[es6] Make new.target work in functions

src/arm/builtins-arm.cc

 // 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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 325 matching lines @@
   if (create_memento) {
     __ jmp(count_incremented);
   } else {
     __ jmp(allocated);
   }
 }
 
 
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
+                                           bool use_new_target,
                                            bool create_memento) {
   // ----------- S t a t e -------------
   //  -- r0     : number of arguments
   //  -- r1     : constructor function
   //  -- r2     : allocation site or undefined
   //  -- r3     : original constructor
   //  -- lr     : return address
   //  -- sp[...]: constructor arguments
   // -----------------------------------
 
   // Should never create mementos for api functions.
   DCHECK(!is_api_function || !create_memento);
 
   Isolate* isolate = masm->isolate();
 
   // Enter a construct frame.
   {
     FrameAndConstantPoolScope scope(masm, StackFrame::CONSTRUCT);
 
     if (create_memento) {
       __ AssertUndefinedOrAllocationSite(r2, r4);
       __ push(r2);
     }
 
-    // Preserve the two incoming parameters on the stack.
+    // Preserve the incoming parameters on the stack.
     __ SmiTag(r0);
-    __ push(r0);  // Smi-tagged arguments count.
-    __ push(r1);  // Constructor function.
+    __ push(r0);
+    __ push(r1);
+    if (use_new_target) {
+      __ push(r3);
+    }
 
     Label rt_call, allocated, normal_new, count_incremented;
     __ cmp(r1, r3);
     __ b(eq, &normal_new);
 
     // Original constructor and function are different.
     Generate_Runtime_NewObject(masm, create_memento, r3, &count_incremented,
                                &allocated);
     __ bind(&normal_new);
 
@@ skipping 219 matching lines @@
     // r1: constructor function
     __ bind(&rt_call);
     Generate_Runtime_NewObject(masm, create_memento, r1, &count_incremented,
                                &allocated);
 
     // Receiver for constructor call allocated.
     // r4: JSObject
     __ bind(&allocated);
 
     if (create_memento) {
-      __ ldr(r2, MemOperand(sp, kPointerSize * 2));
+      int offset = (use_new_target ? 3 : 2) * kPointerSize;
+      __ ldr(r2, MemOperand(sp, offset));
       __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
       __ cmp(r2, r5);
       __ b(eq, &count_incremented);
       // r2 is an AllocationSite. We are creating a memento from it, so we
       // need to increment the memento create count.
       __ ldr(r3, FieldMemOperand(r2,
                                  AllocationSite::kPretenureCreateCountOffset));
       __ add(r3, r3, Operand(Smi::FromInt(1)));
       __ str(r3, FieldMemOperand(r2,
                                  AllocationSite::kPretenureCreateCountOffset));
       __ bind(&count_incremented);
     }
 
-    __ pop(r1);  // Constructor function.
+    // Restore the parameters.
+    if (use_new_target) {
+      __ pop(r3);
+    }
+    __ pop(r1);
 
+    // Retrieve smi-tagged arguments count from the stack.
+    __ ldr(r0, MemOperand(sp));
+    __ SmiUntag(r0);
+
+    // Push new.target onto the construct frame. This is stored just below the
+    // receiver on the stack.
+    if (use_new_target) {
+      __ push(r3);
+    }
     __ push(r4);
     __ push(r4);
 
-    // Reload the number of arguments from the stack.
-    // sp[0]: receiver
-    // sp[1]: receiver
-    // sp[2]: number of arguments (smi-tagged)
-    __ ldr(r3, MemOperand(sp, 2 * kPointerSize));
-
     // Set up pointer to last argument.
     __ add(r2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
 
-    // Set up number of arguments for function call below
-    __ SmiUntag(r0, r3);
-
     // Copy arguments and receiver to the expression stack.
     // r0: number of arguments
     // r1: constructor function
     // r2: address of last argument (caller sp)
     // r3: number of arguments (smi-tagged)
     // sp[0]: receiver
     // sp[1]: receiver
-    // sp[2]: number of arguments (smi-tagged)
+    // sp[2]: new.target (if used)
+    // sp[2/3]: number of arguments (smi-tagged)
     Label loop, entry;
+    __ SmiTag(r3, r0);
     __ b(&entry);
     __ bind(&loop);
     __ ldr(ip, MemOperand(r2, r3, LSL, kPointerSizeLog2 - 1));
     __ push(ip);
     __ bind(&entry);
     __ sub(r3, r3, Operand(2), SetCC);
     __ b(ge, &loop);
 
