[deliverable/binutils-gdb.git] / gdb / c-exp.y

/* 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.

   Note that malloc's and realloc's in this file are transformed to
   xmalloc and xrealloc respectively by the same sed command in the
   makefile that remaps any other malloc/realloc inserted by the parser
   generator.  Doing this with #defines and trying to control the interaction
   with include files (<malloc.h> and <stdlib.h> for example) just became
   too messy, particularly when such includes can be inserted at random
   times by the parser generator.  */
   
%{

#include "defs.h"
#include "expression.h"
#include "value.h"
#include "parser-defs.h"
#include "language.h"
#include "c-lang.h"
#include "bfd.h" /* Required by objfiles.h.  */
#include "symfile.h" /* Required by objfiles.h.  */
#include "objfiles.h" /* For have_full_symbols and have_partial_symbols */

/* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
   as well as gratuitiously global symbol names, so we can have multiple
   yacc generated parsers in gdb.  Note that these are only the variables
   produced by yacc.  If other parser generators (bison, byacc, etc) produce
   additional global names that conflict at link time, then those parser
   generators need to be fixed instead of adding those names to this list. */

#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 yyreds	c_reds		/* With YYDEBUG defined */
#define yytoks	c_toks		/* With YYDEBUG defined */

#ifndef YYDEBUG
#define	YYDEBUG	0		/* Default to no yydebug support */
#endif

int
yyparse PARAMS ((void));

static int
yylex PARAMS ((void));

void
yyerror PARAMS ((char *));

%}

/* 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;
    struct {
      LONGEST val;
      struct type *type;
    } typed_val;
    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 lcurly
%type <lval> rcurly
%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 <typed_val> INT
%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.  */

%token <ssym> NAME_OR_INT 

%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

\f
%%

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_LOGICAL_NOT); }
	;

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

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); }
	;

lcurly	:	'{'
			{ start_arglist (); }
	;

arglist	:
	;

arglist	:	exp
			{ arglist_len = 1; }
	;

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

rcurly	:	'}'
			{ $$ = end_arglist () - 1; }
	;
exp	:	lcurly arglist rcurly	%prec ARROW
			{ write_exp_elt_opcode (OP_ARRAY);
			  write_exp_elt_longcst ((LONGEST) 0);
			  write_exp_elt_longcst ((LONGEST) $3);
			  write_exp_elt_opcode (OP_ARRAY); }
	;

exp	:	lcurly type rcurly 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_BITWISE_AND); }
	;

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

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

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

exp	:	exp OROR exp
			{ write_exp_elt_opcode (BINOP_LOGICAL_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);
			  write_exp_elt_type ($1.type);
			  write_exp_elt_longcst ((LONGEST)($1.val));
			  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);
			  write_exp_elt_type (val.typed_val.type);
			  write_exp_elt_longcst ((LONGEST)val.typed_val.val);
			  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
			{ /* C strings are converted into array constants with
			     an explicit null byte added at the end.  Thus
			     the array upper bound is the string length.
			     There is no such thing in C as a completely empty
			     string. */
			  char *sp = $1.ptr; int count = $1.length;
			  while (count-- > 0)
			    {
			      write_exp_elt_opcode (OP_LONG);
			      write_exp_elt_type (builtin_type_char);
			      write_exp_elt_longcst ((LONGEST)(*sp++));
			      write_exp_elt_opcode (OP_LONG);
			    }
			  write_exp_elt_opcode (OP_LONG);
			  write_exp_elt_type (builtin_type_char);
			  write_exp_elt_longcst ((LONGEST)'\0');
			  write_exp_elt_opcode (OP_LONG);
			  write_exp_elt_opcode (OP_ARRAY);
			  write_exp_elt_longcst ((LONGEST) 0);
			  write_exp_elt_longcst ((LONGEST) ($1.length));
			  write_exp_elt_opcode (OP_ARRAY); }
	;

