symbols.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 2,503 行 · 第 1/4 页

void
define_dollar_label (label)
     long label;
{
  long *i;

  for (i = dollar_labels; i < dollar_labels + dollar_label_count; ++i)
    if (*i == label)
      {
	++dollar_label_instances[i - dollar_labels];
	dollar_label_defines[i - dollar_labels] = 1;
	return;
      }

  /* If we get to here, we don't have label listed yet.  */

  if (dollar_labels == NULL)
    {
      dollar_labels = (long *) xmalloc (DOLLAR_LABEL_BUMP_BY * sizeof (long));
      dollar_label_instances = (long *) xmalloc (DOLLAR_LABEL_BUMP_BY * sizeof (long));
      dollar_label_defines = xmalloc (DOLLAR_LABEL_BUMP_BY);
      dollar_label_max = DOLLAR_LABEL_BUMP_BY;
      dollar_label_count = 0;
    }
  else if (dollar_label_count == dollar_label_max)
    {
      dollar_label_max += DOLLAR_LABEL_BUMP_BY;
      dollar_labels = (long *) xrealloc ((char *) dollar_labels,
					 dollar_label_max * sizeof (long));
      dollar_label_instances = (long *) xrealloc ((char *) dollar_label_instances,
					  dollar_label_max * sizeof (long));
      dollar_label_defines = xrealloc (dollar_label_defines, dollar_label_max);
    }				/* if we needed to grow  */

  dollar_labels[dollar_label_count] = label;
  dollar_label_instances[dollar_label_count] = 1;
  dollar_label_defines[dollar_label_count] = 1;
  ++dollar_label_count;
}

/* Caller must copy returned name: we re-use the area for the next name.

   The mth occurence of label n: is turned into the symbol "Ln^Am"
   where n is the label number and m is the instance number. "L" makes
   it a label discarded unless debugging and "^A"('\1') ensures no
   ordinary symbol SHOULD get the same name as a local label
   symbol. The first "4:" is "L4^A1" - the m numbers begin at 1.

   fb labels get the same treatment, except that ^B is used in place
   of ^A.  */

char *				/* Return local label name.  */
dollar_label_name (n, augend)
     register long n;		/* we just saw "n$:" : n a number.  */
     register int augend;	/* 0 for current instance, 1 for new instance.  */
{
  long i;
  /* Returned to caller, then copied.  Used for created names ("4f").  */
  static char symbol_name_build[24];
  register char *p;
  register char *q;
  char symbol_name_temporary[20];	/* Build up a number, BACKWARDS.  */

  know (n >= 0);
  know (augend == 0 || augend == 1);
  p = symbol_name_build;
#ifdef LOCAL_LABEL_PREFIX
  *p++ = LOCAL_LABEL_PREFIX;
#endif
  *p++ = 'L';

  /* Next code just does sprintf( {}, "%d", n);  */
  /* Label number.  */
  q = symbol_name_temporary;
  for (*q++ = 0, i = n; i; ++q)
    {
      *q = i % 10 + '0';
      i /= 10;
    }
  while ((*p = *--q) != '\0')
    ++p;

  *p++ = DOLLAR_LABEL_CHAR;		/* ^A  */

  /* Instance number.  */
  q = symbol_name_temporary;
  for (*q++ = 0, i = dollar_label_instance (n) + augend; i; ++q)
    {
      *q = i % 10 + '0';
      i /= 10;
    }
  while ((*p++ = *--q) != '\0');;

  /* The label, as a '\0' ended string, starts at symbol_name_build.  */
  return symbol_name_build;
}

/* Sombody else's idea of local labels. They are made by "n:" where n
   is any decimal digit. Refer to them with
    "nb" for previous (backward) n:
   or "nf" for next (forward) n:.

   We do a little better and let n be any number, not just a single digit, but
   since the other guy's assembler only does ten, we treat the first ten
   specially.

   Like someone else's assembler, we have one set of local label counters for
   entire assembly, not one set per (sub)segment like in most assemblers. This
   implies that one can refer to a label in another segment, and indeed some
   crufty compilers have done just that.

   Since there could be a LOT of these things, treat them as a sparse
   array.  */

#define FB_LABEL_SPECIAL (10)

static long fb_low_counter[FB_LABEL_SPECIAL];
static long *fb_labels;
static long *fb_label_instances;
static long fb_label_count;
static long fb_label_max;

/* This must be more than FB_LABEL_SPECIAL.  */
#define FB_LABEL_BUMP_BY (FB_LABEL_SPECIAL + 6)

static void
fb_label_init ()
{
  memset ((void *) fb_low_counter, '\0', sizeof (fb_low_counter));
}

/* Add one to the instance number of this fb label.  */

void
fb_label_instance_inc (label)
     long label;
{
  long *i;

  if (label < FB_LABEL_SPECIAL)
    {
      ++fb_low_counter[label];
      return;
    }

  if (fb_labels != NULL)
    {
      for (i = fb_labels + FB_LABEL_SPECIAL;
	   i < fb_labels + fb_label_count; ++i)
	{
	  if (*i == label)
	    {
	      ++fb_label_instances[i - fb_labels];
	      return;
	    }			/* if we find it  */
	}			/* for each existing label  */
    }

  /* If we get to here, we don't have label listed yet.  */

  if (fb_labels == NULL)
    {
      fb_labels = (long *) xmalloc (FB_LABEL_BUMP_BY * sizeof (long));
      fb_label_instances = (long *) xmalloc (FB_LABEL_BUMP_BY * sizeof (long));
      fb_label_max = FB_LABEL_BUMP_BY;
      fb_label_count = FB_LABEL_SPECIAL;

    }
  else if (fb_label_count == fb_label_max)
    {
      fb_label_max += FB_LABEL_BUMP_BY;
      fb_labels = (long *) xrealloc ((char *) fb_labels,
				     fb_label_max * sizeof (long));
      fb_label_instances = (long *) xrealloc ((char *) fb_label_instances,
					      fb_label_max * sizeof (long));
    }				/* if we needed to grow  */

  fb_labels[fb_label_count] = label;
  fb_label_instances[fb_label_count] = 1;
  ++fb_label_count;
}

static long
fb_label_instance (label)
     long label;
{
  long *i;

  if (label < FB_LABEL_SPECIAL)
    {
      return (fb_low_counter[label]);
    }

  if (fb_labels != NULL)
    {
      for (i = fb_labels + FB_LABEL_SPECIAL;
	   i < fb_labels + fb_label_count; ++i)
	{
	  if (*i == label)
	    {
	      return (fb_label_instances[i - fb_labels]);
	    }			/* if we find it  */
	}			/* for each existing label  */
    }

  /* We didn't find the label, so this must be a reference to the
     first instance.  */
  return 0;
}

/* Caller must copy returned name: we re-use the area for the next name.

   The mth occurence of label n: is turned into the symbol "Ln^Bm"
   where n is the label number and m is the instance number. "L" makes
   it a label discarded unless debugging and "^B"('\2') ensures no
   ordinary symbol SHOULD get the same name as a local label
   symbol. The first "4:" is "L4^B1" - the m numbers begin at 1.

   dollar labels get the same treatment, except that ^A is used in
   place of ^B.  */

char *				/* Return local label name.  */
fb_label_name (n, augend)
     long n;			/* We just saw "n:", "nf" or "nb" : n a number.  */
     long augend;		/* 0 for nb, 1 for n:, nf.  */
{
  long i;
  /* Returned to caller, then copied.  Used for created names ("4f").  */
  static char symbol_name_build[24];
  register char *p;
  register char *q;
  char symbol_name_temporary[20];	/* Build up a number, BACKWARDS.  */

  know (n >= 0);
  know (augend == 0 || augend == 1);
  p = symbol_name_build;
#ifdef LOCAL_LABEL_PREFIX
  *p++ = LOCAL_LABEL_PREFIX;
#endif
  *p++ = 'L';

  /* Next code just does sprintf( {}, "%d", n);  */
  /* Label number.  */
  q = symbol_name_temporary;
  for (*q++ = 0, i = n; i; ++q)
    {
      *q = i % 10 + '0';
      i /= 10;
    }
  while ((*p = *--q) != '\0')
    ++p;

  *p++ = LOCAL_LABEL_CHAR;		/* ^B  */

  /* Instance number.  */
  q = symbol_name_temporary;
  for (*q++ = 0, i = fb_label_instance (n) + augend; i; ++q)
    {
      *q = i % 10 + '0';
      i /= 10;
    }
  while ((*p++ = *--q) != '\0');;

  /* The label, as a '\0' ended string, starts at symbol_name_build.  */
  return (symbol_name_build);
}

