1 // 2 // Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved. 3 // Use of this source code is governed by a BSD-style license that can be 4 // found in the LICENSE file. 5 // 6 7 #ifndef _SYMBOL_TABLE_INCLUDED_ 8 #define _SYMBOL_TABLE_INCLUDED_ 9 10 // 11 // Symbol table for parsing. Has these design characteristics: 12 // 13 // * Same symbol table can be used to compile many shaders, to preserve 14 // effort of creating and loading with the large numbers of built-in 15 // symbols. 16 // 17 // * Name mangling will be used to give each function a unique name 18 // so that symbol table lookups are never ambiguous. This allows 19 // a simpler symbol table structure. 20 // 21 // * Pushing and popping of scope, so symbol table will really be a stack 22 // of symbol tables. Searched from the top, with new inserts going into 23 // the top. 24 // 25 // * Constants: Compile time constant symbols will keep their values 26 // in the symbol table. The parser can substitute constants at parse 27 // time, including doing constant folding and constant propagation. 28 // 29 // * No temporaries: Temporaries made from operations (+, --, .xy, etc.) 30 // are tracked in the intermediate representation, not the symbol table. 31 // 32 33 #include <assert.h> 34 35 #include "compiler/InfoSink.h" 36 #include "compiler/intermediate.h" 37 38 // 39 // Symbol base class. (Can build functions or variables out of these...) 40 // 41 class TSymbol { 42 public: 43 POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator) 44 TSymbol(const TString *n) : name(n) { } 45 virtual ~TSymbol() { /* don't delete name, it's from the pool */ } 46 const TString& getName() const { return *name; } 47 virtual const TString& getMangledName() const { return getName(); } 48 virtual bool isFunction() const { return false; } 49 virtual bool isVariable() const { return false; } 50 void setUniqueId(int id) { uniqueId = id; } 51 int getUniqueId() const { return uniqueId; } 52 virtual void dump(TInfoSink &infoSink) const = 0; 53 TSymbol(const TSymbol&); 54 virtual TSymbol* clone(TStructureMap& remapper) = 0; 55 56 protected: 57 const TString *name; 58 unsigned int uniqueId; // For real comparing during code generation 59 }; 60 61 // 62 // Variable class, meaning a symbol that's not a function. 63 // 64 // There could be a separate class heirarchy for Constant variables; 65 // Only one of int, bool, or float, (or none) is correct for 66 // any particular use, but it's easy to do this way, and doesn't 67 // seem worth having separate classes, and "getConst" can't simply return 68 // different values for different types polymorphically, so this is 69 // just simple and pragmatic. 70 // 71 class TVariable : public TSymbol { 72 public: 73 TVariable(const TString *name, const TType& t, bool uT = false ) : TSymbol(name), type(t), userType(uT), unionArray(0), arrayInformationType(0) { } 74 virtual ~TVariable() { } 75 virtual bool isVariable() const { return true; } 76 TType& getType() { return type; } 77 const TType& getType() const { return type; } 78 bool isUserType() const { return userType; } 79 void setQualifier(TQualifier qualifier) { type.setQualifier(qualifier); } 80 void updateArrayInformationType(TType *t) { arrayInformationType = t; } 81 TType* getArrayInformationType() { return arrayInformationType; } 82 83 virtual void dump(TInfoSink &infoSink) const; 84 85 ConstantUnion* getConstPointer() 86 { 87 if (!unionArray) 88 unionArray = new ConstantUnion[type.getObjectSize()]; 89 90 return unionArray; 91 } 92 93 ConstantUnion* getConstPointer() const { return unionArray; } 94 95 void shareConstPointer( ConstantUnion *constArray) 96 { 97 if (unionArray == constArray) 98 return; 99 100 delete[] unionArray; 