/* 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, (int *) NULL,
					     (struct symtab **) NULL);
			  if (!tem || SYMBOL_CLASS (tem) != LOC_BLOCK)
			    error ("No function \"%s\" in specified context.",
				   copy_name ($3));
			  $$ = SYMBOL_BLOCK_VALUE (tem); }
	;

variable:	block COLONCOLON name
			{ struct symbol *sym;
			  sym = lookup_symbol (copy_name ($3), $1,
					       VAR_NAMESPACE, (int *) NULL,
					       (struct symtab **) NULL);
			  if (sym == 0)
			    error ("No symbol \"%s\" in specified context.",
				   copy_name ($3));

			  write_exp_elt_opcode (OP_VAR_VALUE);
			  /* block_found is set by lookup_symbol.  */
			  write_exp_elt_block (block_found);
			  write_exp_elt_sym (sym);
			  write_exp_elt_opcode (OP_VAR_VALUE); }
	;

qualified_name:	typebase COLONCOLON name
			{
			  struct type *type = $1;
			  if (TYPE_CODE (type) != TYPE_CODE_STRUCT
			      && TYPE_CODE (type) != TYPE_CODE_UNION)
			    error ("`%s' is not defined as an aggregate type.",
				   TYPE_NAME (type));

			  write_exp_elt_opcode (OP_SCOPE);
			  write_exp_elt_type (type);
			  write_exp_string ($3);
			  write_exp_elt_opcode (OP_SCOPE);
			}
	|	typebase COLONCOLON '~' name
			{
			  struct type *type = $1;
			  struct stoken tmp_token;
			  if (TYPE_CODE (type) != TYPE_CODE_STRUCT
			      && TYPE_CODE (type) != TYPE_CODE_UNION)
			    error ("`%s' is not defined as an aggregate type.",
				   TYPE_NAME (type));

			  if (!STREQ (type_name_no_tag (type), $4.ptr))
			    error ("invalid destructor `%s::~%s'",
				   type_name_no_tag (type), $4.ptr);

			  tmp_token.ptr = (char*) alloca ($4.length + 2);
			  tmp_token.length = $4.length + 1;
			  tmp_token.ptr[0] = '~';
			  memcpy (tmp_token.ptr+1, $4.ptr, $4.length);
			  tmp_token.ptr[tmp_token.length] = 0;
			  write_exp_elt_opcode (OP_SCOPE);
			  write_exp_elt_type (type);
			  write_exp_string (tmp_token);
			  write_exp_elt_opcode (OP_SCOPE);
			}
	;

variable:	qualified_name
	|	COLONCOLON name
			{
			  char *name = copy_name ($2);
			  struct symbol *sym;
			  struct minimal_symbol *msymbol;

			  sym =
			    lookup_symbol (name, (const struct block *) NULL,
					   VAR_NAMESPACE, (int *) NULL,
					   (struct symtab **) NULL);
			  if (sym)
			    {
			      write_exp_elt_opcode (OP_VAR_VALUE);
			      write_exp_elt_block (NULL);
			      write_exp_elt_sym (sym);
			      write_exp_elt_opcode (OP_VAR_VALUE);
			      break;
			    }

			  msymbol = lookup_minimal_symbol (name,
				      (struct objfile *) NULL);
			  if (msymbol != NULL)
			    {
			      write_exp_msymbol (msymbol,
						 lookup_function_type (builtin_type_int),
						 builtin_type_int);
			    }
			  else
			    if (!have_full_symbols () && !have_partial_symbols ())
			      error ("No symbol table is loaded.  Use the \"file\" command.");
			    else
			      error ("No symbol \"%s\" in current context.", name);
			}
	;

variable:	name_not_typename
			{ struct symbol *sym = $1.sym;

			  if (sym)
			    {
			      if (symbol_read_needs_frame (sym))
				{
				  if (innermost_block == 0 ||
				      contained_in (block_found, 
						    innermost_block))
				    innermost_block = block_found;
				}

			      write_exp_elt_opcode (OP_VAR_VALUE);
			      /* We want to use the selected frame, not
				 another more inner frame which happens to
				 be in the same block.  */
			      write_exp_elt_block (NULL);
			      write_exp_elt_sym (sym);
			      write_exp_elt_opcode (OP_VAR_VALUE);
			    }
			  else if ($1.is_a_field_of_this)
			    {
			      /* C++: it hangs off of `this'.  Must
			         not inadvertently convert from a method call
				 to data ref.  */
			      if (innermost_block == 0 || 
				  contained_in (block_found, innermost_block))
				innermost_block = block_found;
			      write_exp_elt_opcode (OP_THIS);
			      write_exp_elt_opcode (OP_THIS);
			      write_exp_elt_opcode (STRUCTOP_PTR);
			      write_exp_string ($1.stoken);
			      write_exp_elt_opcode (STRUCTOP_PTR);
			    }
			  else
			    {
			      struct minimal_symbol *msymbol;
			      register char *arg = copy_name ($1.stoken);

