freebsd-nq/contrib/elftoolchain/libdwarf/dwarf_add_AT_location_expr.3
Ed Maste ae500c1ff8 Update to ELF Tool Chain r3668
Highlights:
- Make sure that only TLS sections are sorted into TLS segment.
- Fixed multiple errors in "Section to Segment mapping".
- Man page updates
- ar improvements
- elfcopy: avoid filter_reloc uninitialized variable for rela
- elfcopy: avoid stripping relocations from static binaries
- readelf: avoid printing directory in front of absolute path
- readelf: add NT_FREEBSD_FEATURE_CTL FreeBSD note type
- test improvements

NOTES:

Some of these changes originated in FreeBSD and simply reduce diffs
between contrib and vendor.

ELF Tool Chain ar is not (currently) used in FreeBSD, and there are
improvements in both FreeBSD and ELF Tool Chain ar that are not in
the other.

Sponsored by:	The FreeBSD Foundation
2019-01-10 14:35:23 +00:00

121 lines
3.5 KiB
Groff

.\" Copyright (c) 2011 Kai Wang
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.\" $Id: dwarf_add_AT_location_expr.3 3640 2018-10-14 14:09:13Z jkoshy $
.\"
.Dd September 5, 2011
.Dt DWARF_ADD_AT_LOCATION_EXPR 3
.Os
.Sh NAME
.Nm dwarf_add_AT_location_expr
.Nd create an attribute descriptor for a location expression
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft "Dwarf_P_Attribute"
.Fo dwarf_add_AT_location_expr
.Fa "Dwarf_P_Debug dbg"
.Fa "Dwarf_P_Die die"
.Fa "Dwarf_Half attr"
.Fa "Dwarf_P_Expr loc_expr"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_add_AT_location_expr
creates an attribute descriptor for a location expression and attaches
it to the debugging information entry referenced by argument
.Ar die .
.Pp
Argument
.Ar dbg
should reference a DWARF producer instance allocated using
.Xr dwarf_producer_init 3
or
.Xr dwarf_producer_init_b 3 .
.Pp
Argument
.Ar die
should reference a debugging information entry allocated using
.Xr dwarf_new_die 3 .
.Pp
Argument
.Ar attr
specifies the attribute code of the created attribute descriptor.
.Pp
Argument
.Ar loc_expr
should reference a location expression descriptor allocated using
.Xr dwarf_new_expr 3 .
.Pp
The attribute created by function
.Fn dwarf_add_AT_location_expr
will have one of the DWARF forms
.Dv DW_FORM_block ,
.Dv DW_FORM_block1 ,
.Dv DW_FORM_block2
or
.Dv DW_FORM_block4 ,
depending on the size of the byte stream generated by the location
expression descriptor referenced by argument
.Ar loc_expr .
.Pp
If argument
.Ar err
is not NULL, it will be used by to store error information in case of
an error.
.Sh RETURN VALUES
On success, function
.Fn dwarf_add_AT_location_expr
returns the created attribute descriptor.
In case of an error, function
.Fn dwarf_add_AT_location_expr
returns
.Dv DW_DLV_BADADDR
and sets the argument
.Ar err .
.Sh ERRORS
Function
.Fn dwarf_add_AT_location_expr
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
One of the arguments
.Ar dbg ,
.Ar die
or
.Ar loc_expr
was NULL.
.It Bq Er DW_DLE_MEMORY
An out of memory condition was encountered during the execution of the
function.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_new_die 3 ,
.Xr dwarf_new_expr 3 ,
.Xr dwarf_producer_init 3 ,
.Xr dwarf_producer_init_b 3