symbol.c

体系机构仿真

/*
 * symbol.c - program symbol and line data routines
 *
 * This file is a part of the SimpleScalar tool suite written by
 * Todd M. Austin as a part of the Multiscalar Research Project.
 *  
 * The tool suite is currently maintained by Doug Burger and Todd M. Austin.
 * 
 * Copyright (C) 1994, 1995, 1996, 1997 by Todd M. Austin
 *
 * This source file is distributed "as is" in the hope that it will be
 * useful.  The tool set comes with no warranty, and no author or
 * distributor accepts any responsibility for the consequences of its
 * use. 
 * 
 * Everyone is granted permission to copy, modify and redistribute
 * this tool set under the following conditions:
 * 
 *    This source code is distributed for non-commercial use only. 
 *    Please contact the maintainer for restrictions applying to 
 *    commercial use.
 *
 *    Permission is granted to anyone to make or distribute copies
 *    of this source code, either as received or modified, in any
 *    medium, provided that all copyright notices, permission and
 *    nonwarranty notices are preserved, and that the distributor
 *    grants the recipient permission for further redistribution as
 *    permitted by this document.
 *
 *    Permission is granted to distribute this file in compiled
 *    or executable form under the same conditions that apply for
 *    source code, provided that either:
 *
 *    A. it is accompanied by the corresponding machine-readable
 *       source code,
 *    B. it is accompanied by a written offer, with no time limit,
 *       to give anyone a machine-readable copy of the corresponding
 *       source code in return for reimbursement of the cost of
 *       distribution.  This written offer must permit verbatim
 *       duplication by anyone, or
 *    C. it is distributed by someone who received only the
 *       executable form, and is accompanied by a copy of the
 *       written offer of source code that they received concurrently.
 *
 * In other words, you are welcome to use, share and improve this
 * source file.  You are forbidden to forbid anyone else to use, share
 * and improve what you give them.
 *
 * INTERNET: [e-mail]
 * US Mail:  1210 W. Dayton Street, Madison, WI 53706
 *
 * $Id: symbol.c,v 1.2 1997/04/16 22:11:50 taustin Exp taustin $
 *
 * $Log: symbol.c,v $
 * Revision 1.2  1997/04/16  22:11:50  taustin
 * added standalone loader support
 *
 * Revision 1.1  1997/03/11  01:34:45  taustin
 * Initial revision
 *
 *
 */

#include <stdio.h>
#include <stdlib.h>
#ifdef BFD_LOADER
#include <bfd.h>
#else /* !BFD_LOADER */
#include "ecoff.h"
#endif /* BFD_LOADER */
#include "misc.h"
#include "loader.h"
#include "symbol.h"

/* #define PRINT_SYMS */

/* symbol database in no particular order */
struct sym_sym_t *sym_db = NULL;

/* all symbol sorted by address */
int sym_nsyms = 0;
struct sym_sym_t **sym_syms = NULL;

/* all symbols sorted by name */
struct sym_sym_t **sym_syms_by_name = NULL;

/* text symbols sorted by address */
int sym_ntextsyms = 0;
struct sym_sym_t **sym_textsyms = NULL;

/* text symbols sorted by name */
struct sym_sym_t **sym_textsyms_by_name = NULL;

/* data symbols sorted by address */
int sym_ndatasyms = 0;
struct sym_sym_t **sym_datasyms = NULL;

/* data symbols sorted by name */
struct sym_sym_t **sym_datasyms_by_name = NULL;

/* symbols loaded? */
static int syms_loaded = FALSE;

#ifdef PRINT_SYMS
/* convert BFD symbols flags to a printable string */
static char *			/* symbol flags string */
flags2str(unsigned int flags)	/* bfd symbol flags */
{
  static char buf[256];
  char *p;

  if (!flags)
    return "";

  p = buf;
  *p = '\0';

  if (flags & BSF_LOCAL)
    {
      *p++ = 'L';
      *p++ = '|';
    }
  if (flags & BSF_GLOBAL)
    {
      *p++ = 'G';
      *p++ = '|';
    }
  if (flags & BSF_DEBUGGING)
    {
      *p++ = 'D';
      *p++ = '|';
    }
  if (flags & BSF_FUNCTION)
    {
      *p++ = 'F';
      *p++ = '|';
    }
  if (flags & BSF_KEEP)
    {
      *p++ = 'K';
      *p++ = '|';
    }
  if (flags & BSF_KEEP_G)
    {
      *p++ = 'k'; *p++ = '|';
    }
  if (flags & BSF_WEAK)
    {
      *p++ = 'W';
      *p++ = '|';
    }
  if (flags & BSF_SECTION_SYM)
    {
      *p++ = 'S'; *p++ = '|';
    }
  if (flags & BSF_OLD_COMMON)
    {
      *p++ = 'O';
      *p++ = '|';
    }
  if (flags & BSF_NOT_AT_END)
    {
      *p++ = 'N';
      *p++ = '|';
    }
  if (flags & BSF_CONSTRUCTOR)
    {
      *p++ = 'C';
      *p++ = '|';
    }
  if (flags & BSF_WARNING)
    {
      *p++ = 'w';
      *p++ = '|';
    }
  if (flags & BSF_INDIRECT)
    {
      *p++ = 'I';
      *p++ = '|';
    }
  if (flags & BSF_FILE)
    {
      *p++ = 'f';
      *p++ = '|';
    }