			      msymbol = lookup_minimal_symbol (arg,
					  (struct objfile *) NULL);
			      if (msymbol != NULL)
				{
				  write_exp_msymbol (msymbol,
						     lookup_function_type (builtin_type_int),
						     builtin_type_int);
				}
			      else if (!have_full_symbols () && !have_partial_symbols ())
				error ("No symbol table is loaded.  Use the \"file\" command.");
			      else
				error ("No symbol \"%s\" in current context.",
				       copy_name ($1.stoken));
			    }
			}
	;


ptype	:	typebase
	/* "const" and "volatile" are curently ignored.  A type qualifier
	   before the type is currently handled in the typebase rule.
	   The reason for recognizing these here (shift/reduce conflicts)
	   might be obsolete now that some pointer to member rules have
	   been deleted.  */
	|	typebase CONST_KEYWORD
	|	typebase VOLATILE_KEYWORD
	|	typebase abs_decl
		{ $$ = follow_types ($1); }
	|	typebase CONST_KEYWORD abs_decl
		{ $$ = follow_types ($1); }
	|	typebase VOLATILE_KEYWORD abs_decl
		{ $$ = follow_types ($1); }
	;

abs_decl:	'*'
			{ push_type (tp_pointer); $$ = 0; }
	|	'*' abs_decl
			{ push_type (tp_pointer); $$ = $2; }
	|	'&'
			{ push_type (tp_reference); $$ = 0; }
	|	'&' abs_decl
			{ push_type (tp_reference); $$ = $2; }
	|	direct_abs_decl
	;

direct_abs_decl: '(' abs_decl ')'
			{ $$ = $2; }
	|	direct_abs_decl array_mod
			{
			  push_type_int ($2);
			  push_type (tp_array);
			}
	|	array_mod
			{
			  push_type_int ($1);
			  push_type (tp_array);
			  $$ = 0;
			}

	| 	direct_abs_decl func_mod
			{ push_type (tp_function); }
	|	func_mod
			{ push_type (tp_function); }
	;

array_mod:	'[' ']'
			{ $$ = -1; }
	|	'[' INT ']'
			{ $$ = $2.val; }
	;

func_mod:	'(' ')'
			{ $$ = 0; }
	|	'(' nonempty_typelist ')'
			{ free ((PTR)$2); $$ = 0; }
	;

/* We used to try to recognize more pointer to member types here, but
   that didn't work (shift/reduce conflicts meant that these rules never
   got executed).  The problem is that
     int (foo::bar::baz::bizzle)
   is a function type but
     int (foo::bar::baz::bizzle::*)
   is a pointer to member type.  Stroustrup loses again!  */

type	:	ptype
	|	typebase COLONCOLON '*'
			{ $$ = lookup_member_type (builtin_type_int, $1); }
	;

typebase  /* Implements (approximately): (type-qualifier)* type-specifier */
	:	TYPENAME
			{ $$ = $1.type; }
	|	INT_KEYWORD
			{ $$ = builtin_type_int; }
	|	LONG
			{ $$ = builtin_type_long; }
	|	SHORT
			{ $$ = builtin_type_short; }
	|	LONG INT_KEYWORD
			{ $$ = builtin_type_long; }
	|	UNSIGNED LONG INT_KEYWORD
			{ $$ = builtin_type_unsigned_long; }
	|	LONG LONG
			{ $$ = builtin_type_long_long; }
	|	LONG LONG INT_KEYWORD
			{ $$ = builtin_type_long_long; }
	|	UNSIGNED LONG LONG
			{ $$ = builtin_type_unsigned_long_long; }
	|	UNSIGNED LONG LONG INT_KEYWORD
			{ $$ = builtin_type_unsigned_long_long; }
	|	SHORT INT_KEYWORD
			{ $$ = builtin_type_short; }
	|	UNSIGNED SHORT INT_KEYWORD
			{ $$ = builtin_type_unsigned_short; }
	|	STRUCT name
			{ $$ = lookup_struct (copy_name ($2),
					      expression_context_block); }
	|	CLASS name
			{ $$ = lookup_struct (copy_name ($2),
					      expression_context_block); }
	|	UNION name
			{ $$ = lookup_union (copy_name ($2),
					     expression_context_block); }
	|	ENUM name
			{ $$ = lookup_enum (copy_name ($2),
					    expression_context_block); }
	|	UNSIGNED typename
			{ $$ = lookup_unsigned_typename (TYPE_NAME($2.type)); }
	|	UNSIGNED
			{ $$ = builtin_type_unsigned_int; }
	|	SIGNED_KEYWORD typename
			{ $$ = lookup_signed_typename (TYPE_NAME($2.type)); }
	|	SIGNED_KEYWORD
			{ $$ = builtin_type_int; }
	|	TEMPLATE name '<' type '>'
			{ $$ = lookup_template_type(copy_name($2), $4,
						    expression_context_block);
			}
	/* "const" and "volatile" are curently ignored.  A type qualifier
	   after the type is handled in the ptype rule.  I think these could
	   be too.  */
	|	CONST_KEYWORD typebase { $$ = $2; }
	|	VOLATILE_KEYWORD typebase { $$ = $2; }
	;

