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/* Parse expressions for GDB.

   Copyright 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,

   1998, 1999, 2000, 2001 Free Software Foundation, Inc.

   Modified from expread.y by the Department of Computer Science at the

   State University of New York at Buffalo, 1991.

   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.  */

/* Parse an 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 <ctype.h>

#include "defs.h"

#include "gdb_string.h"

#include "symtab.h"

#include "gdbtypes.h"

#include "frame.h"

#include "expression.h"

#include "value.h"

#include "command.h"

#include "language.h"

#include "parser-defs.h"

#include "gdbcmd.h"

#include "symfile.h"            /* for overlay functions */

#include "inferior.h"           /* for NUM_PSEUDO_REGS.  NOTE: replace 

                                   with "gdbarch.h" when appropriate.  */

/* Symbols which architectures can redefine.  */

/* Some systems have routines whose names start with `$'.  Giving this

   macro a non-zero value tells GDB's expression parser to check for

   such routines when parsing tokens that begin with `$'.

   On HP-UX, certain system routines (millicode) have names beginning

   with `$' or `$$'.  For example, `$$dyncall' is a millicode routine

   that handles inter-space procedure calls on PA-RISC.  */

#ifndef SYMBOLS_CAN_START_WITH_DOLLAR

#define SYMBOLS_CAN_START_WITH_DOLLAR (0)

#endif

/* Global variables declared in parser-defs.h (and commented there).  */

struct expression *expout;

int expout_size;

int expout_ptr;

struct block *expression_context_block;

struct block *innermost_block;

int arglist_len;

union type_stack_elt *type_stack;

int type_stack_depth, type_stack_size;

char *lexptr;

char *namecopy;

int paren_depth;

int comma_terminates;

static int expressiondebug = 0;

extern int hp_som_som_object_present;

static void free_funcalls (void *ignore);

static void prefixify_expression (struct expression *);

static void

prefixify_subexp (struct expression *, struct expression *, int, int);

void _initialize_parse (void);

/* Data structure for saving values of arglist_len for function calls whose

   arguments contain other function calls.  */

struct funcall

  {

    struct funcall *next;

    int arglist_len;

  };

static struct funcall *funcall_chain;

/* Assign machine-independent names to certain registers

   (unless overridden by the REGISTER_NAMES table) */

unsigned num_std_regs = 0;

struct std_regs *std_regs;

/* The generic method for targets to specify how their registers are

   named.  The mapping can be derived from three sources:

   REGISTER_NAME; std_regs; or a target specific alias hook. */

int

target_map_name_to_register (char *str, int len)

{

  int i;

  /* First try target specific aliases. We try these first because on some

     systems standard names can be context dependent (eg. $pc on a

     multiprocessor can be could be any of several PCs).  */

#ifdef REGISTER_NAME_ALIAS_HOOK

  i = REGISTER_NAME_ALIAS_HOOK (str, len);

  if (i >= 0)

    return i;

#endif

  /* Search architectural register name space. */

  for (i = 0; i < NUM_REGS; i++)

    if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i))

        && STREQN (str, REGISTER_NAME (i), len))

      {

        return i;

      }

  /* Try pseudo-registers, if any. */

  for (i = NUM_REGS; i < NUM_REGS + NUM_PSEUDO_REGS; i++)

    if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i))

        && STREQN (str, REGISTER_NAME (i), len))

      {

        return i;

      }

  /* Try standard aliases. */

  for (i = 0; i < num_std_regs; i++)

    if (std_regs[i].name && len == strlen (std_regs[i].name)

        && STREQN (str, std_regs[i].name, len))

      {

        return std_regs[i].regnum;

      }

  return -1;

}

/* Begin counting arguments for a function call,

   saving the data about any containing call.  */

void

start_arglist (void)

{

  register struct funcall *new;

  new = (struct funcall *) xmalloc (sizeof (struct funcall));

  new->next = funcall_chain;

  new->arglist_len = arglist_len;

  arglist_len = 0;

  funcall_chain = new;

}

/* Return the number of arguments in a function call just terminated,

   and restore the data for the containing function call.  */

int

end_arglist (void)

{

  register int val = arglist_len;

  register struct funcall *call = funcall_chain;

  funcall_chain = call->next;

  arglist_len = call->arglist_len;

  xfree (call);

  return val;

}

/* Free everything in the funcall chain.

