gcc2.9.txt

编译原理中的First集与 Follow集生成程序

		  if ($$ != error_mark_node)
                    C_SET_EXP_ORIGINAL_CODE ($$, MODIFY_EXPR); }
	| expr_no_commas ASSIGN expr_no_commas
		{ $$ = build_x_modify_expr ($$, $2, $3); }
	| THROW
		{ $$ = build_throw (NULL_TREE); }
	| THROW expr_no_commas
		{ $$ = build_throw ($2); }
/* These extensions are not defined.  The second arg to build_m_component_ref
   is old, build_m_component_ref now does an implicit
   build_indirect_ref (x, NULL_PTR) on the second argument.
	| object '&' expr_no_commas  %prec UNARY
		{ $$ = build_m_component_ref ($$, build_x_unary_op (ADDR_EXPR, $3)); }
	| object unop expr_no_commas  %prec UNARY
		{ $$ = build_m_component_ref ($$, build_x_unary_op ($2, $3)); }
	| object '(' type_id ')' expr_no_commas  %prec UNARY
		{ tree type = groktypename ($3.t);
		  $$ = build_m_component_ref ($$, build_c_cast (type, $5)); }
	| object primary_no_id  %prec UNARY
		{ $$ = build_m_component_ref ($$, $2); }
*/
	;

notype_unqualified_id:
	  '~' see_typename identifier
		{ $$ = build_parse_node (BIT_NOT_EXPR, $3); }
	| '~' see_typename template_type
		{ $$ = build_parse_node (BIT_NOT_EXPR, $3); }
        | template_id
	| operator_name
	| IDENTIFIER
	| PTYPENAME
	| NSNAME  %prec EMPTY
	;

do_id:
		{
		  /* If lastiddecl is a TREE_LIST, it's a baselink, which
		     means that we're in an expression like S::f<int>, so
		     don't do_identifier; we only do that for unqualified
		     identifiers.  */
		  if (lastiddecl && TREE_CODE (lastiddecl) != TREE_LIST)
		    $$ = do_identifier ($<ttype>-1, 1, NULL_TREE);
		  else
		    $$ = $<ttype>-1;
		}
    ;
    
template_id:
          PFUNCNAME '<' do_id template_arg_list_opt template_close_bracket 
                { $$ = lookup_template_function ($3, $4); }
        | operator_name '<' do_id template_arg_list_opt template_close_bracket
                { $$ = lookup_template_function ($3, $4); }
	;

object_template_id:
        TEMPLATE identifier '<' template_arg_list_opt template_close_bracket
                { $$ = lookup_template_function ($2, $4); }
        | TEMPLATE PFUNCNAME '<' template_arg_list_opt template_close_bracket
                { $$ = lookup_template_function ($2, $4); }
        | TEMPLATE operator_name '<' template_arg_list_opt 
          template_close_bracket
                { $$ = lookup_template_function ($2, $4); }
        ;

unqualified_id:
	  notype_unqualified_id
	| TYPENAME
	| SELFNAME
	;

expr_or_declarator_intern:
	  expr_or_declarator
	| attributes expr_or_declarator
		{
		  /* Provide support for '(' attributes '*' declarator ')'
		     etc */
		  $$ = decl_tree_cons ($1, $2, NULL_TREE);
		}
	;

expr_or_declarator:
	  notype_unqualified_id
	| '*' expr_or_declarator_intern  %prec UNARY
		{ $$ = build_parse_node (INDIRECT_REF, $2); }
	| '&' expr_or_declarator_intern  %prec UNARY
		{ $$ = build_parse_node (ADDR_EXPR, $2); }
	| '(' expr_or_declarator_intern ')'
		{ $$ = $2; }
	;

notype_template_declarator:
	  IDENTIFIER '<' template_arg_list_opt template_close_bracket
                { $$ = lookup_template_function ($1, $3); }
	| NSNAME '<' template_arg_list template_close_bracket
                { $$ = lookup_template_function ($1, $3); }
	;
		
direct_notype_declarator:
	  complex_direct_notype_declarator
	/* This precedence declaration is to prefer this reduce
	   to the Koenig lookup shift in primary, below.  I hate yacc.  */
	| notype_unqualified_id %prec '('
	| notype_template_declarator
	| '(' expr_or_declarator_intern ')'
                { $$ = finish_decl_parsing ($2); }
	;