  if (p == buf)
    panic("no flags detected");

  *--p = '\0';
  return buf;
}
#endif /* PRINT_SYMS */

/* qsort helper function */
static int
acmp(struct sym_sym_t **sym1, struct sym_sym_t **sym2)
{
  return (int)((*sym1)->addr - (*sym2)->addr);
}

/* qsort helper function */
static int
ncmp(struct sym_sym_t **sym1, struct sym_sym_t **sym2)
{
  return strcmp((*sym1)->name, (*sym2)->name);
}

#define RELEVANT_SCOPE(SYM)						\
(/* global symbol */							\
 ((SYM)->flags & BSF_GLOBAL)						\
 || (/* local symbol */							\
     (((SYM)->flags & (BSF_LOCAL|BSF_DEBUGGING)) == BSF_LOCAL)		\
     && (SYM)->name[0] != '$')						\
 || (/* compiler local */						\
     load_locals							\
     && ((/* basic block idents */					\
	  ((SYM)->flags&(BSF_LOCAL|BSF_DEBUGGING))==(BSF_LOCAL|BSF_DEBUGGING)\
	  && (SYM)->name[0] == '$')					\
	 || (/* local constant idents */				\
	     ((SYM)->flags & (BSF_LOCAL|BSF_DEBUGGING)) == (BSF_LOCAL)	\
	     && (SYM)->name[0] == '$'))))
     

/* load symbols out of FNAME */
void
sym_loadsyms(char *fname,	/* file name containing symbols */
	     int load_locals)	/* load local symbols */
{
  int i, debug_cnt;
#ifdef BFD_LOADER
  bfd *abfd;
  asymbol **syms;
  int storage, i, nsyms, debug_cnt;
#else /* !BFD_LOADER */
  int len;
  FILE *fobj;
  struct ecoff_filehdr fhdr;
  struct ecoff_aouthdr ahdr;
  struct ecoff_symhdr_t symhdr;
  char *strtab = NULL;
  struct ecoff_EXTR *extr;
#endif /* BFD_LOADER */

  if (syms_loaded)
    {
      /* symbols are already loaded */
      /* FIXME: can't handle symbols from multiple files */
      return;
    }

#ifdef BFD_LOADER

  /* load the program into memory, try both endians */
  if (!(abfd = bfd_openr(fname, "ss-coff-big")))
    if (!(abfd = bfd_openr(fname, "ss-coff-little")))
      fatal("cannot open executable `%s'", fname);

  /* this call is mainly for its side effect of reading in the sections.
     we follow the traditional behavior of `strings' in that we don't
     complain if we don't recognize a file to be an object file.  */
  if (!bfd_check_format(abfd, bfd_object))
    {
      bfd_close(abfd);
      fatal("cannot open executable `%s'", fname);
    }

  /* sanity check, endian should be the same as loader.c encountered */
  if (abfd->xvec->byteorder_big_p != (unsigned)ld_target_big_endian)
    panic("binary endian changed");

  if ((bfd_get_file_flags(abfd) & (HAS_SYMS|HAS_LOCALS)))
    {
      /* file has locals, read them in */
      storage = bfd_get_symtab_upper_bound(abfd);
      if (storage <= 0)
	fatal("HAS_SYMS is set, but `%s' still lacks symbols", fname);

      syms = (asymbol **)calloc(storage, 1);
      if (!syms)
	fatal("out of virtual memory");

      nsyms = bfd_canonicalize_symtab (abfd, syms);
      if (nsyms <= 0)
	fatal("HAS_SYMS is set, but `%s' still lacks symbols", fname);

      /*
       * convert symbols to local format
       */

      /* first count symbols */
      sym_ndatasyms = 0; sym_ntextsyms = 0;
      for (i=0; i < nsyms; i++)
	{
	  asymbol *sym = syms[i];

