syms.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 1,302 行 · 第 1/3 页

	Print the value and flags of the @var{symbol} supplied to the
	stream @var{file}.
*/
void
bfd_print_symbol_vandf (arg, symbol)
     PTR arg;
     asymbol *symbol;
{
  FILE *file = (FILE *) arg;
  flagword type = symbol->flags;
  if (symbol->section != (asection *) NULL)
    {
      fprintf_vma (file, symbol->value + symbol->section->vma);
    }
  else
    {
      fprintf_vma (file, symbol->value);
    }

  /* This presumes that a symbol can not be both BSF_DEBUGGING and
     BSF_DYNAMIC, nor more than one of BSF_FUNCTION, BSF_FILE, and
     BSF_OBJECT.  */
  fprintf (file, " %c%c%c%c%c%c%c",
	   ((type & BSF_LOCAL)
	    ? (type & BSF_GLOBAL) ? '!' : 'l'
	    : (type & BSF_GLOBAL) ? 'g' : ' '),
	   (type & BSF_WEAK) ? 'w' : ' ',
	   (type & BSF_CONSTRUCTOR) ? 'C' : ' ',
	   (type & BSF_WARNING) ? 'W' : ' ',
	   (type & BSF_INDIRECT) ? 'I' : ' ',
	   (type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
	   ((type & BSF_FUNCTION)
	    ? 'F'
	    : ((type & BSF_FILE)
	       ? 'f'
	       : ((type & BSF_OBJECT) ? 'O' : ' '))));
}

/*
FUNCTION
	bfd_make_empty_symbol

DESCRIPTION
	Create a new <<asymbol>> structure for the BFD @var{abfd}
	and return a pointer to it.

	This routine is necessary because each back end has private
	information surrounding the <<asymbol>>. Building your own
	<<asymbol>> and pointing to it will not create the private
	information, and will cause problems later on.

.#define bfd_make_empty_symbol(abfd) \
.     BFD_SEND (abfd, _bfd_make_empty_symbol, (abfd))
*/

/*
FUNCTION
	bfd_make_debug_symbol

DESCRIPTION
	Create a new <<asymbol>> structure for the BFD @var{abfd},
	to be used as a debugging symbol.  Further details of its use have
	yet to be worked out.

.#define bfd_make_debug_symbol(abfd,ptr,size) \
.        BFD_SEND (abfd, _bfd_make_debug_symbol, (abfd, ptr, size))
*/

struct section_to_type
{
  CONST char *section;
  char type;
};

/* Map section names to POSIX/BSD single-character symbol types.
   This table is probably incomplete.  It is sorted for convenience of
   adding entries.  Since it is so short, a linear search is used.  */
static CONST struct section_to_type stt[] =
{
  {"*DEBUG*", 'N'},
  {".bss", 'b'},
  {"zerovars", 'b'},		/* MRI .bss */
  {".data", 'd'},
  {"vars", 'd'},		/* MRI .data */
  {".rdata", 'r'},		/* Read only data.  */
  {".rodata", 'r'},		/* Read only data.  */
  {".sbss", 's'},		/* Small BSS (uninitialized data).  */
  {".scommon", 'c'},		/* Small common.  */
  {".sdata", 'g'},		/* Small initialized data.  */
  {".text", 't'},
  {"code", 't'},		/* MRI .text */
  {".drectve", 'i'},            /* MSVC's .drective section */
  {".idata", 'i'},              /* MSVC's .idata (import) section */
  {".edata", 'e'},              /* MSVC's .edata (export) section */
  {".pdata", 'p'},              /* MSVC's .pdata (stack unwind) section */
  {".debug", 'N'},              /* MSVC's .debug (non-standard debug syms) */
  {0, 0}
};

/* Return the single-character symbol type corresponding to
   section S, or '?' for an unknown COFF section.

   Check for any leading string which matches, so .text5 returns
   't' as well as .text */

static char
coff_section_type (s)
     const char *s;
{
  CONST struct section_to_type *t;

  for (t = &stt[0]; t->section; t++)
    if (!strncmp (s, t->section, strlen (t->section)))
      return t->type;

  return '?';
}

#ifndef islower
#define islower(c) ((c) >= 'a' && (c) <= 'z')
#endif
#ifndef toupper
#define toupper(c) (islower(c) ? ((c) & ~0x20) : (c))
#endif

/*
FUNCTION
	bfd_decode_symclass

DESCRIPTION
	Return a character corresponding to the symbol
	class of @var{symbol}, or '?' for an unknown class.

