2002-04-09 Pierre Muller <muller@ics.u-strasbg.fr>

[thirdparty/binutils-gdb.git] / gdb / p-exp.y

/* YACC parser for Pascal expressions, for GDB.
   Copyright 2000
   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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* This file is derived from c-exp.y */

/* Parse a Pascal 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.  */

/* FIXME: there are still 21 shift/reduce conflicts
   Other known bugs or limitations:
    - pascal string operations are not supported at all.
    - there are some problems with boolean types.
    - Pascal type hexadecimal constants are not supported
      because they conflict with the internal variables format.
   Probably also lots of other problems, less well defined PM */
%{

#include "defs.h"
#include "gdb_string.h"
#include <ctype.h>
#include "expression.h"
#include "value.h"
#include "parser-defs.h"
#include "language.h"
#include "p-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 pascal_maxdepth
#define yyparse pascal_parse
#define yylex   pascal_lex
#define yyerror pascal_error
#define yylval  pascal_lval
#define yychar  pascal_char
#define yydebug pascal_debug
#define yypact  pascal_pact     
#define yyr1    pascal_r1                       
#define yyr2    pascal_r2                       
#define yydef   pascal_def              
#define yychk   pascal_chk              
#define yypgo   pascal_pgo              
#define yyact   pascal_act
#define yyexca  pascal_exca
#define yyerrflag pascal_errflag
#define yynerrs pascal_nerrs
#define yyps    pascal_ps
#define yypv    pascal_pv
#define yys     pascal_s
#define yy_yys  pascal_yys
#define yystate pascal_state
#define yytmp   pascal_tmp
#define yyv     pascal_v
#define yy_yyv  pascal_yyv
#define yyval   pascal_val
#define yylloc  pascal_lloc
#define yyreds  pascal_reds             /* With YYDEBUG defined */
#define yytoks  pascal_toks             /* With YYDEBUG defined */
#define yylhs   pascal_yylhs
#define yylen   pascal_yylen
#define yydefred pascal_yydefred
#define yydgoto pascal_yydgoto
#define yysindex pascal_yysindex
#define yyrindex pascal_yyrindex
#define yygindex pascal_yygindex
#define yytable  pascal_yytable
#define yycheck  pascal_yycheck

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

int yyparse (void);

static int yylex (void);

void
yyerror (char *);

static char * uptok (char *, int);
%}

/* 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_int;
    struct {
      DOUBLEST dval;
      struct type *type;
    } typed_val_float;
    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 (char *, int, int, YYSTYPE *);
%}

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

/* Fancy type parsing.  */
%type <tval> ptype

%token <typed_val_int> INT
%token <typed_val_float> 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

/* 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 SIZEOF COLONCOLON
%token ERROR

/* Special type cases, put in to allow the parser to distinguish different
   legal basetypes.  */

%token <voidval> VARIABLE


/* Object pascal */
%token THIS
%token <lval> TRUE FALSE

%left ','
%left ABOVE_COMMA
%right ASSIGN
%left NOT
%left OR
%left XOR
%left ANDAND
%left '=' NOTEQUAL
%left '<' '>' LEQ GEQ
%left LSH RSH DIV MOD
%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     :       NOT exp    %prec UNARY
                        { write_exp_elt_opcode (UNOP_LOGICAL_NOT); }
        ;

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

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

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

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 :
         | exp
                        { arglist_len = 1; }
         | arglist ',' exp   %prec ABOVE_COMMA
                        { arglist_len++; }
        ;

exp     :       type '(' exp ')' %prec UNARY
                        { write_exp_elt_opcode (UNOP_CAST);
                          write_exp_elt_type ($1);
                          write_exp_elt_opcode (UNOP_CAST); }
        ;

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

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

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

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

exp     :       exp DIV exp
                        { write_exp_elt_opcode (BINOP_INTDIV); }
        ;

exp     :       exp MOD 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 '=' 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 ANDAND exp
                        { write_exp_elt_opcode (BINOP_BITWISE_AND); }
        ;

exp     :       exp XOR exp
                        { write_exp_elt_opcode (BINOP_BITWISE_XOR); }
        ;

exp     :       exp OR exp
                        { write_exp_elt_opcode (BINOP_BITWISE_IOR); }
        ;

exp     :       exp ASSIGN exp
                        { write_exp_elt_opcode (BINOP_ASSIGN); }
        ;

exp     :       TRUE
                        { write_exp_elt_opcode (OP_BOOL);
                          write_exp_elt_longcst ((LONGEST) $1);
                          write_exp_elt_opcode (OP_BOOL); }
        ;

exp     :       FALSE
                        { write_exp_elt_opcode (OP_BOOL);
                          write_exp_elt_longcst ((LONGEST) $1);
                          write_exp_elt_opcode (OP_BOOL); }
        ;