typename:	TYPENAME
	|	INT_KEYWORD
		{
		  $$.stoken.ptr = "int";
		  $$.stoken.length = 3;
		  $$.type = builtin_type_int;
		}
	|	LONG
		{
		  $$.stoken.ptr = "long";
		  $$.stoken.length = 4;
		  $$.type = builtin_type_long;
		}
	|	SHORT
		{
		  $$.stoken.ptr = "short";
		  $$.stoken.length = 5;
		  $$.type = builtin_type_short;
		}
	;

nonempty_typelist
	:	type
		{ $$ = (struct type **) malloc (sizeof (struct type *) * 2);
		  $<ivec>$[0] = 1;	/* Number of types in vector */
		  $$[1] = $1;
		}
	|	nonempty_typelist ',' type
		{ int len = sizeof (struct type *) * (++($<ivec>1[0]) + 1);
		  $$ = (struct type **) realloc ((char *) $1, len);
		  $$[$<ivec>$[0]] = $3;
		}
	;

name	:	NAME { $$ = $1.stoken; }
	|	BLOCKNAME { $$ = $1.stoken; }
	|	TYPENAME { $$ = $1.stoken; }
	|	NAME_OR_INT  { $$ = $1.stoken; }
	;

name_not_typename :	NAME
	|	BLOCKNAME
/* These would be useful if name_not_typename was useful, but it is just
   a fake for "variable", so these cause reduce/reduce conflicts because
   the parser can't tell whether NAME_OR_INT is a name_not_typename (=variable,
   =exp) or just an exp.  If name_not_typename was ever used in an lvalue
   context where only a name could occur, this might be useful.
  	|	NAME_OR_INT
 */
	;

%%

/* Take care of parsing a number (anything that starts with a digit).
   Set yylval and return the token type; update lexptr.
   LEN is the number of characters in it.  */

/*** Needs some error checking for the float case ***/

static int
parse_number (p, len, parsed_float, putithere)
     register char *p;
     register int len;
     int parsed_float;
     YYSTYPE *putithere;
{
  register LONGEST n = 0;
  register LONGEST prevn = 0;
  register int i = 0;
  register int c;
  register int base = input_radix;
  int unsigned_p = 0;
  int long_p = 0;
  unsigned LONGEST high_bit;
  struct type *signed_type;
  struct type *unsigned_type;

  if (parsed_float)
    {
      /* It's a float since it contains a point or an exponent.  */
      putithere->dval = atof (p);
      return FLOAT;
    }

  /* Handle base-switching prefixes 0x, 0t, 0d, 0 */
  if (p[0] == '0')
    switch (p[1])
      {
      case 'x':
      case 'X':
	if (len >= 3)
	  {
	    p += 2;
	    base = 16;
	    len -= 2;
	  }
	break;

      case 't':
      case 'T':
      case 'd':
      case 'D':
	if (len >= 3)
	  {
	    p += 2;
	    base = 10;
	    len -= 2;
	  }
	break;

      default:
	base = 8;
	break;
      }

  while (len-- > 0)
    {
      c = *p++;
      if (c >= 'A' && c <= 'Z')
	c += 'a' - 'A';
      if (c != 'l' && c != 'u')
	n *= base;
      if (c >= '0' && c <= '9')
	n += i = c - '0';
      else
	{
	  if (base > 10 && c >= 'a' && c <= 'f')
	    n += i = c - 'a' + 10;
	  else if (len == 0 && c == 'l') 
            long_p = 1;
	  else if (len == 0 && c == 'u')
	    unsigned_p = 1;
	  else
	    return ERROR;	/* Char not a digit */
	}
      if (i >= base)
	return ERROR;		/* Invalid digit in this base */

      /* Portably test for overflow (only works for nonzero values, so make
	 a second check for zero).  */
      if((prevn >= n) && n != 0)
	 unsigned_p=1;		/* Try something unsigned */
      /* If range checking enabled, portably test for unsigned overflow.  */
      if(RANGE_CHECK && n!=0)
      {	
	 if((unsigned_p && (unsigned)prevn >= (unsigned)n))
	    range_error("Overflow on numeric constant.");	 
      }
      prevn=n;
    }
 
     /* If the number is too big to be an int, or it's got an l suffix
	then it's a long.  Work out if this has to be a long by
	shifting right and and seeing if anything remains, and the
	target int size is different to the target long size.

