C++ dwarf_siblingof函数代码示例

static struct dwarf_subprogram_t *read_from_cus(Dwarf_Debug dbg)
{
    Dwarf_Unsigned cu_header_length, abbrev_offset, next_cu_header;
    Dwarf_Half version_stamp, address_size;
    Dwarf_Error err;
    Dwarf_Die no_die = 0, cu_die, child_die, next_die;
    int ret = DW_DLV_OK;
    int rc;
    struct dwarf_subprogram_t *subprograms = NULL;

    while (ret == DW_DLV_OK) {
        ret = dwarf_next_cu_header(
                dbg,
                &cu_header_length,
                &version_stamp,
                &abbrev_offset,
                &address_size,
                &next_cu_header,
                &err);
        DWARF_ASSERT(ret, err);

        if (ret == DW_DLV_NO_ENTRY)
            continue;

        /* TODO: If the CU can provide an address range then we can skip over
         * all the entire die if none of our addresses match */

        /* Expect the CU to have a single sibling - a DIE */
        ret = dwarf_siblingof(dbg, no_die, &cu_die, &err);
        if (ret == DW_DLV_ERROR) {
            continue;
        }
        DWARF_ASSERT(ret, err);

        /* Expect the CU DIE to have children */
        ret = dwarf_child(cu_die, &child_die, &err);
        DWARF_ASSERT(ret, err);

        next_die = child_die;

        /* Now go over all children DIEs */
        do {
            subprograms = read_cu_entry(subprograms, dbg, cu_die, child_die);

            rc = dwarf_siblingof(dbg, child_die, &next_die, &err);
            DWARF_ASSERT(rc, err);

            dwarf_dealloc(dbg, child_die, DW_DLA_DIE);

            child_die = next_die;
        } while (rc != DW_DLV_NO_ENTRY);

        dwarf_dealloc(dbg, cu_die, DW_DLA_DIE);
    }

    return subprograms;
}

static VALUE rdwarf_compile_units(VALUE self)
{
    rdwarf_t *rd = GetRDwarf(self);
    Dwarf_Unsigned cu_header_length = 0;
    Dwarf_Unsigned abbrev_offset = 0;
    Dwarf_Half version_stamp = 0;
    Dwarf_Half address_size = 0;
    Dwarf_Unsigned next_cu_offset = 0;
    Dwarf_Error err;
    Dwarf_Die die;
    VALUE ary;

    if (rd->compile_units != Qfalse) {
      return rd->compile_units;
    }
    ary = rb_ary_new();

    while (dwarf_next_cu_header(rd->shared_data->dbg, &cu_header_length, &version_stamp, &abbrev_offset,
                                &address_size, &next_cu_offset, &err) == DW_DLV_OK) {
        if (!chkerr2(dwarf_siblingof(rd->shared_data->dbg, NULL, &die, &err), &err)) {
            continue;
        }
        rb_ary_push(ary, rd_die_new(rd->shared_data, self, Qnil, die));
    }
    rd->compile_units = ary;
    return ary;
}

/* process each compilation unit(CU) in .debug_info */
static int process_CUs(Dwarf_Debug dbg)
{
    Dwarf_Unsigned next_cu_header;
    int ret;

    while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, &next_cu_header, NULL)) == DW_DLV_OK)
    {
        /* process a single compilation unit in .debug_info. */
        Dwarf_Die cu_die;

        ret = dwarf_siblingof(dbg, NULL, &cu_die, NULL);
        if (ret != DW_DLV_OK)
        {
            fprintf(stderr, "SET dwarf: Error in dwarf_siblingof()\n");
            return 1;
        }

        ret = process_die_and_children(dbg, cu_die);
        dwarf_dealloc(dbg, cu_die, DW_DLA_DIE);
        if (ret != 0)
            return 1;
    }
    if (ret == DW_DLV_ERROR)
    {
        fprintf(stderr, "SET dwarf: Error in dwarf_next_cu_header()\n");
        return 1;
    }
    else
        return 0;
}

static void handle_die(
        struct dwarf_subprogram_t **subprograms,
        Dwarf_Debug dbg, Dwarf_Die cu_die, Dwarf_Die the_die, Dwarf_Unsigned language)
{
    int rc;
    Dwarf_Error err;
    Dwarf_Die current_die = the_die;
    Dwarf_Die child_die = NULL;
    Dwarf_Die next_die;

    do {
        *subprograms = read_cu_entry(*subprograms, dbg, cu_die, current_die, language);

