source: src/Parser/parser.yy @ 9059213

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// cfa.y --
//
// Author           : Peter A. Buhr
// Created On       : Sat Sep  1 20:22:55 2001
// Last Modified By : Peter A. Buhr
// Last Modified On : Wed Oct 19 22:19:33 2016
// Update Count     : 2003
//

// This grammar is based on the ANSI99/11 C grammar, specifically parts of EXPRESSION and STATEMENTS, and on the C
// grammar by James A. Roskind, specifically parts of DECLARATIONS and EXTERNAL DEFINITIONS.  While parts have been
// copied, important changes have been made in all sections; these changes are sufficient to constitute a new grammar.
// In particular, this grammar attempts to be more syntactically precise, i.e., it parses less incorrect language syntax
// that must be subsequently rejected by semantic checks.  Nevertheless, there are still several semantic checks
// required and many are noted in the grammar. Finally, the grammar is extended with GCC and CFA language extensions.

// Acknowledgments to Richard Bilson, Glen Ditchfield, and Rodolfo Gabriel Esteves who all helped when I got stuck with
// the grammar.

// The root language for this grammar is ANSI99/11 C. All of ANSI99/11 is parsed, except for:
//
// 1. designation with '=' (use ':' instead)
//
// Most of the syntactic extensions from ANSI90 to ANSI11 C are marked with the comment "C99/C11". This grammar also has
// two levels of extensions. The first extensions cover most of the GCC C extensions, except for:
//
// 1. designation with and without '=' (use ':' instead)
// 2. attributes not allowed in parenthesis of declarator
//
// All of the syntactic extensions for GCC C are marked with the comment "GCC". The second extensions are for Cforall
// (CFA), which fixes several of C's outstanding problems and extends C with many modern language concepts. All of the
// syntactic extensions for CFA C are marked with the comment "CFA". As noted above, there is one unreconcileable
// parsing problem between C99 and CFA with respect to designators; this is discussed in detail before the "designation"
// grammar rule.

%{
#define YYDEBUG_LEXER_TEXT (yylval)                                             // lexer loads this up each time
#define YYDEBUG 1                                                                               // get the pretty debugging code to compile

#undef __GNUC_MINOR__

#include <cstdio>
#include <stack>
#include "lex.h"
#include "parser.h"
#include "ParseNode.h"
#include "TypedefTable.h"
#include "TypeData.h"
#include "LinkageSpec.h"
using namespace std;

extern DeclarationNode * parseTree;
extern LinkageSpec::Spec linkage;
extern TypedefTable typedefTable;

stack< LinkageSpec::Spec > linkageStack;

void appendStr( string *to, string *from ) {
        // "abc" "def" "ghi" => "abcdefghi", remove new text from quotes and insert before last quote in old string.
        to->insert( to->length() - 1, from->substr( 1, from->length() - 2 ) );
} // appendStr
%}

//************************* TERMINAL TOKENS ********************************

// keywords
%token TYPEDEF
%token AUTO EXTERN REGISTER STATIC
%token INLINE                                                                                   // C99
%token FORTRAN                                                                                  // C99, extension ISO/IEC 9899:1999 Section J.5.9(1)
%token CONST VOLATILE
%token RESTRICT                                                                                 // C99
%token FORALL LVALUE                                                                    // CFA
%token VOID CHAR SHORT INT LONG FLOAT DOUBLE SIGNED UNSIGNED
%token VALIST                                                                                   // GCC
%token BOOL COMPLEX IMAGINARY                                                   // C99
%token TYPEOF LABEL                                                                             // GCC
%token ENUM STRUCT UNION
%token OTYPE FTYPE DTYPE TRAIT                                                  // CFA
%token SIZEOF OFFSETOF
%token ATTRIBUTE EXTENSION                                                              // GCC
%token IF ELSE SWITCH CASE DEFAULT DO WHILE FOR BREAK CONTINUE GOTO RETURN
%token CHOOSE DISABLE ENABLE FALLTHRU TRY CATCH CATCHRESUME FINALLY THROW THROWRESUME AT        // CFA
%token ASM                                                                                              // C99, extension ISO/IEC 9899:1999 Section J.5.10(1)
%token ALIGNAS ALIGNOF ATOMIC GENERIC NORETURN STATICASSERT THREADLOCAL // C11

// names and constants: lexer differentiates between identifier and typedef names
%token<tok> IDENTIFIER                  QUOTED_IDENTIFIER               TYPEDEFname                             TYPEGENname
%token<tok> ATTR_IDENTIFIER             ATTR_TYPEDEFname                ATTR_TYPEGENname
%token<tok> INTEGERconstant             FLOATINGconstant                CHARACTERconstant               STRINGliteral
%token<tok> ZERO                                ONE                                             // CFA

// multi-character operators
%token ARROW                                                                                    // ->
%token ICR DECR                                                                                 // ++   --
%token LS RS                                                                                    // <<   >>
%token LE GE EQ NE                                                                              // <=   >=      ==      !=
%token ANDAND OROR                                                                              // &&   ||
%token ELLIPSIS                                                                                 // ...

%token MULTassign       DIVassign       MODassign                               // *=   /=      %=/
%token PLUSassign       MINUSassign                                                     // +=   -=
%token LSassign         RSassign                                                        // <<=  >>=
%token ANDassign        ERassign        ORassign                                // &=   ^=      |=

%token ATassign                                                                                 // @=

// Types declaration
%union
{
        Token tok;
        ParseNode *pn;
        ExpressionNode *en;
        DeclarationNode *decl;
        DeclarationNode::Aggregate aggKey;
        DeclarationNode::TypeClass tclass;
        StatementNode *sn;
        ConstantExpr *constant;
        ForCtl *fctl;
        LabelNode *label;
        InitializerNode *in;
        OperKinds op;
        std::string *str;
        bool flag;
}

%type<tok> identifier  no_01_identifier  no_attr_identifier zero_one
%type<tok> identifier_or_type_name  no_attr_identifier_or_type_name  no_01_identifier_or_type_name
%type<constant> string_literal
%type<str> string_literal_list

// expressions
%type<en> constant
%type<en> tuple                                                 tuple_expression_list
%type<op> ptrref_operator                               unary_operator                          assignment_operator
%type<en> primary_expression                    postfix_expression                      unary_expression
%type<en> cast_expression                               multiplicative_expression       additive_expression                     shift_expression
%type<en> relational_expression                 equality_expression                     AND_expression                          exclusive_OR_expression
%type<en> inclusive_OR_expression               logical_AND_expression          logical_OR_expression           conditional_expression
%type<en> constant_expression                   assignment_expression           assignment_expression_opt
%type<en> comma_expression                              comma_expression_opt
%type<en> argument_expression_list              argument_expression                     assignment_opt
%type<fctl> for_control_expression
%type<en> subrange
%type<en> asm_operands_opt asm_operands_list asm_operand
%type<label> label_list
%type<en> asm_clobbers_list_opt
%type<flag> asm_volatile_opt

// statements
%type<sn> labeled_statement                             compound_statement                      expression_statement            selection_statement
%type<sn> iteration_statement                   jump_statement                          exception_statement                     asm_statement
%type<sn> fall_through_opt                              fall_through
%type<sn> statement                                             statement_list
%type<sn> block_item_list                               block_item
%type<sn> case_clause
%type<en> case_value
%type<sn> case_value_list                               case_label                                      case_label_list
%type<sn> switch_clause_list_opt                switch_clause_list                      choose_clause_list_opt          choose_clause_list
%type<sn> handler_list                                  handler_clause                          finally_clause

// declarations
%type<decl> abstract_array abstract_declarator abstract_function abstract_parameter_array
%type<decl> abstract_parameter_declaration abstract_parameter_declarator abstract_parameter_function
%type<decl> abstract_parameter_ptr abstract_ptr

%type<aggKey> aggregate_key
%type<decl>  aggregate_name

%type<decl> array_dimension array_parameter_1st_dimension array_parameter_dimension multi_array_dimension

%type<decl> assertion assertion_list_opt

%type<en>   bit_subrange_size_opt bit_subrange_size

%type<decl> basic_declaration_specifier basic_type_name basic_type_specifier direct_type_name indirect_type_name

%type<decl> trait_declaration trait_declaration_list trait_declaring_list trait_specifier

%type<decl> declaration declaration_list declaration_list_opt declaration_qualifier_list
%type<decl> declaration_specifier declarator declaring_list

%type<decl> elaborated_type_name

%type<decl> enumerator_list enum_name
%type<en> enumerator_value_opt

%type<decl> exception_declaration external_definition external_definition_list external_definition_list_opt

%type<decl> field_declaration field_declaration_list field_declarator field_declaring_list
%type<en> field field_list
%type<tok> field_name

%type<decl> external_function_definition function_definition function_array function_declarator function_no_ptr function_ptr

%type<decl> identifier_parameter_array identifier_parameter_declarator identifier_parameter_function
%type<decl> identifier_parameter_ptr identifier_list

%type<decl> new_abstract_array new_abstract_declarator_no_tuple new_abstract_declarator_tuple
%type<decl> new_abstract_function new_abstract_parameter_declaration new_abstract_parameter_list
%type<decl> new_abstract_ptr new_abstract_tuple

%type<decl> new_array_parameter_1st_dimension

%type<decl> new_trait_declaring_list new_declaration new_field_declaring_list
%type<decl> new_function_declaration new_function_return new_function_specifier

%type<decl> new_identifier_parameter_array new_identifier_parameter_declarator_no_tuple
%type<decl> new_identifier_parameter_declarator_tuple new_identifier_parameter_ptr

%type<decl> new_parameter_declaration new_parameter_list new_parameter_type_list new_parameter_type_list_opt

%type<decl> new_typedef_declaration new_variable_declaration new_variable_specifier

%type<decl> old_declaration old_declaration_list old_declaration_list_opt old_function_array
%type<decl> old_function_declarator old_function_no_ptr old_function_ptr

%type<decl> parameter_declaration parameter_list parameter_type_list
%type<decl> parameter_type_list_opt

%type<decl> paren_identifier paren_type

%type<decl> storage_class storage_class_list

%type<decl> sue_declaration_specifier sue_type_specifier

%type<tclass> type_class
%type<decl> type_declarator type_declarator_name type_declaring_list

%type<decl> typedef type_array typedef_declaration typedef_declaration_specifier typedef_expression
%type<decl> type_function type_parameter_array type_parameter_function type_parameter_ptr
%type<decl> type_parameter_redeclarator type_ptr variable_type_redeclarator typedef_type_specifier
%type<decl> typegen_declaration_specifier typegen_type_specifier typegen_name

%type<decl> type_name type_name_no_function
%type<decl> type_parameter type_parameter_list

%type<en> type_name_list

%type<decl> type_qualifier type_qualifier_name type_qualifier_list type_qualifier_list_opt type_specifier

%type<decl> variable_abstract_array variable_abstract_declarator variable_abstract_function
%type<decl> variable_abstract_ptr variable_array variable_declarator variable_function variable_ptr

%type<decl> attribute_list_opt attribute_list attribute

// initializers
%type<in>  initializer initializer_list initializer_opt

// designators
%type<en>  designator designator_list designation


// Handle single shift/reduce conflict for dangling else by shifting the ELSE token. For example, this string
// is ambiguous:
// .---------.                          matches IF '(' comma_expression ')' statement
// if ( C ) S1 else S2
// `-----------------'          matches IF '(' comma_expression ')' statement ELSE statement */

%nonassoc THEN  // rule precedence for IF '(' comma_expression ')' statement
%nonassoc ELSE  // token precedence for start of else clause in IF statement

%start translation_unit                                                                 // parse-tree root

%%
//************************* Namespace Management ********************************

// The grammar in the ANSI C standard is not strictly context-free, since it relies upon the distinct terminal symbols
// "identifier" and "TYPEDEFname" 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, there is the possibility that 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" derive the empty string; their only use is to 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.  Unfortunately, these extra rules are necessary to prevent parsing conflicts -- the parser may not have
// enough context and look-ahead information to decide whether a new scope is necessary, so the effect of these extra
// rules is to open a new scope unconditionally.  As the grammar evolves, it may be neccesary to add or move around
// "push" and "pop" nonterminals to resolve conflicts of this sort.

push:
                { typedefTable.enterScope(); }
        ;

pop:
                { typedefTable.leaveScope(); }
        ;

//************************* CONSTANTS ********************************

constant:
                // ENUMERATIONconstant is not included here; it is treated as a variable with type "enumeration constant".
        INTEGERconstant                                                         { $$ = new ExpressionNode( build_constantInteger( *$1 ) ); }
        | FLOATINGconstant                                                      { $$ = new ExpressionNode( build_constantFloat( *$1 ) ); }
        | CHARACTERconstant                                                     { $$ = new ExpressionNode( build_constantChar( *$1 ) ); }
        ;

identifier:
        IDENTIFIER
        | ATTR_IDENTIFIER                                                                       // CFA
        | zero_one                                                                                      // CFA
        ;

no_01_identifier:
        IDENTIFIER
        | ATTR_IDENTIFIER                                                                       // CFA
        ;

no_attr_identifier:
        IDENTIFIER
        | zero_one                                                                                      // CFA
        ;

zero_one:                                                                                               // CFA
        ZERO
        | ONE
        ;

string_literal:
        string_literal_list                                                     { $$ = build_constantStr( *$1 ); }
        ;

string_literal_list:                                                                    // juxtaposed strings are concatenated
        STRINGliteral                                                           { $$ = $1; } // conversion from tok to str
        | string_literal_list STRINGliteral
                {
                        appendStr( $1, $2 );                                            // append 2nd juxtaposed string to 1st
                        delete $2;                                                                      // allocated by lexer
                        $$ = $1;                                                                        // conversion from tok to str
                }
        ;