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_int.type);
                          write_exp_elt_longcst ((LONGEST)val.typed_val_int.val);
                          write_exp_elt_opcode (OP_LONG);
                        }
        ;


exp     :       FLOAT
                        { write_exp_elt_opcode (OP_DOUBLE);
                          write_exp_elt_type ($1.type);
                          write_exp_elt_dblcst ($1.dval);
                          write_exp_elt_opcode (OP_DOUBLE); }
        ;

exp     :       variable
        ;

exp     :       VARIABLE
                        /* Already written by write_dollar_variable. */
        ;

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

/* Object pascal  */
exp     :       THIS
                        { write_exp_elt_opcode (OP_THIS);
                          write_exp_elt_opcode (OP_THIS); }
        ;

/* end of object pascal.  */

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);
                        }
        ;

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, NULL, 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)
                            {
                              /* Object pascal: 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, NULL, 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
        ;

/* 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
                        { $$ = $1.type; }
        |       STRUCT name
                        { $$ = lookup_struct (copy_name ($2),
                                              expression_context_block); }
        |       CLASS name
                        { $$ = lookup_struct (copy_name ($2),
                                              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.  */
        ;

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;
{
  /* FIXME: Shouldn't these be unsigned?  We don't deal with negative values
     here, and we do kind of silly things like cast to unsigned.  */
  register LONGEST n = 0;
  register LONGEST prevn = 0;
  ULONGEST un;

  register int i = 0;
  register int c;
  register int base = input_radix;
  int unsigned_p = 0;

  /* Number of "L" suffixes encountered.  */
  int long_p = 0;

  /* We have found a "L" or "U" suffix.  */
  int found_suffix = 0;

  ULONGEST 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.  */
      char c;
      int num = 0;      /* number of tokens scanned by scanf */
      char saved_char = p[len];

      p[len] = 0;       /* null-terminate the token */
      if (sizeof (putithere->typed_val_float.dval) <= sizeof (float))
        num = sscanf (p, "%g%c", (float *) &putithere->typed_val_float.dval,&c);
      else if (sizeof (putithere->typed_val_float.dval) <= sizeof (double))
        num = sscanf (p, "%lg%c", (double *) &putithere->typed_val_float.dval,&c);
      else
        {
#ifdef SCANF_HAS_LONG_DOUBLE
          num = sscanf (p, "%Lg%c", &putithere->typed_val_float.dval,&c);
#else
          /* Scan it into a double, then assign it to the long double.
             This at least wins with values representable in the range
             of doubles. */
          double temp;
          num = sscanf (p, "%lg%c", &temp,&c);
          putithere->typed_val_float.dval = temp;
#endif
        }
      p[len] = saved_char;      /* restore the input stream */
      if (num != 1)             /* check scanf found ONLY a float ... */
        return ERROR;
      /* See if it has `f' or `l' suffix (float or long double).  */

      c = tolower (p[len - 1]);

      if (c == 'f')
        putithere->typed_val_float.type = builtin_type_float;
      else if (c == 'l')
        putithere->typed_val_float.type = builtin_type_long_double;
      else if (isdigit (c) || c == '.')
        putithere->typed_val_float.type = builtin_type_double;
      else
        return ERROR;

      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')
        {
          if (found_suffix)
            return ERROR;
          n += i = c - '0';
        }
      else
        {
          if (base > 10 && c >= 'a' && c <= 'f')
            {
              if (found_suffix)
                return ERROR;
              n += i = c - 'a' + 10;
            }
          else if (c == 'l')
            {
              ++long_p;
              found_suffix = 1;
            }
          else if (c == 'u')
            {
              unsigned_p = 1;
              found_suffix = 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).  FIXME: Can't we just make n and prevn
         unsigned and avoid this?  */
      if (c != 'l' && c != 'u' && (prevn >= n) && n != 0)
        unsigned_p = 1;         /* Try something unsigned */

      /* Portably test for unsigned overflow.
         FIXME: This check is wrong; for example it doesn't find overflow
         on 0x123456789 when LONGEST is 32 bits.  */
      if (c != 'l' && c != 'u' && n != 0)
        {       
          if ((unsigned_p && (ULONGEST) prevn >= (ULONGEST) n))
            error ("Numeric constant too large.");
        }
      prevn = n;
    }

  /* An integer constant is an int, a long, or a long long.  An L
     suffix forces it to be long; an LL suffix forces it to be long
     long.  If not forced to a larger size, it gets the first type of
     the above that it fits in.  To figure out whether it fits, we
     shift it right and see whether anything remains.  Note that we
     can't shift sizeof (LONGEST) * HOST_CHAR_BIT bits or more in one
     operation, because many compilers will warn about such a shift
     (which always produces a zero result).  Sometimes TARGET_INT_BIT
     or TARGET_LONG_BIT will be that big, sometimes not.  To deal with
     the case where it is we just always shift the value more than
     once, with fewer bits each time.  */

  un = (ULONGEST)n >> 2;
  if (long_p == 0
      && (un >> (TARGET_INT_BIT - 2)) == 0)
    {
      high_bit = ((ULONGEST)1) << (TARGET_INT_BIT-1);