   Used when there is an error inside parsing.  */

static void

free_funcalls (void *ignore)

{

  register struct funcall *call, *next;

  for (call = funcall_chain; call; call = next)

    {

      next = call->next;

      xfree (call);

    }

}

/* This page contains the functions for adding data to the  struct expression

   being constructed.  */

/* Add one element to the end of the expression.  */

/* To avoid a bug in the Sun 4 compiler, we pass things that can fit into

   a register through here */

void

write_exp_elt (union exp_element expelt)

{

  if (expout_ptr >= expout_size)

    {

      expout_size *= 2;

      expout = (struct expression *)

        xrealloc ((char *) expout, sizeof (struct expression)

                  + EXP_ELEM_TO_BYTES (expout_size));

    }

  expout->elts[expout_ptr++] = expelt;

}

void

write_exp_elt_opcode (enum exp_opcode expelt)

{

  union exp_element tmp;

  tmp.opcode = expelt;

  write_exp_elt (tmp);

}

void

write_exp_elt_sym (struct symbol *expelt)

{

  union exp_element tmp;

  tmp.symbol = expelt;

  write_exp_elt (tmp);

}

void

write_exp_elt_block (struct block *b)

{

  union exp_element tmp;

  tmp.block = b;

  write_exp_elt (tmp);

}

void

write_exp_elt_longcst (LONGEST expelt)

{

  union exp_element tmp;

  tmp.longconst = expelt;

  write_exp_elt (tmp);

}

void

write_exp_elt_dblcst (DOUBLEST expelt)

{

  union exp_element tmp;

  tmp.doubleconst = expelt;

  write_exp_elt (tmp);

}

void

write_exp_elt_type (struct type *expelt)

{

  union exp_element tmp;

  tmp.type = expelt;

  write_exp_elt (tmp);

}

void

write_exp_elt_intern (struct internalvar *expelt)

{

  union exp_element tmp;

  tmp.internalvar = expelt;

  write_exp_elt (tmp);

}

/* Add a string constant to the end of the expression.

   String constants are stored by first writing an expression element

   that contains the length of the string, then stuffing the string

   constant itself into however many expression elements are needed

   to hold it, and then writing another expression element that contains

   the length of the string.  I.E. an expression element at each end of

   the string records the string length, so you can skip over the

   expression elements containing the actual string bytes from either

   end of the string.  Note that this also allows gdb to handle

   strings with embedded null bytes, as is required for some languages.

   Don't be fooled by the fact that the string is null byte terminated,

   this is strictly for the convenience of debugging gdb itself.  Gdb

   Gdb does not depend up the string being null terminated, since the

   actual length is recorded in expression elements at each end of the

   string.  The null byte is taken into consideration when computing how

   many expression elements are required to hold the string constant, of

   course. */

void

write_exp_string (struct stoken str)

{

  register int len = str.length;

  register int lenelt;

  register char *strdata;

  /* Compute the number of expression elements required to hold the string

     (including a null byte terminator), along with one expression element

     at each end to record the actual string length (not including the

     null byte terminator). */

  lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);

  /* Ensure that we have enough available expression elements to store

     everything. */

  if ((expout_ptr + lenelt) >= expout_size)

    {

      expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);

      expout = (struct expression *)

        xrealloc ((char *) expout, (sizeof (struct expression)

                                    + EXP_ELEM_TO_BYTES (expout_size)));

    }

  /* Write the leading length expression element (which advances the current

     expression element index), then write the string constant followed by a

     terminating null byte, and then write the trailing length expression

     element. */

  write_exp_elt_longcst ((LONGEST) len);

  strdata = (char *) &expout->elts[expout_ptr];

  memcpy (strdata, str.ptr, len);

  *(strdata + len) = '\0';

  expout_ptr += lenelt - 2;

  write_exp_elt_longcst ((LONGEST) len);

}

/* Add a bitstring constant to the end of the expression.