//************************* EXPRESSIONS ********************************

primary_expression:
        IDENTIFIER                                                                                      // typedef name cannot be used as a variable name
                { $$ = new ExpressionNode( build_varref( $1 ) ); }
        | zero_one
                { $$ = new ExpressionNode( build_varref( $1 ) ); }
        | '(' comma_expression ')'
                { $$ = $2; }
        | '(' compound_statement ')'                                            // GCC, lambda expression
                { $$ = new ExpressionNode( build_valexpr( $2 ) ); }
        ;

postfix_expression:
        primary_expression
        | postfix_expression '[' push assignment_expression pop ']'
                // CFA, comma_expression disallowed in this context because it results in a common user error: subscripting a
                // matrix with x[i,j] instead of x[i][j]. While this change is not backwards compatible, there seems to be
                // little advantage to this feature and many disadvantages. It is possible to write x[(i,j)] in CFA, which is
                // equivalent to the old x[i,j].
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Index, $1, $4 ) ); }
        | postfix_expression '(' argument_expression_list ')'
                { $$ = new ExpressionNode( build_func( $1, $3 ) ); }
                // ambiguity with .0 so space required after field-selection, e.g.
                //   struct S { int 0, 1; } s; s. 0 = 0; s. 1 = 1;
        | postfix_expression '.' no_attr_identifier
                { $$ = new ExpressionNode( build_fieldSel( $1, build_varref( $3 ) ) ); }
        | postfix_expression '.' '[' push field_list pop ']' // CFA, tuple field selector
        | postfix_expression '.' INTEGERconstant
        | postfix_expression ARROW no_attr_identifier
                { $$ = new ExpressionNode( build_pfieldSel( $1, build_varref( $3 ) ) ); }
        | postfix_expression ARROW '[' push field_list pop ']' // CFA, tuple field selector
        | postfix_expression ICR
                { $$ = new ExpressionNode( build_unary_ptr( OperKinds::IncrPost, $1 ) ); }
        | postfix_expression DECR
                { $$ = new ExpressionNode( build_unary_ptr( OperKinds::DecrPost, $1 ) ); }
        | '(' type_name_no_function ')' '{' initializer_list comma_opt '}' // C99
                { $$ = new ExpressionNode( build_compoundLiteral( $2, new InitializerNode( $5, true ) ) ); }
        | postfix_expression '{' argument_expression_list '}' // CFA
                {
                        Token fn;
                        fn.str = new std::string( "?{}" );                      // location undefined - use location of '{'?
                        $$ = new ExpressionNode( new ConstructorExpr( build_func( new ExpressionNode( build_varref( fn ) ), (ExpressionNode *)( $1 )->set_last( $3 ) ) ) );
                }
        ;

argument_expression_list:
        argument_expression
        | argument_expression_list ',' argument_expression
                { $$ = (ExpressionNode *)( $1->set_last( $3 )); }
        ;

argument_expression:
        // empty
                { $$ = 0; }                                                                             // use default argument
        | assignment_expression
        ;

field_list:                                                                                             // CFA, tuple field selector
        field
        | field_list ',' field                                          { $$ = (ExpressionNode *)$1->set_last( $3 ); }
        ;

field:                                                                                                  // CFA, tuple field selector
        field_name
                // ambiguity with .0 so space required after field-selection, e.g.
                //   struct S { int 0, 1; } s; s. 0 = 0; s. 1 = 1;
                { $$ = new ExpressionNode( build_varref( $1 ) ); }
        | field_name '.' field
                { $$ = new ExpressionNode( build_fieldSel( $3, build_varref( $1 ) ) ); }
        | field_name '.' '[' push field_list pop ']'
                { $$ = new ExpressionNode( build_fieldSel( $5, build_varref( $1 ) ) ); }
        | field_name ARROW field
                { $$ = new ExpressionNode( build_pfieldSel( $3, build_varref( $1 ) ) ); }
        | field_name ARROW '[' push field_list pop ']'
                { $$ = new ExpressionNode( build_pfieldSel( $5, build_varref( $1 ) ) ); }
        ;

field_name:
        no_attr_identifier
                // x.1, x.[0, 0.0]
        | INTEGERconstant
        ;

unary_expression:
        postfix_expression
                // first location where constant/string can have operator applied: sizeof 3/sizeof "abc" still requires
                // semantics checks, e.g., ++3, 3--, *3, &&3
        | constant
                { $$ = $1; }
        | string_literal
                { $$ = new ExpressionNode( $1 ); }
        | EXTENSION cast_expression                                                     // GCC
                { $$ = $2->set_extension( true ); }
                // '*' ('&') is separated from unary_operator because of shift/reduce conflict in:
                //              { * X; }         // dereference X
                //              { * int X; } // CFA declaration of pointer to int
        | ptrref_operator cast_expression                                       // CFA
                {
                        switch ( $1 ) {
                          case OperKinds::AddressOf:
                                $$ = new ExpressionNode( build_addressOf( $2 ) );
                                break;
                          case OperKinds::PointTo:
                                $$ = new ExpressionNode( build_unary_val( $1, $2 ) );
                                break;
                          default:
                                assert( false );
                        }
                }
        | unary_operator cast_expression
                { $$ = new ExpressionNode( build_unary_val( $1, $2 ) ); }
        | ICR unary_expression
                { $$ = new ExpressionNode( build_unary_ptr( OperKinds::Incr, $2 ) ); }
        | DECR unary_expression
                { $$ = new ExpressionNode( build_unary_ptr( OperKinds::Decr, $2 ) ); }
        | SIZEOF unary_expression
                { $$ = new ExpressionNode( build_sizeOfexpr( $2 ) ); }
        | SIZEOF '(' type_name_no_function ')'
                { $$ = new ExpressionNode( build_sizeOftype( $3 ) ); }
        | ALIGNOF unary_expression                                                      // GCC, variable alignment
                { $$ = new ExpressionNode( build_alignOfexpr( $2 ) ); }
        | ALIGNOF '(' type_name_no_function ')'                         // GCC, type alignment
                { $$ = new ExpressionNode( build_alignOftype( $3 ) ); }
        | OFFSETOF '(' type_name_no_function ',' no_attr_identifier ')'
                { $$ = new ExpressionNode( build_offsetOf( $3, build_varref( $5 ) ) ); }
        | ATTR_IDENTIFIER
                { $$ = new ExpressionNode( build_attrexpr( build_varref( $1 ), nullptr ) ); }
        | ATTR_IDENTIFIER '(' argument_expression ')'
                { $$ = new ExpressionNode( build_attrexpr( build_varref( $1 ), $3 ) ); }
        | ATTR_IDENTIFIER '(' type_name ')'
                { $$ = new ExpressionNode( build_attrtype( build_varref( $1 ), $3 ) ); }
//      | ANDAND IDENTIFIER                                                                     // GCC, address of label
//              { $$ = new ExpressionNode( new OperatorNode( OperKinds::LabelAddress ), new ExpressionNode( build_varref( $2, true ) ); }
        ;

ptrref_operator:
        '*'                                                                                     { $$ = OperKinds::PointTo; }
        | '&'                                                                           { $$ = OperKinds::AddressOf; }
                // GCC, address of label must be handled by semantic check for ref,ref,label
//      | ANDAND                                                                        { $$ = OperKinds::And; }
        ;

unary_operator:
        '+'                                                                                     { $$ = OperKinds::UnPlus; }
        | '-'                                                                           { $$ = OperKinds::UnMinus; }
        | '!'                                                                           { $$ = OperKinds::Neg; }
        | '~'                                                                           { $$ = OperKinds::BitNeg; }
        ;

cast_expression:
        unary_expression
        | '(' type_name_no_function ')' cast_expression
                { $$ = new ExpressionNode( build_cast( $2, $4 ) ); }
        | '(' type_name_no_function ')' tuple
                { $$ = new ExpressionNode( build_cast( $2, $4 ) ); }
        ;

multiplicative_expression:
        cast_expression
        | multiplicative_expression '*' cast_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Mul, $1, $3 ) ); }
        | multiplicative_expression '/' cast_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Div, $1, $3 ) ); }
        | multiplicative_expression '%' cast_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Mod, $1, $3 ) ); }
        ;

additive_expression:
        multiplicative_expression
        | additive_expression '+' multiplicative_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Plus, $1, $3 ) ); }
        | additive_expression '-' multiplicative_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Minus, $1, $3 ) ); }
        ;

shift_expression:
        additive_expression
        | shift_expression LS additive_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::LShift, $1, $3 ) ); }
        | shift_expression RS additive_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::RShift, $1, $3 ) ); }
        ;

relational_expression:
        shift_expression
        | relational_expression '<' shift_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::LThan, $1, $3 ) ); }
        | relational_expression '>' shift_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::GThan, $1, $3 ) ); }
        | relational_expression LE shift_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::LEThan, $1, $3 ) ); }
        | relational_expression GE shift_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::GEThan, $1, $3 ) ); }
        ;

equality_expression:
        relational_expression
        | equality_expression EQ relational_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Eq, $1, $3 ) ); }
        | equality_expression NE relational_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Neq, $1, $3 ) ); }
        ;

AND_expression:
        equality_expression
        | AND_expression '&' equality_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::BitAnd, $1, $3 ) ); }
        ;

exclusive_OR_expression:
        AND_expression
        | exclusive_OR_expression '^' AND_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::Xor, $1, $3 ) ); }
        ;

inclusive_OR_expression:
        exclusive_OR_expression
        | inclusive_OR_expression '|' exclusive_OR_expression
                { $$ = new ExpressionNode( build_binary_val( OperKinds::BitOr, $1, $3 ) ); }
        ;

logical_AND_expression:
        inclusive_OR_expression
        | logical_AND_expression ANDAND inclusive_OR_expression
                { $$ = new ExpressionNode( build_and_or( $1, $3, true ) ); }
        ;

logical_OR_expression:
        logical_AND_expression
        | logical_OR_expression OROR logical_AND_expression
                { $$ = new ExpressionNode( build_and_or( $1, $3, false ) ); }
        ;

conditional_expression:
        logical_OR_expression
        | logical_OR_expression '?' comma_expression ':' conditional_expression
                { $$ = new ExpressionNode( build_cond( $1, $3, $5 ) ); }
                // FIX ME: this hack computes $1 twice
        | logical_OR_expression '?' /* empty */ ':' conditional_expression // GCC, omitted first operand
                { $$ = new ExpressionNode( build_cond( $1, $1, $4 ) ); }
        | logical_OR_expression '?' comma_expression ':' tuple // CFA, tuple expression
                { $$ = new ExpressionNode( build_cond( $1, $3, $5 ) ); }
        ;

constant_expression:
        conditional_expression
        ;

assignment_expression:
                // CFA, assignment is separated from assignment_operator to ensure no assignment operations for tuples
        conditional_expression
        | unary_expression assignment_operator assignment_expression
                { $$ = new ExpressionNode( build_binary_ptr( $2, $1, $3 ) ); }
        | tuple assignment_opt                                                          // CFA, tuple expression
                { $$ = ( $2 == 0 ) ? $1 : new ExpressionNode( build_binary_ptr( OperKinds::Assign, $1, $2 ) ); }
        ;

assignment_expression_opt:
        // empty
                { $$ = nullptr; }
        | assignment_expression
        ;

assignment_operator:
        '='                                                                                     { $$ = OperKinds::Assign; }
        | ATassign                                                                      { $$ = OperKinds::AtAssn; }
        | MULTassign                                                            { $$ = OperKinds::MulAssn; }
        | DIVassign                                                                     { $$ = OperKinds::DivAssn; }
        | MODassign                                                                     { $$ = OperKinds::ModAssn; }
        | PLUSassign                                                            { $$ = OperKinds::PlusAssn; }
        | MINUSassign                                                           { $$ = OperKinds::MinusAssn; }
        | LSassign                                                                      { $$ = OperKinds::LSAssn; }
        | RSassign                                                                      { $$ = OperKinds::RSAssn; }
        | ANDassign                                                                     { $$ = OperKinds::AndAssn; }
        | ERassign                                                                      { $$ = OperKinds::ERAssn; }
        | ORassign                                                                      { $$ = OperKinds::OrAssn; }
        ;

tuple:                                                                                                  // CFA, tuple
                // CFA, one assignment_expression is factored out of comma_expression to eliminate a shift/reduce conflict with
                // comma_expression in new_identifier_parameter_array and new_abstract_array
        '[' ']'
                { $$ = new ExpressionNode( build_tuple() ); }
        | '[' push assignment_expression pop ']'
                { $$ = new ExpressionNode( build_tuple( $3 ) ); }
        | '[' push ',' tuple_expression_list pop ']'
                { $$ = new ExpressionNode( build_tuple( (ExpressionNode *)(new ExpressionNode( nullptr ) )->set_last( $4 ) ) ); }
        | '[' push assignment_expression ',' tuple_expression_list pop ']'
                { $$ = new ExpressionNode( build_tuple( (ExpressionNode *)$3->set_last( $5 ) ) ); }
        ;

tuple_expression_list:
        assignment_expression_opt
        | tuple_expression_list ',' assignment_expression_opt
                { $$ = (ExpressionNode *)$1->set_last( $3 ); }
        ;

comma_expression:
        assignment_expression
        | comma_expression ',' assignment_expression
                { $$ = new ExpressionNode( build_comma( $1, $3 ) ); }
        ;

comma_expression_opt:
        // empty
                { $$ = 0; }
        | comma_expression
        ;

