C++ dwarf_tag函数代码示例

char *get_type_str(Dwarf_Die *die)
{
	static char buf[256] = "";
	char *ptr = NULL;
	Dwarf_Die tdie;
	Dwarf_Attribute attr;

	if (!dwarf_attr(die, DW_AT_type, &attr))
		return "void";

	dwarf_formref_die(&attr, &tdie);

	if (dwarf_tag(&tdie) == DW_TAG_array_type)
		ptr = "[]";
	else if (dwarf_tag(&tdie) == DW_TAG_pointer_type)
		ptr = "*";
	else
		goto end_ok;

	dwarf_attr(&tdie, DW_AT_type, &attr);
	dwarf_formref_die(&attr, &tdie);

end_ok:
	sprintf(buf, "%s%s", dwarf_diename(&tdie), (ptr) ? ptr : "");

	return buf;
}

struct refl_object *
refl_deref (struct refl *refl, struct refl_object *obj)
{
  struct refl_type *type = refl_object_type (obj);

  Dwarf_Die die = type->die;
  if (__refl_die_strip_cvq (&die, &die) == NULL)
    return NULL;

  /* Cannot dereference non-pointer type.  */
  if (dwarf_tag (&die) != DW_TAG_pointer_type)
    {
      __refl_seterr_2 (REFL_E_REFL, REFL_ME_MISMATCH);
      return NULL;
    }

  if (__refl_die_type (&die, &die) == NULL)
    return NULL;

  /* Cannot dereference function pointer.  */
  if (dwarf_tag (&die) == DW_TAG_subroutine_type)
    {
      __refl_seterr_2 (REFL_E_REFL, REFL_ME_MISMATCH);
      return NULL;
    }

  struct refl_type *ntype = __refl_type_begin (&die);
  if (ntype == NULL)
    return NULL;

  void *ndata = *(void **)refl_object_cdata (obj);
  return __refl_object_begin (ntype, ndata);
}

/** \brief Finds the number of elements in a DW_TAG_subrange_type or DW_TAG_enumeration_type DIE
 *
 *  \param die  the DIE
 *  \param unit DIE of the compilation unit
 *  \return     number of elements in the range
 * */
static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die * die,
                                                Dwarf_Die * unit)
{
  xbt_assert(dwarf_tag(die) == DW_TAG_enumeration_type
             || dwarf_tag(die) == DW_TAG_subrange_type,
             "MC_dwarf_subrange_element_count called with DIE of type %s",
             simgrid::dwarf::tagname(die));

  // Use DW_TAG_count if present:
  if (dwarf_hasattr_integrate(die, DW_AT_count))
    return MC_dwarf_attr_integrate_uint(die, DW_AT_count, 0);
  // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound + 1:

  if (not dwarf_hasattr_integrate(die, DW_AT_upper_bound))
    // This is not really 0, but the code expects this (we do not know):
    return 0;

  uint64_t upper_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_upper_bound, static_cast<uint64_t>(-1));

  uint64_t lower_bound = 0;
  if (dwarf_hasattr_integrate(die, DW_AT_lower_bound))
    lower_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_lower_bound, static_cast<uint64_t>(-1));
  else
    lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit));
  return upper_bound - lower_bound + 1;
}

static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
{
	struct dwarf_callback_param *param = data;
	struct line_finder *lf = param->data;
	struct line_range *lr = lf->lr;

	
	if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die)))
		return DWARF_CB_OK;

	if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
	    die_compare_name(sp_die, lr->function)) {
		lf->fname = dwarf_decl_file(sp_die);
		dwarf_decl_line(sp_die, &lr->offset);
		pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
		lf->lno_s = lr->offset + lr->start;
		if (lf->lno_s < 0)	
			lf->lno_s = INT_MAX;
		lf->lno_e = lr->offset + lr->end;
		if (lf->lno_e < 0)	
			lf->lno_e = INT_MAX;
		pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
		lr->start = lf->lno_s;
		lr->end = lf->lno_e;
		if (dwarf_func_inline(sp_die))
			param->retval = die_walk_instances(sp_die,
						line_range_inline_cb, lf);
		else
			param->retval = find_line_range_by_line(sp_die, lf);
		return DWARF_CB_ABORT;
	}
	return DWARF_CB_OK;
}

struct variable* child_variables(Dwarf_Die *parent, Dwarf_Files *files,
                                 struct expr_context *ctx, bool params)
{
    int ret;
    Dwarf_Die die;
    struct variable *var, *head = NULL, *tail = NULL;
    int desired_tag = params ? DW_TAG_formal_parameter : DW_TAG_variable;

    ret = dwarf_child(parent, &die);
    if (ret != 0)
        return NULL;

    do
    {
        if (dwarf_tag(&die) == desired_tag)
        {
            var = analyze_variable(&die, files, ctx);
            if (!var)
                continue;

            list_append(head, tail, var);
        }
    } while (dwarf_siblingof(&die, &die) == 0);

    return head;
}

static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
                                Dwarf_Die * unit, simgrid::mc::Frame* frame,
                                const char *ns)
{
  int tag = dwarf_tag(die);
  simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag);
  switch (klass) {

