xref: /freebsd/contrib/elftoolchain/libdwarf/dwarf_attr.3 (revision 2de3b87a120614a3b053be7dd845b72f1e9ce804)
1*2de3b87aSKai Wang.\" Copyright (c) 2010 Kai Wang
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25*2de3b87aSKai Wang.\" $Id: dwarf_attr.3 2072 2011-10-27 03:26:49Z jkoshy $
26*2de3b87aSKai Wang.\"
27*2de3b87aSKai Wang.Dd April 8, 2010
28*2de3b87aSKai Wang.Os
29*2de3b87aSKai Wang.Dt DWARF_ATTR 3
30*2de3b87aSKai Wang.Sh NAME
31*2de3b87aSKai Wang.Nm dwarf_attr
32*2de3b87aSKai Wang.Nd retrieve an attribute descriptor associated with a DWARF debugging information entry
33*2de3b87aSKai Wang.Sh LIBRARY
34*2de3b87aSKai Wang.Lb libdwarf
35*2de3b87aSKai Wang.Sh SYNOPSIS
36*2de3b87aSKai Wang.In libdwarf.h
37*2de3b87aSKai Wang.Ft int
38*2de3b87aSKai Wang.Fo dwarf_attr
39*2de3b87aSKai Wang.Fa "Dwarf_Die die"
40*2de3b87aSKai Wang.Fa "Dwarf_Half attr"
41*2de3b87aSKai Wang.Fa "Dwarf_Attribute *atp"
42*2de3b87aSKai Wang.Fa "Dwarf_Error *err"
43*2de3b87aSKai Wang.Fc
44*2de3b87aSKai Wang.Sh DESCRIPTION
45*2de3b87aSKai WangFunction
46*2de3b87aSKai Wang.Fn dwarf_attr
47*2de3b87aSKai Wangretrieves the attribute descriptor for an attribute associated
48*2de3b87aSKai Wangwith the DWARF debugging information entry descriptor in
49*2de3b87aSKai Wangargument
50*2de3b87aSKai Wang.Ar die .
51*2de3b87aSKai Wang.Pp
52*2de3b87aSKai WangDWARF attribute descriptors are represented by value of the opaque
53*2de3b87aSKai Wangtype
54*2de3b87aSKai Wang.Vt Dwarf_Attribute ,
55*2de3b87aSKai Wangsee
56*2de3b87aSKai Wang.Xr dwarf 3 .
57*2de3b87aSKai Wang.Pp
58*2de3b87aSKai WangArgument
59*2de3b87aSKai Wang.Ar attr
60*2de3b87aSKai Wangnames the desired DWARF attribute.
61*2de3b87aSKai WangLegal values for argument
62*2de3b87aSKai Wang.Ar attr
63*2de3b87aSKai Wangare those denoted by the
64*2de3b87aSKai Wang.Dv DW_AT_*
65*2de3b87aSKai Wangconstants in the DWARF specification.
66*2de3b87aSKai Wang.Pp
67*2de3b87aSKai WangArgument
68*2de3b87aSKai Wang.Ar atp
69*2de3b87aSKai Wangpoints to a location into which the returned attribute descriptor
70*2de3b87aSKai Wangwill be written.
71*2de3b87aSKai WangThe returned descriptor may then be passed to the form query functions in the
72*2de3b87aSKai Wang.Xr dwarf 3
73*2de3b87aSKai WangAPI set to access the data associated with the attribute.
74*2de3b87aSKai Wang.Pp
75*2de3b87aSKai WangIf argument
76*2de3b87aSKai Wang.Ar err
77*2de3b87aSKai Wangis non-NULL, it will be used to return an error descriptor in case
78*2de3b87aSKai Wangof an error.
79*2de3b87aSKai Wang.Sh RETURN VALUES
80*2de3b87aSKai WangFunction
81*2de3b87aSKai Wang.Fn dwarf_attr
82*2de3b87aSKai Wangreturns
83*2de3b87aSKai Wang.Dv DW_DLV_OK on success.
84*2de3b87aSKai Wang.Pp
85*2de3b87aSKai WangIf the debugging information entry descriptor denoted by argument
86*2de3b87aSKai Wang.Ar die
87*2de3b87aSKai Wangdoes not contain the named attribute, the function returns
88*2de3b87aSKai Wang.Dv DW_DLV_NO_ENTRY
89*2de3b87aSKai Wangand sets argument
90*2de3b87aSKai Wang.Ar err .
91*2de3b87aSKai WangFor other errors, it returns
92*2de3b87aSKai Wang.Dv DW_DLV_ERROR
93*2de3b87aSKai Wangand sets argument
94*2de3b87aSKai Wang.Ar err .
95*2de3b87aSKai Wang.Sh ERRORS
96*2de3b87aSKai WangFunction
97*2de3b87aSKai Wang.Fn dwarf_attr
98*2de3b87aSKai Wangcan fail with the following errors:
99*2de3b87aSKai Wang.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
100*2de3b87aSKai Wang.It Bq Er DW_DLE_ARGUMENT
101*2de3b87aSKai WangEither of arguments
102*2de3b87aSKai Wang.Ar die
103*2de3b87aSKai Wangor
104*2de3b87aSKai Wang.Ar atp
105*2de3b87aSKai Wangwas NULL.
106*2de3b87aSKai Wang.It Bq Er DW_DLE_NO_ENTRY
107*2de3b87aSKai WangArgument
108*2de3b87aSKai Wang.Ar die
109*2de3b87aSKai Wanghad no attribute corresponding to the value
110*2de3b87aSKai Wangin argument
111*2de3b87aSKai Wang.Ar attr .
112*2de3b87aSKai Wang.El
113*2de3b87aSKai Wang.Sh SEE ALSO
114*2de3b87aSKai Wang.Xr dwarf 3 ,
115*2de3b87aSKai Wang.Xr dwarf_attrlist 3 ,
116*2de3b87aSKai Wang.Xr dwarf_hasattr 3 ,
117*2de3b87aSKai Wang.Xr dwarf_hasform 3 ,
118*2de3b87aSKai Wang.Xr dwarf_whatattr 3 ,
119*2de3b87aSKai Wang.Xr dwarf_whatform 3
120