C++ dwarf_diename函数代码示例

/* Convert subprogram DIE to trace point */
static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
				  bool retprobe, struct probe_trace_point *tp)
{
	Dwarf_Addr eaddr;
	const char *name;

	/* Copy the name of probe point */
	name = dwarf_diename(sp_die);
	if (name) {
		if (dwarf_entrypc(sp_die, &eaddr) != 0) {
			pr_warning("Failed to get entry address of %s\n",
				   dwarf_diename(sp_die));
			return -ENOENT;
		}
		tp->symbol = strdup(name);
		if (tp->symbol == NULL)
			return -ENOMEM;
		tp->offset = (unsigned long)(paddr - eaddr);
	} else
		/* This function has no name. */
		tp->offset = (unsigned long)paddr;

	/* Return probe must be on the head of a subprogram */
	if (retprobe) {
		if (eaddr != paddr) {
			pr_warning("Return probe must be on the head of"
				   " a real function.\n");
			return -EINVAL;
		}
		tp->retprobe = true;
	}

	return 0;
}

bool supported_language(Dwarf_Die *cu)
{
    int ret;
    Dwarf_Word lang;
    Dwarf_Attribute at;

    if (dwarf_attr(cu, DW_AT_language, &at) == NULL)
    {
        warn("CU %s: unknown language", dwarf_diename(cu));
        return false;
    }

    ret = dwarf_formudata(&at, &lang);
    fail_if(ret == -1, "dwarf_formudata");

    switch (lang)
    {
    case DW_LANG_C89:
    case DW_LANG_C:
    case DW_LANG_C99:
        /* good! */
        break;
    case DW_LANG_C_plus_plus:
        warn("CU %s: C++ not supported", dwarf_diename(cu));
        return false;
        break;
    default:
        debug("CU %s: unsupported language: 0x%lx",
             dwarf_diename(cu), (unsigned long)lang);
        return false;
        break;
    }

    return true;
}

/* Convert subprogram DIE to trace point */
static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
				  Dwarf_Addr paddr, bool retprobe,
				  struct probe_trace_point *tp)
{
	Dwarf_Addr eaddr, highaddr;
	GElf_Sym sym;
	const char *symbol;

	/* Verify the address is correct */
	if (dwarf_entrypc(sp_die, &eaddr) != 0) {
		pr_warning("Failed to get entry address of %s\n",
			   dwarf_diename(sp_die));
		return -ENOENT;
	}
	if (dwarf_highpc(sp_die, &highaddr) != 0) {
		pr_warning("Failed to get end address of %s\n",
			   dwarf_diename(sp_die));
		return -ENOENT;
	}
	if (paddr > highaddr) {
		pr_warning("Offset specified is greater than size of %s\n",
			   dwarf_diename(sp_die));
		return -EINVAL;
	}

	symbol = dwarf_diename(sp_die);
	if (!symbol) {
		/* Try to get the symbol name from symtab */
		symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
		if (!symbol) {
			pr_warning("Failed to find symbol at 0x%lx\n",
				   (unsigned long)paddr);
			return -ENOENT;
		}
		eaddr = sym.st_value;
	}
	tp->offset = (unsigned long)(paddr - eaddr);
	tp->address = (unsigned long)paddr;
	tp->symbol = strdup(symbol);
	if (!tp->symbol)
		return -ENOMEM;

	/* Return probe must be on the head of a subprogram */
	if (retprobe) {
		if (eaddr != paddr) {
			pr_warning("Return probe must be on the head of"
				   " a real function.\n");
			return -EINVAL;
		}
		tp->retprobe = true;
	}

	return 0;
}

/**
 * die_match_name - Match diename and glob
 * @dw_die: a DIE
 * @glob: a string of target glob pattern
 *
 * Glob matching the name of @dw_die and @glob. Return false if matching fail.
 */
bool die_match_name(Dwarf_Die *dw_die, const char *glob)
{
	const char *name;

	name = dwarf_diename(dw_die);
	return name ? strglobmatch(name, glob) : false;
}

/**
 * die_compare_name - Compare diename and tname
 * @dw_die: a DIE
 * @tname: a string of target name
 *
 * Compare the name of @dw_die and @tname. Return false if @dw_die has no name.
 */
bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
{
	const char *name;

	name = dwarf_diename(dw_die);
	return name ? (strcmp(tname, name) == 0) : false;
}

static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
	struct probe_finder *pf = data;
	struct perf_probe_point *pp = &pf->pev->point;
	Dwarf_Addr addr;
	int ret;

	if (pp->lazy_line)
		ret = find_probe_point_lazy(in_die, pf);
	else {
		
		if (dwarf_entrypc(in_die, &addr) != 0) {
			pr_warning("Failed to get entry address of %s.\n",
				   dwarf_diename(in_die));
			return -ENOENT;
		}
		pf->addr = addr;
		pf->addr += pp->offset;
		pr_debug("found inline addr: 0x%jx\n",
			 (uintmax_t)pf->addr);

		ret = call_probe_finder(in_die, pf);
	}

	return ret;
}

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);

