c-exp.y

早期freebsd实现

/* YACC parser for C expressions, for GDB.
   Copyright (C) 1986, 1989, 1990, 1991 Free Software Foundation, Inc.

This file is part of GDB.

This program 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 of the License, or
(at your option) any later version.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* Parse a C expression from text in a string,
   and return the result as a  struct expression  pointer.
   That structure contains arithmetic operations in reverse polish,
   with constants represented by operations that are followed by special data.
   See expression.h for the details of the format.
   What is important here is that it can be built up sequentially
   during the process of parsing; the lower levels of the tree always
   come first in the result.  */
   
%{

#include <stdio.h>
#include <string.h>
#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "frame.h"
#include "expression.h"
#include "parser-defs.h"
#include "value.h"
#include "language.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"

/* These MUST be included in any grammar file!!!! Please choose unique names!
   Note that this are a combined list of variables that can be produced
   by any one of bison, byacc, or yacc. */
#define	yymaxdepth c_maxdepth
#define	yyparse	c_parse
#define	yylex	c_lex
#define	yyerror	c_error
#define	yylval	c_lval
#define	yychar	c_char
#define	yydebug	c_debug
#define	yypact	c_pact	
#define	yyr1	c_r1			
#define	yyr2	c_r2			
#define	yydef	c_def		
#define	yychk	c_chk		
#define	yypgo	c_pgo		
#define	yyact	c_act		
#define	yyexca	c_exca
#define yyerrflag c_errflag
#define yynerrs	c_nerrs
#define	yyps	c_ps
#define	yypv	c_pv
#define	yys	c_s
#define	yy_yys	c_yys
#define	yystate	c_state
#define	yytmp	c_tmp
#define	yyv	c_v
#define	yy_yyv	c_yyv
#define	yyval	c_val
#define	yylloc	c_lloc
#define yyss	c_yyss		/* byacc */
#define	yyssp	c_yysp		/* byacc */
#define	yyvs	c_yyvs		/* byacc */
#define	yyvsp	c_yyvsp		/* byacc */

int
yyparse PARAMS ((void));

int
yylex PARAMS ((void));

void
yyerror PARAMS ((char *));

/* #define	YYDEBUG	1 */

%}

/* Although the yacc "value" of an expression is not used,
   since the result is stored in the structure being created,
   other node types do have values.  */

%union
  {
    LONGEST lval;
    unsigned LONGEST ulval;
    double dval;
    struct symbol *sym;
    struct type *tval;
    struct stoken sval;
    struct ttype tsym;
    struct symtoken ssym;
    int voidval;
    struct block *bval;
    enum exp_opcode opcode;
    struct internalvar *ivar;

    struct type **tvec;
    int *ivec;
  }

%{
/* YYSTYPE gets defined by %union */
static int
parse_number PARAMS ((char *, int, int, YYSTYPE *));
%}

%type <voidval> exp exp1 type_exp start variable qualified_name
%type <tval> type typebase
%type <tvec> nonempty_typelist
/* %type <bval> block */

/* Fancy type parsing.  */
%type <voidval> func_mod direct_abs_decl abs_decl
%type <tval> ptype
%type <lval> array_mod

%token <lval> INT CHAR
%token <ulval> UINT
%token <dval> FLOAT

/* Both NAME and TYPENAME tokens represent symbols in the input,
   and both convey their data as strings.
   But a TYPENAME is a string that happens to be defined as a typedef
   or builtin type name (such as int or char)
   and a NAME is any other symbol.
   Contexts where this distinction is not important can use the
   nonterminal "name", which matches either NAME or TYPENAME.  */

%token <sval> STRING
%token <ssym> NAME /* BLOCKNAME defined below to give it higher precedence. */
%token <tsym> TYPENAME
%type <sval> name
%type <ssym> name_not_typename
%type <tsym> typename

/* A NAME_OR_INT is a symbol which is not known in the symbol table,
   but which would parse as a valid number in the current input radix.
   E.g. "c" when input_radix==16.  Depending on the parse, it will be
   turned into a name or into a number.  NAME_OR_UINT ditto.  */

%token <ssym> NAME_OR_INT NAME_OR_UINT

%token STRUCT CLASS UNION ENUM SIZEOF UNSIGNED COLONCOLON
%token TEMPLATE
%token ERROR