	In the expression below, we could have tested
        	(n >> TARGET_INT_BIT)
	to see if it was zero,
	but too many compilers warn about that, when ints and longs
	are the same size.  So we shift it twice, with fewer bits
	each time, for the same result.  */

    if (   (TARGET_INT_BIT != TARGET_LONG_BIT 
            && ((n >> 2) >> (TARGET_INT_BIT-2)))   /* Avoid shift warning */
        || long_p)
      {
         high_bit = ((unsigned LONGEST)1) << (TARGET_LONG_BIT-1);
	 unsigned_type = builtin_type_unsigned_long;
	 signed_type = builtin_type_long;
      }
    else 
      {
	 high_bit = ((unsigned LONGEST)1) << (TARGET_INT_BIT-1);
	 unsigned_type = builtin_type_unsigned_int;
	 signed_type = builtin_type_int;
      }    

   putithere->typed_val.val = n;

   /* If the high bit of the worked out type is set then this number
      has to be unsigned. */

   if (unsigned_p || (n & high_bit)) 
     {
        putithere->typed_val.type = unsigned_type;
     }
   else 
     {
        putithere->typed_val.type = signed_type;
     }

   return INT;
}

struct token
{
  char *operator;
  int token;
  enum exp_opcode opcode;
};

static const struct token tokentab3[] =
  {
    {">>=", ASSIGN_MODIFY, BINOP_RSH},
    {"<<=", ASSIGN_MODIFY, BINOP_LSH}
  };

static const struct token tokentab2[] =
  {
    {"+=", ASSIGN_MODIFY, BINOP_ADD},
    {"-=", ASSIGN_MODIFY, BINOP_SUB},
    {"*=", ASSIGN_MODIFY, BINOP_MUL},
    {"/=", ASSIGN_MODIFY, BINOP_DIV},
    {"%=", ASSIGN_MODIFY, BINOP_REM},
    {"|=", ASSIGN_MODIFY, BINOP_BITWISE_IOR},
    {"&=", ASSIGN_MODIFY, BINOP_BITWISE_AND},
    {"^=", ASSIGN_MODIFY, BINOP_BITWISE_XOR},
    {"++", INCREMENT, BINOP_END},
    {"--", DECREMENT, BINOP_END},
    {"->", ARROW, BINOP_END},
    {"&&", ANDAND, BINOP_END},
    {"||", OROR, BINOP_END},
    {"::", COLONCOLON, BINOP_END},
    {"<<", LSH, BINOP_END},
    {">>", RSH, BINOP_END},
    {"==", EQUAL, BINOP_END},
    {"!=", NOTEQUAL, BINOP_END},
    {"<=", LEQ, BINOP_END},
    {">=", GEQ, BINOP_END}
  };

/* Read one token, getting characters through lexptr.  */

static int
yylex ()
{
  int c;
  int namelen;
  unsigned int i;
  char *tokstart;
  char *tokptr;
  int tempbufindex;
  static char *tempbuf;
  static int tempbufsize;
  
 retry:

  tokstart = lexptr;
  /* See if it is a special token of length 3.  */
  for (i = 0; i < sizeof tokentab3 / sizeof tokentab3[0]; i++)
    if (STREQN (tokstart, tokentab3[i].operator, 3))
      {
	lexptr += 3;
	yylval.opcode = tokentab3[i].opcode;
	return tokentab3[i].token;
      }

  /* See if it is a special token of length 2.  */
  for (i = 0; i < sizeof tokentab2 / sizeof tokentab2[0]; i++)
    if (STREQN (tokstart, tokentab2[i].operator, 2))
      {
	lexptr += 2;
	yylval.opcode = tokentab2[i].opcode;
	return tokentab2[i].token;
      }

  switch (c = *tokstart)
    {
    case 0:
      return 0;

    case ' ':
    case '\t':
    case '\n':
      lexptr++;
      goto retry;

    case '\'':
      /* We either have a character constant ('0' or '\177' for example)
	 or we have a quoted symbol reference ('foo(int,int)' in C++
	 for example). */
      lexptr++;
      c = *lexptr++;
      if (c == '\\')
	c = parse_escape (&lexptr);

      yylval.typed_val.val = c;
      yylval.typed_val.type = builtin_type_char;