  }

}

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;
}

/* 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));
}

static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
{
	Dwarf_Die die_mem;
	int ret;

	pr_debug("Converting variable %s into trace event.\n",
		 dwarf_diename(vr_die));

	ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
					pf->tvar);
	if (ret == -ENOENT)
		pr_err("Failed to find the location of %s at this address.\n"
		       " Perhaps, it has been optimized out.\n", pf->pvar->var);
	else if (ret == -ENOTSUP)
		pr_err("Sorry, we don't support this variable location yet.\n");
	else if (pf->pvar->field) {
		ret = convert_variable_fields(vr_die, pf->pvar->var,
					      pf->pvar->field, &pf->tvar->ref,
					      &die_mem);
		vr_die = &die_mem;
	}
	if (ret == 0)
		ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type);
	
	return ret;
}

static void
HandleFunctionDIE (Dwarf_Debug dwHandle, Dwarf_Die currChildDIE)
{
  char *funcName = NULL;
  Dwarf_Addr lowAddress = 0;
  Dwarf_Addr highAddress = 0;

  int dwDieNameRet = dwarf_diename (currChildDIE,
				    &funcName,
				    NULL);
  int dwDieLowAddrRet = dwarf_lowpc (currChildDIE,
				     &lowAddress,
				     NULL);
  int dwDieHighAddrRet = dwarf_highpc (currChildDIE,
				       &highAddress,
				       NULL);

  if ((dwDieNameRet == DW_DLV_OK) &&
      (dwDieLowAddrRet == DW_DLV_OK) && (dwDieHighAddrRet == DW_DLV_OK))
    {
      FunctionMap_Add (funcName, lowAddress, highAddress);
    }

  if ((dwDieNameRet == DW_DLV_OK) && (funcName != NULL))
    {
      dwarf_dealloc (dwHandle, funcName, DW_DLA_STRING);
    }
}

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_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 int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
				  bool retprobe, struct probe_trace_point *tp)
{
	Dwarf_Addr eaddr, highaddr;
	const char *name;

	
	name = dwarf_diename(sp_die);
	if (name) {
		if (dwarf_entrypc(sp_die, &eaddr) != 0) {
			pr_warning("Failed to get entry address of %s\n",
				   dwarf_diename(sp_die));
			return -ENOENT;
		}
		if (dwarf_highpc(sp_die, &highaddr) != 0) {
			pr_warning("Failed to get end address of %s\n",
				   dwarf_diename(sp_die));
			return -ENOENT;
		}
		if (paddr > highaddr) {
			pr_warning("Offset specified is greater than size of %s\n",
				   dwarf_diename(sp_die));
			return -EINVAL;
		}
		tp->symbol = strdup(name);
		if (tp->symbol == NULL)
			return -ENOMEM;
		tp->offset = (unsigned long)(paddr - eaddr);
	} else
		
		tp->offset = (unsigned long)paddr;

	
	if (retprobe) {
		if (eaddr != paddr) {
			pr_warning("Return probe must be on the head of"
				   " a real function.\n");
			return -EINVAL;
		}
		tp->retprobe = true;
	}

	return 0;
}

static int frame_callback(Dwfl_Frame *frame, void *userdata) {
        struct stack_context *c = userdata;
        Dwarf_Addr pc, pc_adjusted, bias = 0;
        _cleanup_free_ Dwarf_Die *scopes = NULL;
        const char *fname = NULL, *symbol = NULL;
        Dwfl_Module *module;
        bool is_activation;

        assert(frame);
        assert(c);

        if (c->n_frame >= FRAMES_MAX)
                return DWARF_CB_ABORT;

        if (!dwfl_frame_pc(frame, &pc, &is_activation))
                return DWARF_CB_ABORT;

        pc_adjusted = pc - (is_activation ? 0 : 1);

        module = dwfl_addrmodule(c->dwfl, pc_adjusted);
        if (module) {
                Dwarf_Die *s, *cudie;
                int n;

                cudie = dwfl_module_addrdie(module, pc_adjusted, &bias);
                if (cudie) {
                        n = dwarf_getscopes(cudie, pc_adjusted - bias, &scopes);
                        for (s = scopes; s < scopes + n; s++) {
                                if (IN_SET(dwarf_tag(s), DW_TAG_subprogram, DW_TAG_inlined_subroutine, DW_TAG_entry_point)) {
                                        Dwarf_Attribute *a, space;

                                        a = dwarf_attr_integrate(s, DW_AT_MIPS_linkage_name, &space);
                                        if (!a)
                                                a = dwarf_attr_integrate(s, DW_AT_linkage_name, &space);
                                        if (a)
                                                symbol = dwarf_formstring(a);
                                        if (!symbol)
                                                symbol = dwarf_diename(s);

                                        if (symbol)
                                                break;
                                }
                        }
                }

                if (!symbol)
                        symbol = dwfl_module_addrname(module, pc_adjusted);

                fname = dwfl_module_info(module, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
        }

        fprintf(c->f, "#%-2u 0x%016" PRIx64 " %s (%s)\n", c->n_frame, (uint64_t) pc, strna(symbol), strna(fname));
        c->n_frame ++;

        return DWARF_CB_OK;
}