//*************************** STATEMENTS *******************************

statement:
        labeled_statement
        | compound_statement
        | expression_statement                                          { $$ = $1; }
        | selection_statement
        | iteration_statement
        | jump_statement
        | exception_statement
        | asm_statement
        | '^' postfix_expression '{' argument_expression_list '}' ';' // CFA
                {
                        Token fn;
                        fn.str = new string( "^?{}" );                          // location undefined
                        $$ = new StatementNode( build_expr( new ExpressionNode( build_func( new ExpressionNode( build_varref( fn ) ), (ExpressionNode *)( $2 )->set_last( $4 ) ) ) ) );
                }
        ;

labeled_statement:
                // labels cannot be identifiers 0 or 1
        IDENTIFIER ':' attribute_list_opt statement
                {
                        $$ = $4->add_label( $1 );
                }
        ;

compound_statement:
        '{' '}'
                { $$ = new StatementNode( build_compound( (StatementNode *)0 ) ); }
        | '{'
                // Two scopes are necessary because the block itself has a scope, but every declaration within the block also
                // requires its own scope
          push push
          local_label_declaration_opt                                           // GCC, local labels
          block_item_list pop '}'                                                       // C99, intermix declarations and statements
                { $$ = new StatementNode( build_compound( $5 ) ); }
        ;

block_item_list:                                                                                // C99
        block_item
        | block_item_list push block_item
                { if ( $1 != 0 ) { $1->set_last( $3 ); $$ = $1; } }
        ;

block_item:
        declaration                                                                                     // CFA, new & old style declarations
                { $$ = new StatementNode( $1 ); }
        | EXTENSION declaration                                                         // GCC
                {       // mark all fields in list
                        for ( DeclarationNode *iter = $2; iter != nullptr; iter = (DeclarationNode *)iter->get_next() )
                                iter->set_extension( true );
                        $$ = new StatementNode( $2 );
                }
        | function_definition
                { $$ = new StatementNode( $1 ); }
        | statement pop
        ;

statement_list:
        statement
        | statement_list statement
                { if ( $1 != 0 ) { $1->set_last( $2 ); $$ = $1; } }
        ;

expression_statement:
        comma_expression_opt ';'
                { $$ = new StatementNode( build_expr( $1 ) ); }
        ;

selection_statement:
        IF '(' comma_expression ')' statement                           %prec THEN
                // explicitly deal with the shift/reduce conflict on if/else
                { $$ = new StatementNode( build_if( $3, $5, nullptr ) ); }
        | IF '(' comma_expression ')' statement ELSE statement
                { $$ = new StatementNode( build_if( $3, $5, $7 ) ); }
        | SWITCH '(' comma_expression ')' case_clause           // CFA
                { $$ = new StatementNode( build_switch( $3, $5 ) ); }
        | SWITCH '(' comma_expression ')' '{' push declaration_list_opt switch_clause_list_opt '}' // CFA
                {
                        StatementNode *sw = new StatementNode( build_switch( $3, $8 ) );
                        // The semantics of the declaration list is changed to include associated initialization, which is performed
                        // *before* the transfer to the appropriate case clause by hoisting the declarations into a compound
                        // statement around the switch.  Statements after the initial declaration list can never be executed, and
                        // therefore, are removed from the grammar even though C allows it. The change also applies to choose
                        // statement.
                        $$ = $7 != 0 ? new StatementNode( build_compound( (StatementNode *)((new StatementNode( $7 ))->set_last( sw )) ) ) : sw;
                }
        | CHOOSE '(' comma_expression ')' case_clause           // CFA
                { $$ = new StatementNode( build_switch( $3, $5 ) ); }
        | CHOOSE '(' comma_expression ')' '{' push declaration_list_opt choose_clause_list_opt '}' // CFA
                {
                        StatementNode *sw = new StatementNode( build_switch( $3, $8 ) );
                        $$ = $7 != 0 ? new StatementNode( build_compound( (StatementNode *)((new StatementNode( $7 ))->set_last( sw )) ) ) : sw;
                }
        ;

// CASE and DEFAULT clauses are only allowed in the SWITCH statement, precluding Duff's device. In addition, a case
// clause allows a list of values and subranges.

case_value:                                                                                             // CFA
        constant_expression                                                     { $$ = $1; }
        | constant_expression ELLIPSIS constant_expression      // GCC, subrange
                { $$ = new ExpressionNode( build_range( $1, $3 ) ); }
        | subrange                                                                                      // CFA, subrange
        ;

case_value_list:                                                                                // CFA
        case_value                                                                      { $$ = new StatementNode( build_case( $1 ) ); }
                // convert case list, e.g., "case 1, 3, 5:" into "case 1: case 3: case 5"
        | case_value_list ',' case_value                        { $$ = (StatementNode *)($1->set_last( new StatementNode( build_case( $3 ) ) ) ); }
        ;

case_label:                                                                                             // CFA
        CASE case_value_list ':'                                        { $$ = $2; }
        | DEFAULT ':'                                                           { $$ = new StatementNode( build_default() ); }
                // A semantic check is required to ensure only one default clause per switch/choose statement.
        ;

case_label_list:                                                                                // CFA
        case_label
        | case_label_list case_label                            { $$ = (StatementNode *)( $1->set_last( $2 )); }
        ;

case_clause:                                                                                    // CFA
        case_label_list statement                                       { $$ = $1->append_last_case( new StatementNode( build_compound( $2 ) ) ); }
        ;

switch_clause_list_opt:                                                                 // CFA
        // empty
                { $$ = 0; }
        | switch_clause_list
        ;

switch_clause_list:                                                                             // CFA
        case_label_list statement_list
                { $$ = $1->append_last_case( new StatementNode( build_compound( $2 ) ) ); }
        | switch_clause_list case_label_list statement_list
                { $$ = (StatementNode *)( $1->set_last( $2->append_last_case( new StatementNode( build_compound( $3 ) ) ) ) ); }
        ;

choose_clause_list_opt:                                                                 // CFA
        // empty
                { $$ = 0; }
        | choose_clause_list
        ;

choose_clause_list:                                                                             // CFA
        case_label_list fall_through
                { $$ = $1->append_last_case( $2 ); }
        | case_label_list statement_list fall_through_opt
                { $$ = $1->append_last_case( new StatementNode( build_compound( (StatementNode *)$2->set_last( $3 ) ) ) ); }
        | choose_clause_list case_label_list fall_through
                { $$ = (StatementNode *)( $1->set_last( $2->append_last_case( $3 ))); }
        | choose_clause_list case_label_list statement_list fall_through_opt
                { $$ = (StatementNode *)( $1->set_last( $2->append_last_case( new StatementNode( build_compound( (StatementNode *)$3->set_last( $4 ) ) ) ) ) ); }
        ;

fall_through_opt:                                                                               // CFA
        // empty
                { $$ = new StatementNode( build_branch( BranchStmt::Break ) ); } // insert implicit break
        | fall_through
        ;

fall_through:                                                                                   // CFA
        FALLTHRU
                { $$ = 0; }
        | FALLTHRU ';'
                { $$ = 0; }
        ;

iteration_statement:
        WHILE '(' comma_expression ')' statement
                { $$ = new StatementNode( build_while( $3, $5 ) ); }
        | DO statement WHILE '(' comma_expression ')' ';'
                { $$ = new StatementNode( build_while( $5, $2, true ) ); }
        | FOR '(' push for_control_expression ')' statement
                { $$ = new StatementNode( build_for( $4, $6 ) ); }
        ;

for_control_expression:
        comma_expression_opt pop ';' comma_expression_opt ';' comma_expression_opt
                { $$ = new ForCtl( $1, $4, $6 ); }
        | declaration comma_expression_opt ';' comma_expression_opt // C99
                { $$ = new ForCtl( $1, $2, $4 ); }
        ;

jump_statement:
        GOTO IDENTIFIER ';'
                { $$ = new StatementNode( build_branch( $2, BranchStmt::Goto ) ); }
        | GOTO '*' comma_expression ';'                                         // GCC, computed goto
                // The syntax for the GCC computed goto violates normal expression precedence, e.g., goto *i+3; => goto *(i+3);
                // whereas normal operator precedence yields goto (*i)+3;
                { $$ = new StatementNode( build_computedgoto( $3 ) ); }
        | CONTINUE ';'
                // A semantic check is required to ensure this statement appears only in the body of an iteration statement.
                { $$ = new StatementNode( build_branch( BranchStmt::Continue ) ); }
        | CONTINUE IDENTIFIER ';'                                                       // CFA, multi-level continue
                // A semantic check is required to ensure this statement appears only in the body of an iteration statement, and
                // the target of the transfer appears only at the start of an iteration statement.
                { $$ = new StatementNode( build_branch( $2, BranchStmt::Continue ) ); }
        | BREAK ';'
                // A semantic check is required to ensure this statement appears only in the body of an iteration statement.
                { $$ = new StatementNode( build_branch( BranchStmt::Break ) ); }
        | BREAK IDENTIFIER ';'                                                          // CFA, multi-level exit
                // A semantic check is required to ensure this statement appears only in the body of an iteration statement, and
                // the target of the transfer appears only at the start of an iteration statement.
                { $$ = new StatementNode( build_branch( $2, BranchStmt::Break ) ); }
        | RETURN comma_expression_opt ';'
                { $$ = new StatementNode( build_return( $2 ) ); }
        | THROW assignment_expression_opt ';'                           // handles rethrow
                { $$ = new StatementNode( build_throw( $2 ) ); }
        | THROWRESUME assignment_expression_opt ';'                     // handles reresume
                { $$ = new StatementNode( build_throw( $2 ) ); }
        | THROWRESUME assignment_expression_opt AT assignment_expression ';' // handles reresume
                { $$ = new StatementNode( build_throw( $2 ) ); }
        ;

exception_statement:
        TRY compound_statement handler_list
                { $$ = new StatementNode( build_try( $2, $3, 0 ) ); }
        | TRY compound_statement finally_clause
                { $$ = new StatementNode( build_try( $2, 0, $3 ) ); }
        | TRY compound_statement handler_list finally_clause
                { $$ = new StatementNode( build_try( $2, $3, $4 ) ); }
        ;

handler_list:
        handler_clause
                // ISO/IEC 9899:1999 Section 15.3(6 ) If present, a "..." handler shall be the last handler for its try block.
        | CATCH '(' ELLIPSIS ')' compound_statement
                { $$ = new StatementNode( build_catch( 0, $5, true ) ); }
        | handler_clause CATCH '(' ELLIPSIS ')' compound_statement
                { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( 0, $6, true ) ) ); }
        | CATCHRESUME '(' ELLIPSIS ')' compound_statement
                { $$ = new StatementNode( build_catch( 0, $5, true ) ); }
        | handler_clause CATCHRESUME '(' ELLIPSIS ')' compound_statement
                { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( 0, $6, true ) ) ); }
        ;

handler_clause:
        CATCH '(' push push exception_declaration pop ')' compound_statement pop
                { $$ = new StatementNode( build_catch( $5, $8 ) ); }
        | handler_clause CATCH '(' push push exception_declaration pop ')' compound_statement pop
                { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( $6, $9 ) ) ); }
        | CATCHRESUME '(' push push exception_declaration pop ')' compound_statement pop
                { $$ = new StatementNode( build_catch( $5, $8 ) ); }
        | handler_clause CATCHRESUME '(' push push exception_declaration pop ')' compound_statement pop
                { $$ = (StatementNode *)$1->set_last( new StatementNode( build_catch( $6, $9 ) ) ); }
        ;

finally_clause:
        FINALLY compound_statement
                {
                        $$ = new StatementNode( build_finally( $2 ) );
                }
        ;

exception_declaration:
                // A semantic check is required to ensure type_specifier does not create a new type, e.g.:
                //
                //              catch ( struct { int i; } x ) ...
                //
                // This new type cannot catch any thrown type because of name equivalence among types.
        type_specifier
        | type_specifier declarator
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $2->addType( $1 );
                }
        | type_specifier variable_abstract_declarator
                { $$ = $2->addType( $1 ); }
        | new_abstract_declarator_tuple no_attr_identifier      // CFA
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $1->addName( $2 );
                }
        | new_abstract_declarator_tuple                                         // CFA
        ;

asm_statement:
        ASM asm_volatile_opt '(' string_literal ')' ';'
                { $$ = new StatementNode( build_asmstmt( $2, $4, 0 ) ); }
        | ASM asm_volatile_opt '(' string_literal ':' asm_operands_opt ')' ';' // remaining GCC
                { $$ = new StatementNode( build_asmstmt( $2, $4, $6 ) ); }
        | ASM asm_volatile_opt '(' string_literal ':' asm_operands_opt ':' asm_operands_opt ')' ';'
                { $$ = new StatementNode( build_asmstmt( $2, $4, $6, $8 ) ); }
        | ASM asm_volatile_opt '(' string_literal ':' asm_operands_opt ':' asm_operands_opt ':' asm_clobbers_list_opt ')' ';'
                { $$ = new StatementNode( build_asmstmt( $2, $4, $6, $8, $10 ) ); }
        | ASM asm_volatile_opt GOTO '(' string_literal ':' ':' asm_operands_opt ':' asm_clobbers_list_opt ':' label_list ')' ';'
                { $$ = new StatementNode( build_asmstmt( $2, $5, 0, $8, $10, $12 ) ); }
        ;

asm_volatile_opt:                                                                               // GCC
        // empty
                { $$ = false; }
        | VOLATILE
                { $$ = true; }
        ;

asm_operands_opt:                                                                               // GCC
        // empty
                { $$ = 0; }                                                                             // use default argument
        | asm_operands_list
        ;

asm_operands_list:                                                                              // GCC
        asm_operand
        | asm_operands_list ',' asm_operand
                { $$ = (ExpressionNode *)$1->set_last( $3 ); }
        ;

asm_operand:                                                                                    // GCC
        string_literal '(' constant_expression ')'
                { $$ = new ExpressionNode( build_asmexpr( 0, $1, $3 ) ); }
        | '[' constant_expression ']' string_literal '(' constant_expression ')'
                { $$ = new ExpressionNode( build_asmexpr( $2, $4, $6 ) ); }
        ;

asm_clobbers_list_opt:                                                                  // GCC
        // empty
                { $$ = 0; }                                                                             // use default argument
        | string_literal
                { $$ = new ExpressionNode( $1 ); }
        | asm_clobbers_list_opt ',' string_literal
                { $$ = (ExpressionNode *)$1->set_last( new ExpressionNode( $3 ) ); }
        ;

label_list:
        no_attr_identifier
                {
                        $$ = new LabelNode(); $$->labels.push_back( *$1 );
                        delete $1;                                                                      // allocated by lexer
                }
        | label_list ',' no_attr_identifier
                {
                        $$ = $1; $1->labels.push_back( *$3 );
                        delete $3;                                                                      // allocated by lexer
                }
        ;