     // Call the function.
     // r0: number of arguments
     // r1: constructor function
     if (is_api_function) {
       __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
       Handle<Code> code =
           masm->isolate()->builtins()->HandleApiCallConstruct();
       __ Call(code, RelocInfo::CODE_TARGET);
     } else {
       ParameterCount actual(r0);
       __ InvokeFunction(r1, actual, CALL_FUNCTION, NullCallWrapper());
     }
 
     // Store offset of return address for deoptimizer.
-    if (!is_api_function) {
+    // TODO(arv): Remove the "!use_new_target" before supporting optimization
+    // of functions that reference new.target
+    if (!is_api_function && !use_new_target) {
       masm->isolate()->heap()->SetConstructStubDeoptPCOffset(masm->pc_offset());
     }
 
     // Restore context from the frame.
     // r0: result
     // sp[0]: receiver
-    // sp[1]: number of arguments (smi-tagged)
+    // sp[1]: new.target (if used)
+    // sp[1/2]: number of arguments (smi-tagged)
     __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
 
     // If the result is an object (in the ECMA sense), we should get rid
     // of the receiver and use the result; see ECMA-262 section 13.2.2-7
     // on page 74.
     Label use_receiver, exit;
 
     // If the result is a smi, it is *not* an object in the ECMA sense.
     // r0: result
     // sp[0]: receiver (newly allocated object)
-    // sp[1]: number of arguments (smi-tagged)
+    // sp[1]: new.target (if used)
+    // sp[1/2]: number of arguments (smi-tagged)
     __ JumpIfSmi(r0, &use_receiver);
 
     // If the type of the result (stored in its map) is less than
     // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
     __ CompareObjectType(r0, r1, r3, FIRST_SPEC_OBJECT_TYPE);
     __ b(ge, &exit);
 
     // Throw away the result of the constructor invocation and use the
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ ldr(r0, MemOperand(sp));
 
     // Remove receiver from the stack, remove caller arguments, and
     // return.
     __ bind(&exit);
     // r0: result
     // sp[0]: receiver (newly allocated object)
-    // sp[1]: number of arguments (smi-tagged)
-    __ ldr(r1, MemOperand(sp, kPointerSize));
+    // sp[1]: new.target (if used)
+    // sp[1/2]: number of arguments (smi-tagged)
+    int offset = (use_new_target ? 2 : 1) * kPointerSize;
+    __ ldr(r1, MemOperand(sp, offset));
 
     // Leave construct frame.
   }
 
   __ add(sp, sp, Operand(r1, LSL, kPointerSizeLog2 - 1));
   __ add(sp, sp, Operand(kPointerSize));
   __ IncrementCounter(isolate->counters()->constructed_objects(), 1, r1, r2);
   __ Jump(lr);
 }
 
 
 void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, false, FLAG_pretenuring_call_new);
+  Generate_JSConstructStubHelper(masm, false, false, FLAG_pretenuring_call_new);
 }
 
 
 void Builtins::Generate_JSConstructStubApi(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, true, false);
+  Generate_JSConstructStubHelper(masm, true, false, false);
 }
 
 
+void Builtins::Generate_JSConstructStubNewTarget(MacroAssembler* masm) {
+  Generate_JSConstructStubHelper(masm, false, true, FLAG_pretenuring_call_new);
+}
+
+
 void Builtins::Generate_JSConstructStubForDerived(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0     : number of arguments
   //  -- r1     : constructor function
   //  -- r2     : allocation site or undefined
   //  -- r3     : original constructor
   //  -- lr     : return address
   //  -- sp[...]: constructor arguments
   // -----------------------------------
 
@@ skipping 1062 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM