Patch to enhance the source code line information for profiler.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 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 256 matching lines @@
     }
     if (!emit_instructions) continue;
 
     if (FLAG_code_comments && instr->HasInterestingComment(this)) {
       Comment(";;; <@%d,#%d> %s",
               current_instruction_,
               instr->hydrogen_value()->id(),
               instr->Mnemonic());
     }
 
+    RecordAndUpdatePosition(instr->position());
+
     instr->CompileToNative(this);
   }
   EnsureSpaceForLazyDeopt();
   last_lazy_deopt_pc_ = masm()->pc_offset();
   return !is_aborted();
 }
 
 
 bool LCodeGen::GenerateDeferredCode() {
   ASSERT(is_generating());
   if (deferred_.length() > 0) {
     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
       LDeferredCode* code = deferred_[i];
+
+      int pos = instructions_->at(code->instruction_index())->position();
+      RecordAndUpdatePosition(pos);
+
       Comment(";;; <@%d,#%d> "
               "-------------------- Deferred %s --------------------",
               code->instruction_index(),
               code->instr()->hydrogen_value()->id(),
               code->instr()->Mnemonic());
       __ bind(code->entry());
       if (NeedsDeferredFrame()) {
         Comment(";;; Build frame");
         ASSERT(!frame_is_built_);
         ASSERT(info()->IsStub());
@@ skipping 670 matching lines @@
       pointers, Safepoint::kWithRegistersAndDoubles, arguments, deopt_mode);
 }
 
 
 void LCodeGen::RecordPosition(int position) {
   if (position == RelocInfo::kNoPosition) return;
   masm()->positions_recorder()->RecordPosition(position);
 }
 
 
+void LCodeGen::RecordAndUpdatePosition(int position) {
+  if (position >= 0 && position != old_position_) {
+    masm()->positions_recorder()->RecordPosition(position);
+    old_position_ = position;
+  }
+}
+
+
 static const char* LabelType(LLabel* label) {
   if (label->is_loop_header()) return " (loop header)";
   if (label->is_osr_entry()) return " (OSR entry)";
   return "";
 }
 
 
 void LCodeGen::DoLabel(LLabel* label) {
   Comment(";;; <@%d,#%d> -------------------- B%d%s --------------------",
           current_instruction_,
@@ skipping 4849 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal