source: src/ControlStruct/LabelFixer.cc @ 1e30df7

ADTast-experimental
Last change on this file since 1e30df7 was f8965f4, checked in by Thierry Delisle <tdelisle@…>, 2 years ago

Removed unnecessary throw lists

  • Property mode set to 100644
File size: 4.7 KB
Line 
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 : Tue Feb  1 09:12:09 2022
13// Update Count     : 162
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 MultiLevelExitMutator
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
28namespace ControlStruct {
29bool LabelFixer::Entry::insideLoop() {
30        return ( dynamic_cast< ForStmt * > ( definition ) ||
31                dynamic_cast< WhileDoStmt * > ( definition )  );
32}
33
34LabelFixer::LabelFixer( LabelGenerator * gen ) : generator ( gen ) {
35        if ( generator == 0 )
36                generator = LabelGenerator::getGenerator();
37}
38
39void LabelFixer::previsit( FunctionDecl * ) {
40        // need to go into a nested function in a fresh state
41        GuardValue( labelTable );
42        labelTable.clear();
43}
44
45void LabelFixer::postvisit( FunctionDecl * functionDecl ) {
46        PassVisitor<MultiLevelExitMutator> mlem( resolveJumps(), generator );
47        // We start in the body so we can stop when we hit another FunctionDecl.
48        maybeMutate( functionDecl->statements, mlem );
49}
50
51// prune to at most one label definition for each statement
52void LabelFixer::previsit( Statement * stmt ) {
53        std::list< Label > &labels = stmt->get_labels();
54
55        if ( ! labels.empty() ) {
56                // only remember one label for each statement
57                Label current = setLabelsDef( labels, stmt );
58        } // if
59}
60
61void LabelFixer::previsit( BranchStmt * branchStmt ) {
62        previsit( ( Statement *)branchStmt );
63
64        // for labeled branches, add an entry to the label table
65        Label target = branchStmt->get_target();
66        if ( target != "" ) {
67                setLabelsUsg( target, branchStmt );
68        }
69}
70
71void LabelFixer::previsit( LabelAddressExpr * addrExpr ) {
72        Label & target = addrExpr->arg;
73        assert( target != "" );
74        setLabelsUsg( target, addrExpr );
75}
76
77
78// Sets the definition of the labelTable entry to be the provided statement for every label in
79// the list parameter. Happens for every kind of statement.
80Label LabelFixer::setLabelsDef( std::list< Label > & llabel, Statement * definition ) {
81        assert( definition != 0 );
82        assert( llabel.size() > 0 );
83
84        for ( std::list< Label >::iterator i = llabel.begin(); i != llabel.end(); i++ ) {
85                Label & l = *i;
86                l.set_statement( definition ); // attach statement to the label to be used later
87                if ( labelTable.find( l ) == labelTable.end() ) {
88                        // All labels on this statement need to use the same entry,
89                        // so this should only be created once.
90                        // undefined and unused until now, add an entry
91                        labelTable[ l ] = new Entry( definition );
92                } else if ( labelTable[ l ]->defined() ) {
93                        // defined twice, error
94                        SemanticError( l.get_statement()->location,
95                                "Duplicate definition of label: " + l.get_name() );
96                } else {
97                        // used previously, but undefined until now -> link with this entry
98                        // Question: Is changing objects important?
99                        delete labelTable[ l ];
100                        labelTable[ l ] = new Entry( definition );
101                } // if
102        } // for
103
104        // Produce one of the labels attached to this statement to be temporarily used as the
105        // canonical label.
106        return labelTable[ llabel.front() ]->get_label();
107}
108
109// A label was used, add it to the table if it isn't already there
110template< typename UsageNode >
111void LabelFixer::setLabelsUsg( Label orgValue, UsageNode *use ) {
112        assert( use != 0 );
113
114        // add label with an unknown origin
115        if ( labelTable.find( orgValue ) == labelTable.end() ) {
116                labelTable[ orgValue ] = new Entry( 0 );
117        }
118}
119
120// Builds a table that maps a label to its defining statement.
121std::map<Label, Statement * > * LabelFixer::resolveJumps() {
122        std::map< Label, Statement * > *ret = new std::map< Label, Statement * >();
123        for ( std::map< Label, Entry * >::iterator i = labelTable.begin(); i != labelTable.end(); ++i ) {
124                if ( ! i->second->defined() ) {
125                        SemanticError( i->first.get_statement()->location, "Use of undefined label: " + i->first.get_name() );
126                }
127                (*ret)[ i->first ] = i->second->get_definition();
128        }
129
130        return ret;
131}
132}  // namespace ControlStruct
133
134// Local Variables: //
135// tab-width: 4 //
136// mode: c++ //
137// compile-command: "make install" //
138// End: //
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