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 | // LabelFixer.cc -- |
---|
8 | // |
---|
9 | // Author : Rodolfo G. Esteves |
---|
10 | // Created On : Mon May 18 07:44:20 2015 |
---|
11 | // Last Modified By : Peter A. Buhr |
---|
12 | // Last Modified On : Mon Mar 11 22:26:02 2019 |
---|
13 | // Update Count : 159 |
---|
14 | // |
---|
15 | |
---|
16 | #include <cassert> // for assert |
---|
17 | #include <list> // for list, _List_iterator, list... |
---|
18 | #include <string> // for operator+, string, operator== |
---|
19 | #include <utility> // for pair |
---|
20 | |
---|
21 | #include "ControlStruct/LabelGenerator.h" // for LabelGenerator |
---|
22 | #include "LabelFixer.h" |
---|
23 | #include "MLEMutator.h" // for MLEMutator |
---|
24 | #include "SynTree/Declaration.h" // for FunctionDecl |
---|
25 | #include "SynTree/Expression.h" // for NameExpr, Expression, Unty... |
---|
26 | #include "SynTree/Statement.h" // for Statement, BranchStmt, Com... |
---|
27 | |
---|
28 | namespace ControlStruct { |
---|
29 | bool LabelFixer::Entry::insideLoop() { |
---|
30 | return ( dynamic_cast< ForStmt * > ( definition ) || |
---|
31 | dynamic_cast< WhileStmt * > ( definition ) ); |
---|
32 | } |
---|
33 | |
---|
34 | LabelFixer::LabelFixer( LabelGenerator * gen ) : generator ( gen ) { |
---|
35 | if ( generator == 0 ) |
---|
36 | generator = LabelGenerator::getGenerator(); |
---|
37 | } |
---|
38 | |
---|
39 | void LabelFixer::previsit( FunctionDecl * ) { |
---|
40 | // need to go into a nested function in a fresh state |
---|
41 | GuardValue( labelTable ); |
---|
42 | labelTable.clear(); |
---|
43 | } |
---|
44 | |
---|
45 | void LabelFixer::postvisit( FunctionDecl * functionDecl ) { |
---|
46 | PassVisitor<MLEMutator> mlemut( resolveJumps(), generator ); |
---|
47 | functionDecl->acceptMutator( mlemut ); |
---|
48 | } |
---|
49 | |
---|
50 | // prune to at most one label definition for each statement |
---|
51 | void LabelFixer::previsit( Statement * stmt ) { |
---|
52 | std::list< Label > &labels = stmt->get_labels(); |
---|
53 | |
---|
54 | if ( ! labels.empty() ) { |
---|
55 | // only remember one label for each statement |
---|
56 | Label current = setLabelsDef( labels, stmt ); |
---|
57 | } // if |
---|
58 | } |
---|
59 | |
---|
60 | void LabelFixer::previsit( BranchStmt * branchStmt ) { |
---|
61 | previsit( ( Statement *)branchStmt ); |
---|
62 | |
---|
63 | // for labeled branches, add an entry to the label table |
---|
64 | Label target = branchStmt->get_target(); |
---|
65 | if ( target != "" ) { |
---|
66 | setLabelsUsg( target, branchStmt ); |
---|
67 | } |
---|
68 | } |
---|
69 | |
---|
70 | void LabelFixer::previsit( LabelAddressExpr * addrExpr ) { |
---|
71 | Label & target = addrExpr->arg; |
---|
72 | assert( target != "" ); |
---|
73 | setLabelsUsg( target, addrExpr ); |
---|
74 | } |
---|
75 | |
---|
76 | |
---|
77 | // Sets the definition of the labelTable entry to be the provided statement for every label in |
---|
78 | // the list parameter. Happens for every kind of statement. |
---|
79 | Label LabelFixer::setLabelsDef( std::list< Label > & llabel, Statement * definition ) { |
---|
80 | assert( definition != 0 ); |
---|
81 | assert( llabel.size() > 0 ); |
---|
82 | |
---|
83 | for ( std::list< Label >::iterator i = llabel.begin(); i != llabel.end(); i++ ) { |
---|
84 | Label & l = *i; |
---|
85 | l.set_statement( definition ); // attach statement to the label to be used later |
---|
86 | if ( labelTable.find( l ) == labelTable.end() ) { |
---|
87 | // All labels on this statement need to use the same entry, |
---|
88 | // so this should only be created once. |
---|
89 | // undefined and unused until now, add an entry |
---|
90 | labelTable[ l ] = new Entry( definition ); |
---|
91 | } else if ( labelTable[ l ]->defined() ) { |
---|
92 | // defined twice, error |
---|
93 | SemanticError( l.get_statement()->location, |
---|
94 | "Duplicate definition of label: " + l.get_name() ); |
---|
95 | } else { |
---|
96 | // used previously, but undefined until now -> link with this entry |
---|
97 | // Question: Is changing objects important? |
---|
98 | delete labelTable[ l ]; |
---|
99 | labelTable[ l ] = new Entry( definition ); |
---|
100 | } // if |
---|
101 | } // for |
---|
102 | |
---|
103 | // Produce one of the labels attached to this statement to be temporarily used as the |
---|
104 | // canonical label. |
---|
105 | return labelTable[ llabel.front() ]->get_label(); |
---|
106 | } |
---|
107 | |
---|
108 | // A label was used, add it to the table if it isn't already there |
---|
109 | template< typename UsageNode > |
---|
110 | void LabelFixer::setLabelsUsg( Label orgValue, UsageNode *use ) { |
---|
111 | assert( use != 0 ); |
---|
112 | |
---|
113 | // add label with an unknown origin |
---|
114 | if ( labelTable.find( orgValue ) == labelTable.end() ) { |
---|
115 | labelTable[ orgValue ] = new Entry( 0 ); |
---|
116 | } |
---|
117 | } |
---|
118 | |
---|
119 | // Builds a table that maps a label to its defining statement. |
---|
120 | std::map<Label, Statement * > * LabelFixer::resolveJumps() throw ( SemanticErrorException ) { |
---|
121 | std::map< Label, Statement * > *ret = new std::map< Label, Statement * >(); |
---|
122 | for ( std::map< Label, Entry * >::iterator i = labelTable.begin(); i != labelTable.end(); ++i ) { |
---|
123 | if ( ! i->second->defined() ) { |
---|
124 | SemanticError( i->first.get_statement()->location, "Use of undefined label: " + i->first.get_name() ); |
---|
125 | } |
---|
126 | (*ret)[ i->first ] = i->second->get_definition(); |
---|
127 | } |
---|
128 | |
---|
129 | return ret; |
---|
130 | } |
---|
131 | } // namespace ControlStruct |
---|
132 | |
---|
133 | // Local Variables: // |
---|
134 | // tab-width: 4 // |
---|
135 | // mode: c++ // |
---|
136 | // compile-command: "make install" // |
---|
137 | // End: // |
---|