Reland "Fix stepping in for-loops."

src/arm64/full-codegen-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 1091 matching lines @@
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
   // TODO(all): This visitor probably needs better comments and a revisit.
   SetStatementPosition(stmt);
 
   Label loop, exit;
   ForIn loop_statement(this, stmt);
   increment_loop_depth();
 
   // Get the object to enumerate over. If the object is null or undefined, skip
   // over the loop.  See ECMA-262 version 5, section 12.6.4.
+  SetExpressionPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
   __ JumpIfRoot(x0, Heap::kUndefinedValueRootIndex, &exit);
   Register null_value = x15;
   __ LoadRoot(null_value, Heap::kNullValueRootIndex);
   __ Cmp(x0, null_value);
   __ B(eq, &exit);
 
   PrepareForBailoutForId(stmt->PrepareId(), TOS_REG);
 
   // Convert the object to a JS object.
@@ skipping 73 matching lines @@
   __ CompareObjectType(x10, x11, x12, LAST_JS_PROXY_TYPE);
   DCHECK(Smi::FromInt(0) == 0);
   __ CzeroX(x1, le);  // Zero indicates proxy.
   __ Ldr(x2, FieldMemOperand(x0, FixedArray::kLengthOffset));
   // Smi and array, fixed array length (as smi) and initial index.
   __ Push(x1, x0, x2, xzr);
 
   // Generate code for doing the condition check.
   PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
   __ Bind(&loop);
+  SetExpressionPosition(stmt->each());
+
   // Load the current count to x0, load the length to x1.
   __ PeekPair(x0, x1, 0);
   __ Cmp(x0, x1);  // Compare to the array length.
   __ B(hs, loop_statement.break_label());
 
   // Get the current entry of the array into register r3.
   __ Peek(x10, 2 * kXRegSize);
   __ Add(x10, x10, Operand::UntagSmiAndScale(x0, kPointerSizeLog2));
   __ Ldr(x3, MemOperand(x10, FixedArray::kHeaderSize - kHeapObjectTag));
 
@@ skipping 49 matching lines @@
   __ Bind(loop_statement.break_label());
   __ Drop(5);
 
   // Exit and decrement the loop depth.
   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
   __ Bind(&exit);
   decrement_loop_depth();
 }
 
 
-void FullCodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
-  Comment cmnt(masm_, "[ ForOfStatement");
-  SetStatementPosition(stmt);
-
-  Iteration loop_statement(this, stmt);
-  increment_loop_depth();
-
-  // var iterator = iterable[Symbol.iterator]();
-  VisitForEffect(stmt->assign_iterator());
-
-  // Loop entry.
-  __ Bind(loop_statement.continue_label());
-
-  // result = iterator.next()
-  VisitForEffect(stmt->next_result());
-
-  // if (result.done) break;
-  Label result_not_done;
-  VisitForControl(stmt->result_done(),
-                  loop_statement.break_label(),
-                  &result_not_done,
-                  &result_not_done);
-  __ Bind(&result_not_done);
-
-  // each = result.value
-  VisitForEffect(stmt->assign_each());
-
-  // Generate code for the body of the loop.
-  Visit(stmt->body());
-
-  // Check stack before looping.
-  PrepareForBailoutForId(stmt->BackEdgeId(), NO_REGISTERS);
-  EmitBackEdgeBookkeeping(stmt, loop_statement.continue_label());
-  __ B(loop_statement.continue_label());
-
-  // Exit and decrement the loop depth.
-  PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
-  __ Bind(loop_statement.break_label());
-  decrement_loop_depth();
-}
-
-
 void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info,
                                        bool pretenure) {
   // Use the fast case closure allocation code that allocates in new space for
   // nested functions that don't need literals cloning. If we're running with
   // the --always-opt or the --prepare-always-opt flag, we need to use the
   // runtime function so that the new function we are creating here gets a
   // chance to have its code optimized and doesn't just get a copy of the
   // existing unoptimized code.
   if (!FLAG_always_opt &&
       !FLAG_prepare_always_opt &&
@@ skipping 3997 matching lines @@
   return previous_;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64