101 unionArray = constArray; 102 } 103 TVariable(const TVariable&, TStructureMap& remapper); // copy constructor 104 virtual TVariable* clone(TStructureMap& remapper); 105 106 protected: 107 TType type; 108 bool userType; 109 // we are assuming that Pool Allocator will free the memory allocated to unionArray 110 // when this object is destroyed 111 ConstantUnion *unionArray; 112 TType *arrayInformationType; // this is used for updating maxArraySize in all the references to a given symbol 113 }; 114 115 // 116 // The function sub-class of symbols and the parser will need to 117 // share this definition of a function parameter. 118 // 119 struct TParameter { 120 TString *name; 121 TType* type; 122 void copyParam(const TParameter& param, TStructureMap& remapper) 123 { 124 name = NewPoolTString(param.name->c_str()); 125 type = param.type->clone(remapper); 126 } 127 }; 128 129 // 130 // The function sub-class of a symbol. 131 // 132 class TFunction : public TSymbol { 133 public: 134 TFunction(TOperator o) : 135 TSymbol(0), 136 returnType(TType(EbtVoid, EbpUndefined)), 137 op(o), 138 defined(false) { } 139 TFunction(const TString *name, TType& retType, TOperator tOp = EOpNull) : 140 TSymbol(name), 141 returnType(retType), 142 mangledName(TFunction::mangleName(*name)), 143 op(tOp), 144 defined(false) { } 145 virtual ~TFunction(); 146 virtual bool isFunction() const { return true; } 147 148 static TString mangleName(const TString& name) { return name + '('; } 149 static TString unmangleName(const TString& mangledName) 150 { 151 return TString(mangledName.c_str(), mangledName.find_first_of('(')); 152 } 153 154 void addParameter(TParameter& p) 155 { 156 parameters.push_back(p); 157 mangledName = mangledName + p.type->getMangledName(); 158 } 159 160 const TString& getMangledName() const { return mangledName; } 161 const TType& getReturnType() const { return returnType; } 162 163 void relateToOperator(TOperator o) { op = o; } 164 TOperator getBuiltInOp() const { return op; } 165 166 void relateToExtension(const TString& ext) { extension = ext; } 167 const TString& getExtension() const { return extension; } 168 169 void setDefined() { defined = true; } 170 bool isDefined() { return defined; } 171 172 int getParamCount() const { return static_cast<int>(parameters.size()); } 173 const TParameter& getParam(int i) const { return parameters[i]; } 174 175 virtual void dump(TInfoSink &infoSink) const; 176 TFunction(const TFunction&, TStructureMap& remapper); 177 virtual TFunction* clone(TStructureMap& remapper); 178 179 protected: 180 typedef TVector<TParameter> TParamList; 181 TParamList parameters; 182 TType returnType; 183 TString mangledName; 184 TOperator op; 185 TString extension; 186 bool defined; 187 }; 188 189 190 class TSymbolTableLevel { 191 public: 192 typedef TMap<TString, TSymbol*> tLevel; 193 typedef tLevel::const_iterator const_iterator; 194 typedef const tLevel::value_type tLevelPair; 195 typedef std::pair<tLevel::iterator, bool> tInsertResult; 196 197 POOL_ALLOCATOR_NEW_DELETE(GlobalPoolAllocator) 198 TSymbolTableLevel() { } 199 ~TSymbolTableLevel(); 200 201 bool insert(TSymbol& symbol) 202 { 203 // 204 // returning true means symbol was added to the table 205 // 206 tInsertResult result; 207 result = level.insert(tLevelPair(symbol.getMangledName(), &symbol)); 208 209 return result.second; 210 } 211 212 TSymbol* find(const TString& name) const 213 { 214 tLevel::const_iterator it = level.find(name); 215 if (it == level.end()) 216 return 0; 217 else 218 return (*it).second; 219 } 220 221 const_iterator begin() const 222 { 223 return level.begin(); 224 } 225 226 const_iterator end() const 227 { 228 return level.end(); 229 } 230 231 void