bind(&loop);
     __ movq(rbx, Operand(rsp, rcx, times_pointer_size, 0));
     __ movq(Operand(rsp, rcx, times_pointer_size, 1 * kPointerSize), rbx);
     __ decq(rcx);
     __ j(not_sign, &loop);  // While non-negative (to copy return address).
     __ pop(rbx);  // Discard copy of return address.
     __ decq(rax);  // One fewer argument (first argument is new receiver).
   }
 
-  // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin.
-  { Label function;
-    __ testq(rdi, rdi);
-    __ j(not_zero, &function);
+  // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin,
+  //     or a function proxy via CALL_FUNCTION_PROXY.
+  { Label function, non_proxy;
+    __ testq(rdx, rdx);
+    __ j(zero, &function);
     __ Set(rbx, 0);
+    __ SetCallKind(rcx, CALL_AS_METHOD);
+    __ cmpq(rdx, Immediate(1));
+    __ j(not_equal, &non_proxy);
+
+    __ pop(rdx);   // return address
+    __ push(rdi);  // re-add proxy object as additional argument
+    __ push(rdx);
+    __ incq(rax);
+    __ GetBuiltinEntry(rdx, Builtins::CALL_FUNCTION_PROXY);
+    __ jmp(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+           RelocInfo::CODE_TARGET);
+
+    __ bind(&non_proxy);
     __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION);
-    __ SetCallKind(rcx, CALL_AS_METHOD);
     __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
             RelocInfo::CODE_TARGET);
     __ bind(&function);
   }
 
   // 5b. Get the code to call from the function and check that the number of
   //     expected arguments matches what we're providing.  If so, jump
   //     (tail-call) to the code in register edx without checking arguments.
   __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
   __ movsxlq(rbx,
@@ skipping 21 matching lines @@
   __ EnterInternalFrame();
   // Stack frame:
   //    rbp: Old base pointer
   // rbp[1]: return address
   // rbp[2]: function arguments
   // rbp[3]: receiver
   // rbp[4]: function
   static const int kArgumentsOffset = 2 * kPointerSize;
   static const int kReceiverOffset = 3 * kPointerSize;
   static const int kFunctionOffset = 4 * kPointerSize;
+
   __ push(Operand(rbp, kFunctionOffset));
   __ push(Operand(rbp, kArgumentsOffset));
   __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
 
-  // Check the stack for overflow. We are not trying need to catch
+  // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
   __ LoadRoot(kScratchRegister, Heap::kRealStackLimitRootIndex);
   __ movq(rcx, rsp);
   // Make rcx the space we have left. The stack might already be overflowed
   // here which will cause rcx to become negative.
   __ subq(rcx, kScratchRegister);
   // Make rdx the space we need for the array when it is unrolled onto the
   // stack.
   __ PositiveSmiTimesPowerOfTwoToInteger64(rdx, rax, kPointerSizeLog2);
   // Check if the arguments will overflow the stack.
   __ cmpq(rcx, rdx);
   __ j(greater, &okay);  // Signed comparison.
 
   // Out of stack space.
   __ push(Operand(rbp, kFunctionOffset));
   __ push(rax);
   __ InvokeBuiltin(Builtins::APPLY_OVERFLOW, CALL_FUNCTION);
   __ bind(&okay);
   // End of stack check.
 
   // Push current index and limit.
   const int kLimitOffset =
       StandardFrameConstants::kExpressionsOffset - 1 * kPointerSize;
   const int kIndexOffset = kLimitOffset - 1 * kPointerSize;
   __ push(rax);  // limit
   __ push(Immediate(0));  // index
 
-  // Change context eagerly to get the right global object if
-  // necessary.
+  // Get the receiver.
+  __ movq(rbx, Operand(rbp, kReceiverOffset));
+
+  // Check that the function is a JS function (otherwise it must be a proxy).
+  Label push_receiver;
   __ movq(rdi, Operand(rbp, kFunctionOffset));
+  __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
+  __ j(not_equal, &push_receiver);
+
+  // Change context eagerly to get the right global object if necessary.
   __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
-  // Compute the receiver.
-  Label call_to_object, use_global_receiver, push_receiver;
-  __ movq(rbx, Operand(rbp, kReceiverOffset));
-
   // Do not transform the receiver for strict mode functions.
+  Label call_to_object, use_global_receiver;
   __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
   __ testb(FieldOperand(rdx, SharedFunctionInfo::kStrictModeByteOffset),
            Immediate(1 << SharedFunctionInfo::kStrictModeBitWithinByte));
   __ j(not_equal, &push_receiver);
 
   // Do not transform the receiver for natives.
   __ testb(FieldOperand(rdx, SharedFunctionInfo::kNativeByteOffset),
            Immediate(1 << SharedFunctionInfo::kNativeBitWithinByte));
   __ j(not_equal, &push_receiver);
 
@@ skipping 52 matching lines @@
   // Update the index on the stack and in register rax.
   __ movq(rax, Operand(rbp, kIndexOffset));
   __ SmiAddConstant(rax, rax, Smi::FromInt(1));
   __ movq(Operand(rbp, kIndexOffset), rax);
 
   __ bind(&entry);
   __ cmpq(rax, Operand(rbp, kLimitOffset));
   __ j(not_equal, &loop);
 
   // Invoke the function.
+  Label call_proxy;
   ParameterCount actual(rax);
   __ SmiToInteger32(rax, rax);
   __ movq(rdi, Operand(rbp, kFunctionOffset));
+  __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
+  __ j(not_equal, &call_proxy);
   __ InvokeFunction(rdi, actual, CALL_FUNCTION,
                     NullCallWrapper(), CALL_AS_METHOD);
 
   __ LeaveInternalFrame();
-  __ ret(3 * kPointerSize);  // remove function, receiver, and arguments
+  __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
+
+  // Invoke the function proxy.
+  __ bind(&call_proxy);
+  __ push(rdi);  // add function proxy as last argument
+  __ incq(rax);
+  __ Set(rbx, 0);
+  __ SetCallKind(rcx, CALL_AS_METHOD);
+  __ GetBuiltinEntry(rdx, Builtins::CALL_FUNCTION_PROXY);
+  __ call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+          RelocInfo::CODE_TARGET);
+
+  __ LeaveInternalFrame();
+  __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
 }
 
 
 // Number of empty elements to allocate for an empty array.
 static const int kPreallocatedArrayElements = 4;
 
 
 // Allocate an empty JSArray. The allocated array is put into the result
 // register. If the parameter initial_capacity is larger than zero an elements
 // backing store is allocated with this size and filled with the hole values.
@@ skipping 580 matching lines @@
   Deoptimizer::EntryGenerator generator(masm, Deoptimizer::OSR);
   generator.Generate();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64