Index: src/Parser/TypedefTable.cc =================================================================== --- src/Parser/TypedefTable.cc (revision bd946e4dec0434c16bceed37f87da51933bdea63) +++ src/Parser/TypedefTable.cc (revision 3d26610b1bab2688ae61b5b0e34f63763ec3a35b) @@ -10,6 +10,6 @@ // Created On : Sat May 16 15:20:13 2015 // Last Modified By : Peter A. Buhr -// Last Modified On : Tue May 22 08:40:01 2018 -// Update Count : 121 +// Last Modified On : Wed May 30 18:04:38 2018 +// Update Count : 148 // @@ -20,7 +20,7 @@ #if 0 #include -#define debugPrint( x ) cerr << x +#define debugPrint( code ) code #else -#define debugPrint( x ) +#define debugPrint( code ) #endif @@ -29,5 +29,5 @@ TypedefTable::~TypedefTable() { if ( ! SemanticErrorThrow && kindTable.currentScope() != 0 ) { - // std::cerr << "scope failure " << kindTable.currentScope() << endl; + std::cerr << "scope failure " << kindTable.currentScope() << endl; } // if } // TypedefTable::~TypedefTable @@ -54,12 +54,19 @@ void TypedefTable::makeTypedef( const string & name ) { if ( ! typedefTable.exists( name ) ) { - typedefTable.addToEnclosingScope( name, TYPEDEFname ); + typedefTable.addToEnclosingScope( name, TYPEDEFname /*, "MTD"*/ ); } // if } // TypedefTable::makeTypedef -void TypedefTable::addToEnclosingScope( const std::string & identifier, int kind ) { +void TypedefTable::addToScope( const std::string & identifier, int kind /*, const char * locn*/ ) { + auto scope = kindTable.currentScope(); + debugPrint( cerr << "Adding at " /* << locn */ << " " << identifier << " as kind " << kind << " scope " << scope << endl ); + auto ret = kindTable.insertAt( scope, identifier, kind ); + if ( ! ret.second ) ret.first->second = kind; // exists => update +} // TypedefTable::addToScope + +void TypedefTable::addToEnclosingScope( const std::string & identifier, int kind /*, const char * locn*/ ) { assert( kindTable.currentScope() >= 1 ); auto scope = kindTable.currentScope() - 1; - debugPrint( "Adding " << identifier << " as kind " << kind << " scope " << scope << endl ); + debugPrint( cerr << "Adding2 at " /* << locn */ << " " << identifier << " as kind " << kind << " scope " << scope << endl ); auto ret = kindTable.insertAt( scope, identifier, kind ); if ( ! ret.second ) ret.first->second = kind; // exists => update @@ -68,22 +75,30 @@ void TypedefTable::enterScope() { kindTable.beginScope(); - debugPrint( "Entering scope " << kindTable.currentScope() << endl ); + debugPrint( cerr << "Entering scope " << kindTable.currentScope() << endl ); + debugPrint( print() ); } // TypedefTable::enterScope void TypedefTable::leaveScope() { - debugPrint( "Leaving scope " << kindTable.currentScope() << endl ); + debugPrint( cerr << "Leaving scope " << kindTable.currentScope() << endl ); + debugPrint( print() ); kindTable.endScope(); } // TypedefTable::leaveScope -// void TypedefTable::print( void ) const { -// for ( KindTable::const_iterator i = table.begin(); i != table.end(); i++) { -// debugPrint( (*i ).first << ": " ); -// list< Entry > declList = (*i).second; -// for ( list< Entry >::const_iterator j = declList.begin(); j != declList.end(); j++ ) { -// debugPrint( "(" << (*j).scope << " " << (*j).kind << ") " ); -// } -// debugPrint( endl ); -// } // for -// } +void TypedefTable::print( void ) const { + KindTable::size_type scope = kindTable.currentScope(); + debugPrint( cerr << "[" << scope << "]" ); + for ( KindTable::const_iterator i = kindTable.begin(); i != kindTable.end(); i++ ) { + while ( i.get_level() != scope ) { + --scope; + debugPrint( cerr << endl << "[" << scope << "]" ); + } // while + debugPrint( cerr << " " << (*i).first << ":" << (*i).second ); + } // for + while ( scope > 0 ) { + --scope; + debugPrint( cerr << endl << "[" << scope << "]" ); + } + debugPrint( cerr << endl ); +} // Local Variables: // Index: src/Parser/TypedefTable.h =================================================================== --- src/Parser/TypedefTable.h (revision bd946e4dec0434c16bceed37f87da51933bdea63) +++ src/Parser/TypedefTable.h (revision 3d26610b1bab2688ae61b5b0e34f63763ec3a35b) @@ -10,6 +10,6 @@ // Created On : Sat May 16 15:24:36 2015 // Last Modified By : Peter A. Buhr -// Last Modified On : Tue May 22 08:39:29 2018 -// Update Count : 77 +// Last Modified On : Wed May 30 17:02:49 2018 +// Update Count : 82 // @@ -32,8 +32,11 @@ void changeKind( const std::string & identifier, int kind ); void makeTypedef( const std::string & name ); - void addToEnclosingScope( const std::string & identifier, int kind ); + void addToScope( const std::string & identifier, int kind /*, const char **/ ); + void addToEnclosingScope( const std::string & identifier, int kind /*, const char */ ); void enterScope(); void leaveScope(); + + void print( void ) const; }; // TypedefTable Index: src/Parser/parser.yy =================================================================== --- src/Parser/parser.yy (revision bd946e4dec0434c16bceed37f87da51933bdea63) +++ src/Parser/parser.yy (revision 3d26610b1bab2688ae61b5b0e34f63763ec3a35b) @@ -10,6 +10,6 @@ // Created On : Sat Sep 1 20:22:55 2001 // Last Modified By : Peter A. Buhr -// Last Modified On : Wed May 30 20:29:03 2018 -// Update Count : 3432 +// Last Modified On : Thu May 31 15:11:40 2018 +// Update Count : 3444 // @@ -265,5 +265,5 @@ %type statement labeled_statement compound_statement %type statement_decl statement_decl_list statement_list_nodecl -%type selection_statement +%type selection_statement if_statement %type switch_clause_list_opt switch_clause_list %type case_value @@ -404,26 +404,30 @@ //************************* Namespace Management ******************************** -// The grammar in the ANSI C standard is not strictly context-free, since it relies upon the distinct terminal symbols -// "identifier", "TYPEDEFname", and "TYPEGENname" that are lexically identical. While it is possible to write a purely -// context-free grammar, such a grammar would obscure the relationship between syntactic and semantic constructs. -// Hence, this grammar uses the ANSI style. -// -// Cforall compounds this problem by introducing type names local to the scope of a declaration (for instance, those -// introduced through "forall" qualifiers), and by introducing "type generators" -- parameterized types. This latter -// type name creates a third class of identifiers that must be distinguished by the scanner. -// -// Since the scanner cannot distinguish among the different classes of identifiers without some context information, it -// accesses a data structure (TypedefTable) to allow classification of an identifier that it has just read. Semantic -// actions during the parser update this data structure when the class of identifiers change. -// -// Because the Cforall language is block-scoped, an identifier can change its class in a local scope; it must revert to -// its original class at the end of the block. Since type names can be local to a particular declaration, each -// declaration is itself a scope. This requires distinguishing between type names that are local to the current -// declaration scope and those that persist past the end of the declaration (i.e., names defined in "typedef" or "otype" -// declarations). -// -// The non-terminals "push" and "pop" denote the opening and closing of scopes. Every push must have a matching pop, -// although it is regrettable the matching pairs do not always occur within the same rule. These non-terminals may -// appear in more contexts than strictly necessary from a semantic point of view. +// The C grammar is not context free because it relies on the distinct terminal symbols "identifier" and "TYPEDEFname", +// which are lexically identical. +// +// typedef int foo; // identifier foo must now be scanned as TYPEDEFname +// foo f; // to allow it to appear in this context +// +// While it may be possible to write a purely context-free grammar, such a grammar would obscure