freebsd-nq/contrib/elftoolchain/libdwarf/dwarf_formblock.3
Ed Maste b00fe64f4a Update to ELF Tool Chain r3197
Highlights:
 - Fix man page markup, whitespace, and typos
 - Fix sh_info of SHT_GROUP section to point to the correct string
 - Improve validation in readelf and elfcopy/strip
 - Handle DWARF 4's DW_AT_high_pc in addr2line

Sponsored by:	The FreeBSD Foundation
2015-05-14 19:48:15 +00:00

110 lines
3.0 KiB
Groff

.\" Copyright (c) 2010 Joseph Koshy
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.\" $Id: dwarf_formblock.3 3182 2015-04-10 16:08:10Z emaste $
.\"
.Dd July 23, 2010
.Os
.Dt DWARF_FORMBLOCK 3
.Sh NAME
.Nm dwarf_formblock
.Nd return the value of a BLOCK attribute
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_formblock
.Fa "Dwarf_Attribute attr"
.Fa "Dwarf_Block **ret"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_formblock
sets the location pointed to by argument
.Ar ret
to a pointer to a
.Vt Dwarf_Block
structure containing the value of the attribute referenced
by argument
.Ar attr .
The form of argument
.Ar attr
must be one of
.Dv DW_FORM_block ,
.Dv DW_FORM_block1 ,
.Dv DW_FORM_block2
or
.Dv DW_FORM_block4 .
.Pp
If argument
.Ar err
is not NULL, it will be used to return an error descriptor in case
of an error.
.Ss Memory Management
The memory area referenced by the returned pointer is managed by
the DWARF(3) library.
The application should not attempt to free this memory
area.
Portable code may indicate that the memory area is to be freed by
using
.Xr dwarf_dealloc 3 .
.Sh RETURN VALUES
Function
.Fn dwarf_formblock
returns
.Dv DW_DLV_OK
on success.
In case of an error, it returns
.Dv DW_DLV_ERROR
and sets argument
.Ar err .
.Sh ERRORS
Function
.Fn dwarf_formblock
may fail with the following errors:
.Bl -tag -width ".Bq Er DW_DLE_ATTR_FORM_BAD"
.It Bq Er DW_DLE_ARGUMENT
Either of arguments
.Ar attr
or
.Ar ret
was NULL.
.It Bq Er DW_DLE_ATTR_FORM_BAD
The attribute referenced by argument
.Ar attr
was not of a permitted kind.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_attr 3 ,
.Xr dwarf_formflag 3 ,
.Xr dwarf_formref 3 ,
.Xr dwarf_formsdata 3 ,
.Xr dwarf_formsig8 3 ,
.Xr dwarf_formstring 3 ,
.Xr dwarf_formudata 3 ,
.Xr dwarf_hasattr 3