/* Decode name that may have been generated by foo_label_name() above.
   If the name wasn't generated by foo_label_name(), then return it
   unaltered.  This is used for error messages.  */

char *
decode_local_label_name (s)
     char *s;
{
  char *p;
  char *symbol_decode;
  int label_number;
  int instance_number;
  char *type;
  const char *message_format;
  int index = 0;

#ifdef LOCAL_LABEL_PREFIX
  if (s[index] == LOCAL_LABEL_PREFIX)
    ++index;
#endif

  if (s[index] != 'L')
    return s;

  for (label_number = 0, p = s + index + 1; isdigit ((unsigned char) *p); ++p)
    label_number = (10 * label_number) + *p - '0';

  if (*p == DOLLAR_LABEL_CHAR)
    type = "dollar";
  else if (*p == LOCAL_LABEL_CHAR)
    type = "fb";
  else
    return s;

  for (instance_number = 0, p++; isdigit ((unsigned char) *p); ++p)
    instance_number = (10 * instance_number) + *p - '0';

  message_format = _("\"%d\" (instance number %d of a %s label)");
  symbol_decode = obstack_alloc (&notes, strlen (message_format) + 30);
  sprintf (symbol_decode, message_format, label_number, instance_number, type);

  return symbol_decode;
}

/* Get the value of a symbol.  */

valueT
S_GET_VALUE (s)
     symbolS *s;
{
#ifdef BFD_ASSEMBLER
  if (LOCAL_SYMBOL_CHECK (s))
    return ((struct local_symbol *) s)->lsy_offset;
#endif

  if (!s->sy_resolved && s->sy_value.X_op != O_constant)
    resolve_symbol_value (s, 1);
  if (s->sy_value.X_op != O_constant)
    {
      static symbolS *recur;

      /* FIXME: In non BFD assemblers, S_IS_DEFINED and S_IS_COMMON
         may call S_GET_VALUE.  We use a static symbol to avoid the
         immediate recursion.  */
      if (recur == s)
	return (valueT) s->sy_value.X_add_number;
      recur = s;
      if (! s->sy_resolved
	  || s->sy_value.X_op != O_symbol
	  || (S_IS_DEFINED (s) && ! S_IS_COMMON (s)))
	as_bad (_("Attempt to get value of unresolved symbol %s"),
		S_GET_NAME (s));
      recur = NULL;
    }
  return (valueT) s->sy_value.X_add_number;
}

/* Set the value of a symbol.  */

void
S_SET_VALUE (s, val)
     symbolS *s;
     valueT val;
{
#ifdef BFD_ASSEMBLER
  if (LOCAL_SYMBOL_CHECK (s))
    {
      ((struct local_symbol *) s)->lsy_offset = val;
      return;
    }
#endif

  s->sy_value.X_op = O_constant;
  s->sy_value.X_add_number = (offsetT) val;
  s->sy_value.X_unsigned = 0;
}

void
copy_symbol_attributes (dest, src)
     symbolS *dest, *src;
{
  if (LOCAL_SYMBOL_CHECK (dest))
    dest = local_symbol_convert ((struct local_symbol *) dest);
  if (LOCAL_SYMBOL_CHECK (src))
    src = local_symbol_convert ((struct local_symbol *) src);

#ifdef BFD_ASSEMBLER
  /* In an expression, transfer the settings of these flags.
     The user can override later, of course.  */
#define COPIED_SYMFLAGS	(BSF_FUNCTION | BSF_OBJECT)
  dest->bsym->flags |= src->bsym->flags & COPIED_SYMFLAGS;
#endif

#ifdef OBJ_COPY_SYMBOL_ATTRIBUTES
  OBJ_COPY_SYMBOL_ATTRIBUTES (dest, src);
#endif
}

#ifdef BFD_ASSEMBLER

int
S_IS_FUNCTION (s)
     symbolS *s;
{
  flagword flags;

  if (LOCAL_SYMBOL_CHECK (s))
    return 0;

  flags = s->bsym->flags;

  return (flags & BSF_FUNCTION) != 0;
}

int
S_IS_EXTERNAL (s)
     symbolS *s;
{
  flagword flags;

  if (LOCAL_SYMBOL_CHECK (s))
    return 0;

  flags = s->bsym->flags;

