| 1 | //
 | 
|---|
| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
 | 
|---|
| 3 | //
 | 
|---|
| 4 | // The contents of this file are covered under the licence agreement in the
 | 
|---|
| 5 | // file "LICENCE" distributed with Cforall.
 | 
|---|
| 6 | //
 | 
|---|
| 7 | // ScopedMap.h --
 | 
|---|
| 8 | //
 | 
|---|
| 9 | // Author           : Aaron B. Moss
 | 
|---|
| 10 | // Created On       : Fri Feb 19 13:55:00 2016
 | 
|---|
| 11 | // Last Modified By : Peter A. Buhr
 | 
|---|
| 12 | // Last Modified On : Sat Jul 22 09:37:19 2017
 | 
|---|
| 13 | // Update Count     : 2
 | 
|---|
| 14 | //
 | 
|---|
| 15 | 
 | 
|---|
| 16 | #pragma once
 | 
|---|
| 17 | 
 | 
|---|
| 18 | #include <map>
 | 
|---|
| 19 | #include <string>
 | 
|---|
| 20 | #include <utility>
 | 
|---|
| 21 | #include <vector>
 | 
|---|
| 22 | 
 | 
|---|
| 23 | #include "SynTree/Type.h"
 | 
|---|
| 24 | #include "SynTree/Visitor.h"
 | 
|---|
| 25 | 
 | 
|---|
| 26 | namespace ResolvExpr {
 | 
|---|
| 27 | 
 | 
|---|
| 28 |         /// A map from types to some value; lookup is done by structural decomposition on types.
 | 
|---|
| 29 |         /// The TypeMap stores its values by reference, so stored objects should be kept alive by the caller.
 | 
|---|
| 30 |         /// The scoping mechanism essentially by keeping a list of changes to roll back, then rolling them back
 | 
|---|
| 31 |         /// WARNING: This map is only incompletely and approximately consistent with the resolution rules in Unify.cc;
 | 
|---|
| 32 |         /// it has potential, if extended, to form the basis of a resolver that is more performant than the current
 | 
|---|
| 33 |         /// linear-search-by-unification approach, but is only currently used for finding assignment operators in GenPoly::box.
 | 
|---|
| 34 |         template< typename Value >
 | 
|---|
| 35 |         class TypeMap {
 | 
|---|
| 36 |                 /// Map of names to types
 | 
|---|
| 37 |                 typedef typename std::map< std::string, Value* > ValueMap;
 | 
|---|
| 38 |                 typedef typename ValueMap::iterator ValueMapIterator;
 | 
|---|
| 39 | 
 | 
|---|
| 40 |                 Value *voidValue;                                     ///< Value for void type
 | 
|---|
| 41 |                 Value *basicValue[BasicType::NUMBER_OF_BASIC_TYPES];  ///< Values for basic types
 | 
|---|
| 42 |                 Value *pointerValue;                                  ///< Value for all pointer types
 | 
|---|
| 43 |                 Value *voidPointerValue;                              ///< Value for void* types
 | 
|---|
| 44 |                 Value *functionPointerValue;                          ///< Value for all function pointer types
 | 
|---|
| 45 |                 ValueMap structValue;                                 ///< Values for struct types, indexed by name
 | 
|---|
| 46 |                 ValueMap unionValue;                                  ///< Values for struct types, indexed by name
 | 
|---|
| 47 |                 ValueMap enumValue;                                   ///< Values for struct types, indexed by name
 | 
|---|
| 48 | 
 | 
|---|
| 49 |                 /// Information needed to roll back one scope change
 | 
|---|
| 50 |                 struct Rollback {
 | 
|---|
| 51 |                         /// One scope of pointer rollbacks
 | 
|---|
| 52 |                         typedef std::vector< std::pair< Value **, Value* > > PointerScope;
 | 
|---|
| 53 |                         /// One scope of map rollbacks
 | 
|---|
| 54 |                         typedef std::vector< std::pair< ValueMapIterator, Value* > > MapScope;
 | 
|---|
| 55 | 
 | 
|---|
| 56 |                         PointerScope pointers;  ///< Value pointers to roll back to their previous state
 | 
|---|
| 57 |                         MapScope mapNodes;      ///< Value map iterators to roll back to their previous state
 | 
|---|
| 58 | 
 | 
|---|
| 59 |                         void addRollback( Value **loc, Value *old ) {
 | 
|---|
| 60 |                                 pointers.push_back( std::make_pair( loc, old ) );
 | 
|---|
| 61 |                         }
 | 
|---|
| 62 | 
 | 
|---|
| 63 |                         void addRollback( ValueMapIterator loc, Value *old ) {
 | 
|---|
| 64 |                                 mapNodes.push_back( std::make_pair( loc, old ) );
 | 
|---|
| 65 |                         }
 | 
|---|
| 66 |                 };
 | 
|---|
| 67 | 
 | 
|---|
| 68 |                 std::vector< Rollback > scopes;  ///< Scope rollback information
 | 
|---|
| 69 | 
 | 
|---|
| 70 |                 struct Lookup : public Visitor {
 | 
|---|
| 71 |                         Lookup( TypeMap<Value> &typeMap ) : typeMap( typeMap ), found( 0 ), toInsert( 0 ) {}
 | 
|---|
| 72 | 
 | 
|---|
| 73 |                         /// Inserts a new value into the map; returns the old value (if set, NULL otherwise).