      c = *lexptr++;
      if (c != '\'')
	{
	  namelen = skip_quoted (tokstart) - tokstart;
	  if (namelen > 2)
	    {
	      lexptr = tokstart + namelen;
	      if (lexptr[-1] != '\'')
		error ("Unmatched single quote.");
	      namelen -= 2;
	      tokstart++;
	      goto tryname;
	    }
	  error ("Invalid character constant.");
	}
      return INT;

    case '(':
      paren_depth++;
      lexptr++;
      return c;

    case ')':
      if (paren_depth == 0)
	return 0;
      paren_depth--;
      lexptr++;
      return c;

    case ',':
      if (comma_terminates && paren_depth == 0)
	return 0;
      lexptr++;
      return c;

    case '.':
      /* Might be a floating point number.  */
      if (lexptr[1] < '0' || lexptr[1] > '9')
	goto symbol;		/* Nope, must be a symbol. */
      /* FALL THRU into number case.  */

    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      {
	/* It's a number.  */
	int got_dot = 0, got_e = 0, toktype;
	register char *p = tokstart;
	int hex = input_radix > 10;

	if (c == '0' && (p[1] == 'x' || p[1] == 'X'))
	  {
	    p += 2;
	    hex = 1;
	  }
	else if (c == '0' && (p[1]=='t' || p[1]=='T' || p[1]=='d' || p[1]=='D'))
	  {
	    p += 2;
	    hex = 0;
	  }

	for (;; ++p)
	  {
	    /* This test includes !hex because 'e' is a valid hex digit
	       and thus does not indicate a floating point number when
	       the radix is hex.  */
	    if (!hex && !got_e && (*p == 'e' || *p == 'E'))
	      got_dot = got_e = 1;
	    /* This test does not include !hex, because a '.' always indicates
	       a decimal floating point number regardless of the radix.  */
	    else if (!got_dot && *p == '.')
	      got_dot = 1;
	    else if (got_e && (p[-1] == 'e' || p[-1] == 'E')
		     && (*p == '-' || *p == '+'))
	      /* This is the sign of the exponent, not the end of the
		 number.  */
	      continue;
	    /* We will take any letters or digits.  parse_number will
	       complain if past the radix, or if L or U are not final.  */
	    else if ((*p < '0' || *p > '9')
		     && ((*p < 'a' || *p > 'z')
				  && (*p < 'A' || *p > 'Z')))
	      break;
	  }
	toktype = parse_number (tokstart, p - tokstart, got_dot|got_e, &yylval);
        if (toktype == ERROR)
	  {
	    char *err_copy = (char *) alloca (p - tokstart + 1);

	    memcpy (err_copy, tokstart, p - tokstart);
	    err_copy[p - tokstart] = 0;
	    error ("Invalid number \"%s\".", err_copy);
	  }
	lexptr = p;
	return toktype;
      }

    case '+':
    case '-':
    case '*':
    case '/':
    case '%':
    case '|':
    case '&':
    case '^':
    case '~':
    case '!':
    case '@':
    case '<':
    case '>':
    case '[':
    case ']':
    case '?':
    case ':':
    case '=':
    case '{':
    case '}':
    symbol:
      lexptr++;
      return c;

    case '"':

      /* Build the gdb internal form of the input string in tempbuf,
	 translating any standard C escape forms seen.  Note that the
	 buffer is null byte terminated *only* for the convenience of
	 debugging gdb itself and printing the buffer contents when
	 the buffer contains no embedded nulls.  Gdb does not depend
	 upon the buffer being null byte terminated, it uses the length
	 string instead.  This allows gdb to handle C strings (as well
	 as strings in other languages) with embedded null bytes */

      tokptr = ++tokstart;
      tempbufindex = 0;

      do {
	/* Grow the static temp buffer if necessary, including allocating
	   the first one on demand. */
	if (tempbufindex + 1 >= tempbufsize)
	  {
	    tempbuf = (char *) realloc (tempbuf, tempbufsize += 64);
	  }
	switch (*tokptr)
	  {
	  case '\0':
	  case '"':
	    /* Do nothing, loop will terminate. */
	    break;
	  case '\\':
	    tokptr++;
	    c = parse_escape (&tokptr);
	    if (c == -1)
	      {
		continue;
	      }
	    tempbuf[tempbufindex++] = c;
	    break;
	  default:
	    tempbuf[tempbufindex++] = *tokptr++;
	    break;
	  }
      } while ((*tokptr != '"') && (*tokptr != '\0'));
      if (*tokptr++ != '"')
	{
	  error ("Unterminated string in expression.");
	}
      tempbuf[tempbufindex] = '\0';	/* See note above */
      yylval.sval.ptr = tempbuf;
      yylval.sval.length = tempbufindex;
      lexptr = tokptr;
      return (STRING);
    }

  if (!(c == '_' || c == '$'
	|| (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')))
    /* We must have come across a bad character (e.g. ';').  */
    error ("Invalid character '%c' in expression.", c);

