[141b786] | 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 | // Explode.cc -- |
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| 8 | // |
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| 9 | // Author : Rob Schluntz |
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| 10 | // Created On : Wed Nov 9 13:12:24 2016 |
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| 11 | // Last Modified By : Rob Schluntz |
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| 12 | // Last Modified On : Wed Nov 9 13:20:24 2016 |
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| 13 | // Update Count : 2 |
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| 14 | // |
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| 15 | |
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| 16 | #include "Explode.h" |
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[8135d4c] | 17 | #include <list> // for list |
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[03321e4] | 18 | |
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[8135d4c] | 19 | #include "SynTree/Mutator.h" // for Mutator |
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| 20 | #include "Common/PassVisitor.h" // for PassVisitor |
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[141b786] | 21 | |
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| 22 | namespace Tuples { |
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| 23 | namespace { |
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[0b5d871] | 24 | // remove one level of reference from a reference type -- may be useful elsewhere. |
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| 25 | Type * getReferenceBase( Type * t ) { |
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| 26 | if ( ReferenceType * refType = dynamic_cast<ReferenceType *>( t ) ) { |
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| 27 | return refType->get_base(); |
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| 28 | } else { |
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| 29 | // for the moment, I want to know immediately if a non-reference type is ever passed in here. |
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| 30 | assertf( false, "getReferenceBase for non-ref: %s", toString( refType ).c_str() ); |
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| 31 | return nullptr; |
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| 32 | } |
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| 33 | } |
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| 34 | |
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| 35 | struct CastExploder { |
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| 36 | bool castAdded = false; |
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[141b786] | 37 | bool foundUniqueExpr = false; |
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[0b5d871] | 38 | Expression * applyCast( Expression * expr, bool first = true ) { |
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[141b786] | 39 | if ( TupleExpr * tupleExpr = dynamic_cast< TupleExpr * >( expr ) ){ |
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[a64644c] | 40 | foundUniqueExpr = true; |
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[141b786] | 41 | std::list< Expression * > exprs; |
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| 42 | for ( Expression *& expr : tupleExpr->get_exprs() ) { |
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[0b5d871] | 43 | // move cast into tuple exprs |
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| 44 | exprs.push_back( applyCast( expr, false ) ); |
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[141b786] | 45 | } |
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[0b5d871] | 46 | // want the top-level expression to be cast to reference type, but not nested |
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[141b786] | 47 | // tuple expressions |
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| 48 | if ( first ) { |
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[0b5d871] | 49 | castAdded = true; |
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| 50 | Expression * tupleExpr = new TupleExpr( exprs ); |
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| 51 | return new CastExpr( tupleExpr, new ReferenceType( Type::Qualifiers(), tupleExpr->result->clone() ) ); |
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[141b786] | 52 | } else { |
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| 53 | return new TupleExpr( exprs ); |
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| 54 | } |
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| 55 | } |
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[0b5d871] | 56 | if ( dynamic_cast<ReferenceType*>( expr->result ) ) { |
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| 57 | // don't need to cast reference type to another reference type |
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| 58 | return expr->clone(); |
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| 59 | } else { |
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| 60 | // anything else should be cast to reference as normal |
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| 61 | castAdded = true; |
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| 62 | return new CastExpr( expr->clone(), new ReferenceType( Type::Qualifiers(), expr->result->clone() ) ); |
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| 63 | } |
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[141b786] | 64 | } |
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| 65 | |
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[0b5d871] | 66 | Expression * postmutate( UniqueExpr * uniqueExpr ) { |
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| 67 | // move cast into unique expr so that the unique expr has type T& rather than |
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[141b786] | 68 | // type T. In particular, this transformation helps with generating the |
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[0b5d871] | 69 | // correct code for reference-cast member tuple expressions, since the result |
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| 70 | // should now be a tuple of references rather than a reference to a tuple. |
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[141b786] | 71 | // Still, this code is a bit awkward, and could use some improvement. |
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[68f9c43] | 72 | UniqueExpr * newUniqueExpr = new UniqueExpr{ applyCast( uniqueExpr->get_expr() ), uniqueExpr->get_id() }; |
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[0b5d871] | 73 | if ( castAdded ) { |
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| 74 | // if a cast was added by applyCast, then unique expr now has one more layer of reference |
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| 75 | // than it had coming into this function. To ensure types still match correctly, need to cast |
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| 76 | // to reference base so that outer expressions are still correct. |
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| 77 | castAdded = false; |
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| 78 | Type * toType = getReferenceBase( newUniqueExpr->result ); |
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| 79 | return new CastExpr( newUniqueExpr, toType->clone() ); |
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| 80 | } |
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| 81 | return newUniqueExpr; |
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[141b786] | 82 | } |
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| 83 | |
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[0b5d871] | 84 | |
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| 85 | Expression * postmutate( TupleIndexExpr * tupleExpr ) { |
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[141b786] | 86 | // tuple index expr needs to be rebuilt to ensure that the type of the |
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| 87 | // field is consistent with the type of the tuple expr, since the field |
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[0b5d871] | 88 | // may have changed from type T to T&. |
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[8d7bef2] | 89 | return new TupleIndexExpr( tupleExpr->get_tuple(), tupleExpr->get_index() ); |
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[141b786] | 90 | } |
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| 91 | }; |
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| 92 | } // namespace |
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| 93 | |
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[0b5d871] | 94 | Expression * distributeReference( Expression * expr ) { |
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| 95 | PassVisitor<CastExploder> exploder; |
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| 96 | expr = expr->acceptMutator( exploder ); |
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| 97 | if ( ! exploder.pass.foundUniqueExpr ) { |
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| 98 | // if a UniqueExpr was found, then the cast has already been added inside the UniqueExpr as appropriate |
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| 99 | expr = new CastExpr( expr, new ReferenceType( Type::Qualifiers(), expr->result->clone() ) ); |
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[141b786] | 100 | } |
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| 101 | return expr; |
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| 102 | } |
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| 103 | } // namespace Tuples |
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| 104 | |
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| 105 | // Local Variables: // |
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| 106 | // tab-width: 4 // |
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| 107 | // mode: c++ // |
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| 108 | // compile-command: "make install" // |
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| 109 | // End: // |
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