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25.\" $Id: dwarf_formudata.3 3640 2018-10-14 14:09:13Z jkoshy $
26.\"
27.Dd June 21, 2010
28.Dt DWARF_FORMUDATA 3
29.Os
30.Sh NAME
31.Nm dwarf_formudata ,
32.Nm dwarf_formsdata
33.Nd return the value of a CONSTANT class attribute
34.Sh LIBRARY
35.Lb libdwarf
36.Sh SYNOPSIS
37.In libdwarf.h
38.Ft int
39.Fo dwarf_formudata
40.Fa "Dwarf_Attribute attr"
41.Fa "Dwarf_Unsigned *ret"
42.Fa "Dwarf_Error *err"
43.Fc
44.Ft int
45.Fo dwarf_formsdata
46.Fa "Dwarf_Attribute attr"
47.Fa "Dwarf_Signed *ret"
48.Fa "Dwarf_Error *err"
49.Fc
50.Sh DESCRIPTION
51These functions return the value associated with a DWARF attribute
52describing a constant.
53.Pp
54Function
55.Fn dwarf_formudata
56sets the location pointed to by argument
57.Ar ret
58to the value of the attribute referenced by argument
59.Ar attr ,
60treating the value as an unsigned quantity.
61Argument
62.Ar attr
63must have one of the following forms:
64.Dv DW_FORM_data1 ,
65.Dv DW_FORM_data2 ,
66.Dv DW_FORM_data4 ,
67.Dv DW_FORM_data8
68and
69.Dv DW_FORM_udata .
70.Pp
71Function
72.Fn dwarf_formsdata
73sets the location pointed to by argument
74.Ar ret
75to the value of the attribute referenced by argument
76.Ar attr ,
77appropriately sign extended.
78Argument
79.Ar attr
80must have one of the following forms:
81.Dv DW_FORM_data1 ,
82.Dv DW_FORM_data2 ,
83.Dv DW_FORM_data4 ,
84.Dv DW_FORM_data8
85and
86.Dv DW_FORM_sdata .
87.Pp
88If argument
89.Ar err
90is not NULL, it will be used to return an error descriptor in case
91of an error.
92.Sh RETURN VALUES
93These functions return
94.Dv DW_DLV_OK
95on success.
96In case of an error, they return
97.Dv DW_DLV_ERROR
98and set argument
99.Ar err .
100.Sh ERRORS
101These functions may fail with the following errors:
102.Bl -tag -width ".Bq Er DW_DLE_ATTR_FORM_BAD"
103.It Bq Er DW_DLE_ARGUMENT
104Either of arguments
105.Ar attr
106or
107.Ar ret
108was NULL.
109.It Bq Er DW_DLE_ATTR_FORM_BAD
110The attribute referenced by argument
111.Ar attr
112was not of a permitted kind.
113.El
114.Sh SEE ALSO
115.Xr dwarf 3 ,
116.Xr dwarf_attr 3 ,
117.Xr dwarf_formblock 3 ,
118.Xr dwarf_formflag 3 ,
119.Xr dwarf_formref 3 ,
120.Xr dwarf_formsig8 3 ,
121.Xr dwarf_formstring 3 ,
122.Xr dwarf_hasattr 3
123