src/compiler/SymbolTable.h - external/angle - Git at Google

 //
 // Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //

 #ifndef _SYMBOL_TABLE_INCLUDED_
 #define _SYMBOL_TABLE_INCLUDED_

 //
 // Symbol table for parsing.  Has these design characteristics:
 //
 // * Same symbol table can be used to compile many shaders, to preserve
 //   effort of creating and loading with the large numbers of built-in
 //   symbols.
 //
 // * Name mangling will be used to give each function a unique name
 //   so that symbol table lookups are never ambiguous.  This allows
 //   a simpler symbol table structure.
 //
 // * Pushing and popping of scope, so symbol table will really be a stack
 //   of symbol tables.  Searched from the top, with new inserts going into
 //   the top.
 //
 // * Constants:  Compile time constant symbols will keep their values
 //   in the symbol table.  The parser can substitute constants at parse
 //   time, including doing constant folding and constant propagation.
 //
 // * No temporaries:  Temporaries made from operations (+, --, .xy, etc.)
 //   are tracked in the intermediate representation, not the symbol table.
 //

 #include <assert.h>

 #include "common/angleutils.h"
 #include "compiler/InfoSink.h"
 #include "compiler/intermediate.h"

 //
 // Symbol base class.  (Can build functions or variables out of these...)
 //
 class TSymbol {
 public:
     POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator)
     TSymbol(const TString *n) :  name(n) { }
     virtual ~TSymbol() { /* don't delete name, it's from the pool */ }
     const TString& getName() const { return *name; }
     virtual const TString& getMangledName() const { return getName(); }
     virtual bool isFunction() const { return false; }
     virtual bool isVariable() const { return false; }
     void setUniqueId(int id) { uniqueId = id; }
     int getUniqueId() const { return uniqueId; }
     virtual void dump(TInfoSink &infoSink) const = 0;
     void relateToExtension(const TString& ext) { extension = ext; }
     const TString& getExtension() const { return extension; }

 private:
     DISALLOW_COPY_AND_ASSIGN(TSymbol);

     const TString *name;
     unsigned int uniqueId;      // For real comparing during code generation
     TString extension;
 };

 //
 // Variable class, meaning a symbol that's not a function.
 //
 // There could be a separate class heirarchy for Constant variables;
 // Only one of int, bool, or float, (or none) is correct for
 // any particular use, but it's easy to do this way, and doesn't
 // seem worth having separate classes, and "getConst" can't simply return
 // different values for different types polymorphically, so this is
 // just simple and pragmatic.
 //
 class TVariable : public TSymbol {
 public:
     TVariable(const TString *name, const TType& t, bool uT = false ) : TSymbol(name), type(t), userType(uT), unionArray(0) { }
     virtual ~TVariable() { }
     virtual bool isVariable() const { return true; }
     TType& getType() { return type; }
     const TType& getType() const { return type; }
     bool isUserType() const { return userType; }
     void setQualifier(TQualifier qualifier) { type.setQualifier(qualifier); }

     virtual void dump(TInfoSink &infoSink) const;

     ConstantUnion* getConstPointer()
     {
         if (!unionArray)
             unionArray = new ConstantUnion[type.getObjectSize()];

         return unionArray;
     }

     ConstantUnion* getConstPointer() const { return unionArray; }

     void shareConstPointer( ConstantUnion *constArray)
     {
         if (unionArray == constArray)
             return;

         delete[] unionArray;
         unionArray = constArray;
     }

 private:
     DISALLOW_COPY_AND_ASSIGN(TVariable);

     TType type;
     bool userType;
     // we are assuming that Pool Allocator will free the memory allocated to unionArray
     // when this object is destroyed
     ConstantUnion *unionArray;
 };

 //
 // The function sub-class of symbols and the parser will need to
 // share this definition of a function parameter.
 //
 struct TParameter {
     TString *name;
     TType* type;
 };

