libdw, readelf: Read inlining info in NVIDIA extended line map
As of CUDA 11.2, NVIDIA added extensions to the line map section
of CUDA binaries to represent inlined functions. These extensions
include
- two new fields in a line table row to represent inline
information: context, and functionname,
- two new DWARF extended opcodes: DW_LNE_NVIDIA_inlined_call,
DW_LNE_NVIDIA_set_function_name,
- an additional word in the line table header that indicates
the offset in the .debug_str function where the function
names for this line table begin, and
A line table row for an inlined function contains a non-zero "context"
value. The “context” field indicates the index of the line table row
that serves as the call site for an inlined context.
The "functionname" field in a line table row is only meaningful if the
"context" field of the row is non-zero. A meaningful "functionname"
field contains an index into the .debug_str section relative to the
base offset established in the line table header; the position in the
.debug_str section indicates the name of the inlined function.
These extensions resemble the proposed DWARF extensions
(http://dwarfstd.org/ShowIssue.php?issue=140906.1) by Cary Coutant,
but are not identical.
This commit integrates support for handling NVIDIA's extended line
maps into elfutil's libdw library, by adding two functions
dwarf_linecontext and dwarf_linefunctionname, and the readelf
--debug-dump=line command line utility.
Signed-off-by: John M Mellor-Crummey <johnmc@rice.edu>
Signed-off-by: Mark Wielaard <mark@klomp.org>
20 files changed