      /* A large decimal (not hex or octal) constant (between INT_MAX
         and UINT_MAX) is a long or unsigned long, according to ANSI,
         never an unsigned int, but this code treats it as unsigned
         int.  This probably should be fixed.  GCC gives a warning on
         such constants.  */

      unsigned_type = builtin_type_unsigned_int;
      signed_type = builtin_type_int;
    }
  else if (long_p <= 1
           && (un >> (TARGET_LONG_BIT - 2)) == 0)
    {
      high_bit = ((ULONGEST)1) << (TARGET_LONG_BIT-1);
      unsigned_type = builtin_type_unsigned_long;
      signed_type = builtin_type_long;
    }
  else
    {
      int shift;
      if (sizeof (ULONGEST) * HOST_CHAR_BIT < TARGET_LONG_LONG_BIT)
        /* A long long does not fit in a LONGEST.  */
        shift = (sizeof (ULONGEST) * HOST_CHAR_BIT - 1);
      else
        shift = (TARGET_LONG_LONG_BIT - 1);
      high_bit = (ULONGEST) 1 << shift;
      unsigned_type = builtin_type_unsigned_long_long;
      signed_type = builtin_type_long_long;
    }

   putithere->typed_val_int.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_int.type = unsigned_type;
     }
   else
     {
       putithere->typed_val_int.type = signed_type;
     }

   return INT;
}

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

static const struct token tokentab3[] =
  {
    {"shr", RSH, BINOP_END},
    {"shl", LSH, BINOP_END},
    {"and", ANDAND, BINOP_END},
    {"div", DIV, BINOP_END},
    {"not", NOT, BINOP_END},
    {"mod", MOD, BINOP_END},
    {"inc", INCREMENT, BINOP_END},
    {"dec", DECREMENT, BINOP_END},
    {"xor", XOR, BINOP_END}
  };

static const struct token tokentab2[] =
  {
    {"or", OR, BINOP_END},
    {"<>", NOTEQUAL, BINOP_END},
    {"<=", LEQ, BINOP_END},
    {">=", GEQ, BINOP_END},
    {":=", ASSIGN, BINOP_END}
  };

/* Allocate uppercased var */
/* make an uppercased copy of tokstart */
static char * uptok (tokstart, namelen)
  char *tokstart;
  int namelen;
{
  int i;
  char *uptokstart = (char *)malloc(namelen+1);
  for (i = 0;i <= namelen;i++)
    {
      if ((tokstart[i]>='a' && tokstart[i]<='z'))
        uptokstart[i] = tokstart[i]-('a'-'A');
      else
        uptokstart[i] = tokstart[i];
    }
  uptokstart[namelen]='\0';
  return uptokstart;
}
/* Read one token, getting characters through lexptr.  */


static int
yylex ()
{
  int c;
  int namelen;
  unsigned int i;
  char *tokstart;
  char *uptokstart;
  char *tokptr;
  char *p;
  int explen, tempbufindex;
  static char *tempbuf;
  static int tempbufsize;

 retry:

  tokstart = lexptr;
  explen = strlen (lexptr);
  /* See if it is a special token of length 3.  */
  if (explen > 2)
    for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
      if (strncasecmp (tokstart, tokentab3[i].operator, 3) == 0
          && (!isalpha (tokentab3[i].operator[0]) || explen == 3
              || (!isalpha (tokstart[3]) && !isdigit (tokstart[3]) && tokstart[3] != '_')))
        {
          lexptr += 3;
          yylval.opcode = tokentab3[i].opcode;
          return tokentab3[i].token;
        }

  /* See if it is a special token of length 2.  */
  if (explen > 1)
  for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
      if (strncasecmp (tokstart, tokentab2[i].operator, 2) == 0
          && (!isalpha (tokentab2[i].operator[0]) || explen == 2
              || (!isalpha (tokstart[2]) && !isdigit (tokstart[2]) && tokstart[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 object pascal
         for example). */
      lexptr++;
      c = *lexptr++;
      if (c == '\\')
        c = parse_escape (&lexptr);
      else if (c == '\'')
        error ("Empty character constant.");

      yylval.typed_val_int.val = c;
      yylval.typed_val_int.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++;
              uptokstart = uptok(tokstart,namelen);
              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 '}':
    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 == '<');)
    {
      /* Template parameter lists are part of the name.
         FIXME: This mishandles `print $a<4&&$a>3'.  */
      if (c == '<')
        {
          int i = namelen;
          int nesting_level = 1;
          while (tokstart[++i])
            {
              if (tokstart[i] == '<')
                nesting_level++;
              else if (tokstart[i] == '>')
                {
                  if (--nesting_level == 0)
                    break;
                }
            }
          if (tokstart[i] == '>')
            namelen = i;
          else
            break;
        }