primary:
	  notype_unqualified_id
		{
		  if (TREE_CODE ($1) == BIT_NOT_EXPR)
		    $$ = build_x_unary_op (BIT_NOT_EXPR, TREE_OPERAND ($1, 0));
		  else 
		    $$ = finish_id_expr ($1);
		}		
	| CONSTANT
	| boolean.literal
	| string
		{
		  if (processing_template_decl)
		    push_obstacks (&permanent_obstack, &permanent_obstack);
		  $$ = combine_strings ($$);
		  /* combine_strings doesn't set up TYPE_MAIN_VARIANT of
		     a const array the way we want, so fix it.  */
		  if (flag_const_strings)
		    TREE_TYPE ($$) = build_cplus_array_type
		      (TREE_TYPE (TREE_TYPE ($$)),
		       TYPE_DOMAIN (TREE_TYPE ($$)));
		  if (processing_template_decl)
		    pop_obstacks ();
		}
	| '(' expr ')'
		{ $$ = finish_parenthesized_expr ($2); }
	| '(' expr_or_declarator_intern ')'
		{ $2 = reparse_decl_as_expr (NULL_TREE, $2);
		  $$ = finish_parenthesized_expr ($2); }
	| '(' error ')'
		{ $$ = error_mark_node; }
	| '('
		{ tree scope = current_scope ();
		  if (!scope || TREE_CODE (scope) != FUNCTION_DECL)
		    {
		      error ("braced-group within expression allowed only inside a function");
		      YYERROR;
		    }
		  if (pedantic)
		    pedwarn ("ANSI C++ forbids braced-groups within expressions");  
		  $<ttype>$ = begin_stmt_expr (); 
		}
	  compstmt ')'
               { $$ = finish_stmt_expr ($<ttype>2, $3); }
        /* Koenig lookup support
           We could store lastiddecl in $1 to avoid another lookup,
           but that would result in many additional reduce/reduce conflicts. */
        | notype_unqualified_id '(' nonnull_exprlist ')'
               { $$ = finish_call_expr ($1, $3, 1); }
        | notype_unqualified_id LEFT_RIGHT
               { $$ = finish_call_expr ($1, NULL_TREE, 1); }
	| primary '(' nonnull_exprlist ')'
               { $$ = finish_call_expr ($1, $3, 0); }
	| primary LEFT_RIGHT
               { $$ = finish_call_expr ($1, NULL_TREE, 0); }
	| primary '[' expr ']'
		{ $$ = grok_array_decl ($$, $3); }
	| primary PLUSPLUS
		{ $$ = finish_increment_expr ($1, POSTINCREMENT_EXPR); }
	| primary MINUSMINUS
		{ $$ = finish_increment_expr ($1, POSTDECREMENT_EXPR); }
	/* C++ extensions */
	| THIS
		{ $$ = finish_this_expr (); }
	| CV_QUALIFIER '(' nonnull_exprlist ')'
		{
		  /* This is a C cast in C++'s `functional' notation
		     using the "implicit int" extension so that:
		     `const (3)' is equivalent to `const int (3)'.  */
		  tree type;

		  if ($3 == error_mark_node)
		    {
		      $$ = error_mark_node;
		      break;
		    }

