symtab.c

早期freebsd实现

/* Symbol table lookup for the GNU debugger, GDB.
   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992
   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.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "gdbcore.h"
#include "frame.h"
#include "target.h"
#include "value.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdbcmd.h"
#include "call-cmds.h"
#include "regex.h"
#include "expression.h"
#include "language.h"
#include "demangle.h"

#include <obstack.h>
#include <assert.h>

#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <ctype.h>

/* Prototypes for local functions */

static char *
expensive_mangler PARAMS ((const char *));

extern int
find_methods PARAMS ((struct type *, char *, char **, struct symbol **));

static void
completion_list_add_symbol PARAMS ((char *, char *, int));

static struct symtabs_and_lines
decode_line_2 PARAMS ((struct symbol *[], int, int));

static void
rbreak_command PARAMS ((char *, int));

static void
types_info PARAMS ((char *, int));

static void
functions_info PARAMS ((char *, int));

static void
variables_info PARAMS ((char *, int));

static void
sources_info PARAMS ((char *, int));

static void
list_symbols PARAMS ((char *, int, int));

static void
output_source_filename PARAMS ((char *, int *));

static char *
operator_chars PARAMS ((char *, char **));

static int
find_line_common PARAMS ((struct linetable *, int, int *));

static struct partial_symbol *
lookup_partial_symbol PARAMS ((struct partial_symtab *, const char *,
			       int, enum namespace));

static struct partial_symbol *
lookup_demangled_partial_symbol PARAMS ((const struct partial_symtab *,
					 const char *));

static struct symbol *
lookup_demangled_block_symbol PARAMS ((const struct block *, const char *));

static struct symtab *
lookup_symtab_1 PARAMS ((char *));

/* */

/* The single non-language-specific builtin type */
struct type *builtin_type_error;

/* Block in which the most recently searched-for symbol was found.
   Might be better to make this a parameter to lookup_symbol and 
   value_of_this. */

const struct block *block_found;

char no_symtab_msg[] = "No symbol table is loaded.  Use the \"file\" command.";

/* While the C++ support is still in flux, issue a possibly helpful hint on
   using the new command completion feature on single quoted demangled C++
   symbols.  Remove when loose ends are cleaned up.   FIXME -fnf */

void
cplusplus_hint (name)
     char *name;
{
  printf ("Hint: try '%s<TAB> or '%s<ESC-?>\n", name, name);
  printf ("(Note leading single quote.)\n");
}

/* Check for a symtab of a specific name; first in symtabs, then in
   psymtabs.  *If* there is no '/' in the name, a match after a '/'
   in the symtab filename will also work.  */

static struct symtab *
lookup_symtab_1 (name)
     char *name;
{
  register struct symtab *s;
  register struct partial_symtab *ps;
  register char *slash;
  register struct objfile *objfile;

 got_symtab:

  /* First, search for an exact match */

  ALL_SYMTABS (objfile, s)
    if (strcmp (name, s->filename) == 0)
      return s;

  slash = strchr (name, '/');

  /* Now, search for a matching tail (only if name doesn't have any dirs) */

  if (!slash)
    ALL_SYMTABS (objfile, s)
      {
	char *p = s -> filename;
	char *tail = strrchr (p, '/');

	if (tail)
	  p = tail + 1;

	if (strcmp (p, name) == 0)
	  return s;
      }

  /* Same search rules as above apply here, but now we look thru the
     psymtabs.  */

  ALL_PSYMTABS (objfile, ps)
    if (strcmp (name, ps -> filename) == 0)
      goto got_psymtab;

  if (!slash)
    ALL_PSYMTABS (objfile, ps)
      {
	char *p = ps -> filename;
	char *tail = strrchr (p, '/');

	if (tail)
	  p = tail + 1;

	if (strcmp (p, name) == 0)
	  goto got_psymtab;
      }

  return (NULL);

 got_psymtab:

  if (ps -> readin)
    error ("Internal: readin %s pst for `%s' found when no symtab found.",
	   ps -> filename, name);

  s = PSYMTAB_TO_SYMTAB (ps);

  if (s)
    return s;

  /* At this point, we have located the psymtab for this file, but
     the conversion to a symtab has failed.  This usually happens
     when we are looking up an include file.  In this case,
     PSYMTAB_TO_SYMTAB doesn't return a symtab, even though one has
     been created.  So, we need to run through the symtabs again in
     order to find the file.
     XXX - This is a crock, and should be fixed inside of the the
     symbol parsing routines. */
  goto got_symtab;
}