//******************************* DECLARATIONS *********************************

declaration_list_opt:                                                                   // used at beginning of switch statement
        pop
                { $$ = 0; }
        | declaration_list
        ;

declaration_list:
        declaration
        | declaration_list push declaration
                { $$ = $1->appendList( $3 ); }
        ;

old_declaration_list_opt:                                                               // used to declare parameter types in K&R style functions
        pop
                { $$ = 0; }
        | old_declaration_list
        ;

old_declaration_list:
        old_declaration
        | old_declaration_list push old_declaration
                { $$ = $1->appendList( $3 ); }
        ;

local_label_declaration_opt:                                                    // GCC, local label
        // empty
        | local_label_declaration_list
        ;

local_label_declaration_list:                                                   // GCC, local label
        LABEL local_label_list ';'
        | local_label_declaration_list LABEL local_label_list ';'
        ;

local_label_list:                                                                               // GCC, local label
        no_attr_identifier_or_type_name                         {}
        | local_label_list ',' no_attr_identifier_or_type_name {}
        ;

declaration:                                                                                    // CFA, new & old style declarations
        new_declaration
        | old_declaration
        ;

// C declaration syntax is notoriously confusing and error prone. Cforall provides its own type, variable and function
// declarations. CFA declarations use the same declaration tokens as in C; however, CFA places declaration modifiers to
// the left of the base type, while C declarations place modifiers to the right of the base type. CFA declaration
// modifiers are interpreted from left to right and the entire type specification is distributed across all variables in
// the declaration list (as in Pascal).  ANSI C and the new CFA declarations may appear together in the same program
// block, but cannot be mixed within a specific declaration.
//
//                      CFA                                     C
//              [10] int x;                     int x[10];              // array of 10 integers
//              [10] * char y;          char *y[10];    // array of 10 pointers to char

new_declaration:                                                                                // CFA
        new_variable_declaration pop ';'
        | new_typedef_declaration pop ';'
        | new_function_declaration pop ';'
        | type_declaring_list pop ';'
        | trait_specifier pop ';'
        ;

new_variable_declaration:                                                               // CFA
        new_variable_specifier initializer_opt
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $1->addInitializer( $2 );
                }
        | declaration_qualifier_list new_variable_specifier initializer_opt
                // declaration_qualifier_list also includes type_qualifier_list, so a semantic check is necessary to preclude
                // them as a type_qualifier cannot appear in that context.
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $2->addQualifiers( $1 )->addInitializer( $3 );;
                }
        | new_variable_declaration pop ',' push identifier_or_type_name initializer_opt
                {
                        typedefTable.addToEnclosingScope( *$5, TypedefTable::ID );
                        $$ = $1->appendList( $1->cloneType( $5 )->addInitializer( $6 ) );
                }
        ;

new_variable_specifier:                                                                 // CFA
                // A semantic check is required to ensure asm_name only appears on declarations with implicit or explicit static
                // storage-class
        new_abstract_declarator_no_tuple identifier_or_type_name asm_name_opt
                {
                        typedefTable.setNextIdentifier( *$2 );
                        $$ = $1->addName( $2 );
                }
        | new_abstract_tuple identifier_or_type_name asm_name_opt
                {
                        typedefTable.setNextIdentifier( *$2 );
                        $$ = $1->addName( $2 );
                }
        | type_qualifier_list new_abstract_tuple identifier_or_type_name asm_name_opt
                {
                        typedefTable.setNextIdentifier( *$3 );
                        $$ = $2->addQualifiers( $1 )->addName( $3 );
                }
        ;

new_function_declaration:                                                               // CFA
        new_function_specifier
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $1;
                }
        | type_qualifier_list new_function_specifier
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $2->addQualifiers( $1 );
                }
        | declaration_qualifier_list new_function_specifier
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $2->addQualifiers( $1 );
                }
        | declaration_qualifier_list type_qualifier_list new_function_specifier
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $3->addQualifiers( $1 )->addQualifiers( $2 );
                }
        | new_function_declaration pop ',' push identifier_or_type_name
                {
                        typedefTable.addToEnclosingScope( *$5, TypedefTable::ID );
                        $$ = $1->appendList( $1->cloneType( $5 ) );
                }
        ;

new_function_specifier:                                                                 // CFA
        '[' ']' identifier_or_type_name '(' push new_parameter_type_list_opt pop ')' // S/R conflict
                {
                        $$ = DeclarationNode::newFunction( $3, DeclarationNode::newTuple( 0 ), $6, 0, true );
                }
//      '[' ']' identifier '(' push new_parameter_type_list_opt pop ')'
//              {
//                      typedefTable.setNextIdentifier( *$5 );
//                      $$ = DeclarationNode::newFunction( $5, DeclarationNode::newTuple( 0 ), $8, 0, true );
//              }
//      | '[' ']' TYPEDEFname '(' push new_parameter_type_list_opt pop ')'
//              {
//                      typedefTable.setNextIdentifier( *$5 );
//                      $$ = DeclarationNode::newFunction( $5, DeclarationNode::newTuple( 0 ), $8, 0, true );
//              }
//      | '[' ']' typegen_name
                // identifier_or_type_name must be broken apart because of the sequence:
                //
                //   '[' ']' identifier_or_type_name '(' new_parameter_type_list_opt ')'
                //   '[' ']' type_specifier
                //
                // type_specifier can resolve to just TYPEDEFname (e.g., typedef int T; int f( T );). Therefore this must be
                // flattened to allow lookahead to the '(' without having to reduce identifier_or_type_name.
        | new_abstract_tuple identifier_or_type_name '(' push new_parameter_type_list_opt pop ')'
                // To obtain LR(1 ), this rule must be factored out from function return type (see new_abstract_declarator).
                {
                        $$ = DeclarationNode::newFunction( $2, $1, $5, 0, true );
                }
        | new_function_return identifier_or_type_name '(' push new_parameter_type_list_opt pop ')'
                {
                        $$ = DeclarationNode::newFunction( $2, $1, $5, 0, true );
                }
        ;

new_function_return:                                                                    // CFA
        '[' push new_parameter_list pop ']'
                { $$ = DeclarationNode::newTuple( $3 ); }
        | '[' push new_parameter_list pop ',' push new_abstract_parameter_list pop ']'
                // To obtain LR(1 ), the last new_abstract_parameter_list is added into this flattened rule to lookahead to the
                // ']'.
                { $$ = DeclarationNode::newTuple( $3->appendList( $7 ) ); }
        ;

new_typedef_declaration:                                                                // CFA
        TYPEDEF new_variable_specifier
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $2->addTypedef();
                }
        | TYPEDEF new_function_specifier
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $2->addTypedef();
                }
        | new_typedef_declaration pop ',' push no_attr_identifier
                {
                        typedefTable.addToEnclosingScope( *$5, TypedefTable::TD );
                        $$ = $1->appendList( $1->cloneType( $5 ) );
                }
        ;

// Traditionally typedef is part of storage-class specifier for syntactic convenience only. Here, it is factored out as
// a separate form of declaration, which syntactically precludes storage-class specifiers and initialization.

typedef_declaration:
        TYPEDEF type_specifier declarator
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $3->addType( $2 )->addTypedef();
                }
        | typedef_declaration pop ',' push declarator
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $1->appendList( $1->cloneBaseType( $5 )->addTypedef() );
                }
        | type_qualifier_list TYPEDEF type_specifier declarator // remaining OBSOLESCENT (see 2 )
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $4->addType( $3 )->addQualifiers( $1 )->addTypedef();
                }
        | type_specifier TYPEDEF declarator
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $3->addType( $1 )->addTypedef();
                }
        | type_specifier TYPEDEF type_qualifier_list declarator
                {
                        typedefTable.addToEnclosingScope( TypedefTable::TD );
                        $$ = $4->addQualifiers( $1 )->addTypedef()->addType( $1 );
                }
        ;

typedef_expression:
                // GCC, naming expression type: typedef name = exp; gives a name to the type of an expression
        TYPEDEF no_attr_identifier '=' assignment_expression
                {
                        typedefTable.addToEnclosingScope( *$2, TypedefTable::TD );
                        $$ = DeclarationNode::newName( 0 ); // XXX
                }
        | typedef_expression pop ',' push no_attr_identifier '=' assignment_expression
                {
                        typedefTable.addToEnclosingScope( *$5, TypedefTable::TD );
                        $$ = DeclarationNode::newName( 0 ); // XXX
                }
        ;

old_declaration:
        declaring_list pop ';'
        | typedef_declaration pop ';'
        | typedef_expression pop ';'                                            // GCC, naming expression type
        | sue_declaration_specifier pop ';'
        ;

declaring_list:
                // A semantic check is required to ensure asm_name only appears on declarations with implicit or explicit static
                // storage-class
        declaration_specifier declarator asm_name_opt initializer_opt
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = ( $2->addType( $1 ))->addInitializer( $4 );
                }
        | declaring_list ',' attribute_list_opt declarator asm_name_opt initializer_opt
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $1->appendList( $1->cloneBaseType( $4->addInitializer( $6 ) ) );
                }
        ;

declaration_specifier:                                                                  // type specifier + storage class
        basic_declaration_specifier
        | sue_declaration_specifier
        | typedef_declaration_specifier
        | typegen_declaration_specifier
        ;

type_specifier:                                                                                 // declaration specifier - storage class
        basic_type_specifier
        | sue_type_specifier
        | typedef_type_specifier
        | typegen_type_specifier
        ;

type_qualifier_list_opt:                                                                // GCC, used in asm_statement
        // empty
                { $$ = 0; }
        | type_qualifier_list
        ;

type_qualifier_list:
                // A semantic check is necessary to ensure a type qualifier is appropriate for the kind of declaration.
                //
                // ISO/IEC 9899:1999 Section 6.7.3(4 ) : If the same qualifier appears more than once in the same
                // specifier-qualifier-list, either directly or via one or more typedefs, the behavior is the same as if it
                // appeared only once.
        type_qualifier
        | type_qualifier_list type_qualifier
                { $$ = $1->addQualifiers( $2 ); }
        ;

type_qualifier:
        type_qualifier_name
        | attribute
                //{ $$ = DeclarationNode::newQualifier( DeclarationNode::Attribute ); }
        ;

type_qualifier_name:
        CONST
                { $$ = DeclarationNode::newQualifier( DeclarationNode::Const ); }
        | RESTRICT
                { $$ = DeclarationNode::newQualifier( DeclarationNode::Restrict ); }
        | VOLATILE
                { $$ = DeclarationNode::newQualifier( DeclarationNode::Volatile ); }
        | LVALUE                                                                                        // CFA
                { $$ = DeclarationNode::newQualifier( DeclarationNode::Lvalue ); }
        | ATOMIC
                { $$ = DeclarationNode::newQualifier( DeclarationNode::Atomic ); }
        | FORALL '('
                {
                        typedefTable.enterScope();
                }
          type_parameter_list ')'                                                       // CFA
                {
                        typedefTable.leaveScope();
                        $$ = DeclarationNode::newForall( $4 );
                }
        ;

declaration_qualifier_list:
        storage_class_list
        | type_qualifier_list storage_class_list                        // remaining OBSOLESCENT (see 2 )
                { $$ = $1->addQualifiers( $2 ); }
        | declaration_qualifier_list type_qualifier_list storage_class_list
                { $$ = $1->addQualifiers( $2 )->addQualifiers( $3 ); }
        ;

storage_class_list:
                // A semantic check is necessary to ensure a storage class is appropriate for the kind of declaration and that
                // only one of each is specified, except for inline, which can appear with the others.
                //
                // ISO/IEC 9899:1999 Section 6.7.1(2) : At most, one storage-class specifier may be given in the declaration
                // specifiers in a declaration.
        storage_class
        | storage_class_list storage_class
                { $$ = $1->addQualifiers( $2 ); }
        ;

storage_class:
        EXTERN
                { $$ = DeclarationNode::newStorageClass( DeclarationNode::Extern ); }
        | STATIC
                { $$ = DeclarationNode::newStorageClass( DeclarationNode::Static ); }
        | AUTO
                { $$ = DeclarationNode::newStorageClass( DeclarationNode::Auto ); }
        | REGISTER
                { $$ = DeclarationNode::newStorageClass( DeclarationNode::Register ); }
        | INLINE                                                                                        // C99
                //{ $$ = DeclarationNode::newStorageClass( DeclarationNode::Inline ); }
                { $$ = new DeclarationNode; $$->isInline = true; }
        | FORTRAN                                                                                       // C99
                { $$ = DeclarationNode::newStorageClass( DeclarationNode::Fortran ); }
        | NORETURN                                                                                      // C11
                //{ $$ = DeclarationNode::newStorageClass( DeclarationNode::Noreturn ); }
                { $$ = new DeclarationNode; $$->isNoreturn = true; }
        | THREADLOCAL                                                                           // C11
                { $$ = DeclarationNode::newStorageClass( DeclarationNode::Threadlocal ); }
        ;

