[c671112] | 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 | // TypeSubstitution.cc -- |
---|
| 8 | // |
---|
| 9 | // Author : Richard C. Bilson |
---|
| 10 | // Created On : Mon May 18 07:44:20 2015 |
---|
[dafe9e1] | 11 | // Last Modified By : Andrew Beach |
---|
| 12 | // Last Modified On : Mon Jun 3 13:26:00 2017 |
---|
| 13 | // Update Count : 5 |
---|
[c671112] | 14 | // |
---|
| 15 | |
---|
| 16 | #include "Type.hpp" // for TypeInstType, Type, StructInstType, UnionInstType |
---|
| 17 | #include "TypeSubstitution.hpp" |
---|
| 18 | |
---|
| 19 | namespace ast { |
---|
| 20 | |
---|
[c15085d] | 21 | |
---|
[0d070ca] | 22 | // size_t TypeSubstitution::Substituter::traceId = Stats::Heap::new_stacktrace_id("TypeSubstitution"); |
---|
[c15085d] | 23 | |
---|
[c671112] | 24 | TypeSubstitution::TypeSubstitution() { |
---|
| 25 | } |
---|
| 26 | |
---|
| 27 | TypeSubstitution::TypeSubstitution( const TypeSubstitution &other ) : Node() { |
---|
| 28 | initialize( other, *this ); |
---|
| 29 | } |
---|
| 30 | |
---|
[dafe9e1] | 31 | TypeSubstitution::~TypeSubstitution() {} |
---|
[c671112] | 32 | |
---|
| 33 | TypeSubstitution &TypeSubstitution::operator=( const TypeSubstitution &other ) { |
---|
| 34 | if ( this == &other ) return *this; |
---|
| 35 | initialize( other, *this ); |
---|
| 36 | return *this; |
---|
| 37 | } |
---|
| 38 | |
---|
| 39 | void TypeSubstitution::initialize( const TypeSubstitution &src, TypeSubstitution &dest ) { |
---|
[a8b87d3] | 40 | dest.typeMap.clear(); |
---|
[c671112] | 41 | dest.add( src ); |
---|
| 42 | } |
---|
| 43 | |
---|
| 44 | void TypeSubstitution::add( const TypeSubstitution &other ) { |
---|
[a8b87d3] | 45 | for ( TypeMap::const_iterator i = other.typeMap.begin(); i != other.typeMap.end(); ++i ) { |
---|
| 46 | typeMap[ i->first ] = i->second; |
---|
[c671112] | 47 | } // for |
---|
| 48 | } |
---|
| 49 | |
---|
[3e5dd913] | 50 | void TypeSubstitution::add( const TypeInstType * formalType, const Type *actualType ) { |
---|
[a8b87d3] | 51 | typeMap[ *formalType ] = actualType; |
---|
[c671112] | 52 | } |
---|
| 53 | |
---|
[93c10de] | 54 | void TypeSubstitution::add( const TypeEnvKey & key, const Type * actualType) { |
---|
[a8b87d3] | 55 | typeMap[ key ] = actualType; |
---|
[172d9342] | 56 | } |
---|
| 57 | |
---|
[3e5dd913] | 58 | void TypeSubstitution::remove( const TypeInstType * formalType ) { |
---|
[a8b87d3] | 59 | TypeMap::iterator i = typeMap.find( *formalType ); |
---|
| 60 | if ( i != typeMap.end() ) { |
---|
| 61 | typeMap.erase( *formalType ); |
---|
[c671112] | 62 | } // if |
---|
| 63 | } |
---|
| 64 | |
---|
[a8b87d3] | 65 | const Type *TypeSubstitution::lookup( |
---|
[93c10de] | 66 | const TypeEnvKey & formalType ) const { |
---|
[a8b87d3] | 67 | TypeMap::const_iterator i = typeMap.find( formalType ); |
---|
[c671112] | 68 | |
---|
| 69 | // break on not in substitution set |
---|
[a8b87d3] | 70 | if ( i == typeMap.end() ) return 0; |
---|
[c671112] | 71 | |
---|
| 72 | // attempt to transitively follow TypeInstType links. |
---|
| 73 | while ( const TypeInstType *actualType = i->second.as<TypeInstType>()) { |
