gcc2.9.txt

编译原理中的First集与 Follow集生成程序

		{ $$.t = decl_tree_cons (NULL_TREE, $1.t, chainon ($2, $3)); 
		  $$.new_type_flag = $1.new_type_flag; }
	| declmods typespec reserved_declspecs
		{ $$.t = decl_tree_cons (NULL_TREE, $2.t, chainon ($3, $1)); 
		  $$.new_type_flag = $2.new_type_flag; }
	| declmods typespec reserved_typespecquals
		{ $$.t = decl_tree_cons (NULL_TREE, $2.t, chainon ($3, $1)); 
		  $$.new_type_flag = $2.new_type_flag; }
	| declmods typespec reserved_typespecquals reserved_declspecs
		{ $$.t = decl_tree_cons (NULL_TREE, $2.t,
					 chainon ($3, chainon ($4, $1))); 
		  $$.new_type_flag = $2.new_type_flag; }
	;

reserved_declspecs:
	  SCSPEC
		{ if (extra_warnings)
		    warning ("`%s' is not at beginning of declaration",
			     IDENTIFIER_POINTER ($$));
		  $$ = build_decl_list (NULL_TREE, $$); }
	| reserved_declspecs typespecqual_reserved
		{ $$ = decl_tree_cons (NULL_TREE, $2.t, $$); }
	| reserved_declspecs SCSPEC
		{ if (extra_warnings)
		    warning ("`%s' is not at beginning of declaration",
			     IDENTIFIER_POINTER ($2));
		  $$ = decl_tree_cons (NULL_TREE, $2, $$); }
	| reserved_declspecs attributes
		{ $$ = decl_tree_cons ($2, NULL_TREE, $1); }
	| attributes
		{ $$ = decl_tree_cons ($1, NULL_TREE, NULL_TREE); }
	;

/* List of just storage classes and type modifiers.
   A declaration can start with just this, but then it cannot be used
   to redeclare a typedef-name.
   In the result, declspecs have a non-NULL TREE_VALUE, attributes do not.  */

/* We use hash_tree_cons for lists of typeless declspecs so that they end
   up on a persistent obstack.  Otherwise, they could appear at the
   beginning of something like

      static const struct { int foo () { } } b;

   and would be discarded after we finish compiling foo.  We don't need to
   worry once we see a type.  */

declmods:
	  nonempty_cv_qualifiers  %prec EMPTY
		{ $$ = $1.t; TREE_STATIC ($$) = 1; }
	| SCSPEC
		{ $$ = hash_tree_cons (NULL_TREE, $$, NULL_TREE); }
	| declmods CV_QUALIFIER
		{ $$ = hash_tree_cons (NULL_TREE, $2, $$);
		  TREE_STATIC ($$) = 1; }
	| declmods SCSPEC
		{ if (extra_warnings && TREE_STATIC ($$))
		    warning ("`%s' is not at beginning of declaration",
			     IDENTIFIER_POINTER ($2));
		  $$ = hash_tree_cons (NULL_TREE, $2, $$);
		  TREE_STATIC ($$) = TREE_STATIC ($1); }
	| declmods attributes
		{ $$ = hash_tree_cons ($2, NULL_TREE, $1); }
	| attributes  %prec EMPTY
		{ $$ = hash_tree_cons ($1, NULL_TREE, NULL_TREE); }
	;

/* Used instead of declspecs where storage classes are not allowed
   (that is, for typenames and structure components).

   C++ can takes storage classes for structure components.
   Don't accept a typedef-name if anything but a modifier precedes it.  */

typed_typespecs:
	  typespec  %prec EMPTY
		{ $$.t = build_decl_list (NULL_TREE, $1.t); 
		  $$.new_type_flag = $1.new_type_flag; }
	| nonempty_cv_qualifiers typespec
		{ $$.t = decl_tree_cons (NULL_TREE, $2.t, $1.t); 
		  $$.new_type_flag = $2.new_type_flag; }
	| typespec reserved_typespecquals
		{ $$.t = decl_tree_cons (NULL_TREE, $1.t, $2); 
		  $$.new_type_flag = $1.new_type_flag; }
	| nonempty_cv_qualifiers typespec reserved_typespecquals
		{ $$.t = decl_tree_cons (NULL_TREE, $2.t, chainon ($3, $1.t)); 
		  $$.new_type_flag = $1.new_type_flag; }
	;

reserved_typespecquals:
	  typespecqual_reserved
		{ $$ = build_decl_list (NULL_TREE, $1.t); }
	| reserved_typespecquals typespecqual_reserved
		{ $$ = decl_tree_cons (NULL_TREE, $2.t, $1); }
	;

