// Copyright 2016 The SwiftShader Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//    http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "Compiler.h"

#include "intermediate.h"

class TInfoSinkBase;

struct TLoopInfo {

  struct TIndex {

    int id;  // symbol id.

  } index;

  TIntermLoop* loop;

};

typedef TVector<TLoopInfo> TLoopStack;

// Traverses intermediate tree to ensure that the shader does not exceed the

// minimum functionality mandated in GLSL 1.0 spec, Appendix A.

class ValidateLimitations : public TIntermTraverser {

public:

  ValidateLimitations(GLenum shaderType, TInfoSinkBase& sink);

  int numErrors() const { return mNumErrors; }

  virtual bool visitBinary(Visit, TIntermBinary*);

  virtual bool visitUnary(Visit, TIntermUnary*);

  virtual bool visitAggregate(Visit, TIntermAggregate*);

  virtual bool visitLoop(Visit, TIntermLoop*);

private:

  void error(TSourceLoc loc, const char *reason, const char* token);

  bool withinLoopBody() const;

  bool isLoopIndex(const TIntermSymbol* symbol) const;

  bool validateLoopType(TIntermLoop* node);

  bool validateForLoopHeader(TIntermLoop* node, TLoopInfo* info);

  bool validateForLoopInit(TIntermLoop* node, TLoopInfo* info);

  bool validateForLoopCond(TIntermLoop* node, TLoopInfo* info);

  bool validateForLoopExpr(TIntermLoop* node, TLoopInfo* info);

  // Returns true if none of the loop indices is used as the argument to

  // the given function out or inout parameter.

  bool validateFunctionCall(TIntermAggregate* node);

  bool validateOperation(TIntermOperator* node, TIntermNode* operand);

  // Returns true if indexing does not exceed the minimum functionality

  // mandated in GLSL 1.0 spec, Appendix A, Section 5.

  bool isConstExpr(TIntermNode* node);

  bool isConstIndexExpr(TIntermNode* node);

  bool validateIndexing(TIntermBinary* node);

  GLenum mShaderType;

  TInfoSinkBase& mSink;

  int mNumErrors;

  TLoopStack mLoopStack;

};