 //
 // The function sub-class of a symbol.
 //
 class TFunction : public TSymbol {
 public:
     TFunction(TOperator o) :
         TSymbol(0),
         returnType(TType(EbtVoid, EbpUndefined)),
         op(o),
         defined(false) { }
     TFunction(const TString *name, TType& retType, TOperator tOp = EOpNull) :
         TSymbol(name),
         returnType(retType),
         mangledName(TFunction::mangleName(*name)),
         op(tOp),
         defined(false) { }
     virtual ~TFunction();
     virtual bool isFunction() const { return true; }

     static TString mangleName(const TString& name) { return name + '('; }
     static TString unmangleName(const TString& mangledName)
     {
         return TString(mangledName.c_str(), mangledName.find_first_of('('));
     }

     void addParameter(TParameter& p)
     {
         parameters.push_back(p);
         mangledName = mangledName + p.type->getMangledName();
     }

     const TString& getMangledName() const { return mangledName; }
     const TType& getReturnType() const { return returnType; }

     void relateToOperator(TOperator o) { op = o; }
     TOperator getBuiltInOp() const { return op; }

     void setDefined() { defined = true; }
     bool isDefined() { return defined; }

     size_t getParamCount() const { return parameters.size(); }
     const TParameter& getParam(size_t i) const { return parameters[i]; }

     virtual void dump(TInfoSink &infoSink) const;

 private:
     DISALLOW_COPY_AND_ASSIGN(TFunction);

     typedef TVector<TParameter> TParamList;
     TParamList parameters;
     TType returnType;
     TString mangledName;
     TOperator op;
     bool defined;
 };


 class TSymbolTableLevel {
 public:
     typedef TMap<TString, TSymbol*> tLevel;
     typedef tLevel::const_iterator const_iterator;
     typedef const tLevel::value_type tLevelPair;
     typedef std::pair<tLevel::iterator, bool> tInsertResult;

     POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator)
     TSymbolTableLevel() { }
     ~TSymbolTableLevel();

     bool insert(TSymbol& symbol)
     {
         //
         // returning true means symbol was added to the table
         //
         tInsertResult result;
         result = level.insert(tLevelPair(symbol.getMangledName(), &symbol));

         return result.second;
     }

     TSymbol* find(const TString& name) const
     {
         tLevel::const_iterator it = level.find(name);
         if (it == level.end())
             return 0;
         else
             return (*it).second;
     }

     const_iterator begin() const
     {
         return level.begin();
     }

     const_iterator end() const
     {
         return level.end();
     }

     void relateToOperator(const char* name, TOperator op);
     void relateToExtension(const char* name, const TString& ext);
     void dump(TInfoSink &infoSink) const;

 protected:
     tLevel level;
 };

 class TSymbolTable {
 public:
     TSymbolTable() : uniqueId(0)
     {
         //
         // The symbol table cannot be used until push() is called, but
         // the lack of an initial call to push() can be used to detect
         // that the symbol table has not been preloaded with built-ins.
         //
     }

     ~TSymbolTable()
     {
         // level 0 is always built In symbols, so we never pop that out
         while (table.size() > 1)
             pop();
     }

     //
     // When the symbol table is initialized with the built-ins, there should
     // 'push' calls, so that built-ins are at level 0 and the shader
     // globals are at level 1.
     //
     bool isEmpty() { return table.size() == 0; }
     bool atBuiltInLevel() { return table.size() == 1; }
     bool atGlobalLevel() { return table.size() <= 2; }
     void push()
     {
         table.push_back(new TSymbolTableLevel);
         precisionStack.push_back( PrecisionStackLevel() );
     }

     void pop()
     {
         delete table[currentLevel()];
         table.pop_back();
         precisionStack.pop_back();
     }

     bool insert(TSymbol& symbol)
     {
         symbol.setUniqueId(++uniqueId);
         return table[currentLevel()]->insert(symbol);
     }

     TSymbol* find(const TString& name, bool* builtIn = 0, bool *sameScope = 0)
     {
         int level = currentLevel();
         TSymbol* symbol;
         do {
             symbol = table[level]->find(name);
             --level;
         } while (symbol == 0 && level >= 0);
         level++;
         if (builtIn)
             *builtIn = level == 0;
         if (sameScope)
             *sameScope = level == currentLevel();
         return symbol;
     }

     TSymbol *findBuiltIn(const TString &name)
     {
         return table[0]->find(name);
     }

     TSymbolTableLevel* getGlobalLevel() {
         assert(table.size() >= 2);
         return table[1];
     }