    // Type:
  case simgrid::dwarf::TagClass::Type:
    MC_dwarf_handle_type_die(info, die, unit, frame, ns);
    break;

    // Subprogram or scope:
  case simgrid::dwarf::TagClass::Subprogram:
  case simgrid::dwarf::TagClass::Scope:
    MC_dwarf_handle_scope_die(info, die, unit, frame, ns);
    return;

    // Variable:
  case simgrid::dwarf::TagClass::Variable:
    MC_dwarf_handle_variable_die(info, die, unit, frame, ns);
    break;

  case simgrid::dwarf::TagClass::Namespace:
    mc_dwarf_handle_namespace_die(info, die, unit, frame, ns);
    break;

  default:
    break;

  }
}

/* recursively follow the die tree */
extern void
print_die_and_children(Dwarf_Debug dbg, Dwarf_Die in_die_in,
		       char **srcfiles, Dwarf_Signed cnt)
{
    Dwarf_Die child;
    Dwarf_Die sibling;
    Dwarf_Error err;
    int tres;
    int cdres;
    Dwarf_Die in_die = in_die_in;

    for (;;) {
	PUSH_DIE_STACK(in_die);

	if (check_tag_tree) {
	    tag_tree_result.checks++;
	    if (indent_level == 0) {
		Dwarf_Half tag;

		tres = dwarf_tag(in_die, &tag, &err);
		if (tres != DW_DLV_OK) {
		    tag_tree_result.errors++;
		    DWARF_CHECK_ERROR
			("Tag-tree root is not DW_TAG_compile_unit")
		} else if (tag == DW_TAG_compile_unit) {
		    /* OK */
		} else {
		    tag_tree_result.errors++;
		    DWARF_CHECK_ERROR
			("tag-tree root is not DW_TAG_compile_unit")
		}
	    } else {

static VALUE rd_die_new(rd_shared_data_t *sd, VALUE top, VALUE cu, Dwarf_Die die)
{
    rd_die_t *rd_die;
    Dwarf_Off off;
    Dwarf_Half tag;
    Dwarf_Error err;
    VALUE obj;
    VALUE klass;

    chkerr1(dwarf_dieoffset(die, &off, &err), &err, Qnil);
    obj = rb_hash_aref(sd->off2die, LL2NUM(off));
    if (!NIL_P(obj)) {
        return obj;
    }

    chkerr1(dwarf_tag(die, &tag, &err), &err, Qnil);
    klass = rb_hash_aref(rdwarf_tag2class, INT2FIX(tag));
    if (NIL_P(klass)) {
        rb_raise(rb_eRuntimeError, "unknown tag %d\n", tag);
    }
    obj = rd_die_s_alloc(klass);
    rd_die = GetDie(obj);
    rd_die->shared_data = rd_shared_data_ref(sd);
    rd_die->die = die;
    rb_ivar_set(obj, id_at_top, top);
    rb_ivar_set(obj, id_at_cu, NIL_P(cu) ? obj : cu);
    rb_hash_aset(sd->off2die, LL2NUM(off), obj);
    return obj;
}

/* BASE must be a base type DIE referenced by a typed DWARF expression op.  */
static void
print_base_type (Dwarf_Die *base)
{
  assert (dwarf_tag (base) == DW_TAG_base_type);

  Dwarf_Attribute encoding;
  Dwarf_Word enctype;
  if (dwarf_attr (base, DW_AT_encoding, &encoding) == NULL
      || dwarf_formudata (&encoding, &enctype) != 0)
    error (EXIT_FAILURE, 0, "base type without encoding");

  Dwarf_Attribute bsize;
  Dwarf_Word bits;
  if (dwarf_attr (base, DW_AT_byte_size, &bsize) != NULL
      && dwarf_formudata (&bsize, &bits) == 0)
    bits *= 8;
  else if (dwarf_attr (base, DW_AT_bit_size, &bsize) == NULL
	   || dwarf_formudata (&bsize, &bits) != 0)
    error (EXIT_FAILURE, 0, "base type without byte or bit size");

  printf ("{%s,%s,%" PRIu64 "@[%" PRIx64 "]}",
	  dwarf_diename (base),
	  dwarf_encoding_string (enctype),
	  bits,
	  dwarf_dieoffset (base));
}

/**
 * die_is_func_def - Ensure that this DIE is a subprogram and definition
 * @dw_die: a DIE
 *
 * Ensure that this DIE is a subprogram and NOT a declaration. This
 * returns true if @dw_die is a function definition.
 **/
bool die_is_func_def(Dwarf_Die *dw_die)
{
	Dwarf_Attribute attr;

	return (dwarf_tag(dw_die) == DW_TAG_subprogram &&
		dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL);
}

int
dwarf_getsrcfiles (Dwarf_Die *cudie, Dwarf_Files **files, size_t *nfiles)
{
  if (unlikely (cudie == NULL || dwarf_tag (cudie) != DW_TAG_compile_unit))
    return -1;

  int res = -1;

  /* Get the information if it is not already known.  */
  struct Dwarf_CU *const cu = cudie->cu;
  if (cu->lines == NULL)
    {
      Dwarf_Lines *lines;
      size_t nlines;