   Bitstring constants are stored by first writing an expression element

   that contains the length of the bitstring (in bits), then stuffing the

   bitstring constant itself into however many expression elements are

   needed to hold it, and then writing another expression element that

   contains the length of the bitstring.  I.E. an expression element at

   each end of the bitstring records the bitstring length, so you can skip

   over the expression elements containing the actual bitstring bytes from

   either end of the bitstring. */

void

write_exp_bitstring (struct stoken str)

{

  register int bits = str.length;       /* length in bits */

  register int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;

  register int lenelt;

  register char *strdata;

  /* Compute the number of expression elements required to hold the bitstring,

     along with one expression element at each end to record the actual

     bitstring length in bits. */

  lenelt = 2 + BYTES_TO_EXP_ELEM (len);

  /* Ensure that we have enough available expression elements to store

     everything. */

  if ((expout_ptr + lenelt) >= expout_size)

    {

      expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);

      expout = (struct expression *)

        xrealloc ((char *) expout, (sizeof (struct expression)

                                    + EXP_ELEM_TO_BYTES (expout_size)));

    }

  /* Write the leading length expression element (which advances the current

     expression element index), then write the bitstring constant, and then

     write the trailing length expression element. */

  write_exp_elt_longcst ((LONGEST) bits);

  strdata = (char *) &expout->elts[expout_ptr];

  memcpy (strdata, str.ptr, len);

  expout_ptr += lenelt - 2;

  write_exp_elt_longcst ((LONGEST) bits);

}

/* Add the appropriate elements for a minimal symbol to the end of

   the expression.  The rationale behind passing in text_symbol_type and

   data_symbol_type was so that Modula-2 could pass in WORD for

   data_symbol_type.  Perhaps it still is useful to have those types vary

   based on the language, but they no longer have names like "int", so

   the initial rationale is gone.  */

static struct type *msym_text_symbol_type;

static struct type *msym_data_symbol_type;

static struct type *msym_unknown_symbol_type;

void

write_exp_msymbol (struct minimal_symbol *msymbol,

                   struct type *text_symbol_type,

                   struct type *data_symbol_type)

{

  CORE_ADDR addr;

  write_exp_elt_opcode (OP_LONG);

  /* Let's make the type big enough to hold a 64-bit address.  */

  write_exp_elt_type (builtin_type_CORE_ADDR);

  addr = SYMBOL_VALUE_ADDRESS (msymbol);

  if (overlay_debugging)

    addr = symbol_overlayed_address (addr, SYMBOL_BFD_SECTION (msymbol));

  write_exp_elt_longcst ((LONGEST) addr);

  write_exp_elt_opcode (OP_LONG);

  write_exp_elt_opcode (UNOP_MEMVAL);

  switch (msymbol->type)

    {

    case mst_text:

    case mst_file_text:

    case mst_solib_trampoline:

      write_exp_elt_type (msym_text_symbol_type);

      break;

    case mst_data:

    case mst_file_data:

    case mst_bss:

    case mst_file_bss:

      write_exp_elt_type (msym_data_symbol_type);

      break;

    default:

      write_exp_elt_type (msym_unknown_symbol_type);

      break;

    }

  write_exp_elt_opcode (UNOP_MEMVAL);

}

/* Recognize tokens that start with '$'.  These include:

   $regname     A native register name or a "standard

   register name".

   $variable    A convenience variable with a name chosen

   by the user.

   $digits              Value history with index <digits>, starting

   from the first value which has index 1.

   $$digits     Value history with index <digits> relative

   to the last value.  I.E. $$0 is the last

   value, $$1 is the one previous to that, $$2

   is the one previous to $$1, etc.