     TSymbolTableLevel* getOuterLevel() {
         assert(table.size() >= 2);
         return table[currentLevel() - 1];
     }

     void relateToOperator(const char* name, TOperator op) {
         table[0]->relateToOperator(name, op);
     }
     void relateToExtension(const char* name, const TString& ext) {
         table[0]->relateToExtension(name, ext);
     }
     int getMaxSymbolId() { return uniqueId; }
     void dump(TInfoSink &infoSink) const;

     bool setDefaultPrecision( const TPublicType& type, TPrecision prec ){
         if (IsSampler(type.type))
             return true;  // Skip sampler types for the time being
         if (type.type != EbtFloat && type.type != EbtInt)
             return false; // Only set default precision for int/float
         if (type.size != 1 || type.matrix || type.array)
             return false; // Not allowed to set for aggregate types
         int indexOfLastElement = static_cast<int>(precisionStack.size()) - 1;
         precisionStack[indexOfLastElement][type.type] = prec; // Uses map operator [], overwrites the current value
         return true;
     }

     // Searches down the precisionStack for a precision qualifier for the specified TBasicType
     TPrecision getDefaultPrecision( TBasicType type){
         if( type != EbtFloat && type != EbtInt ) return EbpUndefined;
         int level = static_cast<int>(precisionStack.size()) - 1;
         assert( level >= 0); // Just to be safe. Should not happen.
         PrecisionStackLevel::iterator it;
         TPrecision prec = EbpUndefined; // If we dont find anything we return this. Should we error check this?
         while( level >= 0 ){
             it = precisionStack[level].find( type );
             if( it != precisionStack[level].end() ){
                 prec = (*it).second;
                 break;
             }
             level--;
         }
         return prec;
     }

 protected:
     int currentLevel() const { return static_cast<int>(table.size()) - 1; }

     std::vector<TSymbolTableLevel*> table;
     typedef std::map< TBasicType, TPrecision > PrecisionStackLevel;
     std::vector< PrecisionStackLevel > precisionStack;
     int uniqueId;     // for unique identification in code generation
 };

 #endif // _SYMBOL_TABLE_INCLUDED_
	//
	// Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.
	//

	#ifndef _SYMBOL_TABLE_INCLUDED_
	#define _SYMBOL_TABLE_INCLUDED_

	//
	// Symbol table for parsing. Has these design characteristics:
	//
	// * Same symbol table can be used to compile many shaders, to preserve
	// effort of creating and loading with the large numbers of built-in
	// symbols.
	//
	// * Name mangling will be used to give each function a unique name
	// so that symbol table lookups are never ambiguous. This allows
	// a simpler symbol table structure.
	//
	// * Pushing and popping of scope, so symbol table will really be a stack
	// of symbol tables. Searched from the top, with new inserts going into
	// the top.
	//
	// * Constants: Compile time constant symbols will keep their values
	// in the symbol table. The parser can substitute constants at parse
	// time, including doing constant folding and constant propagation.
	//
	// * No temporaries: Temporaries made from operations (+, --, .xy, etc.)
	// are tracked in the intermediate representation, not the symbol table.
	//

	#include <assert.h>

	#include "common/angleutils.h"
	#include "compiler/InfoSink.h"
	#include "compiler/intermediate.h"

	//
	// Symbol base class. (Can build functions or variables out of these...)
	//
	class TSymbol {
	public:
	POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator)
	TSymbol(const TString *n) : name(n) { }
	virtual ~TSymbol() { /* don't delete name, it's from the pool */ }
	const TString& getName() const { return *name; }
	virtual const TString& getMangledName() const { return getName(); }
	virtual bool isFunction() const { return false; }
	virtual bool isVariable() const { return false; }
	void setUniqueId(int id) { uniqueId = id; }
	int getUniqueId() const { return uniqueId; }
	virtual void dump(TInfoSink &infoSink) const = 0;
	void relateToExtension(const TString& ext) { extension = ext; }
	const TString& getExtension() const { return extension; }

	private:
	DISALLOW_COPY_AND_ASSIGN(TSymbol);

	const TString *name;
	unsigned int uniqueId; // For real comparing during code generation
	TString extension;
	};

