c-parse.y

使用yacc和lex编写的cmm语言的词法分析和语法分析程序.

/* YACC parser for C syntax.
   Copyright (C) 1987, 1988, 1989, 1992 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


/* To whomever it may concern: I have heard that such a thing was once
written by AT&T, but I have never seen it.  */

%expect 8

/* These are the 8 conflicts you should get in parse.output;
   the state numbers may vary if minor changes in the grammar are made.

State 41 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
State 92 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
State 99 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
State 103 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
State 119 contains 1 shift/reduce conflict.  (See comment at component_decl.)
State 183 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
State 193 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
State 199 contains 1 shift/reduce conflict.  (Two ways to recover from error.)
*/

%{
#include <stdio.h>
#include <errno.h>
#include <setjmp.h>

#include "config.h"
#include "tree.h"
#include "input.h"
#include "c-lex.h"
#include "c-tree.h"
#include "flags.h"

#ifdef MULTIBYTE_CHARS
#include <stdlib.h>
#include <locale.h>
#endif

#ifndef errno
extern int errno;
#endif

void yyerror ();

/* Like YYERROR but do call yyerror.  */
#define YYERROR1 { yyerror ("syntax error"); YYERROR; }

/* Cause the `yydebug' variable to be defined.  */
#define YYDEBUG 1
%}

%start program

%union {long itype; tree ttype; enum tree_code code;
	char *filename; int lineno; }

/* All identifiers that are not reserved words
   and are not declared typedefs in the current block */
%token IDENTIFIER

/* All identifiers that are declared typedefs in the current block.
   In some contexts, they are treated just like IDENTIFIER,
   but they can also serve as typespecs in declarations.  */
%token TYPENAME

/* Reserved words that specify storage class.
   yylval contains an IDENTIFIER_NODE which indicates which one.  */
%token SCSPEC

/* Reserved words that specify type.
   yylval contains an IDENTIFIER_NODE which indicates which one.  */
%token TYPESPEC

/* Reserved words that qualify type: "const" or "volatile".
   yylval contains an IDENTIFIER_NODE which indicates which one.  */
%token TYPE_QUAL

/* Character or numeric constants.
   yylval is the node for the constant.  */
%token CONSTANT

/* String constants in raw form.
   yylval is a STRING_CST node.  */
%token STRING

/* "...", used for functions with variable arglists.  */
%token ELLIPSIS

/* the reserved words */
%token SIZEOF ENUM STRUCT UNION IF ELSE WHILE DO FOR SWITCH CASE DEFAULT
%token BREAK CONTINUE RETURN GOTO ASM TYPEOF ALIGNOF ALIGN
%token ATTRIBUTE EXTENSION LABEL

/* Add precedence rules to solve dangling else s/r conflict */
%nonassoc IF
%nonassoc ELSE

/* Define the operator tokens and their precedences.
   The value is an integer because, if used, it is the tree code
   to use in the expression made from the operator.  */

%right <code> ASSIGN '='
%right <code> '?' ':'
%left <code> OROR
%left <code> ANDAND
%left <code> '|'
%left <code> '^'
%left <code> '&'
%left <code> EQCOMPARE
%left <code> ARITHCOMPARE
%left <code> LSHIFT RSHIFT
%left <code> '+' '-'
%left <code> '*' '/' '%'
%right <code> UNARY PLUSPLUS MINUSMINUS
%left HYPERUNARY
%left <code> POINTSAT '.' '(' '['

/* The Objective-C keywords, here so our token codes match obj's.  */
%token INTERFACE IMPLEMENTATION END SELECTOR DEFS ENCODE
%token CLASSNAME PUBLIC


%type <code> unop

%type <ttype> identifier IDENTIFIER TYPENAME CONSTANT expr nonnull_exprlist exprlist
%type <ttype> expr_no_commas cast_expr unary_expr primary string STRING
%type <ttype> typed_declspecs reserved_declspecs
%type <ttype> typed_typespecs reserved_typespecquals
%type <ttype> declmods typespec typespecqual_reserved
%type <ttype> SCSPEC TYPESPEC TYPE_QUAL nonempty_type_quals maybe_type_qual
%type <ttype> initdecls notype_initdecls initdcl notype_initdcl
%type <ttype> init initlist maybeasm
%type <ttype> asm_operands nonnull_asm_operands asm_operand asm_clobbers
%type <ttype> maybe_attribute attribute_list attrib