  /* It's a name.  See how long it is.  */
  namelen = 0;
  for (c = tokstart[namelen];
       (c == '_' || c == '$' || (c >= '0' && c <= '9')
	|| (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'));
       c = tokstart[++namelen])
    ;

  /* The token "if" terminates the expression and is NOT 
     removed from the input stream.  */
  if (namelen == 2 && tokstart[0] == 'i' && tokstart[1] == 'f')
    {
      return 0;
    }

  lexptr += namelen;

  /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
     and $$digits (equivalent to $<-digits> if you could type that).
     Make token type LAST, and put the number (the digits) in yylval.  */

  tryname:
  if (*tokstart == '$')
    {
      register int negate = 0;
      c = 1;
      /* Double dollar means negate the number and add -1 as well.
	 Thus $$ alone means -1.  */
      if (namelen >= 2 && tokstart[1] == '$')
	{
	  negate = 1;
	  c = 2;
	}
      if (c == namelen)
	{
	  /* Just dollars (one or two) */
	  yylval.lval = - negate;
	  return LAST;
	}
      /* Is the rest of the token digits?  */
      for (; c < namelen; c++)
	if (!(tokstart[c] >= '0' && tokstart[c] <= '9'))
	  break;
      if (c == namelen)
	{
	  yylval.lval = atoi (tokstart + 1 + negate);
	  if (negate)
	    yylval.lval = - yylval.lval;
	  return LAST;
	}
    }

  /* Handle tokens that refer to machine registers:
     $ followed by a register name.  */

  if (*tokstart == '$') {
    for (c = 0; c < NUM_REGS; c++)
      if (namelen - 1 == strlen (reg_names[c])
	  && STREQN (tokstart + 1, reg_names[c], namelen - 1))
	{
	  yylval.lval = c;
	  return REGNAME;
	}
    for (c = 0; c < num_std_regs; c++)
     if (namelen - 1 == strlen (std_regs[c].name)
	 && STREQN (tokstart + 1, std_regs[c].name, namelen - 1))
       {
	 yylval.lval = std_regs[c].regnum;
	 return REGNAME;
       }
  }
  /* Catch specific keywords.  Should be done with a data structure.  */
  switch (namelen)
    {
    case 8:
      if (STREQN (tokstart, "unsigned", 8))
	return UNSIGNED;
      if (current_language->la_language == language_cplus
	  && STREQN (tokstart, "template", 8))
	return TEMPLATE;
      if (STREQN (tokstart, "volatile", 8))
	return VOLATILE_KEYWORD;
      break;
    case 6:
      if (STREQN (tokstart, "struct", 6))
	return STRUCT;
      if (STREQN (tokstart, "signed", 6))
	return SIGNED_KEYWORD;
      if (STREQN (tokstart, "sizeof", 6))      
	return SIZEOF;
      break;
    case 5:
      if (current_language->la_language == language_cplus
	  && STREQN (tokstart, "class", 5))
	return CLASS;
      if (STREQN (tokstart, "union", 5))
	return UNION;
      if (STREQN (tokstart, "short", 5))
	return SHORT;
      if (STREQN (tokstart, "const", 5))
	return CONST_KEYWORD;
      break;
    case 4:
      if (STREQN (tokstart, "enum", 4))
	return ENUM;
      if (STREQN (tokstart, "long", 4))
	return LONG;
      if (current_language->la_language == language_cplus
	  && STREQN (tokstart, "this", 4))
	{
	  static const char this_name[] =
				 { CPLUS_MARKER, 't', 'h', 'i', 's', '\0' };

	  if (lookup_symbol (this_name, expression_context_block,
			     VAR_NAMESPACE, (int *) NULL,
			     (struct symtab **) NULL))
	    return THIS;
	}
      break;
    case 3:
      if (STREQN (tokstart, "int", 3))
	return INT_KEYWORD;
      break;
    default:
      break;
    }

  yylval.sval.ptr = tokstart;
  yylval.sval.length = namelen;

  /* Any other names starting in $ are debugger internal variables.  */

  if (*tokstart == '$')
    {
      yylval.ivar =  lookup_internalvar (copy_name (yylval.sval) + 1);
      return VARIABLE;
    }