        /* Recursive call handle_die with child, to continue searching within child dies */
        rc = dwarf_child(current_die, &child_die, &err);
        DWARF_ASSERT(rc, err);
        if (rc == DW_DLV_OK && child_die)
            handle_die(subprograms, dbg, cu_die, child_die, language);    

        rc = dwarf_siblingof(dbg, current_die, &next_die, &err);
        DWARF_ASSERT(rc, err);

        dwarf_dealloc(dbg, current_die, DW_DLA_DIE);

        current_die = next_die;
    } while (rc != DW_DLV_NO_ENTRY);
}

/**
 * die_find_child - Generic DIE search function in DIE tree
 * @rt_die: a root DIE
 * @callback: a callback function
 * @data: a user data passed to the callback function
 * @die_mem: a buffer for result DIE
 *
 * Trace DIE tree from @rt_die and call @callback for each child DIE.
 * If @callback returns DIE_FIND_CB_END, this stores the DIE into
 * @die_mem and returns it. If @callback returns DIE_FIND_CB_CONTINUE,
 * this continues to trace the tree. Optionally, @callback can return
 * DIE_FIND_CB_CHILD and DIE_FIND_CB_SIBLING, those means trace only
 * the children and trace only the siblings respectively.
 * Returns NULL if @callback can't find any appropriate DIE.
 */
Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
			  int (*callback)(Dwarf_Die *, void *),
			  void *data, Dwarf_Die *die_mem)
{
	Dwarf_Die child_die;
	int ret;

	ret = dwarf_child(rt_die, die_mem);
	if (ret != 0)
		return NULL;

	do {
		ret = callback(die_mem, data);
		if (ret == DIE_FIND_CB_END)
			return die_mem;

		if ((ret & DIE_FIND_CB_CHILD) &&
		    die_find_child(die_mem, callback, data, &child_die)) {
			memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
			return die_mem;
		}
	} while ((ret & DIE_FIND_CB_SIBLING) &&
		 dwarf_siblingof(die_mem, die_mem) == 0);

	return NULL;
}

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;
}

//file_cmd helper funcs
//DBG init and exit functions
error_t load_dbg(mygdb_info_t* gdb_info){
	Dwarf_Error err;
	Dwarf_Die no_die = 0;
	Dwarf_Unsigned cu_header_length;
	Dwarf_Half version_stamp;
	Dwarf_Unsigned abbrev_offset;
	Dwarf_Half addr_size;
	Dwarf_Unsigned nxt_cu_hdr;


	gdb_info->dbg_fd = open(gdb_info->src_file, O_RDONLY);

	if( dwarf_init(gdb_info->dbg_fd,DW_DLC_READ,0,0, &gdb_info->dbg, &err) != DW_DLV_OK )
		return E_FATAL;

	printf("Succesfully loaded symbol info\n");
	int res;
	if( (res = dwarf_next_cu_header(gdb_info->dbg, &cu_header_length, &version_stamp, &abbrev_offset, &addr_size, &nxt_cu_hdr, &err)) == DW_DLV_ERROR ){
		printf("failed to get next header\n");		
		return E_FATAL;
	}

	if( dwarf_siblingof(gdb_info->dbg, no_die, &gdb_info->cu_die, &err) == DW_DLV_ERROR){
		printf("siblingof() failed\n");
		return E_FATAL;
	}

	
	return E_NONE;
}

/* Recursively follow the DIE tree */
static int process_die_and_children(Dwarf_Debug dbg, Dwarf_Die in_die)
{
    Dwarf_Die cur_die = in_die;
    Dwarf_Die child;
    Dwarf_Die sib_die;
    int is_function;
    int ret;

    ret = process_one_DIE(dbg, in_die, &is_function);
    if (ret != 0)
        return 1;

    while (1)
    {
        if (!is_function)   /* Assume that there is no nested function, so we ignore the children of a function */ 
        {
            ret = dwarf_child(cur_die, &child, NULL);
            if (ret == DW_DLV_ERROR)
            {
                fprintf(stderr, "SET dwarf: Error in dwarf_child()\n");
                return 1;
            }

