Implemented missing pieces of the debugger for ARM

src/arm/codegen-arm.cc

 // Copyright 2006-2009 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 281 matching lines @@
       if (should_trace) {
         frame_->CallRuntime(Runtime::kDebugTrace, 0);
         // Ignore the return value.
       }
 #endif
       VisitStatementsAndSpill(body);
     }
   }
 
   // Generate the return sequence if necessary.
-  if (frame_ != NULL || function_return_.is_linked()) {
+  if (has_valid_frame() || function_return_.is_linked()) {
+    if (!function_return_.is_linked()) {
+      CodeForReturnPosition(fun);
+    }
     // exit
     // r0: result
     // sp: stack pointer
     // fp: frame pointer
     // cp: callee's context
     __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
 
     function_return_.Bind();
     if (FLAG_trace) {
       // Push the return value on the stack as the parameter.
       // Runtime::TraceExit returns the parameter as it is.
       frame_->EmitPush(r0);
       frame_->CallRuntime(Runtime::kTraceExit, 1);
     }
 
+    // Add a label for checking the size of the code used for returning.
+    Label check_exit_codesize;
+    masm_->bind(&check_exit_codesize);
+
     // Tear down the frame which will restore the caller's frame pointer and
     // the link register.
     frame_->Exit();
 
-    __ add(sp, sp, Operand((scope_->num_parameters() + 1) * kPointerSize));
-    __ Jump(lr);
+    // Here we use masm_-> instead of the __ macro to avoid the code coverage
+    // tool from instrumenting as we rely on the code size here.
+    masm_->add(sp, sp, Operand((scope_->num_parameters() + 1) * kPointerSize));
+    masm_->Jump(lr);
+
+    // Check that the size of the code used for returning matches what is
+    // expected by the debugger.
+    ASSERT_EQ(kJSReturnSequenceLength,
+              masm_->InstructionsGeneratedSince(&check_exit_codesize));
+
   }
 
   // Code generation state must be reset.
   ASSERT(!has_cc());
   ASSERT(state_ == NULL);
   ASSERT(!function_return_is_shadowed_);
   function_return_.Unuse();
   DeleteFrame();
 
   // Process any deferred code using the register allocator.
@@ skipping 770 matching lines @@
   target->Branch(cc);
   cc_reg_ = al;
 }
 
 
 void CodeGenerator::CheckStack() {
   VirtualFrame::SpilledScope spilled_scope;
   if (FLAG_check_stack) {
     Comment cmnt(masm_, "[ check stack");
     __ LoadRoot(ip, Heap::kStackLimitRootIndex);
-    // Put the lr setup instruction in the delay slot.  The 'sizeof(Instr)' is
-    // added to the implicit 8 byte offset that always applies to operations
-    // with pc and gives a return address 12 bytes down.
-    masm_->add(lr, pc, Operand(sizeof(Instr)));
+    // Put the lr setup instruction in the delay slot.  kInstrSize is added to
+    // the implicit 8 byte offset that always applies to operations with pc and
+    // gives a return address 12 bytes down.
+    masm_->add(lr, pc, Operand(Assembler::kInstrSize));
     masm_->cmp(sp, Operand(ip));
     StackCheckStub stub;
     // Call the stub if lower.
     masm_->mov(pc,
                Operand(reinterpret_cast<intptr_t>(stub.GetCode().location()),
                        RelocInfo::CODE_TARGET),
                LeaveCC,
                lo);
   }
 }
@@ skipping 245 matching lines @@
   Comment cmnt(masm_, "[ BreakStatement");
   CodeForStatementPosition(node);
   node->target()->break_target()->Jump();
 }
 
 
 void CodeGenerator::VisitReturnStatement(ReturnStatement* node) {
   VirtualFrame::SpilledScope spilled_scope;
   Comment cmnt(masm_, "[ ReturnStatement");
 
+  CodeForStatementPosition(node);
+  LoadAndSpill(node->expression());
   if (function_return_is_shadowed_) {
-    CodeForStatementPosition(node);
-    LoadAndSpill(node->expression());
     frame_->EmitPop(r0);
     function_return_.Jump();
   } else {
-    // Load the returned value.
-    CodeForStatementPosition(node);
-    LoadAndSpill(node->expression());
-
     // Pop the result from the frame and prepare the frame for
     // returning thus making it easier to merge.
     frame_->EmitPop(r0);
     frame_->PrepareForReturn();
 
     function_return_.Jump();
   }
 }
 
 
@@ skipping 4855 matching lines @@
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) >> 28 < (1 << 15));
   return (static_cast<unsigned>(cc_) >> 27) | (strict_ ? 1 : 0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal