Changeset e766208

Timestamp:

Jul 30, 2015, 4:05:02 PM (9 years ago)

Author:

Rob Schluntz <rschlunt@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, ctor, deferred_resn, demangler, enum, forall-pointer-decay, gc_noraii, jacob/cs343-translation, jenkins-sandbox, master, memory, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, string, with_gc

Children:

e01559c

Parents:

51b986f

Message:

simplified label fixer code => no longer rename and consolidate labels

Location:

src/ControlStruct

Files:

• LabelFixer.cc (modified) (6 diffs)
• LabelFixer.h (modified) (3 diffs)

src/ControlStruct/LabelFixer.cc

@@ -10 +10 @@
 // Created On       : Mon May 18 07:44:20 2015
 // Last Modified By : Rob Schluntz
-// Last Modified On : Wed Jul 08 12:36:46 2015
-// Update Count     : 145
+// Last Modified On : Tue Jul 28 13:32:43 2015
+// Update Count     : 156
 //
 
@@ -27 +27 @@
 
 namespace ControlStruct {
-        LabelFixer::Entry::Entry( Statement *to, Statement *from ) : definition ( to ) {
-                if ( from != 0 ) {
-                        UsageLoc loc; loc.stmt = from;
-                        usage.push_back( loc );
-                }
-        }
-
-        LabelFixer::Entry::Entry( Statement *to, Expression *from ) : definition ( to ) {
-                if ( from != 0 ) {
-                        UsageLoc loc; loc.expr = from;
-                        usage.push_back( loc );
-                }
-        }
-
-
         bool LabelFixer::Entry::insideLoop() {
                 return ( dynamic_cast< ForStmt * > ( definition ) ||
                         dynamic_cast< WhileStmt * > ( definition )  );
-        }
-
-        void LabelFixer::Entry::UsageLoc::accept( Visitor & visitor ) {
-                if ( dynamic_cast< Statement * >( stmt ) ) {
-                        stmt->accept( visitor );
-                } else {
-                        expr->accept( visitor );
-                }
         }
 
@@ -77 +54 @@
         // prune to at most one label definition for each statement
         void LabelFixer::visit( Statement *stmt ) {
-                currentStatement = stmt;
                 std::list< Label > &labels = stmt->get_labels();
 
@@ -83 +59 @@
                         // only remember one label for each statement
                         Label current = setLabelsDef( labels, stmt );
-                        labels.clear();
-                        labels.push_front( current );
                 } // if
         }
@@ -130 +104 @@
                         }       else {
                                 // used previously, but undefined until now -> link with this entry
-                                Entry * oldEntry = labelTable[ *i ];
-                                e->add_uses( *oldEntry );
+                                delete labelTable[ *i ];
                                 labelTable[ *i ] = e;
                         } // if
@@ -141 +114 @@
         }
 
-        // Remember all uses of a label.
+        // A label was used, add it ot the table if it isn't already there
         template< typename UsageNode >
         void LabelFixer::setLabelsUsg( Label orgValue, UsageNode *use ) {
                 assert( use != 0 );
 
-                if ( labelTable.find( orgValue ) != labelTable.end() ) {
-                        // the label has been defined or used before
-                        labelTable[ orgValue ]->add_use( use );
-                } else {
-                        labelTable[ orgValue ] = new Entry( 0, use );
+                // add label with an unknown origin
+                if ( labelTable.find( orgValue ) == labelTable.end() ) {
+                        labelTable[ orgValue ] = new Entry( 0 );
                 }
         }
 
-        class LabelGetter : public Visitor {
-                public:
-                LabelGetter( Label &label ) : label( label ) {}
-
-                virtual void visit( BranchStmt * branchStmt ) {
-                        label = branchStmt->get_target();
-                }
-
-                virtual void visit( UntypedExpr * untyped ) {
-                        NameExpr * name = dynamic_cast< NameExpr * >( untyped->get_function() );
-                        assert( name );
-                        assert( name->get_name() == "&&" );
-                        NameExpr * arg = dynamic_cast< NameExpr * >( untyped->get_args().front() );
-                        assert( arg );
-                        label = arg->get_name();
-                }               
-
-                private:
-                        Label &label;
-        };
-
-        class LabelSetter : public Visitor {
-                public:
-                LabelSetter( Label label ) : label( label ) {}
-
-                virtual void visit( BranchStmt * branchStmt ) {
-                        branchStmt->set_target( label );
-                }
-
-                virtual void visit( UntypedExpr * untyped ) {
-                        NameExpr * name = dynamic_cast< NameExpr * >( untyped->get_function() );
-                        assert( name );
-                        assert( name->get_name() == "&&" );
-                        NameExpr * arg = dynamic_cast< NameExpr * >( untyped->get_args().front() );
-                        assert( arg );
-                        arg->set_name( label );
-                }
-
-        private:
-                Label label;
-        };
-
-        // Ultimately builds a table that maps a label to its defining statement.
-        // In the process, 
+        // Builds a table that maps a label to its defining statement.
         std::map<Label, Statement * > *LabelFixer::resolveJumps() throw ( SemanticError ) {
-                std::map< Statement *, Entry * > def_us;
-
-                // combine the entries for all labels that target the same location
-                for ( std::map< Label, Entry *>::iterator i = labelTable.begin(); i != labelTable.end(); ++i ) {
-                        Entry *e = i->second;
-
-                        if ( def_us.find ( e->get_definition() ) == def_us.end() ) {
-                                def_us[ e->get_definition() ] = e;
-                        } else if ( e->used() ) {
-                                def_us[ e->get_definition() ]->add_uses( *e );
+                std::map< Label, Statement * > *ret = new std::map< Label, Statement * >();
+                for ( std::map< Label, Entry * >::iterator i = labelTable.begin(); i != labelTable.end(); ++i ) {
+                        if ( ! i->second->defined() ) {
+                                throw SemanticError( "Use of undefined label: " + i->first );
                         }
-                }
-
-                // create a unique label for each target location. 
-                for ( std::map< Statement *, Entry * >::iterator i = def_us.begin(); i != def_us.end(); ++i ) {
-                        Statement *to = (*i).first;
-                        Entry * entry = (*i).second;
-                        std::list< Entry::UsageLoc > &from = entry->get_uses();
-
-                        // no label definition found
-                        if ( to == 0 ) {
-                                Label undef;
-                                LabelGetter getLabel( undef );
-                                from.back().accept( getLabel );
-                                // Label undef = getLabel( from.back()->get_target() );
-                                throw SemanticError ( "'" + undef + "' label not defined");
-                        } // if
-
-                        // generate a new label, and attach it to its defining statement as the only label on that statement
-                        Label finalLabel = generator->newLabel( to->get_labels().back() );
-                        entry->set_label( finalLabel );
-
-                        to->get_labels().clear();
-                        to->get_labels().push_back( finalLabel );
-
-                        // redirect each of the source branch statements to the new target label
-                        for ( std::list< Entry::UsageLoc >::iterator j = from.begin(); j != from.end(); ++j ) {
-                                LabelSetter setLabel( finalLabel );
-                                (*j).accept( setLabel );
-                                // setLabel( *j, finalLabel );
-
-                                // BranchStmt *jump = *j;
-                                // assert( jump != 0 );
-                                // jump->set_target( finalLabel );
-                        } // for
-                } // for
-
-                // create a table where each label maps to its defining statement
-                std::map< Label, Statement * > *ret = new std::map< Label, Statement * >();
-                for ( std::map< Statement *, Entry * >::iterator i = def_us.begin(); i != def_us.end(); ++i ) {
-                        (*ret)[ (*i).second->get_label() ] = (*i).first;
+                        (*ret)[ i->first ] = i->second->get_definition();
                 }
 

src/ControlStruct/LabelFixer.h

@@ -9 +9 @@
 // Author           : Rodolfo G. Esteves
 // Created On       : Mon May 18 07:44:20 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Mon Jun 29 17:24:39 2015
-// Update Count     : 29
+// Last Modified By : Rob Schluntz
+// Last Modified On : Tue Jul 28 13:09:02 2015
+// Update Count     : 31
 //
 
@@ -63 +63 @@
                 class Entry {
                         public:
-                        union UsageLoc {
-                                Statement * stmt;
-                                Expression * expr;
-
-                                void accept( Visitor &visitor );
-                        };
-
                         Entry( Statement *to ) : definition( to ) {}
-                        Entry( Statement *to, Statement *from );
-                        Entry( Statement *to, Expression *from );
-                        bool used() { return ( usage.empty() ); }
                         bool defined() { return ( definition != 0 ); }
                         bool insideLoop();
@@ -83 +73 @@
                         void set_definition( Statement *def ) { definition = def; }
 
-                        std::list< UsageLoc > &get_uses() { return usage; }
-                        void add_use( Statement *use ) {
-                                UsageLoc loc;
-                                loc.stmt = use;
-                                usage.push_back( loc ); 
-                        }
-                        void add_use( Expression *use ) {
-                                UsageLoc loc;
-                                loc.expr = use;
-                                usage.push_back( loc );                                 
-                        }
-
-                        void add_uses ( Entry &other ) { usage.insert( usage.end(), other.usage.begin(), other.usage.end() ); }
                   private:
                         Label label;  
                         Statement *definition;
-                        std::list<UsageLoc> usage;
                 };
                   
                 std::map < Label, Entry *> labelTable;
                 LabelGenerator *generator;
-                Statement * currentStatement;
         };
 } // namespace ControlStruct