	//
	// Variable class, meaning a symbol that's not a function.
	//
	// There could be a separate class heirarchy for Constant variables;
	// Only one of int, bool, or float, (or none) is correct for
	// any particular use, but it's easy to do this way, and doesn't
	// seem worth having separate classes, and "getConst" can't simply return
	// different values for different types polymorphically, so this is
	// just simple and pragmatic.
	//
	class TVariable : public TSymbol {
	public:
	TVariable(const TString *name, const TType& t, bool uT = false ) : TSymbol(name), type(t), userType(uT), unionArray(0) { }
	virtual ~TVariable() { }
	virtual bool isVariable() const { return true; }
	TType& getType() { return type; }
	const TType& getType() const { return type; }
	bool isUserType() const { return userType; }
	void setQualifier(TQualifier qualifier) { type.setQualifier(qualifier); }

	virtual void dump(TInfoSink &infoSink) const;

	ConstantUnion* getConstPointer()
	{
	if (!unionArray)
	unionArray = new ConstantUnion[type.getObjectSize()];

	return unionArray;
	}

	ConstantUnion* getConstPointer() const { return unionArray; }

	void shareConstPointer( ConstantUnion *constArray)
	{
	if (unionArray == constArray)
	return;

	delete[] unionArray;
	unionArray = constArray;
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(TVariable);

	TType type;
	bool userType;
	// we are assuming that Pool Allocator will free the memory allocated to unionArray
	// when this object is destroyed
	ConstantUnion *unionArray;
	};

	//
	// The function sub-class of symbols and the parser will need to
	// share this definition of a function parameter.
	//
	struct TParameter {
	TString *name;
	TType* type;
	};

	//
	// The function sub-class of a symbol.
	//
	class TFunction : public TSymbol {
	public:
	TFunction(TOperator o) :
	TSymbol(0),
	returnType(TType(EbtVoid, EbpUndefined)),
	op(o),
	defined(false) { }
	TFunction(const TString *name, TType& retType, TOperator tOp = EOpNull) :
	TSymbol(name),
	returnType(retType),
	mangledName(TFunction::mangleName(*name)),
	op(tOp),
	defined(false) { }
	virtual ~TFunction();
	virtual bool isFunction() const { return true; }

	static TString mangleName(const TString& name) { return name + '('; }
	static TString unmangleName(const TString& mangledName)
	{
	return TString(mangledName.c_str(), mangledName.find_first_of('('));
	}

	void addParameter(TParameter& p)
	{
	parameters.push_back(p);
	mangledName = mangledName + p.type->getMangledName();
	}

	const TString& getMangledName() const { return mangledName; }
	const TType& getReturnType() const { return returnType; }

	void relateToOperator(TOperator o) { op = o; }
	TOperator getBuiltInOp() const { return op; }

	void setDefined() { defined = true; }
	bool isDefined() { return defined; }

	size_t getParamCount() const { return parameters.size(); }
	const TParameter& getParam(size_t i) const { return parameters[i]; }

	virtual void dump(TInfoSink &infoSink) const;

	private:
	DISALLOW_COPY_AND_ASSIGN(TFunction);

	typedef TVector<TParameter> TParamList;
	TParamList parameters;
	TType returnType;
	TString mangledName;
	TOperator op;
	bool defined;
	};


	class TSymbolTableLevel {
	public:
	typedef TMap<TString, TSymbol*> tLevel;
	typedef tLevel::const_iterator const_iterator;
	typedef const tLevel::value_type tLevelPair;
	typedef std::pair<tLevel::iterator, bool> tInsertResult;

	POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator)
	TSymbolTableLevel() { }
	~TSymbolTableLevel();

	bool insert(TSymbol& symbol)
	{
	//
	// returning true means symbol was added to the table
	//
	tInsertResult result;
	result = level.insert(tLevelPair(symbol.getMangledName(), &symbol));

	return result.second;
	}

	TSymbol* find(const TString& name) const
	{
	tLevel::const_iterator it = level.find(name);
	if (it == level.end())
	return 0;
	else
	return (*it).second;
	}

	const_iterator begin() const
	{
	return level.begin();
	}

	const_iterator end() const
	{
	return level.end();
	}

	void relateToOperator(const char* name, TOperator op);
	void relateToExtension(const char* name, const TString& ext);
	void dump(TInfoSink &infoSink) const;

	protected:
	tLevel level;
	};

	class TSymbolTable {
	public:
	TSymbolTable() : uniqueId(0)
	{
	//
	// The symbol table cannot be used until push() is called, but
	// the lack of an initial call to push() can be used to detect
	// that the symbol table has not been preloaded with built-ins.
	//
	}