SYNOPSIS
	int bfd_decode_symclass(asymbol *symbol);
*/
int
bfd_decode_symclass (symbol)
     asymbol *symbol;
{
  char c;

  if (bfd_is_com_section (symbol->section))
    return 'C';
  if (bfd_is_und_section (symbol->section))
    {
      if (symbol->flags & BSF_WEAK)
	{
	  /* If weak, determine if it's specifically an object
	     or non-object weak.  */
	  if (symbol->flags & BSF_OBJECT)
	    return 'v';
	  else
	    return 'w';
	}
      else
	return 'U';
    }
  if (bfd_is_ind_section (symbol->section))
    return 'I';
  if (symbol->flags & BSF_WEAK)
    {
      /* If weak, determine if it's specifically an object
	 or non-object weak.  */
      if (symbol->flags & BSF_OBJECT)
	return 'V';
      else
	return 'W';
    }
  if (!(symbol->flags & (BSF_GLOBAL | BSF_LOCAL)))
    return '?';

  if (bfd_is_abs_section (symbol->section))
    c = 'a';
  else if (symbol->section)
    c = coff_section_type (symbol->section->name);
  else
    return '?';
  if (symbol->flags & BSF_GLOBAL)
    c = toupper (c);
  return c;

  /* We don't have to handle these cases just yet, but we will soon:
     N_SETV: 'v';
     N_SETA: 'l';
     N_SETT: 'x';
     N_SETD: 'z';
     N_SETB: 's';
     N_INDR: 'i';
     */
}

/*
FUNCTION
	bfd_is_undefined_symclass

DESCRIPTION
	Returns non-zero if the class symbol returned by
	bfd_decode_symclass represents an undefined symbol.
	Returns zero otherwise.

SYNOPSIS
	boolean bfd_is_undefined_symclass (int symclass);
*/

boolean
bfd_is_undefined_symclass (symclass)
     int symclass;
{
  return symclass == 'U' || symclass == 'w' || symclass == 'v';
}

/*
FUNCTION
	bfd_symbol_info

DESCRIPTION
	Fill in the basic info about symbol that nm needs.
	Additional info may be added by the back-ends after
	calling this function.

SYNOPSIS
	void bfd_symbol_info(asymbol *symbol, symbol_info *ret);
*/

void
bfd_symbol_info (symbol, ret)
     asymbol *symbol;
     symbol_info *ret;
{
  ret->type = bfd_decode_symclass (symbol);

  if (bfd_is_undefined_symclass (ret->type))
    ret->value = 0;
  else
    ret->value = symbol->value + symbol->section->vma;

  ret->name = symbol->name;
}

/*
FUNCTION
	bfd_copy_private_symbol_data

SYNOPSIS
	boolean bfd_copy_private_symbol_data(bfd *ibfd, asymbol *isym, bfd *obfd, asymbol *osym);

DESCRIPTION
	Copy private symbol information from @var{isym} in the BFD
	@var{ibfd} to the symbol @var{osym} in the BFD @var{obfd}.
	Return <<true>> on success, <<false>> on error.  Possible error
	returns are:

	o <<bfd_error_no_memory>> -
	Not enough memory exists to create private data for @var{osec}.

.#define bfd_copy_private_symbol_data(ibfd, isymbol, obfd, osymbol) \
.     BFD_SEND (obfd, _bfd_copy_private_symbol_data, \
.		(ibfd, isymbol, obfd, osymbol))

*/

/* The generic version of the function which returns mini symbols.
   This is used when the backend does not provide a more efficient
   version.  It just uses BFD asymbol structures as mini symbols.  */

long
_bfd_generic_read_minisymbols (abfd, dynamic, minisymsp, sizep)
     bfd *abfd;
     boolean dynamic;
     PTR *minisymsp;
     unsigned int *sizep;
{
  long storage;
  asymbol **syms = NULL;
  long symcount;

  if (dynamic)
    storage = bfd_get_dynamic_symtab_upper_bound (abfd);
  else
    storage = bfd_get_symtab_upper_bound (abfd);
  if (storage < 0)
    goto error_return;

  syms = (asymbol **) bfd_malloc ((size_t) storage);
  if (syms == NULL)
    goto error_return;

  if (dynamic)
    symcount = bfd_canonicalize_dynamic_symtab (abfd, syms);
  else
    symcount = bfd_canonicalize_symtab (abfd, syms);
  if (symcount < 0)
    goto error_return;

