Checking for stack height equality between full codegen and hydrogen.

src/full-codegen.h

Index: src/full-codegen.h
diff --git a/src/full-codegen.h b/src/full-codegen.h
index 148d0c02de2736cc27149e3b6c2be654ffdd86d9..16f484d9c83675b9a55502a1445fd120938d91da 100644
--- a/src/full-codegen.h
+++ b/src/full-codegen.h
@@ -20,6 +20,34 @@
 namespace v8 {
 namespace internal {
 
+#if defined(COMPARE_OPT_STACK_HEIGHT)
+
+class StackHeightWrapper {
+ public:
+  StackHeightWrapper() : stack_height_(0) { }
+
+  void updateBy(int incrementBy) {
+    stack_height_ += incrementBy;
+    ASSERT(stack_height_ >= 0);
+  }
+
+  int get() const { return stack_height_; }
+
+ private:
+  int stack_height_;
+};
+
+#else
+
+class StackHeightWrapper {
+ public:
+  StackHeightWrapper() { }
+  void updateBy(int incrementBy) { }
+  int get() const { return 0; }
+};
+
+#endif  // defined(COMPARE_OPT_STACK_HEIGHT)
+
 // Forward declarations.
 class JumpPatchSite;
 
@@ -155,6 +183,8 @@ class FullCodeGenerator: public AstVisitor {
     }
 
    protected:
+    FullCodeGenerator* codegen() { return codegen_; }
+
     MacroAssembler* masm() { return codegen_->masm(); }
 
     FullCodeGenerator* codegen_;
@@ -565,6 +595,72 @@ class FullCodeGenerator: public AstVisitor {
   void SetStatementPosition(int pos);
   void SetSourcePosition(int pos);
 
+  void AsmPush(Register reg) {
+    masm()->push(reg);
+    UpdateStackHeight(1);
+  }
+
+  void AsmPush(const Operand& op);
+
+  void AsmPushHandle(Handle<Object> handle) {
+    masm()->Push(handle);
+    UpdateStackHeight(1);
+  }
+
+  void AsmPushSmi(Smi* smi) {
+    masm()->Push(smi);
+    UpdateStackHeight(1);
+  }
+
+  void AsmPop(Register reg) {
+    masm()->pop(reg);
+    UpdateStackHeight(-1);
+  }
+
+  void AsmInvokeBuiltin(Builtins::JavaScript id,
+                     InvokeFlag flag,
+                     int arg_count,
+                     const CallWrapper& call_wrapper = NullCallWrapper()) {
+    masm()->InvokeBuiltin(id, flag, call_wrapper);
+    UpdateStackHeight(-arg_count);
+  }
+
+  void AsmDrop(int n) {
+    masm()->Drop(n);
+    UpdateStackHeight(-n);
+  }
+
+  void AsmCallRuntime(const Runtime::Function* f,
+                 int num_arguments,
+                 SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+    masm()->CallRuntime(f, num_arguments, save_doubles);
+    UpdateStackHeight(-num_arguments);
+  }
+
+  void AsmCallRuntime(Runtime::FunctionId id,
+                 int num_arguments,
+                 SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+    masm()->CallRuntime(id, num_arguments, save_doubles);
+    UpdateStackHeight(-num_arguments);
+  }
+
+  void AsmPushTryHandler(StackHandler::Kind kind, int handler_index) {
+    masm()->PushTryHandler(kind, handler_index);
+    UpdateStackHeight(StackHandlerConstants::kSize / kPointerSize);
+  }
+
+  void AsmPopTryHandler() {
+    masm()->PopTryHandler();
+    UpdateStackHeight(-StackHandlerConstants::kSize / kPointerSize);
+  }
+
+  // Call a code stub.  Generate the code if necessary.
+  void AsmCallStub(CodeStub* stub,
+                   int arg_count) {
+    masm()->CallStub(stub);
+    UpdateStackHeight(-arg_count);
+  }
+
   // Non-local control flow support.
   void EnterFinallyBlock();
   void ExitFinallyBlock();
@@ -625,6 +721,7 @@ class FullCodeGenerator: public AstVisitor {
   struct BailoutEntry {
     BailoutId id;
     unsigned pc_and_state;
+    int stack_height;
   };
 
   struct BackEdgeEntry {
@@ -809,12 +906,35 @@ class FullCodeGenerator: public AstVisitor {
     virtual bool IsEffect() const { return true; }
   };
 
+  void CheckStackHeight() {
+#if defined(VERIFY_STACK_HEIGHT)
+    AddStackHeightVerifier();
+#endif  // defined(VERIFY_STACK_HEIGHT)
+  }
+
+  void UpdateStackHeight(int difference) {
+    stack_height_.updateBy(difference);
+  }
+
+  void SetStackHeight(StackHeightWrapper height) {
+    stack_height_ = height;
+  }
+
+  StackHeightWrapper CurrentStackHeight() {
+    return stack_height_;
+  }
+
+#if defined(VERIFY_STACK_HEIGHT)
+  void AddStackHeightVerifier();
+#endif  // defined(VERIFY_STACK_HEIGHT)
+
   MacroAssembler* masm_;
   CompilationInfo* info_;
   Scope* scope_;
   Label return_label_;
   NestedStatement* nesting_stack_;
   int loop_depth_;
+  StackHeightWrapper stack_height_;
   ZoneList<Handle<Object> >* globals_;
   Handle<FixedArray> modules_;
   int module_index_;