		  type = cp_build_qualified_type (integer_type_node,
						  cp_type_qual_from_rid ($1));
		  $$ = build_c_cast (type, build_compound_expr ($3));
		}
	| functional_cast
	| DYNAMIC_CAST '<' type_id '>' '(' expr ')'
		{ tree type = groktypename ($3.t);
		  check_for_new_type ("dynamic_cast", $3);
		  $$ = build_dynamic_cast (type, $6); }
	| STATIC_CAST '<' type_id '>' '(' expr ')'
		{ tree type = groktypename ($3.t);
		  check_for_new_type ("static_cast", $3);
		  $$ = build_static_cast (type, $6); }
	| REINTERPRET_CAST '<' type_id '>' '(' expr ')'
		{ tree type = groktypename ($3.t);
		  check_for_new_type ("reinterpret_cast", $3);
		  $$ = build_reinterpret_cast (type, $6); }
	| CONST_CAST '<' type_id '>' '(' expr ')'
		{ tree type = groktypename ($3.t);
		  check_for_new_type ("const_cast", $3);
		  $$ = build_const_cast (type, $6); }
	| TYPEID '(' expr ')'
		{ $$ = build_x_typeid ($3); }
	| TYPEID '(' type_id ')'
		{ tree type = groktypename ($3.t);
		  check_for_new_type ("typeid", $3);
		  $$ = get_typeid (TYPE_MAIN_VARIANT (type)); }
	| global_scope IDENTIFIER
		{ $$ = do_scoped_id ($2, 1); }
	| global_scope template_id
		{ $$ = $2; }
	| global_scope operator_name
		{
		  got_scope = NULL_TREE;
		  if (TREE_CODE ($2) == IDENTIFIER_NODE)
		    $$ = do_scoped_id ($2, 1);
		  else
		    $$ = $2;
		}
	| overqualified_id  %prec HYPERUNARY
		{ $$ = build_offset_ref (OP0 ($$), OP1 ($$)); }
	| overqualified_id '(' nonnull_exprlist ')'
                { $$ = finish_qualified_call_expr ($1, $3); }
	| overqualified_id LEFT_RIGHT
		{ $$ = finish_qualified_call_expr ($1, NULL_TREE); }
        | object object_template_id %prec UNARY
                { 
		  $$ = build_x_component_ref ($$, $2, NULL_TREE, 1); 
		}
        | object object_template_id '(' nonnull_exprlist ')'
                { $$ = finish_object_call_expr ($2, $1, $4); }
	| object object_template_id LEFT_RIGHT
                { $$ = finish_object_call_expr ($2, $1, NULL_TREE); }
	| object unqualified_id  %prec UNARY
		{ $$ = build_x_component_ref ($$, $2, NULL_TREE, 1); }
	| object overqualified_id  %prec UNARY
		{ if (processing_template_decl)
		    $$ = build_min_nt (COMPONENT_REF, $1, copy_to_permanent ($2));
		  else
		    $$ = build_object_ref ($$, OP0 ($2), OP1 ($2)); }
	| object unqualified_id '(' nonnull_exprlist ')'
                { $$ = finish_object_call_expr ($2, $1, $4); }
	| object unqualified_id LEFT_RIGHT
                { $$ = finish_object_call_expr ($2, $1, NULL_TREE); }
	| object overqualified_id '(' nonnull_exprlist ')'
                { $$ = finish_qualified_object_call_expr ($2, $1, $4); }
	| object overqualified_id LEFT_RIGHT
                { $$ = finish_qualified_object_call_expr ($2, $1, NULL_TREE); }
	/* p->int::~int() is valid -- 12.4 */
	| object '~' TYPESPEC LEFT_RIGHT
		{ $$ = finish_pseudo_destructor_call_expr ($1, NULL_TREE, $3); }
	| object TYPESPEC SCOPE '~' TYPESPEC LEFT_RIGHT
		{ $$ = finish_pseudo_destructor_call_expr ($1, $2, $5); }
	| object error
		{
		  $$ = error_mark_node;
		}
	;

/* Not needed for now.

primary_no_id:
	  '(' expr ')'
		{ $$ = $2; }
	| '(' error ')'
		{ $$ = error_mark_node; }
	| '('
		{ if (current_function_decl == 0)
		    {
		      error ("braced-group within expression allowed only inside a function");
		      YYERROR;
		    }
		  $<ttype>$ = expand_start_stmt_expr (); }
	  compstmt ')'
		{ if (pedantic)
		    pedwarn ("ANSI C++ forbids braced-groups within expressions");
		  $$ = expand_end_stmt_expr ($<ttype>2); }
	| primary_no_id '(' nonnull_exprlist ')'
		{ $$ = build_x_function_call ($$, $3, current_class_ref); }
	| primary_no_id LEFT_RIGHT
		{ $$ = build_x_function_call ($$, NULL_TREE, current_class_ref); }
	| primary_no_id '[' expr ']'
		{ goto do_array; }
	| primary_no_id PLUSPLUS
		{ $$ = build_x_unary_op (POSTINCREMENT_EXPR, $$); }
	| primary_no_id MINUSMINUS
		{ $$ = build_x_unary_op (POSTDECREMENT_EXPR, $$); }
	| SCOPE IDENTIFIER
		{ goto do_scoped_id; }
	| SCOPE operator_name
		{ if (TREE_CODE ($2) == IDENTIFIER_NODE)
		    goto do_scoped_id;
		  goto do_scoped_operator;
		}
	;
*/

new:
	  NEW
		{ $$ = 0; }
	| global_scope NEW
		{ got_scope = NULL_TREE; $$ = 1; }
	;

delete:
	  DELETE
		{ $$ = 0; }
	| global_scope delete
		{ got_scope = NULL_TREE; $$ = 1; }
	;

boolean.literal:
	  CXX_TRUE
		{ $$ = boolean_true_node; }
	| CXX_FALSE
		{ $$ = boolean_false_node; }
	;