  /* Use token-type BLOCKNAME for symbols that happen to be defined as
     functions or symtabs.  If this is not so, then ...
     Use token-type TYPENAME for symbols that happen to be defined
     currently as names of types; NAME for other symbols.
     The caller is not constrained to care about the distinction.  */
  {
    char *tmp = copy_name (yylval.sval);
    struct symbol *sym;
    int is_a_field_of_this = 0;
    int hextype;

    sym = lookup_symbol (tmp, expression_context_block,
			 VAR_NAMESPACE,
			 current_language->la_language == language_cplus
			 ? &is_a_field_of_this : (int *) NULL,
			 (struct symtab **) NULL);
    /* Call lookup_symtab, not lookup_partial_symtab, in case there are
       no psymtabs (coff, xcoff, or some future change to blow away the
       psymtabs once once symbols are read).  */
    if ((sym && SYMBOL_CLASS (sym) == LOC_BLOCK) ||
        lookup_symtab (tmp))
      {
	yylval.ssym.sym = sym;
	yylval.ssym.is_a_field_of_this = is_a_field_of_this;
	return BLOCKNAME;
      }
    if (sym && SYMBOL_CLASS (sym) == LOC_TYPEDEF)
        {
	  char *p;
	  char *namestart;
	  struct symbol *best_sym;

	  /* Look ahead to detect nested types.  This probably should be
	     done in the grammar, but trying seemed to introduce a lot
	     of shift/reduce and reduce/reduce conflicts.  It's possible
	     that it could be done, though.  Or perhaps a non-grammar, but
	     less ad hoc, approach would work well.  */

	  /* Since we do not currently have any way of distinguishing
	     a nested type from a non-nested one (the stabs don't tell
	     us whether a type is nested), we just ignore the
	     containing type.  */

	  p = lexptr;
	  best_sym = sym;
	  while (1)
	    {
	      /* Skip whitespace.  */
	      while (*p == ' ' || *p == '\t' || *p == '\n')
		++p;
	      if (*p == ':' && p[1] == ':')
		{
		  /* Skip the `::'.  */
		  p += 2;
		  /* Skip whitespace.  */
		  while (*p == ' ' || *p == '\t' || *p == '\n')
		    ++p;
		  namestart = p;
		  while (*p == '_' || *p == '$' || (*p >= '0' && *p <= '9')
			 || (*p >= 'a' && *p <= 'z')
			 || (*p >= 'A' && *p <= 'Z'))
		    ++p;
		  if (p != namestart)
		    {
		      struct symbol *cur_sym;
		      /* As big as the whole rest of the expression, which is
			 at least big enough.  */
		      char *tmp = alloca (strlen (namestart));

		      memcpy (tmp, namestart, p - namestart);
		      tmp[p - namestart] = '\0';
		      cur_sym = lookup_symbol (tmp, expression_context_block,
					       VAR_NAMESPACE, (int *) NULL,
					       (struct symtab **) NULL);
		      if (cur_sym)
			{
			  if (SYMBOL_CLASS (cur_sym) == LOC_TYPEDEF)
			    {
			      best_sym = cur_sym;
			      lexptr = p;
			    }
			  else
			    break;
			}
		      else
			break;
		    }
		  else
		    break;
		}
	      else
		break;
	    }

	  yylval.tsym.type = SYMBOL_TYPE (best_sym);
	  return TYPENAME;
        }
    if ((yylval.tsym.type = lookup_primitive_typename (tmp)) != 0)
	return TYPENAME;

    /* Input names that aren't symbols but ARE valid hex numbers,
       when the input radix permits them, can be names or numbers
       depending on the parse.  Note we support radixes > 16 here.  */
    if (!sym && 
        ((tokstart[0] >= 'a' && tokstart[0] < 'a' + input_radix - 10) ||
         (tokstart[0] >= 'A' && tokstart[0] < 'A' + input_radix - 10)))
      {
 	YYSTYPE newlval;	/* Its value is ignored.  */
	hextype = parse_number (tokstart, namelen, 0, &newlval);
	if (hextype == INT)
	  {
	    yylval.ssym.sym = sym;
	    yylval.ssym.is_a_field_of_this = is_a_field_of_this;
	    return NAME_OR_INT;
	  }
      }

    /* Any other kind of symbol */
    yylval.ssym.sym = sym;
    yylval.ssym.is_a_field_of_this = is_a_field_of_this;
    return NAME;
  }
}

void
yyerror (msg)
     char *msg;
{
  error (msg ? msg : "Invalid syntax in expression.");
}