---|
| 74 | // break cycles in the transitive follow |
---|
[a8b87d3] | 75 | if ( formalType == *actualType ) break; |
---|
[c671112] | 76 | |
---|
| 77 | // Look for the type this maps to, returning previous mapping if none-such |
---|
[a8b87d3] | 78 | i = typeMap.find( *actualType ); |
---|
| 79 | if ( i == typeMap.end() ) return actualType; |
---|
[c671112] | 80 | } |
---|
| 81 | |
---|
| 82 | // return type from substitution set |
---|
| 83 | return i->second; |
---|
| 84 | } |
---|
| 85 | |
---|
[a8b87d3] | 86 | const Type *TypeSubstitution::lookup( const TypeInstType * formalType ) const { |
---|
[93c10de] | 87 | return lookup( ast::TypeEnvKey( *formalType ) ); |
---|
[a8b87d3] | 88 | } |
---|
| 89 | |
---|
[c671112] | 90 | bool TypeSubstitution::empty() const { |
---|
[a8b87d3] | 91 | return typeMap.empty(); |
---|
[c671112] | 92 | } |
---|
| 93 | |
---|
| 94 | namespace { |
---|
| 95 | struct EnvTrimmer { |
---|
[55b6476] | 96 | const TypeSubstitution * env; |
---|
[c671112] | 97 | TypeSubstitution * newEnv; |
---|
| 98 | EnvTrimmer( const TypeSubstitution * env, TypeSubstitution * newEnv ) : env( env ), newEnv( newEnv ){} |
---|
[9e23b446] | 99 | void previsit( const FunctionType * ftype ) { |
---|
[c671112] | 100 | // transfer known bindings for seen type variables |
---|
[3e5dd913] | 101 | for (auto & formal : ftype->forall) { |
---|
| 102 | if ( const Type * t = env->lookup( formal ) ) { |
---|
| 103 | newEnv->add( formal, t ); |
---|
| 104 | } |
---|
[c671112] | 105 | } |
---|
| 106 | } |
---|
| 107 | }; |
---|
| 108 | } // namespace |
---|
| 109 | |
---|
| 110 | /// reduce environment to just the parts that are referenced in a given expression |
---|
| 111 | TypeSubstitution * TypeSubstitution::newFromExpr( const Expr * expr, const TypeSubstitution * env ) { |
---|
| 112 | if ( env ) { |
---|
| 113 | TypeSubstitution * newEnv = new TypeSubstitution(); |
---|
| 114 | Pass<EnvTrimmer> trimmer( env, newEnv ); |
---|
| 115 | expr->accept( trimmer ); |
---|
| 116 | return newEnv; |
---|
| 117 | } |
---|
| 118 | return nullptr; |
---|
| 119 | } |
---|
| 120 | |
---|
| 121 | void TypeSubstitution::normalize() { |
---|
[55b6476] | 122 | Pass<Substituter> sub( *this, true ); |
---|
[c671112] | 123 | do { |
---|
[7ff3e522] | 124 | sub.core.subCount = 0; |
---|
| 125 | sub.core.freeOnly = true; |
---|
[a8b87d3] | 126 | for ( TypeMap::iterator i = typeMap.begin(); i != typeMap.end(); ++i ) { |
---|
[55b6476] | 127 | i->second = i->second->accept( sub ); |
---|
[c671112] | 128 | } |
---|
[7ff3e522] | 129 | } while ( sub.core.subCount ); |
---|
[c671112] | 130 | } |
---|
| 131 | |
---|
[55b6476] | 132 | const Type * TypeSubstitution::Substituter::postvisit( const TypeInstType *inst ) { |
---|
[3e5dd913] | 133 | BoundVarsType::const_iterator bound = boundVars.find( *inst ); |
---|
[c671112] | 134 | if ( bound != boundVars.end() ) return inst; |
---|
| 135 | |
---|
[a8b87d3] | 136 | TypeMap::const_iterator i = sub.typeMap.find( *inst ); |
---|
| 137 | if ( i == sub.typeMap.end() ) { |
---|
[c671112] | 138 | return inst; |
---|