basic_type_name:
        CHAR
                { $$ = DeclarationNode::newBasicType( DeclarationNode::Char ); }
        | DOUBLE
                { $$ = DeclarationNode::newBasicType( DeclarationNode::Double ); }
        | FLOAT
                { $$ = DeclarationNode::newBasicType( DeclarationNode::Float ); }
        | INT
                { $$ = DeclarationNode::newBasicType( DeclarationNode::Int ); }
        | LONG
                { $$ = DeclarationNode::newLength( DeclarationNode::Long ); }
        | SHORT
                { $$ = DeclarationNode::newLength( DeclarationNode::Short ); }
        | SIGNED
                { $$ = DeclarationNode::newSignedNess( DeclarationNode::Signed ); }
        | UNSIGNED
                { $$ = DeclarationNode::newSignedNess( DeclarationNode::Unsigned ); }
        | VOID
                { $$ = DeclarationNode::newBasicType( DeclarationNode::Void ); }
        | BOOL                                                                                          // C99
                { $$ = DeclarationNode::newBasicType( DeclarationNode::Bool ); }
        | COMPLEX                                                                                       // C99
                { $$ = DeclarationNode::newComplexType( DeclarationNode::Complex ); }
        | IMAGINARY                                                                                     // C99
                { $$ = DeclarationNode::newComplexType( DeclarationNode::Imaginary ); }
        | VALIST                                                                                        // GCC, __builtin_va_list
                { $$ = DeclarationNode::newBuiltinType( DeclarationNode::Valist ); }
        ;

basic_declaration_specifier:
                // A semantic check is necessary for conflicting storage classes.
        basic_type_specifier
        | declaration_qualifier_list basic_type_specifier
                { $$ = $2->addQualifiers( $1 ); }
        | basic_declaration_specifier storage_class                     // remaining OBSOLESCENT (see 2)
                { $$ = $1->addQualifiers( $2 ); }
        | basic_declaration_specifier storage_class type_qualifier_list
                { $$ = $1->addQualifiers( $2 )->addQualifiers( $3 ); }
        | basic_declaration_specifier storage_class basic_type_specifier
                { $$ = $3->addQualifiers( $2 )->addType( $1 ); }
        ;

basic_type_specifier:
        direct_type_name
        | type_qualifier_list_opt indirect_type_name type_qualifier_list_opt
                { $$ = $2->addQualifiers( $1 )->addQualifiers( $3 ); }
        ;

direct_type_name:
                // A semantic check is necessary for conflicting type qualifiers.
        basic_type_name
        | type_qualifier_list basic_type_name
                { $$ = $2->addQualifiers( $1 ); }
        | direct_type_name type_qualifier
                { $$ = $1->addQualifiers( $2 ); }
        | direct_type_name basic_type_name
                { $$ = $1->addType( $2 ); }
        ;

indirect_type_name:
        TYPEOF '(' type_name ')'                                                        // GCC: typeof(x) y;
                { $$ = $3; }
        | TYPEOF '(' comma_expression ')'                                       // GCC: typeof(a+b) y;
                { $$ = DeclarationNode::newTypeof( $3 ); }
        | ATTR_TYPEGENname '(' type_name ')'                            // CFA: e.g., @type(x) y;
                { $$ = DeclarationNode::newAttr( $1, $3 ); }
        | ATTR_TYPEGENname '(' comma_expression ')'                     // CFA: e.g., @type(a+b) y;
                { $$ = DeclarationNode::newAttr( $1, $3 ); }
        ;

sue_declaration_specifier:
        sue_type_specifier
        | declaration_qualifier_list sue_type_specifier
                { $$ = $2->addQualifiers( $1 ); }
        | sue_declaration_specifier storage_class                       // remaining OBSOLESCENT (see 2)
                { $$ = $1->addQualifiers( $2 ); }
        | sue_declaration_specifier storage_class type_qualifier_list
                { $$ = $1->addQualifiers( $2 )->addQualifiers( $3 ); }
        ;

sue_type_specifier:
        elaborated_type_name                                                            // struct, union, enum
        | type_qualifier_list elaborated_type_name
                { $$ = $2->addQualifiers( $1 ); }
        | sue_type_specifier type_qualifier
                { $$ = $1->addQualifiers( $2 ); }
        ;

typedef_declaration_specifier:
        typedef_type_specifier
        | declaration_qualifier_list typedef_type_specifier
                { $$ = $2->addQualifiers( $1 ); }
        | typedef_declaration_specifier storage_class           // remaining OBSOLESCENT (see 2)
                { $$ = $1->addQualifiers( $2 ); }
        | typedef_declaration_specifier storage_class type_qualifier_list
                { $$ = $1->addQualifiers( $2 )->addQualifiers( $3 ); }
        ;

typedef_type_specifier:                                                                 // typedef types
        TYPEDEFname
                { $$ = DeclarationNode::newFromTypedef( $1 ); }
        | type_qualifier_list TYPEDEFname
                { $$ = DeclarationNode::newFromTypedef( $2 )->addQualifiers( $1 ); }
        | typedef_type_specifier type_qualifier
                { $$ = $1->addQualifiers( $2 ); }
        ;

elaborated_type_name:
        aggregate_name
        | enum_name
        ;

aggregate_name:
        aggregate_key '{' field_declaration_list '}'
                { $$ = DeclarationNode::newAggregate( $1, nullptr, nullptr, $3, true ); }
        | aggregate_key no_attr_identifier_or_type_name
                {
                        typedefTable.makeTypedef( *$2 );
                        $$ = DeclarationNode::newAggregate( $1, $2, nullptr, nullptr, false );
                }
        | aggregate_key no_attr_identifier_or_type_name
                { typedefTable.makeTypedef( *$2 ); }
                '{' field_declaration_list '}'
                { $$ = DeclarationNode::newAggregate( $1, $2, nullptr, $5, true ); }
        | aggregate_key '(' type_name_list ')' '{' field_declaration_list '}' // CFA
                { $$ = DeclarationNode::newAggregate( $1, nullptr, $3, $6, false ); }
        | aggregate_key typegen_name                                            // CFA, S/R conflict
                { $$ = $2; }
        ;

aggregate_key:
        STRUCT attribute_list_opt
                { $$ = DeclarationNode::Struct; }
        | UNION attribute_list_opt
                { $$ = DeclarationNode::Union; }
        ;

field_declaration_list:
        // empty
                { $$ = 0; }
        | field_declaration_list field_declaration
                { $$ = $1 != 0 ? $1->appendList( $2 ) : $2; }
        ;

field_declaration:
        new_field_declaring_list ';'                                            // CFA, new style field declaration
        | EXTENSION new_field_declaring_list ';'                        // GCC
                { $$ = $2->set_extension( true ); }
        | field_declaring_list ';'
        | EXTENSION field_declaring_list ';'                            // GCC
                {       // mark all fields in list
                        for ( DeclarationNode *iter = $2; iter != nullptr; iter = (DeclarationNode *)iter->get_next() )
                                iter->set_extension( true );
                        $$ = $2;
                }
        ;

new_field_declaring_list:                                                               // CFA, new style field declaration
        new_abstract_declarator_tuple                                           // CFA, no field name
        | new_abstract_declarator_tuple no_attr_identifier_or_type_name
                { $$ = $1->addName( $2 ); }
        | new_field_declaring_list ',' no_attr_identifier_or_type_name
                { $$ = $1->appendList( $1->cloneType( $3 ) ); }
        | new_field_declaring_list ','                                          // CFA, no field name
                { $$ = $1->appendList( $1->cloneType( 0 ) ); }
        ;

field_declaring_list:
        type_specifier field_declarator
                { $$ = $2->addType( $1 ); }
        | field_declaring_list ',' attribute_list_opt field_declarator
                { $$ = $1->appendList( $1->cloneBaseType( $4 ) ); }
        ;

field_declarator:
        // empty
                { $$ = DeclarationNode::newName( 0 ); /* XXX */ } // CFA, no field name
        | bit_subrange_size                                                                     // no field name
                { $$ = DeclarationNode::newBitfield( $1 ); }
        | variable_declarator bit_subrange_size_opt
                // A semantic check is required to ensure bit_subrange only appears on base type int.
                { $$ = $1->addBitfield( $2 ); }
        | variable_type_redeclarator bit_subrange_size_opt
                // A semantic check is required to ensure bit_subrange only appears on base type int.
                { $$ = $1->addBitfield( $2 ); }
        | variable_abstract_declarator                                          // CFA, no field name
        ;

bit_subrange_size_opt:
        // empty
                { $$ = 0; }
        | bit_subrange_size
                { $$ = $1; }
        ;

bit_subrange_size:
        ':' constant_expression
                { $$ = $2; }
        ;

enum_key:
        ENUM attribute_list_opt
        ;

enum_name:
        enum_key '{' enumerator_list comma_opt '}'
                { $$ = DeclarationNode::newEnum( nullptr, $3 ); }
        | enum_key no_attr_identifier_or_type_name
                {
                        typedefTable.makeTypedef( *$2 );
                        $$ = DeclarationNode::newEnum( $2, 0 );
                }
        | enum_key no_attr_identifier_or_type_name
                { typedefTable.makeTypedef( *$2 ); }
                '{' enumerator_list comma_opt '}'
                { $$ = DeclarationNode::newEnum( $2, $5 ); }
        ;

enumerator_list:
        no_attr_identifier_or_type_name enumerator_value_opt
                { $$ = DeclarationNode::newEnumConstant( $1, $2 ); }
        | enumerator_list ',' no_attr_identifier_or_type_name enumerator_value_opt
                { $$ = $1->appendList( DeclarationNode::newEnumConstant( $3, $4 ) ); }
        ;

enumerator_value_opt:
        // empty
                { $$ = 0; }
        | '=' constant_expression
                { $$ = $2; }
        ;

// Minimum of one parameter after which ellipsis is allowed only at the end.

new_parameter_type_list_opt:                                                    // CFA
        // empty
                { $$ = 0; }
        | new_parameter_type_list
        ;

new_parameter_type_list:                                                                // CFA, abstract + real
        new_abstract_parameter_list
        | new_parameter_list
        | new_parameter_list pop ',' push new_abstract_parameter_list
                { $$ = $1->appendList( $5 ); }
        | new_abstract_parameter_list pop ',' push ELLIPSIS
                { $$ = $1->addVarArgs(); }
        | new_parameter_list pop ',' push ELLIPSIS
                { $$ = $1->addVarArgs(); }
        ;

new_parameter_list:                                                                             // CFA
                // To obtain LR(1) between new_parameter_list and new_abstract_tuple, the last new_abstract_parameter_list is
                // factored out from new_parameter_list, flattening the rules to get lookahead to the ']'.
        new_parameter_declaration
        | new_abstract_parameter_list pop ',' push new_parameter_declaration
                { $$ = $1->appendList( $5 ); }
        | new_parameter_list pop ',' push new_parameter_declaration
                { $$ = $1->appendList( $5 ); }
        | new_parameter_list pop ',' push new_abstract_parameter_list pop ',' push new_parameter_declaration
                { $$ = $1->appendList( $5 )->appendList( $9 ); }
        ;

new_abstract_parameter_list:                                                    // CFA, new & old style abstract
        new_abstract_parameter_declaration
        | new_abstract_parameter_list pop ',' push new_abstract_parameter_declaration
                { $$ = $1->appendList( $5 ); }
        ;

parameter_type_list_opt:
        // empty
                { $$ = 0; }
        | parameter_type_list
        ;

parameter_type_list:
        parameter_list
        | parameter_list pop ',' push ELLIPSIS
                { $$ = $1->addVarArgs(); }
        ;

parameter_list:                                                                                 // abstract + real
        abstract_parameter_declaration
        | parameter_declaration
        | parameter_list pop ',' push abstract_parameter_declaration
                { $$ = $1->appendList( $5 ); }
        | parameter_list pop ',' push parameter_declaration
                { $$ = $1->appendList( $5 ); }
        ;

// Provides optional identifier names (abstract_declarator/variable_declarator), no initialization, different semantics
// for typedef name by using type_parameter_redeclarator instead of typedef_redeclarator, and function prototypes.

new_parameter_declaration:                                                              // CFA, new & old style parameter declaration
        parameter_declaration
        | new_identifier_parameter_declarator_no_tuple identifier_or_type_name assignment_opt
                { $$ = $1->addName( $2 ); }
        | new_abstract_tuple identifier_or_type_name assignment_opt
                // To obtain LR(1), these rules must be duplicated here (see new_abstract_declarator).
                { $$ = $1->addName( $2 ); }
        | type_qualifier_list new_abstract_tuple identifier_or_type_name assignment_opt
                { $$ = $2->addName( $3 )->addQualifiers( $1 ); }
        | new_function_specifier
        ;

new_abstract_parameter_declaration:                                             // CFA, new & old style parameter declaration
        abstract_parameter_declaration
        | new_identifier_parameter_declarator_no_tuple
        | new_abstract_tuple
                // To obtain LR(1), these rules must be duplicated here (see new_abstract_declarator).
        | type_qualifier_list new_abstract_tuple
                { $$ = $2->addQualifiers( $1 ); }
        | new_abstract_function
        ;

parameter_declaration:
        declaration_specifier identifier_parameter_declarator assignment_opt
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $2->addType( $1 )->addInitializer( new InitializerNode( $3 ) );
                }
        | declaration_specifier type_parameter_redeclarator assignment_opt
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        $$ = $2->addType( $1 )->addInitializer( new InitializerNode( $3 ) );
                }
        ;

abstract_parameter_declaration:
        declaration_specifier
        | declaration_specifier abstract_parameter_declarator
                { $$ = $2->addType( $1 ); }
        ;

// ISO/IEC 9899:1999 Section 6.9.1(6) : "An identifier declared as a typedef name shall not be redeclared as a
// parameter." Because the scope of the K&R-style parameter-list sees the typedef first, the following is based only on
// identifiers.  The ANSI-style parameter-list can redefine a typedef name.