 | 
|---|
| 74 |                         /// key must be non-null.
 | 
|---|
| 75 |                         Value *insert( Type *key, Value *val ) {
 | 
|---|
| 76 |                                 toInsert = val;
 | 
|---|
| 77 |                                 key->accept( *this );
 | 
|---|
| 78 |                                 return found;
 | 
|---|
| 79 |                         }
 | 
|---|
| 80 | 
 | 
|---|
| 81 |                         /// Looks up a value in the map.
 | 
|---|
| 82 |                         /// key must be non-null.
 | 
|---|
| 83 |                         Value *find( Type *key ) {
 | 
|---|
| 84 |                                 //toInsert = 0;
 | 
|---|
| 85 |                                 key->accept( *this );
 | 
|---|
| 86 |                                 return found;
 | 
|---|
| 87 |                         }
 | 
|---|
| 88 | 
 | 
|---|
| 89 |                         void findAndReplace( Value *&loc ) {
 | 
|---|
| 90 |                                 found = loc;
 | 
|---|
| 91 |                                 if ( toInsert ) {
 | 
|---|
| 92 |                                         typeMap.scopes.back().addRollback( &loc, found );
 | 
|---|
| 93 |                                         loc = toInsert;
 | 
|---|
| 94 |                                 }
 | 
|---|
| 95 |                         }
 | 
|---|
| 96 | 
 | 
|---|
| 97 |                         void findAndReplace( ValueMap &map, const std::string &name ) {
 | 
|---|
| 98 |                                 ValueMapIterator loc = map.find( name );
 | 
|---|
| 99 |                                 if ( loc != map.end() ) {
 | 
|---|
| 100 |                                         found = loc->second;
 | 
|---|
| 101 |                                         if ( toInsert ) {
 | 
|---|
| 102 |                                                 typeMap.scopes.back().addRollback( loc, found );
 | 
|---|
| 103 |                                                 loc->second = toInsert;
 | 
|---|
| 104 |                                         }
 | 
|---|
| 105 |                                 } else if ( toInsert ) {
 | 
|---|
| 106 |                                         loc = map.insert( loc, std::make_pair( name, toInsert ) );
 | 
|---|
| 107 |                                         typeMap.scopes.back().addRollback( loc, found );
 | 
|---|
| 108 |                                 }
 | 
|---|
| 109 |                         }
 | 
|---|
| 110 | 
 | 
|---|
| 111 |                         virtual void visit( __attribute__((unused)) VoidType *voidType ) {
 | 
|---|
| 112 |                                 findAndReplace( typeMap.voidValue );
 | 
|---|
| 113 |                         }
 | 
|---|
| 114 | 
 | 
|---|
| 115 |                         virtual void visit( BasicType *basicType ) {
 | 
|---|
| 116 |                                 findAndReplace( typeMap.basicValue[basicType->get_kind()] );
 | 
|---|
| 117 |                         }
 | 
|---|
| 118 | 
 | 
|---|
| 119 |                         virtual void visit( PointerType *pointerType ) {
 | 
|---|
| 120 |                                 // NOTE This is one of the places where the apporoximation of the resolver is (deliberately) poor;
 | 
|---|
| 121 |                                 // A better version would likely not equate all pointer types to a match.