relateToOperator(const char* name, TOperator op); 232 void relateToExtension(const char* name, const TString& ext); 233 void dump(TInfoSink &infoSink) const; 234 TSymbolTableLevel* clone(TStructureMap& remapper); 235 236 protected: 237 tLevel level; 238 }; 239 240 class TSymbolTable { 241 public: 242 TSymbolTable() : uniqueId(0) 243 { 244 // 245 // The symbol table cannot be used until push() is called, but 246 // the lack of an initial call to push() can be used to detect 247 // that the symbol table has not been preloaded with built-ins. 248 // 249 } 250 251 ~TSymbolTable() 252 { 253 // level 0 is always built In symbols, so we never pop that out 254 while (table.size() > 1) 255 pop(); 256 } 257 258 // 259 // When the symbol table is initialized with the built-ins, there should 260 // 'push' calls, so that built-ins are at level 0 and the shader 261 // globals are at level 1. 262 // 263 bool isEmpty() { return table.size() == 0; } 264 bool atBuiltInLevel() { return table.size() == 1; } 265 bool atGlobalLevel() { return table.size() <= 2; } 266 void push() 267 { 268 table.push_back(new TSymbolTableLevel); 269 precisionStack.push_back( PrecisionStackLevel() ); 270 } 271 272 void pop() 273 { 274 delete table[currentLevel()]; 275 table.pop_back(); 276 precisionStack.pop_back(); 277 } 278 279 bool insert(TSymbol& symbol) 280 { 281 symbol.setUniqueId(++uniqueId); 282 return table[currentLevel()]->insert(symbol); 283 } 284 285 TSymbol* find(const TString& name, bool* builtIn = 0, bool *sameScope = 0) 286 { 287 int level = currentLevel(); 288 TSymbol* symbol; 289 do { 290 symbol = table[level]->find(name); 291 --level; 292 } while (symbol == 0 && level >= 0); 293 level++; 294 if (builtIn) 295 *builtIn = level == 0; 296 if (sameScope) 297 *sameScope = level == currentLevel(); 298 return symbol; 299 } 300 301 TSymbolTableLevel* getGlobalLevel() { 302 assert(table.size() >= 2); 303 return table[1]; 304 } 305 void relateToOperator(const char* name, TOperator op) { 306 table[0]->relateToOperator(name, op); 307 } 308 void relateToExtension(const char* name, const TString& ext) { 309 table[0]->relateToExtension(name, ext); 310 } 311 int getMaxSymbolId() { return uniqueId; } 312 void dump(TInfoSink &infoSink) const; 313 void copyTable(const TSymbolTable& copyOf); 314 315 void setDefaultPrecision( TBasicType type, TPrecision prec ){ 316 if( type != EbtFloat && type != EbtInt ) return; // Only set default precision for int/float 317 int indexOfLastElement = static_cast<int>(precisionStack.size()) - 1; 318 precisionStack[indexOfLastElement][type] = prec; // Uses map operator [], overwrites the current value 319 } 320 321 // Searches down the precisionStack for a precision qualifier for the specified TBasicType 322 TPrecision getDefaultPrecision( TBasicType type){ 323 if( type != EbtFloat && type != EbtInt ) return EbpUndefined; 324 int level = static_cast<int>(precisionStack.size()) - 1; 325 assert( level >= 0); // Just to be safe. Should not happen. 326 PrecisionStackLevel::iterator it; 327 TPrecision prec = EbpUndefined; // If we dont find anything we return this. Should we error check this? 328 while( level >= 0 ){ 329 it = precisionStack[level].find( type ); 330 if( it != precisionStack[level].end() ){ 331 prec = (*it).second; 332 break; 333 } 334 level--; 335 } 336 return prec; 337 } 338 339 protected: 340 int currentLevel() const { return static_cast<int>(table.size()) - 1; } 341 342 std::vector<TSymbolTableLevel*> table; 343 typedef std::map< TBasicType, TPrecision > PrecisionStackLevel; 344 std::vector< PrecisionStackLevel > precisionStack; 345 int uniqueId; // for unique identification in code generation 346 }; 347 348 #endif // _SYMBOL_TABLE_INCLUDED_ 349