            /* Recursive call */
            if (ret == DW_DLV_OK)
            {
                ret = process_die_and_children(dbg, child);
                dwarf_dealloc(dbg, child, DW_DLA_DIE);
                if (ret != 0)
                    return 1;
            }
        }

        /* Current DIE has no children */
        ret = dwarf_siblingof(dbg, cur_die, &sib_die, NULL);
        if (ret == DW_DLV_ERROR)
        {
            fprintf(stderr, "SET dwarf: Error in dwarf_siblingof()\n");
            return 1;
        }

        if (cur_die != in_die)
            dwarf_dealloc(dbg, cur_die, DW_DLA_DIE);

        if (ret == DW_DLV_NO_ENTRY)
        {
            /* Done at this level */
            break;
        }

        /* ret == DW_DLV_OK */
        cur_die = sib_die;
        ret = process_one_DIE(dbg, cur_die, &is_function);
        if (ret != 0)
            return 1;
    }
    return 0;
}

/*
	Return DW_DLV_OK, ERROR, or NO_ENTRY.
*/
static int
handle_debug_info(Dwarf_Debug dbg, int *errval)
{
    Dwarf_Unsigned nxtoff = 1;
    Dwarf_Unsigned hdr_length;
    Dwarf_Half version_stamp;
    Dwarf_Unsigned abbrev_offset;
    Dwarf_Half addr_size;
    Dwarf_Error err;
    int terminate_now = 0;
    int res = 0;
    Dwarf_Die sibdie;
    int sibres;
    int nres = DW_DLV_OK;


    for (nres = dwarf_next_cu_header(dbg, &hdr_length, &version_stamp,
				     &abbrev_offset,
				     &addr_size, &nxtoff, &err);
	 terminate_now == 0 && nres == DW_DLV_OK;
	 nres = dwarf_next_cu_header(dbg, &hdr_length, &version_stamp,
				     &abbrev_offset,
				     &addr_size, &nxtoff, &err)
	) {

	Dwarf_Die curdie = 0;

	/* try to get the compilation unit die */
	sibres = dwarf_siblingof(dbg, curdie, &sibdie, &err);
	if (sibres == DW_DLV_OK) {
	    res = do_this_die_and_dealloc(dbg, sibdie, errval);
	    switch (res) {
	    case DW_DLV_OK:
		break;
	    case DW_DLV_NO_ENTRY:
		break;
	    default:
	    case DW_DLV_ERROR:
		return DW_DLV_ERROR;
	    }
	} else if (sibres == DW_DLV_ERROR) {
	    *errval = (int) dwarf_errno(err);
	    return DW_DLV_ERROR;
	} else {
	    /* NO ENTRY! */
	    /* impossible? */
	}

    }
    if (nres == DW_DLV_ERROR) {
	int localerr = (int) dwarf_errno(err);

	*errval = localerr;
	return DW_DLV_ERROR;
    }
    return DW_DLV_OK;
}

static void DC_show_info_for_containing_pc_ranges(Dwarf_Die die, int enclosing, unsigned long iaddr){

  /*This function visits the children of a die in sequence, 
   *applying the action() function to each*/
  Dwarf_Attribute highattr;
  Dwarf_Attribute lowattr;
  Dwarf_Addr loval,hival;
  Dwarf_Bool has;
  Dwarf_Error error;
  Dwarf_Half tag; 
  
  loval = hival = 0x0;
  int enc = 0;

  dwarf_tag(die,&tag,&error);
 
  if( tag == DW_TAG_variable ||
      tag == DW_TAG_formal_parameter ){

    if(enclosing){
      char *name;
      dwarf_diename(die,&name,&error);
      fprintf(stderr,"%s, ",name);
      //show_all_attrs(die,0,NULL);
    }
     