  *minisymsp = (PTR) syms;
  *sizep = sizeof (asymbol *);
  return symcount;

 error_return:
  if (syms != NULL)
    free (syms);
  return -1;
}

/* The generic version of the function which converts a minisymbol to
   an asymbol.  We don't worry about the sym argument we are passed;
   we just return the asymbol the minisymbol points to.  */

/*ARGSUSED*/
asymbol *
_bfd_generic_minisymbol_to_symbol (abfd, dynamic, minisym, sym)
     bfd *abfd ATTRIBUTE_UNUSED;
     boolean dynamic ATTRIBUTE_UNUSED;
     const PTR minisym;
     asymbol *sym ATTRIBUTE_UNUSED;
{
  return *(asymbol **) minisym;
}

/* Look through stabs debugging information in .stab and .stabstr
   sections to find the source file and line closest to a desired
   location.  This is used by COFF and ELF targets.  It sets *pfound
   to true if it finds some information.  The *pinfo field is used to
   pass cached information in and out of this routine; this first time
   the routine is called for a BFD, *pinfo should be NULL.  The value
   placed in *pinfo should be saved with the BFD, and passed back each
   time this function is called.  */

/* We use a cache by default.  */

#define ENABLE_CACHING

/* We keep an array of indexentry structures to record where in the
   stabs section we should look to find line number information for a
   particular address.  */

struct indexentry
{
  bfd_vma val;
  bfd_byte *stab;
  bfd_byte *str;
  char *directory_name;
  char *file_name;
  char *function_name;
};

/* Compare two indexentry structures.  This is called via qsort.  */

static int
cmpindexentry (a, b)
     const PTR a;
     const PTR b;
{
  const struct indexentry *contestantA = (const struct indexentry *) a;
  const struct indexentry *contestantB = (const struct indexentry *) b;

  if (contestantA->val < contestantB->val)
    return -1;
  else if (contestantA->val > contestantB->val)
    return 1;
  else
    return 0;
}

/* A pointer to this structure is stored in *pinfo.  */

struct stab_find_info
{
  /* The .stab section.  */
  asection *stabsec;
  /* The .stabstr section.  */
  asection *strsec;
  /* The contents of the .stab section.  */
  bfd_byte *stabs;
  /* The contents of the .stabstr section.  */
  bfd_byte *strs;

  /* A table that indexes stabs by memory address.  */
  struct indexentry *indextable;
  /* The number of entries in indextable.  */
  int indextablesize;

#ifdef ENABLE_CACHING
  /* Cached values to restart quickly.  */
  struct indexentry *cached_indexentry;
  bfd_vma cached_offset;
  bfd_byte *cached_stab;
  char *cached_file_name;
#endif

  /* Saved ptr to malloc'ed filename.  */
  char *filename;
};

boolean
_bfd_stab_section_find_nearest_line (abfd, symbols, section, offset, pfound,
				     pfilename, pfnname, pline, pinfo)
     bfd *abfd;
     asymbol **symbols;
     asection *section;
     bfd_vma offset;
     boolean *pfound;
     const char **pfilename;
     const char **pfnname;
     unsigned int *pline;
     PTR *pinfo;
{
  struct stab_find_info *info;
  bfd_size_type stabsize, strsize;
  bfd_byte *stab, *str;
  bfd_byte *last_stab = NULL;
  bfd_size_type stroff;
  struct indexentry *indexentry;
  char *directory_name, *file_name;
  int saw_fun;

  *pfound = false;
  *pfilename = bfd_get_filename (abfd);
  *pfnname = NULL;
  *pline = 0;

  /* Stabs entries use a 12 byte format:
       4 byte string table index
       1 byte stab type
       1 byte stab other field
       2 byte stab desc field
       4 byte stab value
     FIXME: This will have to change for a 64 bit object format.

     The stabs symbols are divided into compilation units.  For the
     first entry in each unit, the type of 0, the value is the length
     of the string table for this unit, and the desc field is the
     number of stabs symbols for this unit.  */