[0dd3a2f] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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[5382492] | 7 | // TypeSubstitution.cc -- |
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[0dd3a2f] | 8 | // |
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| 9 | // Author : Richard C. Bilson |
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| 10 | // Created On : Mon May 18 07:44:20 2015 |
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[6f95000] | 11 | // Last Modified By : Peter A. Buhr |
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| 12 | // Last Modified On : Thu Mar 16 15:54:35 2017 |
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| 13 | // Update Count : 4 |
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[0dd3a2f] | 14 | // |
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[51b7345] | 15 | |
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[ea6332d] | 16 | #include <ostream> // for ostream, basic_ostream, operator<<, endl |
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| 17 | |
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| 18 | #include "Type.h" // for TypeInstType, Type, StructInstType, UnionInstType |
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[51b7345] | 19 | #include "TypeSubstitution.h" |
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| 20 | |
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[0dd3a2f] | 21 | TypeSubstitution::TypeSubstitution() { |
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| 22 | } |
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[51b7345] | 23 | |
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[0dd3a2f] | 24 | TypeSubstitution::TypeSubstitution( const TypeSubstitution &other ) { |
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| 25 | initialize( other, *this ); |
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[51b7345] | 26 | } |
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| 27 | |
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[0dd3a2f] | 28 | TypeSubstitution::~TypeSubstitution() { |
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| 29 | for ( TypeEnvType::iterator i = typeEnv.begin(); i != typeEnv.end(); ++i ) { |
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| 30 | delete( i->second ); |
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| 31 | } |
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| 32 | for ( VarEnvType::iterator i = varEnv.begin(); i != varEnv.end(); ++i ) { |
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| 33 | delete( i->second ); |
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| 34 | } |
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[51b7345] | 35 | } |
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| 36 | |
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[0dd3a2f] | 37 | TypeSubstitution &TypeSubstitution::operator=( const TypeSubstitution &other ) { |
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| 38 | if ( this == &other ) return *this; |
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| 39 | initialize( other, *this ); |
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| 40 | return *this; |
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[51b7345] | 41 | } |
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| 42 | |
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[0dd3a2f] | 43 | void TypeSubstitution::initialize( const TypeSubstitution &src, TypeSubstitution &dest ) { |
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| 44 | dest.typeEnv.clear(); |
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| 45 | dest.varEnv.clear(); |
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| 46 | dest.add( src ); |
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[51b7345] | 47 | } |
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| 48 | |
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[0dd3a2f] | 49 | void TypeSubstitution::add( const TypeSubstitution &other ) { |
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| 50 | for ( TypeEnvType::const_iterator i = other.typeEnv.begin(); i != other.typeEnv.end(); ++i ) { |
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| 51 | typeEnv[ i->first ] = i->second->clone(); |
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| 52 | } // for |
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| 53 | for ( VarEnvType::const_iterator i = other.varEnv.begin(); i != other.varEnv.end(); ++i ) { |
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| 54 | varEnv[ i->first ] = i->second->clone(); |
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| 55 | } // for |
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[51b7345] | 56 | } |
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| 57 | |
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[0dd3a2f] | 58 | void TypeSubstitution::add( std::string formalType, Type *actualType ) { |
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| 59 | TypeEnvType::iterator i = typeEnv.find( formalType ); |
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| 60 | if ( i != typeEnv.end() ) { |
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| 61 | delete i->second; |
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| 62 | } // if |
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| 63 | typeEnv[ formalType ] = actualType->clone(); |
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[51b7345] | 64 | } |
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| 65 | |
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[0dd3a2f] | 66 | void TypeSubstitution::remove( std::string formalType ) { |
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| 67 | TypeEnvType::iterator i = typeEnv.find( formalType ); |
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| 68 | if ( i != typeEnv.end() ) { |
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| 69 | delete i->second; |
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| 70 | typeEnv.erase( formalType ); |
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| 71 | } // if |
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[51b7345] | 72 | } |
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| 73 | |
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[0dd3a2f] | 74 | Type *TypeSubstitution::lookup( std::string formalType ) const { |
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| 75 | TypeEnvType::const_iterator i = typeEnv.find( formalType ); |
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[8c49c0e] | 76 | |
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[084184b] | 77 | // break on not in substitution set |
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| 78 | if ( i == typeEnv.end() ) return 0; |
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[8c49c0e] | 79 | |
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[084184b] | 80 | // attempt to transitively follow TypeInstType links. |
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| 81 | while ( TypeInstType *actualType = dynamic_cast< TypeInstType* >( i->second ) ) { |
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| 82 | const std::string& typeName = actualType->get_name(); |
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[8c49c0e] | 83 | |
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[084184b] | 84 | // break cycles in the transitive follow |
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| 85 | if ( formalType == typeName ) break; |
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[8c49c0e] | 86 | |