| 139 | } else { |
---|
| 140 | // cut off infinite loop for the case where a type is bound to itself. |
---|
| 141 | // Note: this does not prevent cycles in the general case, so it may be necessary to do something more sophisticated here. |
---|
| 142 | // TODO: investigate preventing type variables from being bound to themselves in the first place. |
---|
[55b6476] | 143 | if ( const TypeInstType * replacement = i->second.as<TypeInstType>() ) { |
---|
[3e5dd913] | 144 | if ( *inst == *replacement ) { |
---|
[c671112] | 145 | return inst; |
---|
| 146 | } |
---|
| 147 | } |
---|
| 148 | // std::cerr << "found " << inst->name << ", replacing with " << i->second << std::endl; |
---|
| 149 | subCount++; |
---|
[55b6476] | 150 | ptr<Type> newType = i->second; // force clone if needed |
---|
| 151 | add_qualifiers( newType, inst->qualifiers ); |
---|
[2890212] | 152 | // Note: need to recursively apply substitution to the new type because normalize does not |
---|
[55b6476] | 153 | // substitute bound vars, but bound vars must be substituted when not in freeOnly mode. |
---|
| 154 | newType = newType->accept( *visitor ); |
---|
| 155 | return newType.release(); |
---|
[c671112] | 156 | } // if |
---|
| 157 | } |
---|
| 158 | |
---|
[361bf01] | 159 | void TypeSubstitution::Substituter::previsit( const FunctionType * ptype ) { |
---|
[c671112] | 160 | GuardValue( boundVars ); |
---|
| 161 | // bind type variables from forall-qualifiers |
---|
| 162 | if ( freeOnly ) { |
---|
[3e5dd913] | 163 | for ( auto & tyvar : ptype->forall ) { |
---|
| 164 | boundVars.insert( *tyvar ); |
---|
[c671112] | 165 | } // for |
---|
| 166 | } // if |
---|
| 167 | } |
---|
| 168 | |
---|
[3e5dd913] | 169 | /* |
---|
[98e8b3b] | 170 | void TypeSubstitution::Substituter::handleAggregateType( const BaseInstType * type ) { |
---|
[c671112] | 171 | GuardValue( boundVars ); |
---|
| 172 | // bind type variables from forall-qualifiers |
---|
| 173 | if ( freeOnly ) { |
---|
| 174 | // bind type variables from generic type instantiations |
---|
[55b6476] | 175 | if ( auto decl = type->aggr() ) { |
---|
[417117e] | 176 | if ( ! type->params.empty() ) { |
---|
| 177 | for ( const TypeDecl * tyvar : decl->params ) { |
---|
[3e5dd913] | 178 | boundVars.insert( *tyvar ); |
---|
[55b6476] | 179 | } // for |
---|
| 180 | } // if |
---|
| 181 | } |
---|
[c671112] | 182 | } // if |
---|
| 183 | } |
---|
| 184 | |
---|
[55b6476] | 185 | void TypeSubstitution::Substituter::previsit( const StructInstType * aggregateUseType ) { |
---|
[c671112] | 186 | handleAggregateType( aggregateUseType ); |
---|
| 187 | } |
---|
| 188 | |
---|
[55b6476] | 189 | void TypeSubstitution::Substituter::previsit( const UnionInstType *aggregateUseType ) { |
---|
[c671112] | 190 | handleAggregateType( aggregateUseType ); |
---|
| 191 | } |
---|
[3e5dd913] | 192 | */ |
---|
[c671112] | 193 | |
---|
| 194 | } // namespace ast |
---|
| 195 | |
---|
| 196 | // Local Variables: // |
---|
| 197 | // tab-width: 4 // |
---|
| 198 | // mode: c++ // |
---|
| 199 | // compile-command: "make install" // |
---|
| 200 | // End: // |
---|