/* A typespec (but not a type qualifier).
   Once we have seen one of these in a declaration,
   if a typedef name appears then it is being redeclared.  */

typespec:
	  structsp
	| TYPESPEC  %prec EMPTY
		{ $$.t = $1; $$.new_type_flag = 0; }
	| complete_type_name
		{ $$.t = $1; $$.new_type_flag = 0; }
	| TYPEOF '(' expr ')'
		{ $$.t = finish_typeof ($3);
		  $$.new_type_flag = 0; }
	| TYPEOF '(' type_id ')'
		{ $$.t = groktypename ($3.t);
		  $$.new_type_flag = 0; }
	| SIGOF '(' expr ')'
		{ tree type = TREE_TYPE ($3);

                  $$.new_type_flag = 0;
		  if (IS_AGGR_TYPE (type))
		    {
		      sorry ("sigof type specifier");
		      $$.t = type;
		    }
		  else
		    {
		      error ("`sigof' applied to non-aggregate expression");
		      $$.t = error_mark_node;
		    }
		}
	| SIGOF '(' type_id ')'
		{ tree type = groktypename ($3.t);

                  $$.new_type_flag = 0;
		  if (IS_AGGR_TYPE (type))
		    {
		      sorry ("sigof type specifier");
		      $$.t = type;
		    }
		  else
		    {
		      error("`sigof' applied to non-aggregate type");
		      $$.t = error_mark_node;
		    }
		}
	;

/* A typespec that is a reserved word, or a type qualifier.  */

typespecqual_reserved:
	  TYPESPEC
		{ $$.t = $1; $$.new_type_flag = 0; }
	| CV_QUALIFIER
		{ $$.t = $1; $$.new_type_flag = 0; }
	| structsp
	;

initdecls:
	  initdcl0
	| initdecls ',' initdcl
            { check_multiple_declarators (); }
	;

notype_initdecls:
	  notype_initdcl0
	| notype_initdecls ',' initdcl
            { check_multiple_declarators (); }
	;

nomods_initdecls:
	  nomods_initdcl0
	| nomods_initdecls ',' initdcl
            { check_multiple_declarators (); }
	;

maybeasm:
	  /* empty */
		{ $$ = NULL_TREE; }
	| asm_keyword '(' string ')'
		{ if (TREE_CHAIN ($3)) $3 = combine_strings ($3); $$ = $3; }
	;

initdcl:
	  declarator maybeasm maybe_attribute '='
		{ $<ttype>$ = start_decl ($<ttype>1, current_declspecs, 1,
					  $3, prefix_attributes); }
	  init
/* Note how the declaration of the variable is in effect while its init is parsed! */
		{ cp_finish_decl ($<ttype>5, $6, $2, 1, LOOKUP_ONLYCONVERTING); }
	| declarator maybeasm maybe_attribute
		{ $<ttype>$ = start_decl ($<ttype>1, current_declspecs, 0,
					  $3, prefix_attributes);
		  cp_finish_decl ($<ttype>$, NULL_TREE, $2, 1, 0); }
	;