	  /* decode symbol type */
	  if (/* from the data section */
	      (!strcmp(sym->section->name, ".rdata")
	       || !strcmp(sym->section->name, ".data")
	       || !strcmp(sym->section->name, ".sdata")
	       || !strcmp(sym->section->name, ".bss")
	       || !strcmp(sym->section->name, ".sbss"))
	      /* from a scope we are interested in */
	      && RELEVANT_SCOPE(sym))
	    {
	      /* data segment symbol */
	      sym_ndatasyms++;
#ifdef PRINT_SYMS
	      fprintf(stderr,
		      "+sym: %s  sect: %s  flags: %s  value: 0x%08lx\n",
		      sym->name, sym->section->name, flags2str(sym->flags),
		      sym->value + sym->section->vma);
#endif /* PRINT_SYMS */
	    }
	  else if (/* from the text section */
		   !strcmp(sym->section->name, ".text")
		   /* from a scope we are interested in */
		   && RELEVANT_SCOPE(sym))
	    {
	      /* text segment symbol */
	      sym_ntextsyms++;
#ifdef PRINT_SYMS
	      fprintf(stderr,
		      "+sym: %s  sect: %s  flags: %s  value: 0x%08lx\n",
		      sym->name, sym->section->name, flags2str(sym->flags),
		      sym->value + sym->section->vma);
#endif /* PRINT_SYMS */
	    }
	  else
	    {
	      /* non-segment sections */
#ifdef PRINT_SYMS
	      fprintf(stderr,
		      "-sym: %s  sect: %s  flags: %s  value: 0x%08lx\n",
		      sym->name, sym->section->name, flags2str(sym->flags),
		      sym->value + sym->section->vma);
#endif /* PRINT_SYMS */
	    }
	}
      sym_nsyms = sym_ntextsyms + sym_ndatasyms;
      if (sym_nsyms <= 0)
	fatal("`%s' has no text or data symbols", fname);

      /* allocate symbol space */
      sym_db = (struct sym_sym_t *)calloc(sym_nsyms, sizeof(struct sym_sym_t));
      if (!sym_db)
	fatal("out of virtual memory");

      /* convert symbols to internal format */
      for (debug_cnt=0, i=0; i < nsyms; i++)
	{
	  asymbol *sym = syms[i];

	  /* decode symbol type */
	  if (/* from the data section */
	      (!strcmp(sym->section->name, ".rdata")
	       || !strcmp(sym->section->name, ".data")
	       || !strcmp(sym->section->name, ".sdata")
	       || !strcmp(sym->section->name, ".bss")
	       || !strcmp(sym->section->name, ".sbss"))
	      /* from a scope we are interested in */
	      && RELEVANT_SCOPE(sym))
	    {
	      /* data segment symbol, insert into symbol database */
	      sym_db[debug_cnt].name = mystrdup((char *)sym->name);
	      sym_db[debug_cnt].seg = ss_data;
	      sym_db[debug_cnt].initialized =
		(!strcmp(sym->section->name, ".rdata")
		 || !strcmp(sym->section->name, ".data")
		 || !strcmp(sym->section->name, ".sdata"));
	      sym_db[debug_cnt].pub = (sym->flags & BSF_GLOBAL);
	      sym_db[debug_cnt].local = (sym->name[0] == '$');
	      sym_db[debug_cnt].addr = sym->value + sym->section->vma;

	      debug_cnt++;
	    }
	  else if (/* from the text section */
		   !strcmp(sym->section->name, ".text")
		   /* from a scope we are interested in */
		   && RELEVANT_SCOPE(sym))
	    {
	      /* text segment symbol, insert into symbol database */
	      sym_db[debug_cnt].name = mystrdup((char *)sym->name);
	      sym_db[debug_cnt].seg = ss_text;
	      sym_db[debug_cnt].initialized = /* seems reasonable */TRUE;
	      sym_db[debug_cnt].pub = (sym->flags & BSF_GLOBAL);
	      sym_db[debug_cnt].local = (sym->name[0] == '$');
	      sym_db[debug_cnt].addr = sym->value + sym->section->vma;

	      debug_cnt++;
	    }
	  else
	    {
	      /* non-segment sections */
	    }
	}
      /* sanity check */
      if (debug_cnt != sym_nsyms)
	panic("could not locate all counted symbols");

      /* release bfd symbol storage */
      free(syms);
    }

  /* done with file, close if */
  if (!bfd_close(abfd))
    fatal("could not close executable `%s'", fname);

#else /* !BFD_LOADER */

  /* load the program into memory, try both endians */
#ifdef __CYGWIN32__
  fobj = fopen(fname, "rb");
#else
  fobj = fopen(fname, "r");
#endif
  if (!fobj)
    fatal("cannot open executable `%s'", fname);