[51b7345] | 1 | #include <list> |
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| 2 | #include <cassert> |
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| 3 | |
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| 4 | #include "LabelFixer.h" |
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| 5 | #include "MLEMutator.h" |
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| 6 | #include "SynTree/Statement.h" |
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| 7 | #include "SynTree/Declaration.h" |
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| 8 | #include "utility.h" |
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| 9 | |
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| 10 | namespace ControlStruct { |
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| 11 | LabelFixer::Entry::Entry( Statement *to, Statement *from ) : |
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| 12 | definition ( to ) |
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| 13 | { |
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| 14 | if ( from != 0 ) |
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| 15 | usage.push_back( from ); |
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| 16 | } |
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| 17 | |
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| 18 | bool LabelFixer::Entry::insideLoop() |
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| 19 | { |
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| 20 | return ( dynamic_cast< ForStmt * > ( definition ) || |
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| 21 | dynamic_cast< WhileStmt * > ( definition ) ); |
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| 22 | } |
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| 23 | |
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| 24 | LabelFixer::LabelFixer( LabelGenerator *gen ) : generator ( gen ) |
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| 25 | { |
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| 26 | if ( generator == 0 ) |
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| 27 | generator = LabelGenerator::getGenerator(); |
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| 28 | } |
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| 29 | |
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| 30 | void LabelFixer::visit(FunctionDecl *functionDecl) |
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| 31 | { |
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| 32 | if ( functionDecl->get_statements() != 0 ) |
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| 33 | functionDecl->get_statements()->accept( *this ); |
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| 34 | |
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| 35 | MLEMutator mlemut( resolveJumps(), generator ); |
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| 36 | functionDecl->acceptMutator( mlemut ); |
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| 37 | } |
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| 38 | |
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| 39 | void LabelFixer::visit(Statement *stmt ) |
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| 40 | { |
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| 41 | std::list< Label > &labels = stmt->get_labels(); |
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| 42 | |
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| 43 | if ( ! labels.empty() ) { |
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| 44 | Label current = setLabelsDef( labels, stmt ); |
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| 45 | labels.clear(); |
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| 46 | labels.push_front( current ); |
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| 47 | } |
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| 48 | } |
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| 49 | |
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| 50 | void LabelFixer::visit(BranchStmt *branchStmt) |
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| 51 | { |
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| 52 | visit ( ( Statement * )branchStmt ); // the labels this statement might have |
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| 53 | |
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| 54 | Label target; |
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| 55 | if ( (target = branchStmt->get_target()) != "" ) { |
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| 56 | setLabelsUsg( target, branchStmt ); |
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| 57 | } //else /* computed goto or normal exit-loop statements */ |
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| 58 | } |
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| 59 | |
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| 60 | |
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| 61 | Label LabelFixer::setLabelsDef( std::list< Label > &llabel, Statement *definition ) |
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| 62 | { |
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| 63 | assert( definition != 0 ); |
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| 64 | Entry *entry = new Entry( definition ); |
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| 65 | bool used = false; |
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| 66 | |
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| 67 | for ( std::list< Label >::iterator i = llabel.begin(); i != llabel.end(); i++ ) |
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| 68 | if ( labelTable.find( *i ) == labelTable.end() ) |
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| 69 | { used = true; labelTable[ *i ] = entry; } // undefined and unused |
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| 70 | else |
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| 71 | if( labelTable[ *i ]->defined() ) |
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| 72 | throw SemanticError("Duplicate definition of label: " + *i ); |
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| 73 | else |
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| 74 | labelTable[ *i ]->set_definition( definition ); |
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| 75 | |
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| 76 | if (! used ) delete entry; |
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| 77 | |
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| 78 | return labelTable[ llabel.front() ]->get_label(); // this *must* exist |
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| 79 | } |
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| 80 | |
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| 81 | Label LabelFixer::setLabelsUsg( Label orgValue, Statement *use ) |
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| 82 | { |
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| 83 | assert( use != 0 ); |
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| 84 | |
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| 85 | if ( labelTable.find( orgValue ) != labelTable.end() ) |
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| 86 | labelTable[ orgValue ]->add_use( use ); // the label has been defined or used before |
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| 87 | else |
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| 88 | labelTable[ orgValue ] = new Entry( 0, use ); |
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| 89 | |
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| 90 | return labelTable[ orgValue ]->get_label(); |
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| 91 | } |
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| 92 | |
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| 93 | std::map < Label, Statement * > *LabelFixer::resolveJumps() throw ( SemanticError ) |
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| 94 | { |
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| 95 | std::map < Statement *, Entry * > def_us; |
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| 96 | |
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| 97 | for( std::map < Label, Entry *>::iterator i = labelTable.begin(); i != labelTable.end(); i++ ) { |
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| 98 | Entry *e = i->second; |
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| 99 | |
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| 100 | if ( def_us.find ( e->get_definition() ) == def_us.end() ) |
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| 101 | def_us[ e->get_definition() ] = e; |
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| 102 | else |
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| 103 | if(e->used()) |
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| 104 | def_us[ e->get_definition() ]->add_uses( e->get_uses() ); |
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| 105 | } |
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| 106 | |
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| 107 | // get rid of labelTable |
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| 108 | for( std::map < Statement *, Entry * >::iterator i = def_us.begin(); i != def_us.end(); i++ ) { |
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| 109 | Statement *to = (*i).first; |
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| 110 | std::list < Statement *> &from = (*i).second->get_uses(); |
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| 111 | Label finalLabel = generator->newLabel(); |
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| 112 | (*i).second->set_label( finalLabel ); |
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| 113 | |
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| 114 | if ( to == 0 ) { |
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| 115 | BranchStmt *first_use = dynamic_cast<BranchStmt *>(from.back()); |
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| 116 | Label undef(""); |
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| 117 | if ( first_use != 0 ) |
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| 118 | undef = first_use->get_target(); |
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| 119 | throw SemanticError ( "'" + undef + "' label not defined"); |
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| 120 | } |
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| 121 | |
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| 122 | to->get_labels().clear(); |
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| 123 | to->get_labels().push_back( finalLabel ); |
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| 124 | |
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| 125 | for ( std::list< Statement *>::iterator j = from.begin(); j != from.end(); j++ ) { |
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| 126 | BranchStmt *jumpTo = dynamic_cast < BranchStmt * > ( *j ); |
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| 127 | assert( jumpTo != 0 ); |
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| 128 | jumpTo->set_target( finalLabel ); |
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| 129 | } |
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| 130 | } |
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| 131 | |
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| 132 | // reverse table |
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| 133 | std::map < Label, Statement * > *ret = new std::map < Label, Statement * >(); |
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| 134 | for(std::map < Statement *, Entry * >::iterator i = def_us.begin(); i != def_us.end(); i++ ) |
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| 135 | (*ret)[ (*i).second->get_label() ] = (*i).first; |
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| 136 | |
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| 137 | return ret; |
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| 138 | } |
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| 139 | |
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| 140 | } // namespace ControlStruct |
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