 | 
|---|
| 122 |                                 if ( dynamic_cast< FunctionType* >( pointerType->get_base() ) ) {
 | 
|---|
| 123 |                                         findAndReplace( typeMap.functionPointerValue );
 | 
|---|
| 124 |                                 } else if ( dynamic_cast< VoidType* >( pointerType->get_base() ) ) {
 | 
|---|
| 125 |                                         findAndReplace( typeMap.voidPointerValue );
 | 
|---|
| 126 |                                 } else {
 | 
|---|
| 127 |                                         findAndReplace( typeMap.pointerValue );
 | 
|---|
| 128 |                                 }
 | 
|---|
| 129 |                         }
 | 
|---|
| 130 | 
 | 
|---|
| 131 |                         virtual void visit( ArrayType *arrayType ) {
 | 
|---|
| 132 |                                 if ( dynamic_cast< FunctionType* >( arrayType->get_base() ) ) {
 | 
|---|
| 133 |                                         findAndReplace( typeMap.functionPointerValue );
 | 
|---|
| 134 |                                 } else {
 | 
|---|
| 135 |                                         findAndReplace( typeMap.pointerValue );
 | 
|---|
| 136 |                                 }
 | 
|---|
| 137 |                         }
 | 
|---|
| 138 | 
 | 
|---|
| 139 |                         virtual void visit( __attribute__((unused)) FunctionType *functionType ) {
 | 
|---|
| 140 |                                 findAndReplace( typeMap.functionPointerValue );
 | 
|---|
| 141 |                         }
 | 
|---|
| 142 | 
 | 
|---|
| 143 |                         virtual void visit( StructInstType *structType ) {
 | 
|---|
| 144 |                                 findAndReplace( typeMap.structValue, structType->get_name() );
 | 
|---|
| 145 |                         }
 | 
|---|
| 146 | 
 | 
|---|
| 147 |                         virtual void visit( UnionInstType *unionType ) {
 | 
|---|
| 148 |                                 findAndReplace( typeMap.unionValue, unionType->get_name() );
 | 
|---|
| 149 |                         }
 | 
|---|
| 150 | 
 | 
|---|
| 151 |                         virtual void visit( EnumInstType *enumType ) {
 | 
|---|
| 152 |                                 findAndReplace( typeMap.enumValue, enumType->get_name() );
 | 
|---|
| 153 |                         }
 | 
|---|
| 154 | 
 | 
|---|
| 155 |                         TypeMap<Value> &typeMap;  ///< map storage
 | 
|---|
| 156 |                         Value *found;             ///< Value found (NULL if none yet)
 | 
|---|
| 157 |                         Value *toInsert;          ///< Value to insert (NULL if a lookup)
 | 
|---|
| 158 |                 };  // struct Lookup
 | 
|---|
| 159 |                 friend struct Lookup;
 | 
|---|
| 160 | 
 | 
|---|
| 161 |         public:
 | 
|---|
| 162 |                 /// Starts a new scope
 | 
|---|
| 163 |                 void beginScope() {
 | 
|---|
| 164 |                         Rollback scope;
 | 
|---|
| 165 |                         scopes.push_back(scope);
 | 
|---|
| 166 |                 }
 | 
|---|
| 167 | 
 | 
|---|
| 168 |                 /// Ends a scope; rolls back any changes made during that scope
 | 
|---|
| 169 |                 void endScope() {
 | 
|---|
| 170 |                         Rollback &scope = scopes.back();
 | 
|---|
| 171 |                         /// Roll back pointer changes
 | 
|---|
| 172 |                         for (unsigned i = 0; i < scope.pointers.size(); ++i) {
 | 
|---|
| 173 |                                 *scope.pointers[i].first = scope.pointers[i].second;
 | 
|---|
| 174 |                         }
 | 
|---|
| 175 |                         /// Roll back map changes
 | 
|---|
| 176 |                         for (unsigned i = 0; i < scope.mapNodes.size(); ++i) {
 | 
|---|
| 177 |                                 scope.mapNodes[i].first->second = scope.mapNodes[i].second;
 | 
|---|
| 178 |                         }
 | 
|---|
| 179 |                         scopes.pop_back();
 | 
|---|
| 180 |                 }
 | 
|---|
| 181 | 
 | 
|---|
| 182 |                 TypeMap() : voidValue( 0 ), pointerValue( 0 ), voidPointerValue( 0 ), functionPointerValue( 0 ), structValue(), unionValue(), enumValue(), scopes() {
 | 
|---|
| 183 |                         beginScope();
 | 
|---|
| 184 |                         for (int i = 0; i < BasicType::NUMBER_OF_BASIC_TYPES; ++i) { basicValue[i] = 0; }
 | 
|---|
| 185 |                 }
 | 
|---|
| 186 | 
 | 
|---|
| 187 |                 /// Inserts a new value into the map; returns the old value (if set, NULL otherwise).
 | 
|---|
| 188 |                 /// key, val must be non-null.
 | 
|---|
| 189 |                 Value *insert( Type *key, Value *val ) {
 | 
|---|
| 190 |                         Lookup searcher( *this );
 | 
|---|
| 191 |                         return searcher.insert( key, val );
 | 
|---|
| 192 |                 }
 | 
|---|
| 193 | 
 | 
|---|
| 194 |                 /// Looks up a value in the map.
 | 
|---|
| 195 |                 /// key must be non-null
 | 
|---|
| 196 |                 Value *find( Type *key ) {
 | 
|---|
| 197 |                         Lookup searcher( *this );
 | 
|---|
| 198 |                         return searcher.find( key );
 | 
|---|
| 199 |                 }
 | 
|---|
| 200 | 
 | 
|---|
| 201 |         }; // class TypeMap
 | 
|---|
| 202 | 
 | 
|---|
| 203 | }  // namespace ResolvExpr
 | 
|---|
| 204 | 
 | 
|---|
| 205 | // Local Variables: //
 | 
|---|
| 206 | // tab-width: 4 //
 | 
|---|
| 207 | // mode: c++ //
 | 
|---|
| 208 | // compile-command: "make install" //
 | 
|---|
| 209 | // End: //
 | 
|---|