  }

  if( tag == DW_TAG_lexical_block || tag == DW_TAG_subprogram ){
    if( dwarf_lowpc(die,&loval,&error) == DW_DLV_OK  && dwarf_highpc(die,&hival,&error) == DW_DLV_OK
        && iaddr >=loval && iaddr <= hival ){ 
      enc = 1;
      fprintf(stderr,"\n=================================\n");
      show_all_attrs(die,0,NULL);
      fprintf(stderr,"=================================\n");
    }
  
  }
  
  Dwarf_Die kid;
  if( dwarf_child(die,&kid,&error) == DW_DLV_NO_ENTRY ){
    return;
  }
  DC_show_info_for_containing_pc_ranges(kid, enc, iaddr); 
  //visit_die(kid,level+1,action,adata); 

  int chret;
  while( (chret = dwarf_siblingof(d,kid,&kid,&error)) != DW_DLV_NO_ENTRY &&
           chret != DW_DLV_ERROR){

    DC_show_info_for_containing_pc_ranges(kid, enc, iaddr); 
    //visit_die(kid,level+1,action,adata);

  }

  return;
}

static struct dwarf_subprogram_t *read_from_cus(Dwarf_Debug dbg)
{
    Dwarf_Unsigned cu_header_length, abbrev_offset, next_cu_header;
    Dwarf_Half version_stamp, address_size;
    Dwarf_Error err;
    Dwarf_Die no_die = 0, cu_die, child_die;
    int ret = DW_DLV_OK;
    struct dwarf_subprogram_t *subprograms = NULL;
    Dwarf_Unsigned language = 0;
    Dwarf_Attribute language_attr = 0;

    while (ret == DW_DLV_OK) {
        ret = dwarf_next_cu_header(
                dbg,
                &cu_header_length,
                &version_stamp,
                &abbrev_offset,
                &address_size,
                &next_cu_header,
                &err);
        DWARF_ASSERT(ret, err);

        if (ret == DW_DLV_NO_ENTRY)
            continue;

        /* TODO: If the CU can provide an address range then we can skip over
         * all the entire die if none of our addresses match */

        /* Expect the CU to have a single sibling - a DIE */
        ret = dwarf_siblingof(dbg, no_die, &cu_die, &err);
        if (ret == DW_DLV_ERROR) {
            continue;
        }
        DWARF_ASSERT(ret, err);

        /* Get compilation unit language attribute */
        ret = dwarf_attr(cu_die, DW_AT_language, &language_attr, &err);
        DWARF_ASSERT(ret, err);
        if (ret != DW_DLV_NO_ENTRY) {
            /* Get language attribute data */
            ret = dwarf_formudata(language_attr, &language, &err);
            DWARF_ASSERT(ret, err);
            dwarf_dealloc(dbg, language_attr, DW_DLA_ATTR);
        }

        /* Expect the CU DIE to have children */
        ret = dwarf_child(cu_die, &child_die, &err);
        DWARF_ASSERT(ret, err);

        handle_die(&subprograms, dbg, cu_die, child_die, language);  

        dwarf_dealloc(dbg, cu_die, DW_DLA_DIE);
    }

    return subprograms;
}

static void DC_get_info_for_scoped_variable(Dwarf_Die die, int enclosing, unsigned long iaddr, const char *varname, Dwarf_Die *retDie){

  /*This function visits the children of a die in sequence, 
   *applying the action() function to each*/
  Dwarf_Attribute highattr;
  Dwarf_Attribute lowattr;
  Dwarf_Addr loval,hival;
  Dwarf_Bool has;
  Dwarf_Error error;
  Dwarf_Half tag; 
  
  loval = hival = 0x0;
  int enc = 0;

  dwarf_tag(die,&tag,&error);
 
  if( tag == DW_TAG_variable ||
      tag == DW_TAG_formal_parameter ){

    if(enclosing){
      char *name;
      dwarf_diename(die,&name,&error);
      if(!strncmp(name,varname,strlen(name))){
        *retDie = die;
        return;
      }
    }
     