        /* This rule assumes a certain configuration of the parser stack.
	   In particular, $0, the element directly before the beginning of
	   this rule on the stack, must be a maybeasm.  $-1 must be a
	   declarator or notype_declarator.  And $-2 must be some declmods
	   or declspecs.  We can't move the maybeasm into this rule because
	   we need that reduce so we prefer fn.def1 when appropriate.  */
initdcl0_innards:
	  maybe_attribute '='
		{ $<itype>2 = parse_decl ($<ttype>-1, $<ttype>-2, 
					   $1, 1, &$<ttype>$); }
          /* Note how the declaration of the variable is in effect
	     while its init is parsed! */ 
	  init
		{ cp_finish_decl ($<ttype>3, $4, $<ttype>0, 1,
				  LOOKUP_ONLYCONVERTING);
		  $$ = $<itype>2; }
	| maybe_attribute
		{ tree d;
		  $$ = parse_decl ($<ttype>-1, $<ttype>-2, $1, 0, &d);
		  cp_finish_decl (d, NULL_TREE, $<ttype>0, 1, 0); }
  	;
  
initdcl0:
	  declarator maybeasm initdcl0_innards
            { $$ = $3; }
    ;
      
notype_initdcl0:
          notype_declarator maybeasm initdcl0_innards
            { $$ = $3; }
        ;
  
nomods_initdcl0:
          notype_declarator maybeasm
            { /* Set things up as initdcl0_innards expects.  */
	      $<ttype>2 = $1; 
              $1 = NULL_TREE; }
          initdcl0_innards 
            {}
	| constructor_declarator maybeasm maybe_attribute
		{ tree d;
		  parse_decl($1, NULL_TREE, $3, 0, &d);
		  cp_finish_decl (d, NULL_TREE, $2, 1, 0); }
	;

/* the * rules are dummies to accept the Apollo extended syntax
   so that the header files compile.  */
maybe_attribute:
	  /* empty */
  		{ $$ = NULL_TREE; }
	| attributes
		{ $$ = $1; }
	;
 
attributes:
      attribute
		{ $$ = $1; }
	| attributes attribute
		{ $$ = chainon ($1, $2); }
	;

attribute:
      ATTRIBUTE '(' '(' attribute_list ')' ')'
		{ $$ = $4; }
	;

attribute_list:
      attrib
		{ $$ = $1; }
	| attribute_list ',' attrib
		{ $$ = chainon ($1, $3); }
	;
 
attrib:
	  /* empty */
		{ $$ = NULL_TREE; }
	| any_word
		{ $$ = build_tree_list ($1, NULL_TREE); }
	| any_word '(' IDENTIFIER ')'
		{ $$ = build_tree_list ($1, build_tree_list (NULL_TREE, $3)); }
	| any_word '(' IDENTIFIER ',' nonnull_exprlist ')'
		{ $$ = build_tree_list ($1, tree_cons (NULL_TREE, $3, $5)); }
	| any_word '(' nonnull_exprlist ')'
		{ $$ = build_tree_list ($1, $3); }
	;

/* This still leaves out most reserved keywords,
   shouldn't we include them?  */

any_word:
	  identifier
	| SCSPEC
	| TYPESPEC
	| CV_QUALIFIER
	;

/* A nonempty list of identifiers, including typenames.  */
identifiers_or_typenames:
	  identifier
		{ $$ = build_tree_list (NULL_TREE, $1); }
	| identifiers_or_typenames ',' identifier
		{ $$ = chainon ($1, build_tree_list (NULL_TREE, $3)); }
	;

maybe_init:
	  /* empty */  %prec EMPTY
		{ $$ = NULL_TREE; }
	| '=' init
		{ $$ = $2; }
    ;
    
/* If we are processing a template, we don't want to expand this
   initializer yet.  */

init:
	  expr_no_commas  %prec '='
	| '{' '}'
		{ $$ = build_nt (CONSTRUCTOR, NULL_TREE, NULL_TREE);
		  TREE_HAS_CONSTRUCTOR ($$) = 1; }
	| '{' initlist '}'
		{ $$ = build_nt (CONSTRUCTOR, NULL_TREE, nreverse ($2));
		  TREE_HAS_CONSTRUCTOR ($$) = 1; }
	| '{' initlist ',' '}'
		{ $$ = build_nt (CONSTRUCTOR, NULL_TREE, nreverse ($2));
		  TREE_HAS_CONSTRUCTOR ($$) = 1; }
	| error
		{ $$ = NULL_TREE; }
	;