   $ | $0 | $$0 The last value in the value history.

   $$           An abbreviation for the second to the last

   value in the value history, I.E. $$1

 */

void

write_dollar_variable (struct stoken str)

{

  /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)

     and $$digits (equivalent to $<-digits> if you could type that). */

  int negate = 0;

  int i = 1;

  /* Double dollar means negate the number and add -1 as well.

     Thus $$ alone means -1.  */

  if (str.length >= 2 && str.ptr[1] == '$')

    {

      negate = 1;

      i = 2;

    }

  if (i == str.length)

    {

      /* Just dollars (one or two) */

      i = -negate;

      goto handle_last;

    }

  /* Is the rest of the token digits?  */

  for (; i < str.length; i++)

    if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))

      break;

  if (i == str.length)

    {

      i = atoi (str.ptr + 1 + negate);

      if (negate)

        i = -i;

      goto handle_last;

    }

  /* Handle tokens that refer to machine registers:

     $ followed by a register name.  */

  i = target_map_name_to_register (str.ptr + 1, str.length - 1);

  if (i >= 0)

    goto handle_register;

  if (SYMBOLS_CAN_START_WITH_DOLLAR)

    {

      struct symbol *sym = NULL;

      struct minimal_symbol *msym = NULL;

      /* On HP-UX, certain system routines (millicode) have names beginning

         with $ or $$, e.g. $$dyncall, which handles inter-space procedure

         calls on PA-RISC. Check for those, first. */

      /* This code is not enabled on non HP-UX systems, since worst case

         symbol table lookup performance is awful, to put it mildly. */

      sym = lookup_symbol (copy_name (str), (struct block *) NULL,

                           VAR_NAMESPACE, (int *) NULL, (struct symtab **) NULL);

      if (sym)

        {

          write_exp_elt_opcode (OP_VAR_VALUE);

          write_exp_elt_block (block_found);    /* set by lookup_symbol */

          write_exp_elt_sym (sym);

          write_exp_elt_opcode (OP_VAR_VALUE);

          return;

        }

      msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);

      if (msym)

        {

          write_exp_msymbol (msym,

                             lookup_function_type (builtin_type_int),

                             builtin_type_int);

          return;

        }

    }

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

  write_exp_elt_opcode (OP_INTERNALVAR);

  write_exp_elt_intern (lookup_internalvar (copy_name (str) + 1));

  write_exp_elt_opcode (OP_INTERNALVAR);

  return;

handle_last:

  write_exp_elt_opcode (OP_LAST);

  write_exp_elt_longcst ((LONGEST) i);

  write_exp_elt_opcode (OP_LAST);

  return;

handle_register:

  write_exp_elt_opcode (OP_REGISTER);

  write_exp_elt_longcst (i);

  write_exp_elt_opcode (OP_REGISTER);

  return;

}

/* Parse a string that is possibly a namespace / nested class

   specification, i.e., something of the form A::B::C::x.  Input

   (NAME) is the entire string; LEN is the current valid length; the

   output is a string, TOKEN, which points to the largest recognized

   prefix which is a series of namespaces or classes.  CLASS_PREFIX is

   another output, which records whether a nested class spec was

   recognized (= 1) or a fully qualified variable name was found (=

   0).  ARGPTR is side-effected (if non-NULL) to point to beyond the

   string recognized and consumed by this routine.

   The return value is a pointer to the symbol for the base class or

   variable if found, or NULL if not found.  Callers must check this

   first -- if NULL, the outputs may not be correct.

   This function is used c-exp.y.  This is used specifically to get

   around HP aCC (and possibly other compilers), which insists on

   generating names with embedded colons for namespace or nested class

   members.

   (Argument LEN is currently unused. 1997-08-27)

   Callers must free memory allocated for the output string TOKEN.  */

static const char coloncolon[2] =

{':', ':'};

struct symbol *

parse_nested_classes_for_hpacc (char *name, int len, char **token,

                                int *class_prefix, char **argptr)

{

  /* Comment below comes from decode_line_1 which has very similar

     code, which is called for "break" command parsing. */

  /* We have what looks like a class or namespace

     scope specification (A::B), possibly with many

     levels of namespaces or classes (A::B::C::D).