identifier_list:                                                                                // K&R-style parameter list => no types
        no_attr_identifier
                { $$ = DeclarationNode::newName( $1 ); }
        | identifier_list ',' no_attr_identifier
                { $$ = $1->appendList( DeclarationNode::newName( $3 ) ); }
        ;

identifier_or_type_name:
        identifier
        | TYPEDEFname
        | TYPEGENname
        ;

no_01_identifier_or_type_name:
        no_01_identifier
        | TYPEDEFname
        | TYPEGENname
        ;

no_attr_identifier_or_type_name:
        no_attr_identifier
        | TYPEDEFname
        | TYPEGENname
        ;

type_name_no_function:                                                                  // sizeof, alignof, cast (constructor)
        new_abstract_declarator_tuple                                           // CFA
        | type_specifier
        | type_specifier variable_abstract_declarator
                { $$ = $2->addType( $1 ); }
        ;

type_name:                                                                                              // typeof, assertion
        new_abstract_declarator_tuple                                           // CFA
        | new_abstract_function                                                         // CFA
        | type_specifier
        | type_specifier abstract_declarator
                { $$ = $2->addType( $1 ); }
        ;

initializer_opt:
        // empty
                { $$ = 0; }
        | '=' initializer
                { $$ = $2; }
        | ATassign initializer
                { $$ = $2->set_maybeConstructed( false ); }
        ;

initializer:
        assignment_expression                                           { $$ = new InitializerNode( $1 ); }
        | '{' initializer_list comma_opt '}'            { $$ = new InitializerNode( $2, true ); }
        ;

initializer_list:
        // empty
                { $$ = 0; }
        | initializer
        | designation initializer                                       { $$ = $2->set_designators( $1 ); }
        | initializer_list ',' initializer                      { $$ = (InitializerNode *)( $1->set_last( $3 ) ); }
        | initializer_list ',' designation initializer
                { $$ = (InitializerNode *)( $1->set_last( $4->set_designators( $3 ) ) ); }
        ;

// There is an unreconcileable parsing problem between C99 and CFA with respect to designators. The problem is use of
// '=' to separator the designator from the initializer value, as in:
//
//              int x[10] = { [1] = 3 };
//
// The string "[1] = 3" can be parsed as a designator assignment or a tuple assignment.  To disambiguate this case, CFA
// changes the syntax from "=" to ":" as the separator between the designator and initializer. GCC does uses ":" for
// field selection. The optional use of the "=" in GCC, or in this case ":", cannot be supported either due to
// shift/reduce conflicts

designation:
        designator_list ':'                                                                     // C99, CFA uses ":" instead of "="
        | no_attr_identifier_or_type_name ':'                           // GCC, field name
                { $$ = new ExpressionNode( build_varref( $1 ) ); }
        ;

designator_list:                                                                                // C99
        designator
        | designator_list designator
                { $$ = (ExpressionNode *)( $1->set_last( $2 ) ); }
        //| designator_list designator                                          { $$ = new ExpressionNode( $1, $2 ); }
        ;

designator:
        '.' no_attr_identifier_or_type_name                                     // C99, field name
                { $$ = new ExpressionNode( build_varref( $2 ) ); }
        | '[' push assignment_expression pop ']'                        // C99, single array element
                // assignment_expression used instead of constant_expression because of shift/reduce conflicts with tuple.
                { $$ = $3; }
        | '[' push subrange pop ']'                                                     // CFA, multiple array elements
                { $$ = $3; }
        | '[' push constant_expression ELLIPSIS constant_expression pop ']' // GCC, multiple array elements
                { $$ = new ExpressionNode( build_range( $3, $5 ) ); }
        | '.' '[' push field_list pop ']'                                       // CFA, tuple field selector
                { $$ = $4; }
        ;

// The CFA type system is based on parametric polymorphism, the ability to declare functions with type parameters,
// rather than an object-oriented type system. This required four groups of extensions:
//
// Overloading: function, data, and operator identifiers may be overloaded.
//
// Type declarations: "type" is used to generate new types for declaring objects. Similarly, "dtype" is used for object
//     and incomplete types, and "ftype" is used for function types. Type declarations with initializers provide
//     definitions of new types. Type declarations with storage class "extern" provide opaque types.
//
// Polymorphic functions: A forall clause declares a type parameter. The corresponding argument is inferred at the call
//     site. A polymorphic function is not a template; it is a function, with an address and a type.
//
// Specifications and Assertions: Specifications are collections of declarations parameterized by one or more
//     types. They serve many of the purposes of abstract classes, and specification hierarchies resemble subclass
//     hierarchies. Unlike classes, they can define relationships between types.  Assertions declare that a type or
//     types provide the operations declared by a specification.  Assertions are normally used to declare requirements
//     on type arguments of polymorphic functions.

typegen_declaration_specifier:                                                  // CFA
        typegen_type_specifier
        | declaration_qualifier_list typegen_type_specifier
                { $$ = $2->addQualifiers( $1 ); }
        | typegen_declaration_specifier storage_class           // remaining OBSOLESCENT (see 2)
                { $$ = $1->addQualifiers( $2 ); }
        | typegen_declaration_specifier storage_class type_qualifier_list
                { $$ = $1->addQualifiers( $2 )->addQualifiers( $3 ); }
        ;

typegen_type_specifier:                                                                 // CFA
        typegen_name
        | type_qualifier_list typegen_name
                { $$ = $2->addQualifiers( $1 ); }
        | typegen_type_specifier type_qualifier
                { $$ = $1->addQualifiers( $2 ); }
        ;

typegen_name:                                                                                   // CFA
        TYPEGENname '(' type_name_list ')'
                { $$ = DeclarationNode::newFromTypeGen( $1, $3 ); }
        ;

type_parameter_list:                                                                    // CFA
        type_parameter assignment_opt
        | type_parameter_list ',' type_parameter assignment_opt
                { $$ = $1->appendList( $3 ); }
        ;

type_parameter:                                                                                 // CFA
        type_class no_attr_identifier_or_type_name
                { typedefTable.addToEnclosingScope( *$2, TypedefTable::TD ); }
          assertion_list_opt
                { $$ = DeclarationNode::newTypeParam( $1, $2 )->addAssertions( $4 ); }
        | type_specifier identifier_parameter_declarator
        ;

type_class:                                                                                             // CFA
        OTYPE
                { $$ = DeclarationNode::Otype; }
        | DTYPE
                { $$ = DeclarationNode::Ftype; }
        | FTYPE
                { $$ = DeclarationNode::Dtype; }
        ;

assertion_list_opt:                                                                             // CFA
        // empty
                { $$ = 0; }
        | assertion_list_opt assertion
                { $$ = $1 != 0 ? $1->appendList( $2 ) : $2; }
        ;

assertion:                                                                                              // CFA
        '|' no_attr_identifier_or_type_name '(' type_name_list ')'
                {
                        typedefTable.openTrait( *$2 );
                        $$ = DeclarationNode::newTraitUse( $2, $4 );
                }
        | '|' '{' push trait_declaration_list '}'
                { $$ = $4; }
        | '|' '(' push type_parameter_list pop ')' '{' push trait_declaration_list '}' '(' type_name_list ')'
                { $$ = 0; }
        ;

type_name_list:                                                                                 // CFA
        type_name
                { $$ = new ExpressionNode( build_typevalue( $1 ) ); }
        | assignment_expression
        | type_name_list ',' type_name
                { $$ = (ExpressionNode *)( $1->set_last( new ExpressionNode( build_typevalue( $3 ) ) ) ); }
        | type_name_list ',' assignment_expression
                { $$ = (ExpressionNode *)( $1->set_last( $3 )); }
        ;

type_declaring_list:                                                                    // CFA
        OTYPE type_declarator
                { $$ = $2; }
        | storage_class_list OTYPE type_declarator
                { $$ = $3->addQualifiers( $1 ); }
        | type_declaring_list ',' type_declarator
                { $$ = $1->appendList( $3->copyStorageClasses( $1 ) ); }
        ;

type_declarator:                                                                                // CFA
        type_declarator_name assertion_list_opt
                { $$ = $1->addAssertions( $2 ); }
        | type_declarator_name assertion_list_opt '=' type_name
                { $$ = $1->addAssertions( $2 )->addType( $4 ); }
        ;

type_declarator_name:                                                                   // CFA
        no_attr_identifier_or_type_name
                {
                        typedefTable.addToEnclosingScope( *$1, TypedefTable::TD );
                        $$ = DeclarationNode::newTypeDecl( $1, 0 );
                }
        | no_01_identifier_or_type_name '(' push type_parameter_list pop ')'
                {
                        typedefTable.addToEnclosingScope( *$1, TypedefTable::TG );
                        $$ = DeclarationNode::newTypeDecl( $1, $4 );
                }
        ;

trait_specifier:                                                                                // CFA
        TRAIT no_attr_identifier_or_type_name '(' push type_parameter_list pop ')' '{' '}'
                {
                        typedefTable.addToEnclosingScope( *$2, TypedefTable::ID );
                        $$ = DeclarationNode::newTrait( $2, $5, 0 );
                }
        | TRAIT no_attr_identifier_or_type_name '(' push type_parameter_list pop ')' '{'
                {
                        typedefTable.enterTrait( *$2 );
                        typedefTable.enterScope();
                }
          trait_declaration_list '}'
                {
                        typedefTable.leaveTrait();
                        typedefTable.addToEnclosingScope( *$2, TypedefTable::ID );
                        $$ = DeclarationNode::newTrait( $2, $5, $10 );
                }
        ;

trait_declaration_list:                                                         // CFA
        trait_declaration
        | trait_declaration_list push trait_declaration
                { $$ = $1->appendList( $3 ); }
        ;

trait_declaration:                                                                      // CFA
        new_trait_declaring_list pop ';'
        | trait_declaring_list pop ';'
        ;

new_trait_declaring_list:                                                               // CFA
        new_variable_specifier
                {
                        typedefTable.addToEnclosingScope2( TypedefTable::ID );
                        $$ = $1;
                }
        | new_function_specifier
                {
                        typedefTable.addToEnclosingScope2( TypedefTable::ID );
                        $$ = $1;
                }
        | new_trait_declaring_list pop ',' push identifier_or_type_name
                {
                        typedefTable.addToEnclosingScope2( *$5, TypedefTable::ID );
                        $$ = $1->appendList( $1->cloneType( $5 ) );
                }
        ;

trait_declaring_list:                                                                   // CFA
        type_specifier declarator
                {
                        typedefTable.addToEnclosingScope2( TypedefTable::ID );
                        $$ = $2->addType( $1 );
                }
        | trait_declaring_list pop ',' push declarator
                {
                        typedefTable.addToEnclosingScope2( TypedefTable::ID );
                        $$ = $1->appendList( $1->cloneBaseType( $5 ) );
                }
        ;

//***************************** EXTERNAL DEFINITIONS *****************************

translation_unit:
        // empty
                {}                                                                                              // empty input file
        | external_definition_list
                { parseTree = parseTree != nullptr ? parseTree->appendList( $1 ) : $1;  }
        ;

external_definition_list:
        external_definition
        | external_definition_list push external_definition
                { $$ = $1 != nullptr ? $1->appendList( $3 ) : $3; }
        ;

external_definition_list_opt:
        // empty
                { $$ = 0; }
        | external_definition_list
        ;

external_definition:
        declaration
        | external_function_definition
        | asm_statement                                                                         // GCC, global assembler statement
                {}
        | EXTERN STRINGliteral
                {
                        linkageStack.push( linkage );                           // handle nested extern "C"/"Cforall"
                        linkage = LinkageSpec::linkageCheck( $2 );
                }
          '{' external_definition_list_opt '}'                          // C++-style linkage specifier
                {
                        linkage = linkageStack.top();
                        linkageStack.pop();
                        $$ = $5;
                }
        | EXTENSION external_definition
                {       // mark all fields in list
                        for ( DeclarationNode *iter = $2; iter != nullptr; iter = (DeclarationNode *)iter->get_next() )
                                iter->set_extension( true );
                        $$ = $2;
                }
        ;

external_function_definition:
        function_definition
                // These rules are a concession to the "implicit int" type_specifier because there is a significant amount of
                // legacy code with global functions missing the type-specifier for the return type, and assuming "int".
                // Parsing is possible because function_definition does not appear in the context of an expression (nested
                // functions preclude this concession, i.e., all nested function must have a return type). A function prototype
                // declaration must still have a type_specifier.  OBSOLESCENT (see 1)
        | function_declarator compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $1->addFunctionBody( $2 );
                }
        | old_function_declarator push old_declaration_list_opt compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $1->addOldDeclList( $3 )->addFunctionBody( $4 );
                }
        ;

function_definition:
        new_function_declaration compound_statement                     // CFA
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $1->addFunctionBody( $2 );
                }
        | declaration_specifier function_declarator compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $2->addFunctionBody( $3 )->addType( $1 );
                }
        | type_qualifier_list function_declarator compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $2->addFunctionBody( $3 )->addQualifiers( $1 );
                }
        | declaration_qualifier_list function_declarator compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $2->addFunctionBody( $3 )->addQualifiers( $1 );
                }
        | declaration_qualifier_list type_qualifier_list function_declarator compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $3->addFunctionBody( $4 )->addQualifiers( $2 )->addQualifiers( $1 );
                }

                // Old-style K&R function definition, OBSOLESCENT (see 4)
        | declaration_specifier old_function_declarator push old_declaration_list_opt compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $2->addOldDeclList( $4 )->addFunctionBody( $5 )->addType( $1 );
                }
        | type_qualifier_list old_function_declarator push old_declaration_list_opt compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $2->addOldDeclList( $4 )->addFunctionBody( $5 )->addQualifiers( $1 );
                }

