[PATCH v2 0/8] Initial support for ROCm platform (AMD GPU) debugging

[Simon Marchi <simon.marchi@polymtl.ca>]

This is the v2 of:

  https://inbox.sourceware.org/gdb-patches/20221206135729.3937767-1-simon.marchi@efficios.com/

I pushed patches 5, 7, 8 and 9, since I considered them good chances even
outside of this series.

Most other preparatory patches have been reviewed and LGTM'ed by Andrew
Burgess, but they are not really useful on their own, so they are still
in this series.  There are no changes in them, except a typo fix in
patch 3.

The only preparatory patch which was not reviewed is "gdb/solib-svr4:
don't disable probes interface if probe not found".

The only changes in the last patch are in the doc.  I reduced the size
and scope of the documentation drastically.  There was a lot of
information that was only tangentially relevant to GDB, about the
behavior of the rest of the ROCm platform.  We agreed that this kind of
information is not relevant for the upstream GDB project (it can still
continue to exist in the downstream ROCm GDB documentation).   So I
removed anything that was not documenting concrete use cases of GDB
itself.

Other than that, the last patch didn't change since v1.

Here is the original cover letter (with patch numbers updated):

This patch series adds initial support for debugging programs offloaded
to AMD GPUs using the ROCm platform.

Patches 1 to 7 are preparatory patches, and patch 8 is the big one.
We included in that patch only what we consider to be the bare minimum
for a cohesive first step, something that can be run and tested.  See
the commit message of patch 8 for more details.

At the end of this series, it is possible to hit breakpoints in GPU code
and resume execution until the end of the program.  Notably, GDB is not
able to compute the backtrace, which is of course an important piece to
do any real debugging.  Supporting this will require GDB to support some
extensions to DWARF, which is a big piece in itself.  This part, as well
as other features, will come as future patches.

Patch 8 also contains documentation changes.  This series was tested on
Ubuntu 22.04, and no regressions appear for x86-64 / Linux debugging
when and the AMDGPU / ROCm platform support is compiled in.
Built-tested with --enable-targets=all.

Porting GDB to the ROCm platform brought up many challenges and has a
few interesting differences, compared to a "standard" CPU port.  We did
a presentation at the 2022 Cauldron, in Prague, that explains some of
them:

  https://www.youtube.com/watch?v=X1iZ_Ta7jOo

Lancelot SIX (1):
  gdb: add supports_arch_info callback to gdbarch_register

Pedro Alves (1):
  gdb: make install_breakpoint return a non-owning reference

Simon Marchi (6):
  gdbsupport: add type definitions for pid, lwp and tid
  gdb: add inferior_pre_detach observable
  gdb: add gdbarch_up
  gdb/solib-svr4: don't disable probes interface if probe not found
  gdb: make gdb_printing_disassembler::stream public
  gdb: initial support for ROCm platform (AMDGPU) debugging

 gdb/Makefile.in                   |   17 +-
 gdb/NEWS                          |    7 +
 gdb/README                        |   15 +
 gdb/amd-dbgapi-target.c           | 1966 +++++++++++++++++++++++++++++
 gdb/amd-dbgapi-target.h           |  116 ++
 gdb/amdgpu-tdep.c                 | 1367 ++++++++++++++++++++
 gdb/amdgpu-tdep.h                 |   93 ++
 gdb/arch-utils.c                  |    9 +-
 gdb/breakpoint.c                  |    4 +-
 gdb/breakpoint.h                  |    8 +-
 gdb/configure                     |  425 +++++--
 gdb/configure.ac                  |   52 +
 gdb/configure.tgt                 |   23 +-
 gdb/disasm.h                      |    4 +-
 gdb/doc/gdb.texinfo               |  291 +++++
 gdb/gdbarch.h                     |   12 +-
 gdb/observable.c                  |    1 +
 gdb/observable.h                  |    3 +
 gdb/regcache.c                    |    3 +-
 gdb/solib-rocm.c                  |  679 ++++++++++
 gdb/solib-svr4.c                  |   15 +-
 gdb/target.c                      |    2 +
 gdb/testsuite/gdb.rocm/simple.cpp |   48 +
 gdb/testsuite/gdb.rocm/simple.exp |   52 +
 gdb/testsuite/lib/future.exp      |   38 +
 gdb/testsuite/lib/gdb.exp         |    7 +
 gdb/testsuite/lib/rocm.exp        |   94 ++
 gdbsupport/ptid.h                 |   18 +-
 28 files changed, 5210 insertions(+), 159 deletions(-)
 create mode 100644 gdb/amd-dbgapi-target.c
 create mode 100644 gdb/amd-dbgapi-target.h
 create mode 100644 gdb/amdgpu-tdep.c
 create mode 100644 gdb/amdgpu-tdep.h
 create mode 100644 gdb/solib-rocm.c
 create mode 100644 gdb/testsuite/gdb.rocm/simple.cpp
 create mode 100644 gdb/testsuite/gdb.rocm/simple.exp
 create mode 100644 gdb/testsuite/lib/rocm.exp


base-commit: 1a8605a8c79b0c4ebc71f5691e36a1338d407837
-- 
2.39.0