partial-stab.h

早期freebsd实现

/* Shared code to pre-read a stab (dbx-style), when building a psymtab.
   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.  */

/* The following need to be defined:
   SET_NAMESTRING() --Set namestring to name of symbol.
   CUR_SYMBOL_TYPE --Type code of current symbol.
   CUR_SYMBOL_VALUE --Value field of current symbol.  May be adjusted here.
 */

/* End of macro definitions, now let's handle them symbols!  */

      switch (CUR_SYMBOL_TYPE)
	{
	  char *p;
	  /*
	   * Standard, external, non-debugger, symbols
	   */

	case N_TEXT | N_EXT:
	case N_NBTEXT | N_EXT:
	  CUR_SYMBOL_VALUE += ANOFFSET (section_offsets, SECT_OFF_TEXT);
	  goto record_it;

	case N_DATA | N_EXT:
	case N_NBDATA | N_EXT:
	  CUR_SYMBOL_VALUE += ANOFFSET (section_offsets, SECT_OFF_DATA);
	  goto record_it;

	case N_BSS | N_EXT:
	case N_NBBSS | N_EXT:
        case N_SETV | N_EXT:		/* FIXME, is this in BSS? */
	  CUR_SYMBOL_VALUE += ANOFFSET (section_offsets, SECT_OFF_BSS);
	  goto record_it;

	case N_ABS | N_EXT:
	record_it:
#ifdef DBXREAD_ONLY
	  SET_NAMESTRING();

	bss_ext_symbol:
	  record_minimal_symbol (namestring, CUR_SYMBOL_VALUE,
				 CUR_SYMBOL_TYPE, objfile); /* Always */
#endif /* DBXREAD_ONLY */
	  continue;

	  /* Standard, local, non-debugger, symbols */

	case N_NBTEXT:

	  /* We need to be able to deal with both N_FN or N_TEXT,
	     because we have no way of knowing whether the sys-supplied ld
	     or GNU ld was used to make the executable.  Sequents throw
	     in another wrinkle -- they renumbered N_FN.  */

	case N_FN:
	case N_FN_SEQ:
	case N_TEXT:
#ifdef DBXREAD_ONLY
	  CUR_SYMBOL_VALUE += ANOFFSET (section_offsets, SECT_OFF_TEXT);
	  SET_NAMESTRING();
	  if ((namestring[0] == '-' && namestring[1] == 'l')
	      || (namestring [(nsl = strlen (namestring)) - 1] == 'o'
		  && namestring [nsl - 2] == '.')
#ifdef GDB_TARGET_IS_HPPA
              /* some cooperation from gcc to get around ld stupidity */
              || (namestring[0] == 'e' && !strcmp (namestring, "end_file."))
#endif
	      )
	    {
#ifndef GDB_TARGET_IS_HPPA
	      if (objfile -> ei.entry_point <  CUR_SYMBOL_VALUE &&
		  objfile -> ei.entry_point >= last_o_file_start)
		{
		  objfile -> ei.entry_file_lowpc = last_o_file_start;
		  objfile -> ei.entry_file_highpc = CUR_SYMBOL_VALUE;
		}
#endif
	      if (past_first_source_file && pst
		  /* The gould NP1 uses low values for .o and -l symbols
		     which are not the address.  */
		  && CUR_SYMBOL_VALUE >= pst->textlow)
		{
		  END_PSYMTAB (pst, psymtab_include_list, includes_used,
			       symnum * symbol_size, CUR_SYMBOL_VALUE,
			       dependency_list, dependencies_used);
		  pst = (struct partial_symtab *) 0;
		  includes_used = 0;
		  dependencies_used = 0;
		}
	      else
		past_first_source_file = 1;
	      last_o_file_start = CUR_SYMBOL_VALUE;
	    }
#endif /* DBXREAD_ONLY */
	  continue;

	case N_DATA:
#ifdef DBXREAD_ONLY
	  CUR_SYMBOL_VALUE += ANOFFSET (section_offsets, SECT_OFF_DATA);
	  SET_NAMESTRING ();
	  /* Check for __DYNAMIC, which is used by Sun shared libraries. 
	     Record it even if it's local, not global, so we can find it.
	     Same with virtual function tables, both global and static.  */
	  if ((namestring[8] == 'C' && (strcmp ("__DYNAMIC", namestring) == 0))
	      || VTBL_PREFIX_P ((namestring+HASH_OFFSET)))
	    {
	      record_minimal_symbol (namestring, CUR_SYMBOL_VALUE,
				    CUR_SYMBOL_TYPE, objfile); /* Always */
	    }
#endif /* DBXREAD_ONLY */
	  continue;

	case N_UNDF | N_EXT:
#ifdef DBXREAD_ONLY
	  if (CUR_SYMBOL_VALUE != 0) {
	    /* This is a "Fortran COMMON" symbol.  See if the target
	       environment knows where it has been relocated to.  */

	    CORE_ADDR reladdr;