the relationship +// between syntactic and semantic constructs. Cforall compounds this problem by introducing type names local to the +// scope of a declaration (for instance, those introduced through "forall" qualifiers), and by introducing "type +// generators" -- parameterized types. This latter type name creates a third class of identifiers, "TYPEGENname", which +// must be distinguished by the lexical scanner. +// +// Since the scanner cannot distinguish among the different classes of identifiers without some context information, +// there is a type table (typedefTable), which holds type names and identifiers that override type names, for each named +// scope. During parsing, semantic actions update the type table by adding new identifiers in the current scope. For +// each context that introduces a name scope, a new level is created in the type table and that level is popped on +// exiting the scope. Since type names can be local to a particular declaration, each declaration is itself a scope. +// This requires distinguishing between type names that are local to the current declaration scope and those that +// persist past the end of the declaration (i.e., names defined in "typedef" or "otype" declarations). +// +// The non-terminals "push" and "pop" denote the opening and closing of named scopes. Every push has a matching pop in +// the production rule. There are multiple lists of declarations, where each declaration is a named scope, so pop/push +// around the list separator. +// +// int f( forall(T) T (*f1) T , forall( S ) S (*f2)( S ) ); +// push pop push pop push: @@ -952,9 +956,8 @@ selection_statement: - IF '(' push if_control_expression ')' statement pop %prec THEN - // explicitly deal with the shift/reduce conflict on if/else - { $$ = new StatementNode( build_if( $4, $6, nullptr ) ); } - | IF '(' push if_control_expression ')' statement ELSE statement pop - { $$ = new StatementNode( build_if( $4, $6, $8 ) ); } + // pop causes a S/R conflict without separating the IF statement into a non-terminal even after resolving + // the inherent S/R conflict with THEN/ELSE. + push if_statement pop + { $$ = $2; } | SWITCH '(' comma_expression ')' case_clause { $$ = new StatementNode( build_switch( true, $3, $5 ) ); } @@ -977,4 +980,13 @@ } ; + +if_statement: + IF '(' if_control_expression ')' statement %prec THEN + // explicitly deal with the shift/reduce conflict on if/else + { $$ = new StatementNode( build_if( $3, $5, nullptr ) ); } + | IF '(' if_control_expression ')' statement ELSE statement + { $$ = new StatementNode( build_if( $3, $5, $7 ) ); } + ; + if_control_expression: @@ -1172,8 +1184,8 @@ handler_clause: - handler_key '(' push push exception_declaration pop handler_predicate_opt ')' compound_statement pop - { $$ = new StatementNode( build_catch( $1, $5, $7, $9 ) ); } - | handler_clause handler_key '(' push push exception_declaration pop handler_predicate_opt ')' compound_statement pop - { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( $2, $6, $8, $10 ) ) ); } + handler_key '(' push exception_declaration pop handler_predicate_opt ')' compound_statement pop + { $$ = new StatementNode( build_catch( $1, $4, $6, $8 ) ); } + | handler_clause handler_key '(' push exception_declaration pop handler_predicate_opt ')' compound_statement pop + { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( $2, $5, $7, $9 ) ) ); } ; Index: src/main.cc =================================================================== --- src/main.cc (revision bd946e4dec0434c16bceed37f87da51933bdea63) +++ src/main.cc (revision 3d26610b1bab2688ae61b5b0e34f63763ec3a35b) @@ -10,6 +10,6 @@ // Created On : Fri May 15 23:12:02 2015 // Last Modified By : Peter A. Buhr -// Last Modified On : Mon May 7 14:35:57 2018 -// Update Count : 492 +// Last Modified On : Wed May 30 17:53:14 2018 +// Update Count : 496 // @@ -573,5 +573,4 @@ yyin = input; yylineno = 1; - typedefTable.enterScope(); int parseStatus = yyparse();