---
name: "dwarf_formsdata"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/dwarf_formsdata"
---

# dwarf\_formsdata(3)

return the value of a CONSTANT class attribute

## NAME

**dwarf\_formudata**, **dwarf\_formsdata** – return the value of a CONSTANT class attribute

## LIBRARY

library “libdwarf”

## SYNOPSIS

**#include \<libdwarf.h\>**

*int*\

**dwarf\_formudata**(*Dwarf\_Attribute attr*, *Dwarf\_Unsigned \*ret*, *Dwarf\_Error \*err*);

*int*\

**dwarf\_formsdata**(*Dwarf\_Attribute attr*, *Dwarf\_Signed \*ret*, *Dwarf\_Error \*err*);

## DESCRIPTION

These functions return the value associated with a DWARF attribute describing a constant.

Function **dwarf\_formudata**() sets the location pointed to by argument *ret* to the value of the attribute referenced by argument *attr*, treating the value as an unsigned quantity. Argument *attr* must have one of the following forms: DW\_FORM\_data1, DW\_FORM\_data2, DW\_FORM\_data4, DW\_FORM\_data8 and DW\_FORM\_udata.

Function **dwarf\_formsdata**() sets the location pointed to by argument *ret* to the value of the attribute referenced by argument *attr*, appropriately sign extended. Argument *attr* must have one of the following forms: DW\_FORM\_data1, DW\_FORM\_data2, DW\_FORM\_data4, DW\_FORM\_data8 and DW\_FORM\_sdata.

If argument *err* is not NULL, it will be used to return an error descriptor in case of an error.

## RETURN VALUES

These functions return DW\_DLV\_OK on success. In case of an error, they return DW\_DLV\_ERROR and set argument *err*.

## ERRORS

These functions may fail with the following errors:

- \[DW\_DLE\_ARGUMENT\]

  Either of arguments *attr* or *ret* was NULL.

- \[DW\_DLE\_ATTR\_FORM\_BAD\]

  The attribute referenced by argument *attr* was not of a permitted kind.

## SEE ALSO

[dwarf(3)](/dwarf/3.md), [dwarf\_attr(3)](/dwarf_attr/3.md), [dwarf\_formblock(3)](/dwarf_formblock/3.md), [dwarf\_formflag(3)](/dwarf_formflag/3.md), [dwarf\_formref(3)](/dwarf_formref/3.md), [dwarf\_formsig8(3)](/dwarf_formsig8/3.md), [dwarf\_formstring(3)](/dwarf_formstring/3.md), [dwarf\_hasattr(3)](/dwarf_hasattr/3.md)