  }

  if( tag == DW_TAG_lexical_block || tag == DW_TAG_subprogram ){
    if( dwarf_lowpc(die,&loval,&error) == DW_DLV_OK  && dwarf_highpc(die,&hival,&error) == DW_DLV_OK
        && iaddr >=loval && iaddr <= hival ){ 
      enc = 1;
    }
  
  }
  
  Dwarf_Die kid;
  if( dwarf_child(die,&kid,&error) == DW_DLV_NO_ENTRY ){
    return;
  }
  DC_get_info_for_scoped_variable(kid, enc, iaddr,varname,retDie); 

  int chret;
  while( (chret = dwarf_siblingof(d,kid,&kid,&error)) != DW_DLV_NO_ENTRY &&
           chret != DW_DLV_ERROR){

    DC_get_info_for_scoped_variable(kid, enc, iaddr,varname,retDie); 

  }

  return;

}

static void 
read_cu_list(Dwarf_Debug dbg)
{
    Dwarf_Unsigned cu_header_length = 0;
    Dwarf_Half version_stamp = 0;
    Dwarf_Unsigned abbrev_offset = 0;
    Dwarf_Half address_size = 0;
    Dwarf_Unsigned next_cu_header = 0;
    Dwarf_Error error;
    int cu_number = 0;

    for(;;++cu_number) {

        /*edit by liupo*/
        //printf("\n--------------CU_NUMBER-%d-----------------\n", cu_number);
        /*end edit*/

        struct srcfilesdata sf;
        sf.srcfilesres = DW_DLV_ERROR;
        sf.srcfiles = 0;
        sf.srcfilescount = 0;
        Dwarf_Die no_die = 0;
        Dwarf_Die cu_die = 0;
        int res = DW_DLV_ERROR;
        res = dwarf_next_cu_header(dbg,&cu_header_length,
            &version_stamp, &abbrev_offset, &address_size,
            &next_cu_header, &error);
        if(res == DW_DLV_ERROR) {
            printf("Error in dwarf_next_cu_header\n");
            exit(1);
        }
        if(res == DW_DLV_NO_ENTRY) {
            /*edit by liupo*/
            //printf("\n-------------CU_NUMBER--------------\n");
            /*end edit*/
            /* Done. */
            return;
        }
        /* The CU will have a single sibling, a cu_die. */
        res = dwarf_siblingof(dbg,no_die,&cu_die,&error);
        if(res == DW_DLV_ERROR) {
            printf("Error in dwarf_siblingof on CU die \n");
            exit(1);
        }
        if(res == DW_DLV_NO_ENTRY) {
            /* Impossible case. */
            printf("no entry! in dwarf_siblingof on CU die \n");
            exit(1);
        }
        get_die_and_siblings(dbg,cu_die,0,&sf);
        dwarf_dealloc(dbg,cu_die,DW_DLA_DIE);
        resetsrcfiles(dbg,&sf);
    }
}

static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
                                     Dwarf_Die * unit, simgrid::mc::Frame* frame,
                                     const char *ns)
{
  // For each child DIE:
  Dwarf_Die child;
  int res;
  for (res = dwarf_child(die, &child); res == 0;
       res = dwarf_siblingof(&child, &child))
    MC_dwarf_handle_die(info, &child, unit, frame, ns);
}

Dwarf_Die DieHolder::get_sibling(void)
{
  Dwarf_Die sibling_die = NULL;
  Dwarf_Error err = NULL;

  // there may be no sibling
  CHECK_DWERR2(dwarf_siblingof(m_dbg, m_die, &sibling_die, &err) == DW_DLV_ERROR, err,
               "error when asking for a DIE sibling");

  return sibling_die;
}