/* Lookup the symbol table of a source file named NAME.  Try a couple
   of variations if the first lookup doesn't work.  */

struct symtab *
lookup_symtab (name)
     char *name;
{
  register struct symtab *s;
  register char *copy;

  s = lookup_symtab_1 (name);
  if (s) return s;

  /* If name not found as specified, see if adding ".c" helps.  */

  copy = (char *) alloca (strlen (name) + 3);
  strcpy (copy, name);
  strcat (copy, ".c");
  s = lookup_symtab_1 (copy);
  if (s) return s;

  /* We didn't find anything; die.  */
  return 0;
}

/* Lookup the partial symbol table of a source file named NAME.  This
   only returns true on an exact match (ie. this semantics are
   different from lookup_symtab.  */

struct partial_symtab *
lookup_partial_symtab (name)
char *name;
{
  register struct partial_symtab *pst;
  register struct objfile *objfile;
  
  ALL_PSYMTABS (objfile, pst)
    {
      if (strcmp (name, pst -> filename) == 0)
	{
	  return (pst);
	}
    }
  return (NULL);
}

/* Demangle a GDB method stub type.  */
char *
gdb_mangle_name (type, i, j)
     struct type *type;
     int i, j;
{
  int mangled_name_len;
  char *mangled_name;
  struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
  struct fn_field *method = &f[j];
  char *field_name = TYPE_FN_FIELDLIST_NAME (type, i);
  char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
  char *newname = type_name_no_tag (type);
  int is_constructor = strcmp(field_name, newname) == 0;
  int is_destructor = is_constructor && physname[0] == '_'
      && physname[1] == CPLUS_MARKER && physname[2] == '_';
  /* Need a new type prefix.  */
  char *const_prefix = method->is_const ? "C" : "";
  char *volatile_prefix = method->is_volatile ? "V" : "";
  char buf[20];
#ifndef GCC_MANGLE_BUG
  int len = strlen (newname);

  if (is_destructor)
    {
      mangled_name = (char*) xmalloc(strlen(physname)+1);
      strcpy(mangled_name, physname);
      return mangled_name;
    }

  sprintf (buf, "__%s%s%d", const_prefix, volatile_prefix, len);
  mangled_name_len = ((is_constructor ? 0 : strlen (field_name))
			  + strlen (buf) + len
			  + strlen (physname)
			  + 1);

  /* Only needed for GNU-mangled names.  ANSI-mangled names
     work with the normal mechanisms.  */
  if (OPNAME_PREFIX_P (field_name))
    {
      char *opname = cplus_mangle_opname (field_name + 3, 0);
      if (opname == NULL)
	error ("No mangling for \"%s\"", field_name);
      mangled_name_len += strlen (opname);
      mangled_name = (char *)xmalloc (mangled_name_len);

      strncpy (mangled_name, field_name, 3);
      mangled_name[3] = '\0';
      strcat (mangled_name, opname);
    }
  else
    {
      mangled_name = (char *)xmalloc (mangled_name_len);
      if (is_constructor)
	mangled_name[0] = '\0';
      else
	strcpy (mangled_name, field_name);
    }
  strcat (mangled_name, buf);
  strcat (mangled_name, newname);
#else
  char *opname;

  if (is_constructor)
    {
      buf[0] = '\0';
    }
  else
    {
      sprintf (buf, "__%s%s", const_prefix, volatile_prefix);
    }

  mangled_name_len = ((is_constructor ? 0 : strlen (field_name))
		      + strlen (buf) + strlen (physname) + 1);

  /* Only needed for GNU-mangled names.  ANSI-mangled names
     work with the normal mechanisms.  */
  if (OPNAME_PREFIX_P (field_name))
    {
      opname = cplus_mangle_opname (field_name + 3, 0);
      if (opname == NULL)
	{
	  error ("No mangling for \"%s\"", field_name);
	}
      mangled_name_len += strlen (opname);
      mangled_name = (char *) xmalloc (mangled_name_len);

      strncpy (mangled_name, field_name, 3);
      strcpy (mangled_name + 3, opname);
    }
  else
    {
      mangled_name = (char *) xmalloc (mangled_name_len);
      if (is_constructor)
	{
	  mangled_name[0] = '\0';
	}
      else
	{
	  strcpy (mangled_name, field_name);
	}
    }
  strcat (mangled_name, buf);