/* Special type cases, put in to allow the parser to distinguish different
   legal basetypes.  */
%token SIGNED_KEYWORD LONG SHORT INT_KEYWORD CONST_KEYWORD VOLATILE_KEYWORD

%token <lval> LAST REGNAME

%token <ivar> VARIABLE

%token <opcode> ASSIGN_MODIFY

/* C++ */
%token THIS

%left ','
%left ABOVE_COMMA
%right '=' ASSIGN_MODIFY
%right '?'
%left OROR
%left ANDAND
%left '|'
%left '^'
%left '&'
%left EQUAL NOTEQUAL
%left '<' '>' LEQ GEQ
%left LSH RSH
%left '@'
%left '+' '-'
%left '*' '/' '%'
%right UNARY INCREMENT DECREMENT
%right ARROW '.' '[' '('
%token <ssym> BLOCKNAME 
%type <bval> block
%left COLONCOLON

%{
/* Ensure that if the generated parser contains any calls to malloc/realloc,
   that they get mapped to xmalloc/xrealloc.  We have to do this here
   rather than earlier in the file because this is the first point after
   the place where the SVR4 yacc includes <malloc.h>, and if we do it
   before that, then the remapped declarations in <malloc.h> will collide
   with the ones in "defs.h". */

#define malloc	xmalloc
#define realloc	xrealloc
%}


%%

start   :	exp1
	|	type_exp
	;

type_exp:	type
			{ write_exp_elt_opcode(OP_TYPE);
			  write_exp_elt_type($1);
			  write_exp_elt_opcode(OP_TYPE);}
	;

/* Expressions, including the comma operator.  */
exp1	:	exp
	|	exp1 ',' exp
			{ write_exp_elt_opcode (BINOP_COMMA); }
	;

/* Expressions, not including the comma operator.  */
exp	:	'*' exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_IND); }

exp	:	'&' exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_ADDR); }

exp	:	'-' exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_NEG); }
	;

exp	:	'!' exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_ZEROP); }
	;

exp	:	'~' exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_LOGNOT); }
	;

exp	:	INCREMENT exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_PREINCREMENT); }
	;

exp	:	DECREMENT exp    %prec UNARY
			{ write_exp_elt_opcode (UNOP_PREDECREMENT); }
	;

exp	:	exp INCREMENT    %prec UNARY
			{ write_exp_elt_opcode (UNOP_POSTINCREMENT); }
	;

exp	:	exp DECREMENT    %prec UNARY
			{ write_exp_elt_opcode (UNOP_POSTDECREMENT); }
	;

exp	:	SIZEOF exp       %prec UNARY
			{ write_exp_elt_opcode (UNOP_SIZEOF); }
	;

exp	:	exp ARROW name
			{ write_exp_elt_opcode (STRUCTOP_PTR);
			  write_exp_string ($3);
			  write_exp_elt_opcode (STRUCTOP_PTR); }
	;

exp	:	exp ARROW qualified_name
			{ /* exp->type::name becomes exp->*(&type::name) */
			  /* Note: this doesn't work if name is a
			     static member!  FIXME */
			  write_exp_elt_opcode (UNOP_ADDR);
			  write_exp_elt_opcode (STRUCTOP_MPTR); }
	;
exp	:	exp ARROW '*' exp
			{ write_exp_elt_opcode (STRUCTOP_MPTR); }
	;

exp	:	exp '.' name
			{ write_exp_elt_opcode (STRUCTOP_STRUCT);
			  write_exp_string ($3);
			  write_exp_elt_opcode (STRUCTOP_STRUCT); }
	;

exp	:	exp '.' qualified_name
			{ /* exp.type::name becomes exp.*(&type::name) */
			  /* Note: this doesn't work if name is a
			     static member!  FIXME */
			  write_exp_elt_opcode (UNOP_ADDR);
			  write_exp_elt_opcode (STRUCTOP_MEMBER); }
	;

exp	:	exp '.' '*' exp
			{ write_exp_elt_opcode (STRUCTOP_MEMBER); }
	;

exp	:	exp '[' exp1 ']'
			{ write_exp_elt_opcode (BINOP_SUBSCRIPT); }
	;