	    SET_NAMESTRING();
	    if (target_lookup_symbol (namestring, &reladdr)) {
	      continue;		/* Error in lookup; ignore symbol for now.  */
	    }
	    CUR_SYMBOL_TYPE ^= (N_BSS^N_UNDF);	/* Define it as a bss-symbol */
	    CUR_SYMBOL_VALUE = reladdr;
	    goto bss_ext_symbol;
	  }
#endif /* DBXREAD_ONLY */
	  continue;	/* Just undefined, not COMMON */

	case N_UNDF:
#ifdef DBXREAD_ONLY
	  if (processing_acc_compilation && bufp->n_strx == 1) {
	    /* Deal with relative offsets in the string table
	       used in ELF+STAB under Solaris.  If we want to use the
	       n_strx field, which contains the name of the file,
	       we must adjust file_string_table_offset *before* calling
	       SET_NAMESTRING().  */
	    past_first_source_file = 1;
	    file_string_table_offset = next_file_string_table_offset;
	    next_file_string_table_offset =
	      file_string_table_offset + bufp->n_value;
	    if (next_file_string_table_offset < file_string_table_offset)
	      error ("string table offset backs up at %d", symnum);
  /* FIXME -- replace error() with complaint.  */
	    continue;
	  }
#endif /* DBXREAD_ONLY */
	  continue;

	    /* Lots of symbol types we can just ignore.  */

	case N_ABS:
	case N_BSS:
	case N_NBDATA:
	case N_NBBSS:
	  continue;

	  /* Keep going . . .*/

	  /*
	   * Special symbol types for GNU
	   */
	case N_INDR:
	case N_INDR | N_EXT:
	case N_SETA:
	case N_SETA | N_EXT:
	case N_SETT:
	case N_SETT | N_EXT:
	case N_SETD:
	case N_SETD | N_EXT:
	case N_SETB:
	case N_SETB | N_EXT:
	case N_SETV:
	  continue;

	  /*
	   * Debugger symbols
	   */

	case N_SO: {
	  unsigned long valu = CUR_SYMBOL_VALUE;
	  static int prev_so_symnum = -10;
	  static int first_so_symnum;
	  char *p;
	  
	  past_first_source_file = 1;

	  if (prev_so_symnum != symnum - 1)
	    {			/* Here if prev stab wasn't N_SO */
	      first_so_symnum = symnum;

	      if (pst)
		{
		  END_PSYMTAB (pst, psymtab_include_list, includes_used,
			       symnum * symbol_size, valu,
			       dependency_list, dependencies_used);
		  pst = (struct partial_symtab *) 0;
		  includes_used = 0;
		  dependencies_used = 0;
		}
	    }

	  prev_so_symnum = symnum;

	  /* End the current partial symtab and start a new one */

	  SET_NAMESTRING();

	  valu += ANOFFSET (section_offsets, SECT_OFF_TEXT);

	  /* Some compilers (including gcc) emit a pair of initial N_SOs.
	     The first one is a directory name; the second the file name.
	     If pst exists, is empty, and has a filename ending in '/',
	     we assume the previous N_SO was a directory name. */

	  p = strrchr (namestring, '/');
	  if (p && *(p+1) == '\000')
	    continue;		/* Simply ignore directory name SOs */

	  /* Some other compilers (C++ ones in particular) emit useless
	     SOs for non-existant .c files.  We ignore all subsequent SOs that
	     immediately follow the first.  */

	  if (!pst)
	    pst = START_PSYMTAB (objfile, section_offsets,
				 namestring, valu,
				 first_so_symnum * symbol_size,
				 objfile -> global_psymbols.next,
				 objfile -> static_psymbols.next);
	  continue;
	}

	case N_BINCL:
#ifdef DBXREAD_ONLY
	  /* Add this bincl to the bincl_list for future EXCLs.  No
	     need to save the string; it'll be around until
	     read_dbx_symtab function returns */

	  SET_NAMESTRING();

	  add_bincl_to_list (pst, namestring, CUR_SYMBOL_VALUE);

	  /* Mark down an include file in the current psymtab */

	  psymtab_include_list[includes_used++] = namestring;
	  if (includes_used >= includes_allocated)
	    {
	      char **orig = psymtab_include_list;

	      psymtab_include_list = (char **)
		alloca ((includes_allocated *= 2) *
			sizeof (char *));
	      memcpy ((PTR)psymtab_include_list, (PTR)orig,
		      includes_used * sizeof (char *));
	    }

#endif /* DBXREAD_ONLY */
	  continue;

	case N_SOL:
	  /* Mark down an include file in the current psymtab */

	  SET_NAMESTRING();

	  /* In C++, one may expect the same filename to come round many
	     times, when code is coming alternately from the main file
	     and from inline functions in other files. So I check to see
	     if this is a file we've seen before -- either the main
	     source file, or a previously included file.

	     This seems to be a lot of time to be spending on N_SOL, but
	     things like "break c-exp.y:435" need to work (I
	     suppose the psymtab_include_list could be hashed or put
	     in a binary tree, if profiling shows this is a major hog).  */
	  if (pst && !strcmp (namestring, pst->filename))
	    continue;
	  {
	    register int i;
	    for (i = 0; i < includes_used; i++)
	      if (!strcmp (namestring, psymtab_include_list[i]))
		{
		  i = -1; 
		  break;
		}
	    if (i == -1)
	      continue;
	  }

	  psymtab_include_list[includes_used++] = namestring;
	  if (includes_used >= includes_allocated)
	    {
	      char **orig = psymtab_include_list;

	      psymtab_include_list = (char **)
		alloca ((includes_allocated *= 2) *
			sizeof (char *));
	      memcpy ((PTR)psymtab_include_list, (PTR)orig,
		      includes_used * sizeof (char *));
	    }
	  continue;

	case N_LSYM:		/* Typedef or automatic variable. */
	case N_STSYM:		/* Data seg var -- static  */
	case N_LCSYM:		/* BSS      "  */
	case N_ROSYM:		/* Read-only data seg var -- static.  */