added basic dataflow analysis to skslc

src/sksl/SkSLIRGenerator.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
  
 #ifndef SKSL_IRGENERATOR
 #define SKSL_IRGENERATOR
 
@@ skipping 27 matching lines @@
 #include "ir/SkSLExpression.h"
 #include "ir/SkSLExtension.h"
 #include "ir/SkSLFunctionDefinition.h"
 #include "ir/SkSLInterfaceBlock.h"
 #include "ir/SkSLModifiers.h"
 #include "ir/SkSLModifiersDeclaration.h"
 #include "ir/SkSLSymbolTable.h"
 #include "ir/SkSLStatement.h"
 #include "ir/SkSLType.h"
 #include "ir/SkSLTypeReference.h"
-#include "ir/SkSLVarDeclaration.h"
+#include "ir/SkSLVarDeclarations.h"
 
 namespace SkSL {
 
 /**
  * Performs semantic analysis on an abstract syntax tree (AST) and produces the corresponding 
  * (unoptimized) intermediate representation (IR).
  */
 class IRGenerator {
 public:
     IRGenerator(const Context* context, std::shared_ptr<SymbolTable> root, 
@@ skipping 50 matching lines @@
     std::unique_ptr<Statement> convertVarDeclarationStatement(const ASTVarDeclarationStatement& s);
     std::unique_ptr<Statement> convertWhile(const ASTWhileStatement& w);
 
     void checkValid(const Expression& expr);
     void markReadFrom(const Variable& var);
     void markWrittenTo(const Expression& expr);
 
     const Context& fContext;
     const FunctionDeclaration* fCurrentFunction;
     std::shared_ptr<SymbolTable> fSymbolTable;
+    int fLoopLevel;
     ErrorReporter& fErrors;
 
     friend class AutoSymbolTable;
+    friend class AutoLoopLevel;
     friend class Compiler;
 };
 
 }
 
 #endif