exp	:	exp '(' 
			/* This is to save the value of arglist_len
			   being accumulated by an outer function call.  */
			{ start_arglist (); }
		arglist ')'	%prec ARROW
			{ write_exp_elt_opcode (OP_FUNCALL);
			  write_exp_elt_longcst ((LONGEST) end_arglist ());
			  write_exp_elt_opcode (OP_FUNCALL); }
	;

arglist	:
	;

arglist	:	exp
			{ arglist_len = 1; }
	;

arglist	:	arglist ',' exp   %prec ABOVE_COMMA
			{ arglist_len++; }
	;

exp	:	'{' type '}' exp  %prec UNARY
			{ write_exp_elt_opcode (UNOP_MEMVAL);
			  write_exp_elt_type ($2);
			  write_exp_elt_opcode (UNOP_MEMVAL); }
	;

exp	:	'(' type ')' exp  %prec UNARY
			{ write_exp_elt_opcode (UNOP_CAST);
			  write_exp_elt_type ($2);
			  write_exp_elt_opcode (UNOP_CAST); }
	;

exp	:	'(' exp1 ')'
			{ }
	;

/* Binary operators in order of decreasing precedence.  */

exp	:	exp '@' exp
			{ write_exp_elt_opcode (BINOP_REPEAT); }
	;

exp	:	exp '*' exp
			{ write_exp_elt_opcode (BINOP_MUL); }
	;

exp	:	exp '/' exp
			{ write_exp_elt_opcode (BINOP_DIV); }
	;

exp	:	exp '%' exp
			{ write_exp_elt_opcode (BINOP_REM); }
	;

exp	:	exp '+' exp
			{ write_exp_elt_opcode (BINOP_ADD); }
	;

exp	:	exp '-' exp
			{ write_exp_elt_opcode (BINOP_SUB); }
	;

exp	:	exp LSH exp
			{ write_exp_elt_opcode (BINOP_LSH); }
	;

exp	:	exp RSH exp
			{ write_exp_elt_opcode (BINOP_RSH); }
	;

exp	:	exp EQUAL exp
			{ write_exp_elt_opcode (BINOP_EQUAL); }
	;

exp	:	exp NOTEQUAL exp
			{ write_exp_elt_opcode (BINOP_NOTEQUAL); }
	;

exp	:	exp LEQ exp
			{ write_exp_elt_opcode (BINOP_LEQ); }
	;

exp	:	exp GEQ exp
			{ write_exp_elt_opcode (BINOP_GEQ); }
	;

exp	:	exp '<' exp
			{ write_exp_elt_opcode (BINOP_LESS); }
	;

exp	:	exp '>' exp
			{ write_exp_elt_opcode (BINOP_GTR); }
	;

exp	:	exp '&' exp
			{ write_exp_elt_opcode (BINOP_LOGAND); }
	;

exp	:	exp '^' exp
			{ write_exp_elt_opcode (BINOP_LOGXOR); }
	;

exp	:	exp '|' exp
			{ write_exp_elt_opcode (BINOP_LOGIOR); }
	;

exp	:	exp ANDAND exp
			{ write_exp_elt_opcode (BINOP_AND); }
	;

exp	:	exp OROR exp
			{ write_exp_elt_opcode (BINOP_OR); }
	;

exp	:	exp '?' exp ':' exp	%prec '?'
			{ write_exp_elt_opcode (TERNOP_COND); }
	;
			  
exp	:	exp '=' exp
			{ write_exp_elt_opcode (BINOP_ASSIGN); }
	;

exp	:	exp ASSIGN_MODIFY exp
			{ write_exp_elt_opcode (BINOP_ASSIGN_MODIFY);
			  write_exp_elt_opcode ($2);
			  write_exp_elt_opcode (BINOP_ASSIGN_MODIFY); }
	;

exp	:	INT
			{ write_exp_elt_opcode (OP_LONG);
			  if ($1 == (int) $1 || $1 == (unsigned int) $1)
			    write_exp_elt_type (builtin_type_int);
			  else
			    write_exp_elt_type (BUILTIN_TYPE_LONGEST);
			  write_exp_elt_longcst ((LONGEST) $1);
			  write_exp_elt_opcode (OP_LONG); }
	;