  /* Sanity check.  */
  if ((flags & BSF_LOCAL) && (flags & BSF_GLOBAL))
    abort ();

  return (flags & BSF_GLOBAL) != 0;
}

int
S_IS_WEAK (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return 0;
  return (s->bsym->flags & BSF_WEAK) != 0;
}

int
S_IS_COMMON (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return 0;
  return bfd_is_com_section (s->bsym->section);
}

int
S_IS_DEFINED (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return ((struct local_symbol *) s)->lsy_section != undefined_section;
  return s->bsym->section != undefined_section;
}

int
S_IS_DEBUG (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return 0;
  if (s->bsym->flags & BSF_DEBUGGING)
    return 1;
  return 0;
}

int
S_IS_LOCAL (s)
     symbolS *s;
{
  flagword flags;
  const char *name;

  if (LOCAL_SYMBOL_CHECK (s))
    return 1;

  flags = s->bsym->flags;

  /* Sanity check.  */
  if ((flags & BSF_LOCAL) && (flags & BSF_GLOBAL))
    abort ();

  if (bfd_get_section (s->bsym) == reg_section)
    return 1;

  if (flag_strip_local_absolute
      && (flags & BSF_GLOBAL) == 0
      && bfd_get_section (s->bsym) == absolute_section)
    return 1;

  name = S_GET_NAME (s);
  return (name != NULL
	  && ! S_IS_DEBUG (s)
	  && (strchr (name, DOLLAR_LABEL_CHAR)
	      || strchr (name, LOCAL_LABEL_CHAR)
	      || (! flag_keep_locals
		  && (bfd_is_local_label (stdoutput, s->bsym)
		      || (flag_mri
			  && name[0] == '?'
			  && name[1] == '?')))));
}

int
S_IS_EXTERN (s)
     symbolS *s;
{
  return S_IS_EXTERNAL (s);
}

int
S_IS_STABD (s)
     symbolS *s;
{
  return S_GET_NAME (s) == 0;
}

CONST char *
S_GET_NAME (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return ((struct local_symbol *) s)->lsy_name;
  return s->bsym->name;
}

segT
S_GET_SEGMENT (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return ((struct local_symbol *) s)->lsy_section;
  return s->bsym->section;
}

void
S_SET_SEGMENT (s, seg)
     symbolS *s;
     segT seg;
{
  /* Don't reassign section symbols.  The direct reason is to prevent seg
     faults assigning back to const global symbols such as *ABS*, but it
     shouldn't happen anyway.  */

  if (LOCAL_SYMBOL_CHECK (s))
    {
      if (seg == reg_section)
	s = local_symbol_convert ((struct local_symbol *) s);
      else
	{
	  ((struct local_symbol *) s)->lsy_section = seg;
	  return;
	}
    }

  if (s->bsym->flags & BSF_SECTION_SYM)
    {
      if (s->bsym->section != seg)
	abort ();
    }
  else
    s->bsym->section = seg;
}

void
S_SET_EXTERNAL (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    s = local_symbol_convert ((struct local_symbol *) s);
  if ((s->bsym->flags & BSF_WEAK) != 0)
    {
      /* Let .weak override .global.  */
      return;
    }
  if (s->bsym->flags & BSF_SECTION_SYM)
    {
      char * file;
      unsigned int line;
      
      /* Do not reassign section symbols.  */
      as_where (& file, & line);
      as_warn_where (file, line,
		     _("Section symbols are already global"));
      return;
    }
  s->bsym->flags |= BSF_GLOBAL;
  s->bsym->flags &= ~(BSF_LOCAL | BSF_WEAK);
}

void
S_CLEAR_EXTERNAL (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    return;
  if ((s->bsym->flags & BSF_WEAK) != 0)
    {
      /* Let .weak override.  */
      return;
    }
  s->bsym->flags |= BSF_LOCAL;
  s->bsym->flags &= ~(BSF_GLOBAL | BSF_WEAK);
}

void
S_SET_WEAK (s)
     symbolS *s;
{
  if (LOCAL_SYMBOL_CHECK (s))
    s = local_symbol_convert ((struct local_symbol *) s);
  s->bsym->flags |= BSF_WEAK;
  s->bsym->flags &= ~(BSF_GLOBAL | BSF_LOCAL);
}

void
S_SET_NAME (s, name)
     symbolS *s;
     char *name;
{
  if (LOCAL_SYMBOL_CHECK (s))
    {
      ((struct local_symbol *) s)->lsy_name = name;
      return;
    }
  s->bsym->name = name;
}
#endif /* BFD_ASSEMBLER */

#ifdef SYMBOLS_NEED_BACKPOINTERS

/* Return the previous symbol in a chain.  */

symbolS *
symbol_previous (s)