/* This chain is built in reverse order,
   and put in forward order where initlist is used.  */
initlist:
	  init
		{ $$ = build_tree_list (NULL_TREE, $$); }
	| initlist ',' init
		{ $$ = expr_tree_cons (NULL_TREE, $3, $$); }
	/* These are for labeled elements.  */
	| '[' expr_no_commas ']' init
		{ $$ = build_expr_list ($2, $4); }
	| identifier ':' init
		{ $$ = build_expr_list ($$, $3); }
	| initlist ',' identifier ':' init
		{ $$ = expr_tree_cons ($3, $5, $$); }
	;

fn.defpen:
	PRE_PARSED_FUNCTION_DECL
		{ start_function (NULL_TREE, TREE_VALUE ($1),
				  NULL_TREE, 2);
		  reinit_parse_for_function (); }
    ;
    
pending_inline:
	  fn.defpen maybe_return_init ctor_initializer_opt compstmt_or_error
		{
		  int nested = (hack_decl_function_context
				(current_function_decl) != NULL_TREE);
		  finish_function (lineno, (int)$3 | 2, nested);
		  process_next_inline ($1);
		}
	| fn.defpen maybe_return_init function_try_block
		{ 
		  int nested = (hack_decl_function_context
				(current_function_decl) != NULL_TREE);
		  finish_function (lineno, (int)$3 | 2, nested); 
                  process_next_inline ($1);
		}
	| fn.defpen maybe_return_init error
		{ process_next_inline ($1); }
	;

pending_inlines:
	/* empty */
	| pending_inlines pending_inline eat_saved_input
	;

/* A regurgitated default argument.  The value of DEFARG_MARKER will be
   the TREE_LIST node for the parameter in question.  */
defarg_again:
	DEFARG_MARKER expr_no_commas END_OF_SAVED_INPUT
		{ replace_defarg ($1, $2); }
	| DEFARG_MARKER error END_OF_SAVED_INPUT
		{ replace_defarg ($1, error_mark_node); }
    ;

pending_defargs:
	  /* empty */ %prec EMPTY
	| pending_defargs defarg_again
		{ do_pending_defargs (); }
	| pending_defargs error
		{ do_pending_defargs (); }
	;

structsp:
	  ENUM identifier '{'
		{ $<itype>3 = suspend_momentary ();
		  $<ttype>$ = current_enum_type;
		  current_enum_type = start_enum ($2); }
	  enumlist maybecomma_warn '}'
		{ TYPE_VALUES (current_enum_type) = $5;
		  $$.t = finish_enum (current_enum_type);
		  $$.new_type_flag = 1;
		  current_enum_type = $<ttype>4;
		  resume_momentary ((int) $<itype>3);
		  check_for_missing_semicolon ($$.t); }
	| ENUM identifier '{' '}'
		{ $$.t = finish_enum (start_enum ($2));
		  $$.new_type_flag = 1;
		  check_for_missing_semicolon ($$.t); }
	| ENUM '{'
		{ $<itype>2 = suspend_momentary ();
		  $<ttype>$ = current_enum_type;
		  current_enum_type = start_enum (make_anon_name ()); }
	  enumlist maybecomma_warn '}'
                { TYPE_VALUES (current_enum_type) = $4;
		  $$.t = finish_enum (current_enum_type);
		  $$.new_type_flag = 1;
		  current_enum_type = $<ttype>3;
		  resume_momentary ((int) $<itype>1);
		  check_for_missing_semicolon ($$.t); }
	| ENUM '{' '}'
		{ $$.t = finish_enum (start_enum (make_anon_name()));
		  $$.new_type_flag = 1;
		  check_for_missing_semicolon ($$.t); }
	| ENUM identifier
		{ $$.t = xref_tag (enum_type_node, $2, 1); 
		  $$.new_type_flag = 0; }
	| ENUM complex_type_name
		{ $$.t = xref_tag (enum_type_node, $2, 1); 
		  $$.new_type_flag = 0; }
	| TYPENAME_KEYWORD typename_sub
		{ $$.t = $2;
		  $$.new_type_flag = 0; 
		  if (!processing_template_decl)
		    cp_pedwarn ("using `typename' outside of template"); }
	/* C++ extensions, merged with C to avoid shift/reduce conflicts */
	| class_head '{'
                { $1.t = begin_class_definition ($1.t); }