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[084184b] | 87 | // Look for the type this maps to, returning previous mapping if none-such |
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| 88 | i = typeEnv.find( typeName ); |
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| 89 | if ( i == typeEnv.end() ) return actualType; |
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| 90 | } |
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[8c49c0e] | 91 | |
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[084184b] | 92 | // return type from substitution set |
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| 93 | return i->second; |
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[8c49c0e] | 94 | |
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[084184b] | 95 | #if 0 |
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[0dd3a2f] | 96 | if ( i == typeEnv.end() ) { |
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| 97 | return 0; |
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| 98 | } else { |
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| 99 | return i->second; |
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| 100 | } // if |
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[084184b] | 101 | #endif |
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[51b7345] | 102 | } |
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| 103 | |
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[0dd3a2f] | 104 | bool TypeSubstitution::empty() const { |
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| 105 | return typeEnv.empty() && varEnv.empty(); |
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[51b7345] | 106 | } |
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| 107 | |
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[2ec65ad] | 108 | namespace { |
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| 109 | struct EnvTrimmer { |
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[02fdb8e] | 110 | const TypeSubstitution * env; |
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| 111 | TypeSubstitution * newEnv; |
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| 112 | EnvTrimmer( const TypeSubstitution * env, TypeSubstitution * newEnv ) : env( env ), newEnv( newEnv ){} |
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[2ec65ad] | 113 | void previsit( TypeDecl * tyDecl ) { |
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| 114 | // transfer known bindings for seen type variables |
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| 115 | if ( Type * t = env->lookup( tyDecl->name ) ) { |
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| 116 | newEnv->add( tyDecl->name, t ); |
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| 117 | } |
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| 118 | } |
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| 119 | }; |
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| 120 | } // namespace |
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| 121 | |
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| 122 | /// reduce environment to just the parts that are referenced in a given expression |
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[02fdb8e] | 123 | TypeSubstitution * TypeSubstitution::newFromExpr( Expression * expr, const TypeSubstitution * env ) { |
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[2ec65ad] | 124 | if ( env ) { |
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| 125 | TypeSubstitution * newEnv = new TypeSubstitution(); |
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| 126 | PassVisitor<EnvTrimmer> trimmer( env, newEnv ); |
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| 127 | expr->accept( trimmer ); |
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| 128 | return newEnv; |
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| 129 | } |
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| 130 | return nullptr; |
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| 131 | } |
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| 132 | |
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[0dd3a2f] | 133 | void TypeSubstitution::normalize() { |
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[e9a715d3] | 134 | PassVisitor<Substituter> sub( *this, true ); |
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[0dd3a2f] | 135 | do { |
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[e9a715d3] | 136 | sub.pass.subCount = 0; |
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| 137 | sub.pass.freeOnly = true; |
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[0dd3a2f] | 138 | for ( TypeEnvType::iterator i = typeEnv.begin(); i != typeEnv.end(); ++i ) { |
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[e9a715d3] | 139 | i->second = i->second->acceptMutator( sub ); |
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[0dd3a2f] | 140 | } |
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[e9a715d3] | 141 | } while ( sub.pass.subCount ); |
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[51b7345] | 142 | } |
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| 143 | |
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[e9a715d3] | 144 | Type * TypeSubstitution::Substituter::postmutate( TypeInstType *inst ) { |
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| 145 | BoundVarsType::const_iterator bound = boundVars.find( inst->name ); |
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[0dd3a2f] | 146 | if ( bound != boundVars.end() ) return inst; |
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[5382492] | 147 | |
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[e9a715d3] | 148 | TypeEnvType::const_iterator i = sub.typeEnv.find( inst->get_name() ); |
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| 149 | if ( i == sub.typeEnv.end() ) { |
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[0dd3a2f] | 150 | return inst; |
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| 151 | } else { |
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[d0d5054] | 152 | // cut off infinite loop for the case where a type is bound to itself. |
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| 153 | // Note: this does not prevent cycles in the general case, so it may be necessary to do something more sophisticated here. |
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| 154 | // TODO: investigate preventing type variables from being bound to themselves in the first place. |
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| 155 | if ( TypeInstType * replacement = dynamic_cast< TypeInstType * >( i->second ) ) { |
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| 156 | if ( inst->name == replacement->name ) { |
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| 157 | return inst; |
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| 158 | } |
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| 159 | } |
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| 160 | // std::cerr << "found " << inst->name << ", replacing with " << i->second << std::endl; |
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[0dd3a2f] | 161 | subCount++; |
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[e9a715d3] | 162 | Type * newtype = i->second->clone(); |
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[6f95000] | 163 | newtype->get_qualifiers() |= inst->get_qualifiers(); |
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[0dd3a2f] | 164 | delete inst; |
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[d0d5054] | 165 | // Note: need to recursively apply substitution to the new type because normalize does not substitute bound vars, but bound vars must be substituted when not in freeOnly mode. |