                // Old-style K&R function definition with "implicit int" type_specifier, OBSOLESCENT (see 4)
        | declaration_qualifier_list old_function_declarator push old_declaration_list_opt compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $2->addOldDeclList( $4 )->addFunctionBody( $5 )->addQualifiers( $1 );
                }
        | declaration_qualifier_list type_qualifier_list old_function_declarator push old_declaration_list_opt compound_statement
                {
                        typedefTable.addToEnclosingScope( TypedefTable::ID );
                        typedefTable.leaveScope();
                        $$ = $3->addOldDeclList( $5 )->addFunctionBody( $6 )->addQualifiers( $2 )->addQualifiers( $1 );
                }
        ;

declarator:
        variable_declarator
        | variable_type_redeclarator
        | function_declarator
        ;

subrange:
        constant_expression '~' constant_expression                     // CFA, integer subrange
                { $$ = new ExpressionNode( build_range( $1, $3 ) ); }
        ;

asm_name_opt:                                                                                   // GCC
        // empty
        | ASM '(' string_literal_list ')' attribute_list_opt { delete $3; }     // FIX ME: unimplemented
        ;

attribute_list_opt:                                                                             // GCC
        // empty
                { $$ = 0; }
        | attribute_list
        ;

attribute_list:                                                                                 // GCC
        attribute
        | attribute_list attribute
                { $$ = $2->addQualifiers( $1 ); }
        ;

attribute:                                                                                              // GCC
        ATTRIBUTE '(' '(' attribute_parameter_list ')' ')'
        //              { $$ = DeclarationNode::newQualifier( DeclarationNode::Attribute ); }
                { $$ = 0; }
        ;

attribute_parameter_list:                                                               // GCC
        attrib
        | attribute_parameter_list ',' attrib
        ;

attrib:                                                                                                 // GCC
        // empty
        | any_word
        | any_word '(' comma_expression_opt ')' { delete $3; } // FIX ME: unimplemented
        ;

any_word:                                                                                               // GCC
        identifier_or_type_name { delete $1; }                          // FIX ME: unimplemented
        | storage_class { delete $1; }                                          // FIX ME: unimplemented
        | basic_type_name { delete $1; }                                        // FIX ME: unimplemented
        | type_qualifier { delete $1; }                                         // FIX ME: unimplemented
        ;

// ============================================================================
// The following sections are a series of grammar patterns used to parse declarators. Multiple patterns are necessary
// because the type of an identifier in wrapped around the identifier in the same form as its usage in an expression, as
// in:
//
//              int (*f())[10] { ... };
//              ... (*f())[3] += 1;             // definition mimics usage
//
// Because these patterns are highly recursive, changes at a lower level in the recursion require copying some or all of
// the pattern. Each of these patterns has some subtle variation to ensure correct syntax in a particular context.
// ============================================================================

// ----------------------------------------------------------------------------
// The set of valid declarators before a compound statement for defining a function is less than the set of declarators
// to define a variable or function prototype, e.g.:
//
//              valid declaration               invalid definition
//              -----------------               ------------------
//              int f;                                  int f {}
//              int *f;                                 int *f {}
//              int f[10];                              int f[10] {}
//              int (*f)(int);                  int (*f)(int) {}
//
// To preclude this syntactic anomaly requires separating the grammar rules for variable and function declarators, hence
// variable_declarator and function_declarator.
// ----------------------------------------------------------------------------

// This pattern parses a declaration of a variable that is not redefining a typedef name. The pattern precludes
// declaring an array of functions versus a pointer to an array of functions.

variable_declarator:
        paren_identifier attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | variable_ptr
        | variable_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | variable_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

paren_identifier:
        identifier
                {
                        typedefTable.setNextIdentifier( *$1 );
                        $$ = DeclarationNode::newName( $1 );
                }
        | '(' paren_identifier ')'                                                      // redundant parenthesis
                { $$ = $2; }
        ;

variable_ptr:
        ptrref_operator variable_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list variable_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' variable_ptr ')'
                { $$ = $2; }
        ;

variable_array:
        paren_identifier array_dimension
                { $$ = $1->addArray( $2 ); }
        | '(' variable_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' variable_array ')' multi_array_dimension          // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' variable_array ')'                                                        // redundant parenthesis
                { $$ = $2; }
        ;

variable_function:
        '(' variable_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        | '(' variable_function ')'                                                     // redundant parenthesis
                { $$ = $2; }
        ;

// This pattern parses a function declarator that is not redefining a typedef name. For non-nested functions, there is
// no context where a function definition can redefine a typedef name, i.e., the typedef and function name cannot exist
// is the same scope.  The pattern precludes returning arrays and functions versus pointers to arrays and functions.

function_declarator:
        function_no_ptr attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | function_ptr
        | function_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

function_no_ptr:
        paren_identifier '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $1->addParamList( $4 ); }
        | '(' function_ptr ')' '(' push parameter_type_list_opt pop ')'
                { $$ = $2->addParamList( $6 ); }
        | '(' function_no_ptr ')'                                                       // redundant parenthesis
                { $$ = $2; }
        ;

function_ptr:
        ptrref_operator function_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list function_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' function_ptr ')'
                { $$ = $2; }
        ;

function_array:
        '(' function_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' function_array ')' multi_array_dimension          // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' function_array ')'                                                        // redundant parenthesis
                { $$ = $2; }
        ;

// This pattern parses an old-style K&R function declarator (OBSOLESCENT, see 4) that is not redefining a typedef name
// (see function_declarator for additional comments). The pattern precludes returning arrays and functions versus
// pointers to arrays and functions.

old_function_declarator:
        old_function_no_ptr
        | old_function_ptr
        | old_function_array
        ;

old_function_no_ptr:
        paren_identifier '(' identifier_list ')'                        // function_declarator handles empty parameter
                { $$ = $1->addIdList( $3 ); }
        | '(' old_function_ptr ')' '(' identifier_list ')'
                { $$ = $2->addIdList( $5 ); }
        | '(' old_function_no_ptr ')'                                           // redundant parenthesis
                { $$ = $2; }
        ;

old_function_ptr:
        ptrref_operator old_function_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list old_function_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' old_function_ptr ')'
                { $$ = $2; }
        ;

old_function_array:
        '(' old_function_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' old_function_array ')' multi_array_dimension      // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' old_function_array ')'                                            // redundant parenthesis
                { $$ = $2; }
        ;

// This pattern parses a declaration for a variable or function prototype that redefines a type name, e.g.:
//
//              typedef int foo;
//              {
//                 int foo; // redefine typedef name in new scope
//              }
//
// The pattern precludes declaring an array of functions versus a pointer to an array of functions, and returning arrays
// and functions versus pointers to arrays and functions.

variable_type_redeclarator:
        paren_type attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | type_ptr
        | type_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | type_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

paren_type:
        typedef
        | '(' paren_type ')'
                { $$ = $2; }
        ;

type_ptr:
        ptrref_operator variable_type_redeclarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list variable_type_redeclarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' type_ptr ')'
                { $$ = $2; }
        ;

type_array:
        paren_type array_dimension
                { $$ = $1->addArray( $2 ); }
        | '(' type_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' type_array ')' multi_array_dimension                      // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' type_array ')'                                                            // redundant parenthesis
                { $$ = $2; }
        ;

type_function:
        paren_type '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $1->addParamList( $4 ); }
        | '(' type_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        | '(' type_function ')'                                                         // redundant parenthesis
                { $$ = $2; }
        ;

// This pattern parses a declaration for a parameter variable or function prototype that is not redefining a typedef
// name and allows the C99 array options, which can only appear in a parameter list.  The pattern precludes declaring an
// array of functions versus a pointer to an array of functions, and returning arrays and functions versus pointers to
// arrays and functions.

identifier_parameter_declarator:
        paren_identifier attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | identifier_parameter_ptr
        | identifier_parameter_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | identifier_parameter_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

identifier_parameter_ptr:
        ptrref_operator identifier_parameter_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list identifier_parameter_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' identifier_parameter_ptr ')'
                { $$ = $2; }
        ;

identifier_parameter_array:
        paren_identifier array_parameter_dimension
                { $$ = $1->addArray( $2 ); }
        | '(' identifier_parameter_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' identifier_parameter_array ')' multi_array_dimension // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' identifier_parameter_array ')'                            // redundant parenthesis
                { $$ = $2; }
        ;

identifier_parameter_function:
        paren_identifier '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $1->addParamList( $4 ); }
        | '(' identifier_parameter_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        | '(' identifier_parameter_function ')'                         // redundant parenthesis
                { $$ = $2; }
        ;

// This pattern parses a declaration for a parameter variable or function prototype that is redefining a typedef name,
// e.g.:
//
//              typedef int foo;
//              int f( int foo ); // redefine typedef name in new scope
//
// and allows the C99 array options, which can only appear in a parameter list.  In addition, the pattern handles the
// special meaning of parenthesis around a typedef name:
//
//              ISO/IEC 9899:1999 Section 6.7.5.3(11) : "In a parameter declaration, a single typedef name in
//              parentheses is taken to be an abstract declarator that specifies a function with a single parameter,
//              not as redundant parentheses around the identifier."
//
// For example:
//
//              typedef float T;
//              int f( int ( T [5] ) );                                 // see abstract_parameter_declarator
//              int g( int ( T ( int ) ) );                             // see abstract_parameter_declarator
//              int f( int f1( T a[5] ) );                              // see identifier_parameter_declarator
//              int g( int g1( T g2( int p ) ) );               // see identifier_parameter_declarator
//
// In essence, a '(' immediately to the left of typedef name, T, is interpreted as starting a parameter type list, and
// not as redundant parentheses around a redeclaration of T. Finally, the pattern also precludes declaring an array of
// functions versus a pointer to an array of functions, and returning arrays and functions versus pointers to arrays and
// functions.

type_parameter_redeclarator:
        typedef attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | type_parameter_ptr
        | type_parameter_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | type_parameter_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

typedef:
        TYPEDEFname
                {
                        typedefTable.setNextIdentifier( *$1 );
                        $$ = DeclarationNode::newName( $1 );
                }
        | TYPEGENname
                {
                        typedefTable.setNextIdentifier( *$1 );
                        $$ = DeclarationNode::newName( $1 );
                }
        ;

type_parameter_ptr:
        ptrref_operator type_parameter_redeclarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list type_parameter_redeclarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' type_parameter_ptr ')'
                { $$ = $2; }
        ;

type_parameter_array:
        typedef array_parameter_dimension
                { $$ = $1->addArray( $2 ); }
        | '(' type_parameter_ptr ')' array_parameter_dimension
                { $$ = $2->addArray( $4 ); }
        ;

type_parameter_function:
        typedef '(' push parameter_type_list_opt pop ')'        // empty parameter list OBSOLESCENT (see 3)
                { $$ = $1->addParamList( $4 ); }
        | '(' type_parameter_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        ;

// This pattern parses a declaration of an abstract variable or function prototype, i.e., there is no identifier to
// which the type applies, e.g.:
//
//              sizeof( int );
//              sizeof( int [10] );
//
// The pattern precludes declaring an array of functions versus a pointer to an array of functions, and returning arrays
// and functions versus pointers to arrays and functions.

abstract_declarator:
        abstract_ptr
        | abstract_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | abstract_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

abstract_ptr:
        ptrref_operator
                { $$ = DeclarationNode::newPointer( 0 ); }
        | ptrref_operator type_qualifier_list
                { $$ = DeclarationNode::newPointer( $2 ); }
        | ptrref_operator abstract_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list abstract_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' abstract_ptr ')'
                { $$ = $2; }
        ;

abstract_array:
        array_dimension
        | '(' abstract_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' abstract_array ')' multi_array_dimension          // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' abstract_array ')'                                                        // redundant parenthesis
                { $$ = $2; }
        ;

abstract_function:
        '(' push parameter_type_list_opt pop ')'                        // empty parameter list OBSOLESCENT (see 3)
                { $$ = DeclarationNode::newFunction( nullptr, nullptr, $3, nullptr ); }
        | '(' abstract_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        | '(' abstract_function ')'                                                     // redundant parenthesis
                { $$ = $2; }
        ;

array_dimension:
                // Only the first dimension can be empty.
        '[' ']'
                { $$ = DeclarationNode::newArray( 0, 0, false ); }
        | '[' ']' multi_array_dimension
                { $$ = DeclarationNode::newArray( 0, 0, false )->addArray( $3 ); }
        | multi_array_dimension
        ;

multi_array_dimension:
        '[' push assignment_expression pop ']'
                { $$ = DeclarationNode::newArray( $3, 0, false ); }
        | '[' push '*' pop ']'                                                          // C99
                { $$ = DeclarationNode::newVarArray( 0 ); }
        | multi_array_dimension '[' push assignment_expression pop ']'
                { $$ = $1->addArray( DeclarationNode::newArray( $4, 0, false ) ); }
        | multi_array_dimension '[' push '*' pop ']'            // C99
                { $$ = $1->addArray( DeclarationNode::newVarArray( 0 ) ); }
        ;

// This pattern parses a declaration of a parameter abstract variable or function prototype, i.e., there is no
// identifier to which the type applies, e.g.:
//
//              int f( int );                   // abstract variable parameter; no parameter name specified
//              int f( int (int) );             // abstract function-prototype parameter; no parameter name specified
//
// The pattern precludes declaring an array of functions versus a pointer to an array of functions, and returning arrays
// and functions versus pointers to arrays and functions.

