| 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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| 7 | // PtrsAssignable.cc -- | 
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| 8 | // | 
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| 9 | // Author           : Richard C. Bilson | 
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| 10 | // Created On       : Sun May 17 11:44:11 2015 | 
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| 11 | // Last Modified By : Peter A. Buhr | 
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| 12 | // Last Modified On : Wed Mar  2 17:36:05 2016 | 
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| 13 | // Update Count     : 8 | 
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| 14 | // | 
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| 15 |  | 
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| 16 | #include "Common/PassVisitor.h" | 
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| 17 | #include "ResolvExpr/TypeEnvironment.h"  // for EqvClass, TypeEnvironment | 
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| 18 | #include "SynTree/Type.h"                // for TypeInstType, Type, BasicType | 
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| 19 | #include "SynTree/Visitor.h"             // for Visitor | 
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| 20 |  | 
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| 21 |  | 
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| 22 | namespace ResolvExpr { | 
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| 23 | struct PtrsAssignable : public WithShortCircuiting { | 
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| 24 | PtrsAssignable( Type *dest, const TypeEnvironment &env ); | 
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| 25 |  | 
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| 26 | int get_result() const { return result; } | 
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| 27 |  | 
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| 28 | void previsit( Type * ) { visit_children = false; } | 
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| 29 |  | 
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| 30 | void postvisit( VoidType * voidType ); | 
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| 31 | void postvisit( BasicType * basicType ); | 
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| 32 | void postvisit( PointerType * pointerType ); | 
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| 33 | void postvisit( ArrayType * arrayType ); | 
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| 34 | void postvisit( FunctionType * functionType ); | 
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| 35 | void postvisit( StructInstType * inst ); | 
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| 36 | void postvisit( UnionInstType * inst ); | 
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| 37 | void postvisit( EnumInstType * inst ); | 
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| 38 | void postvisit( TraitInstType * inst ); | 
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| 39 | void postvisit( TypeInstType * inst ); | 
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| 40 | void postvisit( TupleType * tupleType ); | 
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| 41 | void postvisit( VarArgsType * varArgsType ); | 
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| 42 | void postvisit( ZeroType * zeroType ); | 
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| 43 | void postvisit( OneType * oneType ); | 
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| 44 | private: | 
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| 45 | Type *dest; | 
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| 46 | int result; | 
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| 47 | const TypeEnvironment &env; | 
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| 48 | }; | 
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| 49 |  | 
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| 50 | int ptrsAssignable( Type *src, Type *dest, const TypeEnvironment &env ) { | 
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| 51 | // std::cerr << "assignable: " << src << " | " << dest << std::endl; | 
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| 52 | if ( TypeInstType *destAsTypeInst = dynamic_cast< TypeInstType* >( dest ) ) { | 
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| 53 | EqvClass eqvClass; | 
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| 54 | if ( env.lookup( destAsTypeInst->get_name(), eqvClass ) ) { | 
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| 55 | return ptrsAssignable( src, eqvClass.type, env ); | 
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| 56 | } // if | 
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| 57 | } // if | 
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| 58 | if ( dynamic_cast< VoidType* >( dest ) ) { | 
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| 59 | // void * = T * for any T is unsafe | 
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| 60 | // xxx - this should be safe, but that currently breaks the build | 
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| 61 | return -1; | 
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| 62 | } else { | 
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| 63 | PassVisitor<PtrsAssignable> ptrs( dest, env ); | 
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| 64 | src->accept( ptrs ); | 
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| 65 | return ptrs.pass.get_result(); | 
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| 66 | } // if | 
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| 67 | } | 
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| 68 |  | 
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| 69 | PtrsAssignable::PtrsAssignable( Type *dest, const TypeEnvironment &env ) : dest( dest ), result( 0 ), env( env ) {} | 
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| 70 |  | 
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| 71 | void PtrsAssignable::postvisit( VoidType * ) { | 
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| 72 | // T * = void * is disallowed - this is a change from C, where any | 
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| 73 | // void * can be assigned or passed to a non-void pointer without a cast. | 
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| 74 | } | 
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| 75 |  | 
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| 76 | void PtrsAssignable::postvisit( __attribute__((unused)) BasicType *basicType ) {} | 
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| 77 | void PtrsAssignable::postvisit( __attribute__((unused)) PointerType *pointerType ) {} | 
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| 78 | void PtrsAssignable::postvisit( __attribute__((unused)) ArrayType *arrayType ) {} | 
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| 79 | void PtrsAssignable::postvisit( __attribute__((unused)) FunctionType *functionType ) {} | 
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| 80 |  | 
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| 81 | void PtrsAssignable::postvisit(  __attribute__((unused)) StructInstType *inst ) {} | 
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| 82 | void PtrsAssignable::postvisit(  __attribute__((unused)) UnionInstType *inst ) {} | 
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| 83 |  | 
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| 84 | void PtrsAssignable::postvisit( EnumInstType * ) { | 
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| 85 | if ( dynamic_cast< BasicType* >( dest ) ) { | 
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| 86 | // int * = E *, etc. is safe. This isn't technically correct, as each | 
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| 87 | // enum has one basic type that it is compatible with, an that type can | 
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| 88 | // differ from enum to enum. Without replicating GCC's internal logic, | 
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| 89 | // there is no way to know which type this particular enum is compatible | 
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| 90 | // with, so punt on this for now. | 
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| 91 | result = 1; | 
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| 92 | } | 
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| 93 | } | 
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| 94 |  | 
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| 95 | void PtrsAssignable::postvisit(  __attribute__((unused)) TraitInstType *inst ) {} | 
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| 96 | void PtrsAssignable::postvisit( TypeInstType *inst ) { | 
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| 97 | EqvClass eqvClass; | 
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| 98 | if ( env.lookup( inst->get_name(), eqvClass ) && eqvClass.type ) { | 
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| 99 | // T * = S * for any S depends on the type bound to T | 
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| 100 | result = ptrsAssignable( eqvClass.type, dest, env ); | 
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| 101 | } // if | 
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| 102 | } | 
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| 103 |  | 
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| 104 | void PtrsAssignable::postvisit(  __attribute__((unused)) TupleType *tupleType ) {} | 
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| 105 | void PtrsAssignable::postvisit(  __attribute__((unused)) VarArgsType *varArgsType ) {} | 
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| 106 | void PtrsAssignable::postvisit(  __attribute__((unused)) ZeroType *zeroType ) {} | 
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| 107 | void PtrsAssignable::postvisit(  __attribute__((unused)) OneType *oneType ) {} | 
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| 108 |  | 
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| 109 | } // namespace ResolvExpr | 
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| 110 |  | 
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| 111 | // Local Variables: // | 
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| 112 | // tab-width: 4 // | 
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| 113 | // mode: c++ // | 
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| 114 | // compile-command: "make install" // | 
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| 115 | // End: // | 
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