xref: /freebsd/contrib/elftoolchain/libdwarf/dwarf_hasform.3 (revision ae500c1ff8974130f7f2692772cf288b90349e0d)
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24.\" $Id: dwarf_hasform.3 3640 2018-10-14 14:09:13Z jkoshy $
25.\"
26.Dd May 22, 2010
27.Dt DWARF_HASFORM 3
28.Os
29.Sh NAME
30.Nm dwarf_hasform ,
31.Nm dwarf_whatform ,
32.Nm dwarf_whatform_direct
33.Nd query attribute forms
34.Sh LIBRARY
35.Lb libdwarf
36.Sh SYNOPSIS
37.In libdwarf.h
38.Ft int
39.Fo dwarf_hasform
40.Fa "Dwarf_Attribute attr"
41.Fa "Dwarf_Half form"
42.Fa "Dwarf_Bool *ret"
43.Fa "Dwarf_Error *err"
44.Fc
45.Ft int
46.Fo dwarf_whatform
47.Fa "Dwarf_Attribute attr"
48.Fa "Dwarf_Half *retform"
49.Fa "Dwarf_Error *err"
50.Fc
51.Ft int
52.Fo dwarf_whatform_direct
53.Fa "Dwarf_Attribute attr"
54.Fa "Dwarf_Half *retform"
55.Fa "Dwarf_Error *err"
56.Fc
57.Sh DESCRIPTION
58Function
59.Fn dwarf_hasform
60indicates whether the DWARF attribute denoted by argument
61.Ar attr
62has the attribute form specified by argument
63.Ar form .
64If the attribute has the specified form, then
65argument
66.Ar ret
67is set to a non-zero value, otherwise it is set to zero.
68If argument
69.Ar err
70is non-NULL, it will be used to return an error descriptor in
71case of an error.
72.Pp
73Function
74.Fn dwarf_whatform
75sets the location specified by argument
76.Ar retform
77to the attribute form code for the DWARF attribute referenced
78by argument
79.Ar attr .
80If the attribute referenced by argument
81.Ar attr
82has an indirect form attribute, this function will return the final
83form for the attribute.
84If argument
85.Ar err
86is non-NULL, it will be used to return an error descriptor in
87case of an error.
88.Pp
89Function
90.Fn dwarf_whatform_direct
91sets the location specified by argument
92.Ar retform
93to the attribute form code for the DWARF attribute referenced
94by argument
95.Ar attr .
96If the form is an indirect form, the function sets the location
97specified by argument
98.Ar retform
99to
100.Dv DW_FORM_indirect .
101If argument
102.Ar err
103is non-NULL, it will be used to return an error descriptor in
104case of an error.
105.Sh RETURN VALUES
106These functions return
107.Dv DW_DLV_OK
108on success.
109In case of an error, these functions return
110.Dv DW_DLV_ERR
111and set argument
112.Ar err .
113.Sh ERRORS
114These functions may fail with the following errors:
115.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
116.It Bq Er DW_DLE_ARGUMENT
117Any of the arguments
118.Ar attr ,
119.Ar ret ,
120or
121.Ar retform
122was NULL.
123.El
124.Sh SEE ALSO
125.Xr dwarf 3 ,
126.Xr dwarf_attr 3 ,
127.Xr dwarf_hasattr 3
128