[PATCH 00/26] gdbserver: refactor regcache and allow gradually populating

[Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>]

Hello,

Gdbserver's regcache is defined and used in a way that it is either
invalid or fetches all the registers from the target prior to being
used.  It also seems some regcache functions have two different contracts
based on argument values (e.g. a buffer being nullptr).

This is an attempt to refactor the regcache in gdbserver to

  - convert several free functions to methods.
  - use and update register statuses more consistently.
  - allow populating register values gradually, instead of having to
    fetch all register values from the target.

The last item above is utilized in our (Intel) downstream debugger.
No gdbserver low target is modified to utilize that feature in this
series.

Regression-tested on X86_64 Linux using the native-gdbserver and
native-extended-gdbserver board files.

Tankut Baris Aktemur (26):
  gdbserver: convert init_register_cache into regcache::initialize
  gdbserver: convert new_register_cache into a regcache constructor
  gdbserver: by-pass regcache to access tdesc only
  gdbserver: boolify and defaultize the 'fetch' parameter of
    get_thread_regcache
  gdbserver: add a pointer to the owner thread in regcache
  gdbserver: turn part of get_thread_regcache into regcache::fetch
  gdbserver: convert regcache_cpy into regcache::copy_from
  gdbserver: convert free_register_cache into a destructor of regcache
  gdbserver: extract out regcache::invalidate and regcache::discard
  gdbserver: convert registers_to_string into
    regcache::registers_to_string
  gdbserver: convert registers_from_string into
    regcache::registers_from_string
  gdbserver: convert supply_regblock to regcache::supply_regblock
  gdbserver: convert register_data into regcache::register_data
  gdbserver: introduce and use regcache::set_register_status
  gdbserver: check for nullptr condition in
    regcache::get_register_status
  gdbserver: boolify regcache fields
  gdbserver: rename regcache's registers_valid to registers_fetched
  gdbsupport: fix a typo in a comment in common-regcache.h
  gdbserver: fix the declared type of register_status in regcache
  gdbserver: make some regcache fields private
  gdbserver: use REG_UNKNOWN for a regcache's register statuses
  gdbserver: zero-out register values in regcache-discard
  gdbserver: set register statuses in registers_from_string
  gdbserver: return tracked register status in
    regcache_raw_read_unsigned
  gdbserver: refuse null argument in regcache::supply_regblock
  gdbserver: allow gradually populating and selectively storing a
    regcache

 gdbserver/gdbthread.h          |   2 +-
 gdbserver/linux-aarch32-low.cc |   2 +-
 gdbserver/linux-low.cc         |  18 +-
 gdbserver/linux-ppc-low.cc     |  12 +-
 gdbserver/linux-s390-low.cc    |  14 +-
 gdbserver/linux-x86-low.cc     |   9 +-
 gdbserver/mem-break.cc         |   4 +-
 gdbserver/proc-service.cc      |   2 +-
 gdbserver/regcache.cc          | 305 ++++++++++++++++++++-------------
 gdbserver/regcache.h           |  92 ++++++----
 gdbserver/remote-utils.cc      |   2 +-
 gdbserver/server.cc            |  16 +-
 gdbserver/tracepoint.cc        |  25 ++-
 gdbserver/win32-low.cc         |   2 +-
 gdbsupport/common-regcache.h   |  11 +-
 15 files changed, 302 insertions(+), 214 deletions(-)

-- 
2.25.1

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