exp	:	NAME_OR_INT
			{ YYSTYPE val;
			  parse_number ($1.stoken.ptr, $1.stoken.length, 0, &val);
			  write_exp_elt_opcode (OP_LONG);
			  if (val.lval == (int) val.lval ||
			      val.lval == (unsigned int) val.lval)
			    write_exp_elt_type (builtin_type_int);
			  else
			    write_exp_elt_type (BUILTIN_TYPE_LONGEST);
			  write_exp_elt_longcst (val.lval);
			  write_exp_elt_opcode (OP_LONG); }
	;

exp	:	UINT
			{
			  write_exp_elt_opcode (OP_LONG);
			  if ($1 == (unsigned int) $1)
			    write_exp_elt_type (builtin_type_unsigned_int);
			  else
			    write_exp_elt_type (BUILTIN_TYPE_UNSIGNED_LONGEST);
			  write_exp_elt_longcst ((LONGEST) $1);
			  write_exp_elt_opcode (OP_LONG);
			}
	;

exp	:	NAME_OR_UINT
			{ YYSTYPE val;
			  parse_number ($1.stoken.ptr, $1.stoken.length, 0, &val);
			  write_exp_elt_opcode (OP_LONG);
			  if (val.ulval == (unsigned int) val.ulval)
			    write_exp_elt_type (builtin_type_unsigned_int);
			  else
			    write_exp_elt_type (BUILTIN_TYPE_UNSIGNED_LONGEST);
			  write_exp_elt_longcst ((LONGEST)val.ulval);
			  write_exp_elt_opcode (OP_LONG);
			}
	;

exp	:	CHAR
			{ write_exp_elt_opcode (OP_LONG);
			  write_exp_elt_type (builtin_type_char);
			  write_exp_elt_longcst ((LONGEST) $1);
			  write_exp_elt_opcode (OP_LONG); }
	;

exp	:	FLOAT
			{ write_exp_elt_opcode (OP_DOUBLE);
			  write_exp_elt_type (builtin_type_double);
			  write_exp_elt_dblcst ($1);
			  write_exp_elt_opcode (OP_DOUBLE); }
	;

exp	:	variable
	;

exp	:	LAST
			{ write_exp_elt_opcode (OP_LAST);
			  write_exp_elt_longcst ((LONGEST) $1);
			  write_exp_elt_opcode (OP_LAST); }
	;

exp	:	REGNAME
			{ write_exp_elt_opcode (OP_REGISTER);
			  write_exp_elt_longcst ((LONGEST) $1);
			  write_exp_elt_opcode (OP_REGISTER); }
	;

exp	:	VARIABLE
			{ write_exp_elt_opcode (OP_INTERNALVAR);
			  write_exp_elt_intern ($1);
			  write_exp_elt_opcode (OP_INTERNALVAR); }
	;

exp	:	SIZEOF '(' type ')'	%prec UNARY
			{ write_exp_elt_opcode (OP_LONG);
			  write_exp_elt_type (builtin_type_int);
			  write_exp_elt_longcst ((LONGEST) TYPE_LENGTH ($3));
			  write_exp_elt_opcode (OP_LONG); }
	;

exp	:	STRING
			{ write_exp_elt_opcode (OP_STRING);
			  write_exp_string ($1);
			  write_exp_elt_opcode (OP_STRING); }
	;

/* C++.  */
exp	:	THIS
			{ write_exp_elt_opcode (OP_THIS);
			  write_exp_elt_opcode (OP_THIS); }
	;

/* end of C++.  */

block	:	BLOCKNAME
			{
			  if ($1.sym != 0)
			      $$ = SYMBOL_BLOCK_VALUE ($1.sym);
			  else
			    {
			      struct symtab *tem =
				  lookup_symtab (copy_name ($1.stoken));
			      if (tem)
				$$ = BLOCKVECTOR_BLOCK
					 (BLOCKVECTOR (tem), STATIC_BLOCK);
			      else
				error ("No file or function \"%s\".",
				       copy_name ($1.stoken));
			    }
			}
	;

block	:	block COLONCOLON name
			{ struct symbol *tem
			    = lookup_symbol (copy_name ($3), $1,
					     VAR_NAMESPACE, 0, NULL);
			  if (!tem || SYMBOL_CLASS (tem) != LOC_BLOCK)