/* Produces a STRING_CST with perhaps more STRING_CSTs chained onto it.  */
string:
	  STRING
	| string STRING
		{ $$ = chainon ($$, $2); }
	;

nodecls:
	  /* empty */
		{
		  if (! current_function_parms_stored)
		    store_parm_decls ();
		  setup_vtbl_ptr ();
		  /* Always keep the BLOCK node associated with the outermost
		     pair of curley braces of a function.  These are needed
		     for correct operation of dwarfout.c.  */
		  keep_next_level ();
		}
	;

object:
	  primary '.'
		{ got_object = TREE_TYPE ($$); }
	| primary POINTSAT
		{
		  $$ = build_x_arrow ($$); 
		  got_object = TREE_TYPE ($$);
		}
	;

decl:
	  typespec initdecls ';'
		{
		  resume_momentary ($2);
		  if ($1.t && IS_AGGR_TYPE_CODE (TREE_CODE ($1.t)))
		    note_got_semicolon ($1.t);
		}
	| typed_declspecs initdecls ';'
		{
		  resume_momentary ($2);
		  note_list_got_semicolon ($1.t);
		}
	| declmods notype_initdecls ';'
		{ resume_momentary ($2); }
	| typed_declspecs ';'
		{
		  shadow_tag ($1.t);
		  note_list_got_semicolon ($1.t);
		}
	| declmods ';'
		{ warning ("empty declaration"); }
	| extension decl
		{ pedantic = $<itype>1; }
	;

/* Any kind of declarator (thus, all declarators allowed
   after an explicit typespec).  */

declarator:
	  after_type_declarator  %prec EMPTY
	| notype_declarator  %prec EMPTY
	;

/* This is necessary to postpone reduction of `int()()()()'.  */
fcast_or_absdcl:
	  LEFT_RIGHT  %prec EMPTY
		{ $$ = make_call_declarator (NULL_TREE, empty_parms (),
					     NULL_TREE, NULL_TREE); }
	| fcast_or_absdcl LEFT_RIGHT  %prec EMPTY
		{ $$ = make_call_declarator ($$, empty_parms (), NULL_TREE,
					     NULL_TREE); }
	;

/* ANSI type-id (8.1) */
type_id:
	  typed_typespecs absdcl
		{ $$.t = build_decl_list ($1.t, $2); 
		  $$.new_type_flag = $1.new_type_flag; }
	| nonempty_cv_qualifiers absdcl
		{ $$.t = build_decl_list ($1.t, $2); 
		  $$.new_type_flag = $1.new_type_flag; }
	| typespec absdcl
		{ $$.t = build_decl_list (build_decl_list (NULL_TREE, $1.t),
					  $2); 
		  $$.new_type_flag = $1.new_type_flag; }
	| typed_typespecs  %prec EMPTY
		{ $$.t = build_decl_list ($1.t, NULL_TREE);
		  $$.new_type_flag = $1.new_type_flag;  }
	| nonempty_cv_qualifiers  %prec EMPTY
		{ $$.t = build_decl_list ($1.t, NULL_TREE); 
		  $$.new_type_flag = $1.new_type_flag; }
	;

/* Declspecs which contain at least one type specifier or typedef name.
   (Just `const' or `volatile' is not enough.)
   A typedef'd name following these is taken as a name to be declared.
   In the result, declspecs have a non-NULL TREE_VALUE, attributes do not.  */

typed_declspecs:
	  typed_typespecs  %prec EMPTY
	| typed_declspecs1
	;

typed_declspecs1:
	  declmods typespec
		{ $$.t = decl_tree_cons (NULL_TREE, $2.t, $1); 
		  $$.new_type_flag = $2.new_type_flag; }
	| typespec reserved_declspecs  %prec HYPERUNARY
		{ $$.t = decl_tree_cons (NULL_TREE, $1.t, $2); 
		  $$.new_type_flag = $1.new_type_flag; }
	| typespec reserved_typespecquals reserved_declspecs