      /* do NOT uppercase internals because of registers !!! */
      c = tokstart[++namelen];
    }

  uptokstart = uptok(tokstart,namelen);

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

  lexptr += namelen;

  tryname:

  /* Catch specific keywords.  Should be done with a data structure.  */
  switch (namelen)
    {
    case 6:
      if (STREQ (uptokstart, "OBJECT"))
        return CLASS;
      if (STREQ (uptokstart, "RECORD"))
        return STRUCT;
      if (STREQ (uptokstart, "SIZEOF"))
        return SIZEOF;
      break;
    case 5:
      if (STREQ (uptokstart, "CLASS"))
        return CLASS;
      if (STREQ (uptokstart, "FALSE"))
        {
          yylval.lval = 0;
          return FALSE;
        }
      break;
    case 4:
      if (STREQ (uptokstart, "TRUE"))
        {
          yylval.lval = 1;
          return TRUE;
        }
      if (STREQ (uptokstart, "SELF"))
        {
          /* here we search for 'this' like
             inserted in FPC stabs debug info */
          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;
    default:
      break;
    }

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

  if (*tokstart == '$')
    {
      /* $ is the normal prefix for pascal hexadecimal values
        but this conflicts with the GDB use for debugger variables
        so in expression to enter hexadecimal values
        we still need to use C syntax with 0xff  */
      write_dollar_variable (yylval.sval);
      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,
                         &is_a_field_of_this,
                         (struct symtab **) NULL);
    /* second chance uppercased (as Free Pascal does).  */
    if (!sym && !is_a_field_of_this)
      {
       for (i = 0; i <= namelen; i++)
         {
           if ((tmp[i] >= 'a' && tmp[i] <= 'z'))
             tmp[i] -= ('a'-'A');
         }
       sym = lookup_symbol (tmp, expression_context_block,
                        VAR_NAMESPACE,
                        &is_a_field_of_this,
                        (struct symtab **) NULL);
       if (sym || is_a_field_of_this)
         for (i = 0; i <= namelen; i++)
           {
             if ((tokstart[i] >= 'a' && tokstart[i] <= 'z'))
               tokstart[i] -= ('a'-'A');
           }
      }
    /* Third chance Capitalized (as GPC does).  */
    if (!sym && !is_a_field_of_this)
      {
       for (i = 0; i <= namelen; i++)
         {
           if (i == 0)
             {
              if ((tmp[i] >= 'a' && tmp[i] <= 'z'))
                tmp[i] -= ('a'-'A');
             }
           else
           if ((tmp[i] >= 'A' && tmp[i] <= 'Z'))
             tmp[i] -= ('A'-'a');
          }
       sym = lookup_symbol (tmp, expression_context_block,
                         VAR_NAMESPACE,
                         &is_a_field_of_this,
                         (struct symtab **) NULL);
        if (sym || is_a_field_of_this)
          for (i = 0; i <= namelen; i++)
            {
              if (i == 0)
                {
                  if ((tokstart[i] >= 'a' && tokstart[i] <= 'z'))
                    tokstart[i] -= ('a'-'A');
                }
              else
                if ((tokstart[i] >= 'A' && tokstart[i] <= 'Z'))
                  tokstart[i] -= ('A'-'a');
            }
      }
    /* 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)
        {
#if 1
          /* Despite the following flaw, we need to keep this code enabled.
             Because we can get called from check_stub_method, if we don't
             handle nested types then it screws many operations in any
             program which uses nested types.  */
          /* In "A::x", if x is a member function of A and there happens
             to be a type (nested or not, since the stabs don't make that
             distinction) named x, then this code incorrectly thinks we
             are dealing with nested types rather than a member function.  */

          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 *ncopy = alloca (strlen (tmp)+strlen (namestart)+3);
                      char *tmp1;

                      tmp1 = ncopy;
                      memcpy (tmp1, tmp, strlen (tmp));
                      tmp1 += strlen (tmp);
                      memcpy (tmp1, "::", 2);
                      tmp1 += 2;
                      memcpy (tmp1, namestart, p - namestart);
                      tmp1[p - namestart] = '\0';
                      cur_sym = lookup_symbol (ncopy, 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);
#else /* not 0 */
          yylval.tsym.type = SYMBOL_TYPE (sym);
#endif /* not 0 */
          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;
          }
      }

    free(uptokstart);
    /* 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 ("A %s in expression, near `%s'.", (msg ? msg : "error"), lexptr);
}