	~TSymbolTable()
	{
	// level 0 is always built In symbols, so we never pop that out
	while (table.size() > 1)
	pop();
	}

	//
	// When the symbol table is initialized with the built-ins, there should
	// 'push' calls, so that built-ins are at level 0 and the shader
	// globals are at level 1.
	//
	bool isEmpty() { return table.size() == 0; }
	bool atBuiltInLevel() { return table.size() == 1; }
	bool atGlobalLevel() { return table.size() <= 2; }
	void push()
	{
	table.push_back(new TSymbolTableLevel);
	precisionStack.push_back( PrecisionStackLevel() );
	}

	void pop()
	{
	delete table[currentLevel()];
	table.pop_back();
	precisionStack.pop_back();
	}

	bool insert(TSymbol& symbol)
	{
	symbol.setUniqueId(++uniqueId);
	return table[currentLevel()]->insert(symbol);
	}

	TSymbol* find(const TString& name, bool* builtIn = 0, bool *sameScope = 0)
	{
	int level = currentLevel();
	TSymbol* symbol;
	do {
	symbol = table[level]->find(name);
	--level;
	} while (symbol == 0 && level >= 0);
	level++;
	if (builtIn)
	*builtIn = level == 0;
	if (sameScope)
	*sameScope = level == currentLevel();
	return symbol;
	}

	TSymbol *findBuiltIn(const TString &name)
	{
	return table[0]->find(name);
	}

	TSymbolTableLevel* getGlobalLevel() {
	assert(table.size() >= 2);
	return table[1];
	}

	TSymbolTableLevel* getOuterLevel() {
	assert(table.size() >= 2);
	return table[currentLevel() - 1];
	}

	void relateToOperator(const char* name, TOperator op) {
	table[0]->relateToOperator(name, op);
	}
	void relateToExtension(const char* name, const TString& ext) {
	table[0]->relateToExtension(name, ext);
	}
	int getMaxSymbolId() { return uniqueId; }
	void dump(TInfoSink &infoSink) const;

	bool setDefaultPrecision( const TPublicType& type, TPrecision prec ){
	if (IsSampler(type.type))
	return true; // Skip sampler types for the time being
	if (type.type != EbtFloat && type.type != EbtInt)
	return false; // Only set default precision for int/float
	if (type.size != 1 \|\| type.matrix \|\| type.array)
	return false; // Not allowed to set for aggregate types
	int indexOfLastElement = static_cast<int>(precisionStack.size()) - 1;
	precisionStack[indexOfLastElement][type.type] = prec; // Uses map operator [], overwrites the current value
	return true;
	}

	// Searches down the precisionStack for a precision qualifier for the specified TBasicType
	TPrecision getDefaultPrecision( TBasicType type){
	if( type != EbtFloat && type != EbtInt ) return EbpUndefined;
	int level = static_cast<int>(precisionStack.size()) - 1;
	assert( level >= 0); // Just to be safe. Should not happen.
	PrecisionStackLevel::iterator it;
	TPrecision prec = EbpUndefined; // If we dont find anything we return this. Should we error check this?
	while( level >= 0 ){
	it = precisionStack[level].find( type );
	if( it != precisionStack[level].end() ){
	prec = (*it).second;
	break;
	}
	level--;
	}
	return prec;
	}

	protected:
	int currentLevel() const { return static_cast<int>(table.size()) - 1; }

	std::vector<TSymbolTableLevel*> table;
	typedef std::map< TBasicType, TPrecision > PrecisionStackLevel;
	std::vector< PrecisionStackLevel > precisionStack;
	int uniqueId; // for unique identification in code generation
	};

	#endif // _SYMBOL_TABLE_INCLUDED_