     Some versions of the HP ANSI C++ compiler (as also possibly

     other compilers) generate class/function/member names with

     embedded double-colons if they are inside namespaces. To

     handle this, we loop a few times, considering larger and

     larger prefixes of the string as though they were single

     symbols.  So, if the initially supplied string is

     A::B::C::D::foo, we have to look up "A", then "A::B",

     then "A::B::C", then "A::B::C::D", and finally

     "A::B::C::D::foo" as single, monolithic symbols, because

     A, B, C or D may be namespaces.

     Note that namespaces can nest only inside other

     namespaces, and not inside classes.  So we need only

     consider *prefixes* of the string; there is no need to look up

     "B::C" separately as a symbol in the previous example. */

  register char *p;

  char *start, *end;

  char *prefix = NULL;

  char *tmp;

  struct symbol *sym_class = NULL;

  struct symbol *sym_var = NULL;

  struct type *t;

  int prefix_len = 0;

  int done = 0;

  char *q;

  /* Check for HP-compiled executable -- in other cases

     return NULL, and caller must default to standard GDB

     behaviour. */

  if (!hp_som_som_object_present)

    return (struct symbol *) NULL;

  p = name;

  /* Skip over whitespace and possible global "::" */

  while (*p && (*p == ' ' || *p == '\t'))

    p++;

  if (p[0] == ':' && p[1] == ':')

    p += 2;

  while (*p && (*p == ' ' || *p == '\t'))

    p++;

  while (1)

    {

      /* Get to the end of the next namespace or class spec. */

      /* If we're looking at some non-token, fail immediately */

      start = p;

      if (!(isalpha (*p) || *p == '$' || *p == '_'))

        return (struct symbol *) NULL;

      p++;

      while (*p && (isalnum (*p) || *p == '$' || *p == '_'))

        p++;

      if (*p == '<')

        {

          /* If we have the start of a template specification,

             scan right ahead to its end */

          q = find_template_name_end (p);

          if (q)

            p = q;

        }

      end = p;

      /* Skip over "::" and whitespace for next time around */

      while (*p && (*p == ' ' || *p == '\t'))

        p++;

      if (p[0] == ':' && p[1] == ':')

        p += 2;

      while (*p && (*p == ' ' || *p == '\t'))

        p++;

      /* Done with tokens? */

      if (!*p || !(isalpha (*p) || *p == '$' || *p == '_'))

        done = 1;

      tmp = (char *) alloca (prefix_len + end - start + 3);

      if (prefix)

        {

          memcpy (tmp, prefix, prefix_len);

          memcpy (tmp + prefix_len, coloncolon, 2);

          memcpy (tmp + prefix_len + 2, start, end - start);

          tmp[prefix_len + 2 + end - start] = '\000';

        }

      else

        {

          memcpy (tmp, start, end - start);

          tmp[end - start] = '\000';

        }

      prefix = tmp;

      prefix_len = strlen (prefix);

      /* See if the prefix we have now is something we know about */

      if (!done)

        {

          /* More tokens to process, so this must be a class/namespace */

          sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE,

                                     0, (struct symtab **) NULL);

        }

      else

        {

          /* No more tokens, so try as a variable first */

          sym_var = lookup_symbol (prefix, 0, VAR_NAMESPACE,

                                   0, (struct symtab **) NULL);

          /* If failed, try as class/namespace */

          if (!sym_var)

            sym_class = lookup_symbol (prefix, 0, STRUCT_NAMESPACE,

                                       0, (struct symtab **) NULL);

        }

      if (sym_var ||

          (sym_class &&

           (t = check_typedef (SYMBOL_TYPE (sym_class)),

            (TYPE_CODE (t) == TYPE_CODE_STRUCT

             || TYPE_CODE (t) == TYPE_CODE_UNION))))

        {

          /* We found a valid token */

          *token = (char *) xmalloc (prefix_len + 1);

          memcpy (*token, prefix, prefix_len);

          (*token)[prefix_len] = '\000';

          break;

        }