      /* Let the more generic function do the work.  It'll create more
	 data but that will be needed in an real program anyway.  */
      res = dwarf_getsrclines (cudie, &lines, &nlines);
    }
  else if (cu->files != (void *) -1l)
    /* We already have the information.  */
    res = 0;

  if (likely (res == 0))
    {
      assert (cu->files != NULL && cu->files != (void *) -1l);
      *files = cu->files;
      if (nfiles != NULL)
	*nfiles = cu->files->nfiles;
    }

  // XXX Eventually: unlocking here.

  return res;
}

static void
print_die_data(Dwarf_Debug dbg, Dwarf_Die print_me,int level)
{
    char *name = 0;
    Dwarf_Error error = 0;
    Dwarf_Half tag = 0;
    const char *tagname = 0;
    int res = dwarf_diename(print_me,&name,&error);
    if(res == DW_DLV_ERROR) {
        printf("Error in dwarf_diename , level %d \n",level);
        exit(1);
    }
    if(res == DW_DLV_NO_ENTRY) {
        return;
    }
    res = dwarf_tag(print_me,&tag,&error);
    if(res != DW_DLV_OK) {
        printf("Error in dwarf_tag , level %d \n",level);
        exit(1);
    }
    res = dwarf_get_TAG_name(tag,&tagname);
    if(res != DW_DLV_OK) {
        printf("Error in dwarf_get_TAG_name , level %d \n",level);
        exit(1);
    }
    printf("<%d> tag: %d %s  name: %s\n",level,tag,tagname,name);
    dwarf_dealloc(dbg,name,DW_DLA_STRING);
}

static void DC_resolve_type(Dwarf_Die v, DC_type *t){
 
  /*TODO: Error Handling*/ 
  Dwarf_Error error;
  Dwarf_Attribute type;
  Dwarf_Off off;
  Dwarf_Die typeDie;
  Dwarf_Half tag = 0; 
  
 /*
 * Start with the variable,  not its type.  The loop
 * unwraps all the types.
 */
  dwarf_attr(v, DW_AT_type, &type, &error);
  dwarf_formref(type, &off, &error);
  DC_get_die_from_CU_relative_offset(v, off, &typeDie);

  int points = 0;
  int arrs = 0;
  while( 1 ){

    Dwarf_Bool has;
    dwarf_hasattr(typeDie,DW_AT_type,&has,&error);
    if(!has){ 

      /*We've reached a base or structure type*/
      dwarf_diename(typeDie,&(t->name),&error);
  
      Dwarf_Attribute bsize;
      dwarf_attr(typeDie,DW_AT_byte_size,&bsize,&error);
      dwarf_formudata(bsize,(Dwarf_Unsigned*)(&t->byteSize),&error);
      t->indirectionLevel = points;
      t->arrayLevel = arrs;
      return;
      /*Note: I am assuming this must happen eventually.  can there
 *            be mutually referencing types?*/

    }

    /*Otherwise: this type has a type, so it is a pointer or a typedef
 *               or an array type.  For now, we're only going to correctly
 *               handle pointer types.(TODO:)
 */
    dwarf_tag(typeDie,&tag,&error);
    if(tag == DW_TAG_pointer_type){
      points++;
    }
    if(tag == DW_TAG_array_type){
      arrs++;
    }
    
    dwarf_attr(typeDie, DW_AT_type, &type, &error);
    dwarf_formref(type, &off, &error);

    /*Note, the next line uses v, because it can use anything in the CU*/
    DC_get_die_from_CU_relative_offset(v, off, &typeDie);

  }

}

static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
{
	struct __instance_walk_param *iwp = data;
	Dwarf_Attribute attr_mem;
	Dwarf_Die origin_mem;
	Dwarf_Attribute *attr;
	Dwarf_Die *origin;
	int tmp;

	attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
	if (attr == NULL)
		return DIE_FIND_CB_CONTINUE;

	origin = dwarf_formref_die(attr, &origin_mem);
	if (origin == NULL || origin->addr != iwp->addr)
		return DIE_FIND_CB_CONTINUE;

	/* Ignore redundant instances */
	if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) {
		dwarf_decl_line(origin, &tmp);
		if (die_get_call_lineno(inst) == tmp) {
			tmp = die_get_decl_fileno(origin);
			if (die_get_call_fileno(inst) == tmp)
				return DIE_FIND_CB_CONTINUE;
		}
	}

	iwp->retval = iwp->callback(inst, iwp->data);

	return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
}

/**
 * die_get_real_type - Get a type die, but skip qualifiers and typedef
 * @vr_die: a DIE of a variable
 * @die_mem: where to store a type DIE
 *
 * Get a DIE of the type of given variable (@vr_die), and store
 * it to die_mem. Return NULL if fails to get a type DIE.
 * If the type is qualifiers (e.g. const) or typedef, this skips it
 * and tries to find real type (structure or basic types, e.g. int).
 */
Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
{
	do {
		vr_die = __die_get_real_type(vr_die, die_mem);
	} while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);

	return vr_die;
}