%type <ttype> compstmt

%type <ttype> declarator
%type <ttype> notype_declarator after_type_declarator
%type <ttype> parm_declarator

%type <ttype> structsp component_decl_list component_decl_list2
%type <ttype> component_decl components component_declarator
%type <ttype> enumlist enumerator
%type <ttype> typename absdcl absdcl1 type_quals
%type <ttype> xexpr parms parm identifiers

%type <ttype> parmlist parmlist_1 parmlist_2
%type <ttype> parmlist_or_identifiers parmlist_or_identifiers_1
%type <ttype> identifiers_or_typenames

%type <itype> setspecs

%type <filename> save_filename
%type <lineno> save_lineno

%{
/* Number of statements (loosely speaking) seen so far.  */
static int stmt_count;

/* Input file and line number of the end of the body of last simple_if;
   used by the stmt-rule immediately after simple_if returns.  */
static char *if_stmt_file;
static int if_stmt_line;

/* List of types and structure classes of the current declaration.  */
static tree current_declspecs;

/* Stack of saved values of current_declspecs.  */
static tree declspec_stack;

/* 1 if we explained undeclared var errors.  */
static int undeclared_variable_notice;

/* Tell yyparse how to print a token's value, if yydebug is set.  */

#define YYPRINT(FILE,YYCHAR,YYLVAL) yyprint(FILE,YYCHAR,YYLVAL)
extern void yyprint ();
%}

%%
program: /* empty */
		{ if (pedantic)
		    pedwarn ("ANSI C forbids an empty source file"); }
	| extdefs
	;

/* the reason for the strange actions in this rule
 is so that notype_initdecls when reached via datadef
 can find a valid list of type and sc specs in $0. */

extdefs:
	{$<ttype>$ = NULL_TREE; } extdef
	| extdefs {$<ttype>$ = NULL_TREE; } extdef
	;

extdef:
	fndef
	| datadef
	| ASM '(' expr ')' ';'
		{ STRIP_NOPS ($3);
		  if ((TREE_CODE ($3) == ADDR_EXPR
		       && TREE_CODE (TREE_OPERAND ($3, 0)) == STRING_CST)
		      || TREE_CODE ($3) == STRING_CST)
		    assemble_asm ($3);
		  else
		    error ("argument of `asm' is not a constant string"); }
	;

datadef:
	  setspecs notype_initdecls ';'
		{ if (pedantic)
		    error ("ANSI C forbids data definition with no type or storage class");
		  else if (!flag_traditional)
		    warning ("data definition has no type or storage class"); }
        | declmods setspecs notype_initdecls ';'
	  {}
	| typed_declspecs setspecs initdecls ';'
	  {}
        | declmods ';'
	  { error ("empty declaration"); }
	| typed_declspecs ';'
	  { shadow_tag ($1); }
	| error ';'
	| error '}'
	| ';'
		{ if (pedantic)
		    pedwarn ("ANSI C does not allow extra `;' outside of a function"); }
	;

fndef:
	  typed_declspecs setspecs declarator
		{ if (! start_function ($1, $3, 0))
		    YYERROR1;
		  reinit_parse_for_function (); }
	  xdecls
		{ store_parm_decls (); }
	  compstmt_or_error
		{ finish_function (0); }
	| typed_declspecs setspecs declarator error
		{ }
	| declmods setspecs notype_declarator
		{ if (! start_function ($1, $3, 0))
		    YYERROR1;
		  reinit_parse_for_function (); }
	  xdecls
		{ store_parm_decls (); }
	  compstmt_or_error
		{ finish_function (0); }
	| declmods setspecs notype_declarator error
		{ }
	| setspecs notype_declarator
		{ if (! start_function (0, $2, 0))
		    YYERROR1;
		  reinit_parse_for_function (); }
	  xdecls
		{ store_parm_decls (); }
	  compstmt_or_error
		{ finish_function (0); }
	| setspecs notype_declarator error
		{ }
	;

identifier:
	IDENTIFIER
	| TYPENAME
	;