abstract_parameter_declarator:
        abstract_parameter_ptr
        | abstract_parameter_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | abstract_parameter_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

abstract_parameter_ptr:
        ptrref_operator
                { $$ = DeclarationNode::newPointer( 0 ); }
        | ptrref_operator type_qualifier_list
                { $$ = DeclarationNode::newPointer( $2 ); }
        | ptrref_operator abstract_parameter_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list abstract_parameter_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' abstract_parameter_ptr ')'
                { $$ = $2; }
        ;

abstract_parameter_array:
        array_parameter_dimension
        | '(' abstract_parameter_ptr ')' array_parameter_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' abstract_parameter_array ')' multi_array_dimension // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' abstract_parameter_array ')'                                      // redundant parenthesis
                { $$ = $2; }
        ;

abstract_parameter_function:
        '(' push parameter_type_list_opt pop ')'                        // empty parameter list OBSOLESCENT (see 3)
                { $$ = DeclarationNode::newFunction( nullptr, nullptr, $3, nullptr ); }
        | '(' abstract_parameter_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        | '(' abstract_parameter_function ')'                           // redundant parenthesis
                { $$ = $2; }
        ;

array_parameter_dimension:
                // Only the first dimension can be empty or have qualifiers.
        array_parameter_1st_dimension
        | array_parameter_1st_dimension multi_array_dimension
                { $$ = $1->addArray( $2 ); }
        | multi_array_dimension
        ;

// The declaration of an array parameter has additional syntax over arrays in normal variable declarations:
//
//              ISO/IEC 9899:1999 Section 6.7.5.2(1) : "The optional type qualifiers and the keyword static shall appear only in
//              a declaration of a function parameter with an array type, and then only in the outermost array type derivation."

array_parameter_1st_dimension:
        '[' ']'
                { $$ = DeclarationNode::newArray( 0, 0, false ); }
        // multi_array_dimension handles the '[' '*' ']' case
        | '[' push type_qualifier_list '*' pop ']'                      // remaining C99
                { $$ = DeclarationNode::newVarArray( $3 ); }
        | '[' push type_qualifier_list pop ']'
                { $$ = DeclarationNode::newArray( 0, $3, false ); }
        // multi_array_dimension handles the '[' assignment_expression ']' case
        | '[' push type_qualifier_list assignment_expression pop ']'
                { $$ = DeclarationNode::newArray( $4, $3, false ); }
        | '[' push STATIC type_qualifier_list_opt assignment_expression pop ']'
                { $$ = DeclarationNode::newArray( $5, $4, true ); }
        | '[' push type_qualifier_list STATIC assignment_expression pop ']'
                { $$ = DeclarationNode::newArray( $5, $3, true ); }
        ;

// This pattern parses a declaration of an abstract variable, i.e., there is no identifier to which the type applies,
// e.g.:
//
//              sizeof( int ); // abstract variable; no identifier name specified
//
// The pattern precludes declaring an array of functions versus a pointer to an array of functions, and returning arrays
// and functions versus pointers to arrays and functions.

variable_abstract_declarator:
        variable_abstract_ptr
        | variable_abstract_array attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        | variable_abstract_function attribute_list_opt
                { $$ = $1->addQualifiers( $2 ); }
        ;

variable_abstract_ptr:
        ptrref_operator
                { $$ = DeclarationNode::newPointer( 0 ); }
        | ptrref_operator type_qualifier_list
                { $$ = DeclarationNode::newPointer( $2 ); }
        | ptrref_operator variable_abstract_declarator
                { $$ = $2->addPointer( DeclarationNode::newPointer( 0 ) ); }
        | ptrref_operator type_qualifier_list variable_abstract_declarator
                { $$ = $3->addPointer( DeclarationNode::newPointer( $2 ) ); }
        | '(' variable_abstract_ptr ')'
                { $$ = $2; }
        ;

variable_abstract_array:
        array_dimension
        | '(' variable_abstract_ptr ')' array_dimension
                { $$ = $2->addArray( $4 ); }
        | '(' variable_abstract_array ')' multi_array_dimension // redundant parenthesis
                { $$ = $2->addArray( $4 ); }
        | '(' variable_abstract_array ')'                                       // redundant parenthesis
                { $$ = $2; }
        ;

variable_abstract_function:
        '(' variable_abstract_ptr ')' '(' push parameter_type_list_opt pop ')' // empty parameter list OBSOLESCENT (see 3)
                { $$ = $2->addParamList( $6 ); }
        | '(' variable_abstract_function ')'                            // redundant parenthesis
                { $$ = $2; }
        ;

// This pattern parses a new-style declaration for a parameter variable or function prototype that is either an
// identifier or typedef name and allows the C99 array options, which can only appear in a parameter list.

new_identifier_parameter_declarator_tuple:                              // CFA
        new_identifier_parameter_declarator_no_tuple
        | new_abstract_tuple
        | type_qualifier_list new_abstract_tuple
                { $$ = $2->addQualifiers( $1 ); }
        ;

new_identifier_parameter_declarator_no_tuple:                   // CFA
        new_identifier_parameter_ptr
        | new_identifier_parameter_array
        ;

new_identifier_parameter_ptr:                                                   // CFA
        ptrref_operator type_specifier
                { $$ = $2->addNewPointer( DeclarationNode::newPointer( 0 ) ); }
        | type_qualifier_list ptrref_operator type_specifier
                { $$ = $3->addNewPointer( DeclarationNode::newPointer( $1 ) ); }
        | ptrref_operator new_abstract_function
                { $$ = $2->addNewPointer( DeclarationNode::newPointer( 0 ) ); }
        | type_qualifier_list ptrref_operator new_abstract_function
                { $$ = $3->addNewPointer( DeclarationNode::newPointer( $1 ) ); }
        | ptrref_operator new_identifier_parameter_declarator_tuple
                { $$ = $2->addNewPointer( DeclarationNode::newPointer( 0 ) ); }
        | type_qualifier_list ptrref_operator new_identifier_parameter_declarator_tuple
                { $$ = $3->addNewPointer( DeclarationNode::newPointer( $1 ) ); }
        ;

new_identifier_parameter_array:                                                 // CFA
                // Only the first dimension can be empty or have qualifiers. Empty dimension must be factored out due to
                // shift/reduce conflict with new-style empty (void) function return type.
        '[' ']' type_specifier
                { $$ = $3->addNewArray( DeclarationNode::newArray( 0, 0, false ) ); }
        | new_array_parameter_1st_dimension type_specifier
                { $$ = $2->addNewArray( $1 ); }
        | '[' ']' multi_array_dimension type_specifier
                { $$ = $4->addNewArray( $3 )->addNewArray( DeclarationNode::newArray( 0, 0, false ) ); }
        | new_array_parameter_1st_dimension multi_array_dimension type_specifier
                { $$ = $3->addNewArray( $2 )->addNewArray( $1 ); }
        | multi_array_dimension type_specifier
                { $$ = $2->addNewArray( $1 ); }

        | '[' ']' new_identifier_parameter_ptr
                { $$ = $3->addNewArray( DeclarationNode::newArray( 0, 0, false ) ); }
        | new_array_parameter_1st_dimension new_identifier_parameter_ptr
                { $$ = $2->addNewArray( $1 ); }
        | '[' ']' multi_array_dimension new_identifier_parameter_ptr
                { $$ = $4->addNewArray( $3 )->addNewArray( DeclarationNode::newArray( 0, 0, false ) ); }
        | new_array_parameter_1st_dimension multi_array_dimension new_identifier_parameter_ptr
                { $$ = $3->addNewArray( $2 )->addNewArray( $1 ); }
        | multi_array_dimension new_identifier_parameter_ptr
                { $$ = $2->addNewArray( $1 ); }
        ;

new_array_parameter_1st_dimension:
        '[' push type_qualifier_list '*' pop ']'                        // remaining C99
                { $$ = DeclarationNode::newVarArray( $3 ); }
        | '[' push type_qualifier_list assignment_expression pop ']'
                { $$ = DeclarationNode::newArray( $4, $3, false ); }
        | '[' push declaration_qualifier_list assignment_expression pop ']'
                // declaration_qualifier_list must be used because of shift/reduce conflict with
                // assignment_expression, so a semantic check is necessary to preclude them as a type_qualifier cannot
                // appear in this context.
                { $$ = DeclarationNode::newArray( $4, $3, true ); }
        | '[' push declaration_qualifier_list type_qualifier_list assignment_expression pop ']'
                { $$ = DeclarationNode::newArray( $5, $4->addQualifiers( $3 ), true ); }
        ;

// This pattern parses a new-style declaration of an abstract variable or function prototype, i.e., there is no
// identifier to which the type applies, e.g.:
//
//              [int] f( int );                         // abstract variable parameter; no parameter name specified
//              [int] f( [int] (int) );         // abstract function-prototype parameter; no parameter name specified
//
// These rules need LR(3):
//
//              new_abstract_tuple identifier_or_type_name
//              '[' new_parameter_list ']' identifier_or_type_name '(' new_parameter_type_list_opt ')'
//
// since a function return type can be syntactically identical to a tuple type:
//
//              [int, int] t;
//              [int, int] f( int );
//
// Therefore, it is necessary to look at the token after identifier_or_type_name to know when to reduce
// new_abstract_tuple. To make this LR(1), several rules have to be flattened (lengthened) to allow the necessary
// lookahead. To accomplish this, new_abstract_declarator has an entry point without tuple, and tuple declarations are
// duplicated when appearing with new_function_specifier.

new_abstract_declarator_tuple:                                                  // CFA
        new_abstract_tuple
        | type_qualifier_list new_abstract_tuple
                { $$ = $2->addQualifiers( $1 ); }
        | new_abstract_declarator_no_tuple
        ;

new_abstract_declarator_no_tuple:                                               // CFA
        new_abstract_ptr
        | new_abstract_array
        ;

new_abstract_ptr:                                                                               // CFA
        ptrref_operator type_specifier
                { $$ = $2->addNewPointer( DeclarationNode::newPointer( 0 ) ); }
        | type_qualifier_list ptrref_operator type_specifier
                { $$ = $3->addNewPointer( DeclarationNode::newPointer( $1 ) ); }
        | ptrref_operator new_abstract_function
                { $$ = $2->addNewPointer( DeclarationNode::newPointer( 0 ) ); }
        | type_qualifier_list ptrref_operator new_abstract_function
                { $$ = $3->addNewPointer( DeclarationNode::newPointer( $1 ) ); }
        | ptrref_operator new_abstract_declarator_tuple
                { $$ = $2->addNewPointer( DeclarationNode::newPointer( 0 ) ); }
        | type_qualifier_list ptrref_operator new_abstract_declarator_tuple
                { $$ = $3->addNewPointer( DeclarationNode::newPointer( $1 ) ); }
        ;

new_abstract_array:                                                                             // CFA
                // Only the first dimension can be empty. Empty dimension must be factored out due to shift/reduce conflict with
                // empty (void) function return type.
        '[' ']' type_specifier
                { $$ = $3->addNewArray( DeclarationNode::newArray( nullptr, nullptr, false ) ); }
        | '[' ']' multi_array_dimension type_specifier
                { $$ = $4->addNewArray( $3 )->addNewArray( DeclarationNode::newArray( nullptr, nullptr, false ) ); }
        | multi_array_dimension type_specifier
                { $$ = $2->addNewArray( $1 ); }
        | '[' ']' new_abstract_ptr
                { $$ = $3->addNewArray( DeclarationNode::newArray( nullptr, nullptr, false ) ); }
        | '[' ']' multi_array_dimension new_abstract_ptr
                { $$ = $4->addNewArray( $3 )->addNewArray( DeclarationNode::newArray( nullptr, nullptr, false ) ); }
        | multi_array_dimension new_abstract_ptr
                { $$ = $2->addNewArray( $1 ); }
        ;

new_abstract_tuple:                                                                             // CFA
        '[' push new_abstract_parameter_list pop ']'
                { $$ = DeclarationNode::newTuple( $3 ); }
        ;

new_abstract_function:                                                                  // CFA
        '[' ']' '(' new_parameter_type_list_opt ')'
                { $$ = DeclarationNode::newFunction( nullptr, DeclarationNode::newTuple( nullptr ), $4, nullptr ); }
        | new_abstract_tuple '(' push new_parameter_type_list_opt pop ')'
                { $$ = DeclarationNode::newFunction( nullptr, $1, $4, nullptr ); }
        | new_function_return '(' push new_parameter_type_list_opt pop ')'
                { $$ = DeclarationNode::newFunction( nullptr, $1, $4, nullptr ); }
        ;

// 1) ISO/IEC 9899:1999 Section 6.7.2(2) : "At least one type specifier shall be given in the declaration specifiers in
//    each declaration, and in the specifier-qualifier list in each structure declaration and type name."
//
// 2) ISO/IEC 9899:1999 Section 6.11.5(1) : "The placement of a storage-class specifier other than at the beginning of
//    the declaration specifiers in a declaration is an obsolescent feature."
//
// 3) ISO/IEC 9899:1999 Section 6.11.6(1) : "The use of function declarators with empty parentheses (not
//    prototype-format parameter type declarators) is an obsolescent feature."
//
// 4) ISO/IEC 9899:1999 Section 6.11.7(1) : "The use of function definitions with separate parameter identifier and
//    declaration lists (not prototype-format parameter type and identifier declarators) is an obsolescent feature.

//************************* MISCELLANEOUS ********************************

comma_opt:                                                                                              // redundant comma
        // empty
        | ','
        ;

assignment_opt:
        // empty
                { $$ = 0; }
        | '=' assignment_expression
                { $$ = $2; }
        ;

%%
// ----end of grammar----

extern char *yytext;

void yyerror( const char * ) {
        cout << "Error ";
        if ( yyfilename ) {
                cout << "in file " << yyfilename << " ";
        } // if
        cout << "at line " << yylineno << " reading token \"" << (yytext[0] == '\0' ? "EOF" : yytext) << "\"" << endl;
}

// Local Variables: //
// mode: c++ //
// tab-width: 4 //
// compile-command: "make install" //
// End: //