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| 166 | return newtype->acceptMutator( *visitor ); |
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[0dd3a2f] | 167 | } // if |
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| 168 | } |
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| 169 | |
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[e9a715d3] | 170 | Expression * TypeSubstitution::Substituter::postmutate( NameExpr * nameExpr ) { |
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| 171 | VarEnvType::const_iterator i = sub.varEnv.find( nameExpr->name ); |
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| 172 | if ( i == sub.varEnv.end() ) { |
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[0dd3a2f] | 173 | return nameExpr; |
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| 174 | } else { |
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| 175 | subCount++; |
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| 176 | delete nameExpr; |
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| 177 | return i->second->clone(); |
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| 178 | } // if |
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[51b7345] | 179 | } |
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| 180 | |
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[e9a715d3] | 181 | void TypeSubstitution::Substituter::premutate( Type * type ) { |
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| 182 | GuardValue( boundVars ); |
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[37a3b8f9] | 183 | // bind type variables from forall-qualifiers |
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[0dd3a2f] | 184 | if ( freeOnly ) { |
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[e9a715d3] | 185 | for ( Type::ForallList::const_iterator tyvar = type->forall.begin(); tyvar != type->forall.end(); ++tyvar ) { |
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| 186 | boundVars.insert( (*tyvar)->name ); |
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[0dd3a2f] | 187 | } // for |
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| 188 | } // if |
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[51b7345] | 189 | } |
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| 190 | |
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[37a3b8f9] | 191 | template< typename TypeClass > |
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[e9a715d3] | 192 | void TypeSubstitution::Substituter::handleAggregateType( TypeClass * type ) { |
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| 193 | GuardValue( boundVars ); |
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[37a3b8f9] | 194 | // bind type variables from forall-qualifiers |
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| 195 | if ( freeOnly ) { |
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[e9a715d3] | 196 | for ( Type::ForallList::const_iterator tyvar = type->forall.begin(); tyvar != type->forall.end(); ++tyvar ) { |
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| 197 | boundVars.insert( (*tyvar)->name ); |
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[37a3b8f9] | 198 | } // for |
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[c7a3081] | 199 | // bind type variables from generic type instantiations |
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| 200 | std::list< TypeDecl* > *baseParameters = type->get_baseParameters(); |
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[e9a715d3] | 201 | if ( baseParameters && ! type->parameters.empty() ) { |
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[c7a3081] | 202 | for ( std::list< TypeDecl* >::const_iterator tyvar = baseParameters->begin(); tyvar != baseParameters->end(); ++tyvar ) { |
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[e9a715d3] | 203 | boundVars.insert( (*tyvar)->name ); |
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[c7a3081] | 204 | } // for |
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| 205 | } // if |
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[ed94eac] | 206 | } // if |
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[44b7088] | 207 | } |
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| 208 | |
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[e9a715d3] | 209 | void TypeSubstitution::Substituter::premutate( StructInstType * aggregateUseType ) { |
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| 210 | handleAggregateType( aggregateUseType ); |
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[89e6ffc] | 211 | } |
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| 212 | |
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[e9a715d3] | 213 | void TypeSubstitution::Substituter::premutate( UnionInstType *aggregateUseType ) { |
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| 214 | handleAggregateType( aggregateUseType ); |
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[89e6ffc] | 215 | } |
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| 216 | |
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[50377a4] | 217 | void TypeSubstitution::print( std::ostream &os, Indenter indent ) const { |
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| 218 | os << indent << "Types:" << std::endl; |
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[0dd3a2f] | 219 | for ( TypeEnvType::const_iterator i = typeEnv.begin(); i != typeEnv.end(); ++i ) { |
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[50377a4] | 220 | os << indent+1 << i->first << " -> "; |
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| 221 | i->second->print( os, indent+2 ); |
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[0dd3a2f] | 222 | os << std::endl; |
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| 223 | } // for |
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[50377a4] | 224 | os << indent << "Non-types:" << std::endl; |
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[0dd3a2f] | 225 | for ( VarEnvType::const_iterator i = varEnv.begin(); i != varEnv.end(); ++i ) { |
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[50377a4] | 226 | os << indent+1 << i->first << " -> "; |
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| 227 | i->second->print( os, indent+2 ); |
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[0dd3a2f] | 228 | os << std::endl; |
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| 229 | } // for |
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[51b7345] | 230 | } |
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| 231 | |
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[5382492] | 232 | std::ostream & operator<<( std::ostream & out, const TypeSubstitution & sub ) { |
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| 233 | sub.print( out ); |
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| 234 | return out; |
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| 235 | } |
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| 236 | |
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| 237 | |
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[0dd3a2f] | 238 | // Local Variables: // |
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| 239 | // tab-width: 4 // |
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| 240 | // mode: c++ // |
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| 241 | // compile-command: "make install" // |
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| 242 | // End: // |
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