unop:     '&'
		{ $$ = ADDR_EXPR; }
	| '-'
		{ $$ = NEGATE_EXPR; }
	| '+'
		{ $$ = CONVERT_EXPR; }
	| PLUSPLUS
		{ $$ = PREINCREMENT_EXPR; }
	| MINUSMINUS
		{ $$ = PREDECREMENT_EXPR; }
	| '~'
		{ $$ = BIT_NOT_EXPR; }
	| '!'
		{ $$ = TRUTH_NOT_EXPR; }
	;

expr:	nonnull_exprlist
		{ $$ = build_compound_expr ($1); }
	;

exprlist:
	  /* empty */
		{ $$ = NULL_TREE; }
	| nonnull_exprlist
	;

nonnull_exprlist:
	expr_no_commas
		{ $$ = build_tree_list (NULL_TREE, $1); }
	| nonnull_exprlist ',' expr_no_commas
		{ chainon ($1, build_tree_list (NULL_TREE, $3)); }
	;

unary_expr:
	primary
	| '*' cast_expr   %prec UNARY
		{ $$ = build_indirect_ref ($2, "unary *"); }
	/* __extension__ turns off -pedantic for following primary.  */
	| EXTENSION
		{ $<itype>1 = pedantic;
		  pedantic = 0; }
	  cast_expr	  %prec UNARY
		{ $$ = $3;
		  pedantic = $<itype>1; }
	| unop cast_expr  %prec UNARY
		{ $$ = build_unary_op ($1, $2, 0); }
	/* Refer to the address of a label as a pointer.  */
	| ANDAND identifier
		{ tree label = lookup_label ($2);
		  TREE_USED (label) = 1;
		  $$ = build1 (ADDR_EXPR, ptr_type_node, label);
		  TREE_CONSTANT ($$) = 1; }
/* This seems to be impossible on some machines, so let's turn it off.
	| '&' ELLIPSIS
		{ tree types = TYPE_ARG_TYPES (TREE_TYPE (current_function_decl));
		  $$ = error_mark_node;
		  if (TREE_VALUE (tree_last (types)) == void_type_node)
		    error ("`&...' used in function with fixed number of arguments");
		  else
		    {
		      if (pedantic)
			pedwarn ("ANSI C forbids `&...'");
		      $$ = tree_last (DECL_ARGUMENTS (current_function_decl));
		      $$ = build_unary_op (ADDR_EXPR, $$, 0);
		    } }
*/
	| SIZEOF unary_expr  %prec UNARY
		{ if (TREE_CODE ($2) == COMPONENT_REF
		      && DECL_BIT_FIELD (TREE_OPERAND ($2, 1)))
		    error ("`sizeof' applied to a bit-field");
		  $$ = c_sizeof (TREE_TYPE ($2)); }
	| SIZEOF '(' typename ')'  %prec HYPERUNARY
		{ $$ = c_sizeof (groktypename ($3)); }
	| ALIGNOF unary_expr  %prec UNARY
		{ $$ = c_alignof_expr ($2); }
	| ALIGNOF '(' typename ')'  %prec HYPERUNARY
		{ $$ = c_alignof (groktypename ($3)); }
	;

cast_expr:
	unary_expr
	| '(' typename ')' cast_expr  %prec UNARY
		{ tree type = groktypename ($2);
		  $$ = build_c_cast (type, $4); }
	| '(' typename ')' '{' initlist maybecomma '}'  %prec UNARY
		{ tree type = groktypename ($2);
		  char *name;
		  if (pedantic)
		    pedwarn ("ANSI C forbids constructor expressions");
		  if (TYPE_NAME (type) != 0)
		    {
		      if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
			name = IDENTIFIER_POINTER (TYPE_NAME (type));
		      else
			name = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type)));
		    }
		  else
		    name = "";
		  $$ = digest_init (type, build_nt (CONSTRUCTOR, NULL_TREE, nreverse ($5)),
				    0, 0, 0, name);
		  if (TREE_CODE (type) == ARRAY_TYPE && TYPE_SIZE (type) == 0)
		    {
		      int failure = complete_array_type (type, $$, 1);
		      if (failure)
			abort ();
		    }
		}
	;

expr_no_commas:
	  cast_expr
	| expr_no_commas '+' expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas '-' expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas '*' expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas '/' expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas '%' expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas LSHIFT expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas RSHIFT expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas ARITHCOMPARE expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas EQCOMPARE expr_no_commas
		{ $$ = parser_build_binary_op ($2, $1, $3); }
	| expr_no_commas '&' expr_no_commas