#endif
  strcat (mangled_name, physname);
  return (mangled_name);
}


/* Find which partial symtab on contains PC.  Return 0 if none.  */

struct partial_symtab *
find_pc_psymtab (pc)
     register CORE_ADDR pc;
{
  register struct partial_symtab *pst;
  register struct objfile *objfile;

  ALL_PSYMTABS (objfile, pst)
    {
      if (pc >= pst -> textlow && pc < pst -> texthigh)
	{
	  return (pst);
	}
    }
  return (NULL);
}

/* Find which partial symbol within a psymtab contains PC.  Return 0
   if none.  Check all psymtabs if PSYMTAB is 0.  */
struct partial_symbol *
find_pc_psymbol (psymtab, pc)
     struct partial_symtab *psymtab;
     CORE_ADDR pc;
{
  struct partial_symbol *best, *p;
  CORE_ADDR best_pc;
  
  if (!psymtab)
    psymtab = find_pc_psymtab (pc);
  if (!psymtab)
    return 0;

  best_pc = psymtab->textlow - 1;

  for (p = psymtab->objfile->static_psymbols.list + psymtab->statics_offset;
       (p - (psymtab->objfile->static_psymbols.list + psymtab->statics_offset)
	< psymtab->n_static_syms);
       p++)
    if (SYMBOL_NAMESPACE (p) == VAR_NAMESPACE
	&& SYMBOL_CLASS (p) == LOC_BLOCK
	&& pc >= SYMBOL_VALUE_ADDRESS (p)
	&& SYMBOL_VALUE_ADDRESS (p) > best_pc)
      {
	best_pc = SYMBOL_VALUE_ADDRESS (p);
	best = p;
      }
  if (best_pc == psymtab->textlow - 1)
    return 0;
  return best;
}


/* Find the definition for a specified symbol name NAME
   in namespace NAMESPACE, visible from lexical block BLOCK.
   Returns the struct symbol pointer, or zero if no symbol is found.
   If SYMTAB is non-NULL, store the symbol table in which the
   symbol was found there, or NULL if not found.
   C++: if IS_A_FIELD_OF_THIS is nonzero on entry, check to see if
   NAME is a field of the current implied argument `this'.  If so set
   *IS_A_FIELD_OF_THIS to 1, otherwise set it to zero. 
   BLOCK_FOUND is set to the block in which NAME is found (in the case of
   a field of `this', value_of_this sets BLOCK_FOUND to the proper value.) */

struct symbol *
lookup_symbol (name, block, namespace, is_a_field_of_this, symtab)
     const char *name;
     register const struct block *block;
     const enum namespace namespace;
     int *is_a_field_of_this;
     struct symtab **symtab;
{
  register struct symbol *sym;
  register struct symtab *s;
  register struct partial_symtab *ps;
  struct blockvector *bv;
  register struct objfile *objfile;
  register struct block *b;
  register struct minimal_symbol *msymbol;
  char *temp;
  extern char *gdb_completer_word_break_characters;

  /* If NAME contains any characters from gdb_completer_word_break_characters
     then it is probably from a quoted name string.  So check to see if it
     has a C++ mangled equivalent, and if so, use the mangled equivalent. */

  if (strpbrk (name, gdb_completer_word_break_characters) != NULL)
    {
      if ((temp = expensive_mangler (name)) != NULL)
	{
	  name = temp;
	}
    }

  /* Search specified block and its superiors.  */

  while (block != 0)
    {
      sym = lookup_block_symbol (block, name, namespace);
      if (sym) 
	{
	  block_found = block;
	  if (symtab != NULL)
	    {
	      /* Search the list of symtabs for one which contains the
		 address of the start of this block.  */
	      ALL_SYMTABS (objfile, s)
		{
		  bv = BLOCKVECTOR (s);
		  b = BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK);
		  if (BLOCK_START (b) <= BLOCK_START (block)
		      && BLOCK_END (b) > BLOCK_START (block))
		    goto found;
		}
found:
	      *symtab = s;
	    }

	  return (sym);
	}
      block = BLOCK_SUPERBLOCK (block);
    }

  /* But that doesn't do any demangling for the STATIC_BLOCK.