[PATCH i-g-t v3 00/31] tools: remove unnecessary shared library dependencies from standalone tools

[Sebastian Brzezinka <sebastian.brzezinka@intel.com>]

This issue was raised by the community back in 2019: 
https://bugs.freedesktop.org/show_bug.cgi?id=110249

Standalone tools linked libigt.so as a side effect, pulling in cairo,
pixman and libX11 even without framebuffer use.

Following intel_gpu_top's approach, each tool now links only the static
sub-libraries it needs. Five new ones are introduced:

lib_igt_tools_stub, lib_igt_drm_stub, lib_igt_halffloat,
lib_i915_decode, lib_igt_reg_tools.

igt_load_igtrc() is moved to igt_device_scan.c so lsgpu can use
lib_igt_device_scan without pulling in libigt.so.

All 20 tools: 35 shared libs -> 3-8.

Behavioural differences vs original binaries (no-hardware runs):

intel_backlight, intel_lid, intel_gpu_time, intel_audio_dump,
intel_infoframes, intel_panel_fitter, intel_firmware_decode:
assertion failure format: IGT CRITICAL block -> single-line message;
exit code: 98 (IGT_EXIT_FAILURE) -> 1.

intel_gtt, intel_display_poller, intel_watermark:
same as above; additionally print an extra "Test requirement passed:
pci_dev" line on stderr (previously suppressed by IGT log layer).

intel_guc_logger:
same exit code change (98->1); --help drops IGT framework options
(--list-subtests, --run-subtest, --device, etc.) which had no effect
on guc_logger since it opens debugfs directly, not via IGT device
selection; --version, --debug, --hook also removed.
Unknown option exit code: 79 (IGT_EXIT_INVALID) -> 1.

intel_gvtg_test:
skip message: IGT skip block -> single-line; exit code unchanged (77).

Tested on Intel Meteor Lake-P (device 0x7d45) with the series applied:
lsgpu                enumerates card0/renderD128
intel_gpu_frequency  reads cur/min/max/RP1 frequencies
intel_stepping       reports device 0x7d45 rev 0x04
intel_error_decode   parses empty error state
igt_stats            computes median from stdin
intel_backlight      reads current backlight value: 0%
intel_gtt            dumps GTT linear mappings
intel_gpu_time       user: 0.000322s, GPU: 0.0%
intel_infoframes     runs, reports hardware not yet supported
intel_panel_fitter   shows usage with -l/-p/-x/-y options
intel_audio_dump     dumps meteorlake audio registers
intel_watermark      dumps WM_LINETIME and plane watermarks
intel_display_poller shows usage (requires --test option)
intel_lid            polls lid state: open (loops by design)
intel_forcewaked     locks forcewake, restarts daemon on gpu reset
intel_gvtg_test      exits 77, no GVT-g hardware
intel_guc_logger     --help prints usage correctly
intel_vbt_decode     --help prints usage correctly
intel_firmware_decode runs, fails on missing CSR file as expected
intel_dump_decode    runs, rejects unknown options as expected
---
v2 -> v3:
 - lib/igt_tools_stub: replace magic exit code 77 with IGT_EXIT_SKIP
   (+ comment), fix missing blank line after if block, unify
   multi line comment style
 - lib/igt_drm_stub: replace long MIT license text with SPDX
   identifier, document which libigt files this reimplements, name
   the "16" magic constant IGT_DRM_STUB_MAX_CARDS
 - runner/executor: add missing igt_device_scan.h include so
   igt_load_igtrc() has a visible prototype under HAVE_OPING builds
 - lib/i915/intel_decode: reorder so "replace igt.h with minimal
   headers" lands right before "introduce static sub-library for
   tools" - previously the sub-library patch tried to build
   intel_decode.c while it still pulled in igt.h (and transitively
   cairo.h), breaking bisectability

v1 -> v2:
 - Rename all patch subjects
 - Split  tools/intel_gtt  into two patches:  tools/intel_gtt  and  tools/intel_dump_decode 
 - Split  tools/lsgpu  into  lib/igt_core: move igt_load_igtrc to igt_device_scan  +  tools/lsgpu 
 - Shorten  tools/intel_gpu_top  subject (was over 72 chars)

Sebastian Brzezinka (31):
  lib/igt_tools_stub: introduce static sub-library for tools
  lib/igt_stats: introduce static sub-library for tools
  tools/igt_stats: link with minimal sub-libraries
  tools/intel_firmware_decode: link with minimal sub-libraries
  lib/igt_tools_stub: add stubs needed by tools
  lib/igt_drm_stub: introduce for tools needing driver detection
  lib/igt_device_scan: wire to use static sub-libraries
  tools/intel_gpu_top: add explicit drm/tools-stub deps
  lib/igt_halffloat: introduce static sub-library for tools
  lib/i915/intel_decode: replace igt.h with minimal headers
  lib/i915/intel_decode: introduce static sub-library for tools
  lib/intel_mmio: introduce lib_igt_reg_tools static sub-library for
    tools
  tools/intel_gpu_frequency: link with minimal sub-libraries
  tools/intel_stepping: link with minimal sub-libraries
  tools/intel_gtt: link with minimal sub-libraries
  tools/intel_dump_decode: link with minimal sub-libraries
  tools/intel_error_decode: link with minimal sub-libraries
  tools/intel_vbt_decode: link with minimal sub-libraries
  tools/intel_backlight: link with minimal sub-libraries
  tools/intel_lid: link with minimal sub-libraries
  tools/intel_gpu_time: link with minimal sub-libraries
  tools/intel_audio_dump: link with minimal sub-libraries
  tools/intel_forcewaked: link with minimal sub-libraries
  tools/intel_guc_logger: link with minimal sub-libraries
  tools/intel_infoframes: link with minimal sub-libraries
  tools/intel_panel_fitter: link with minimal sub-libraries
  tools/intel_watermark: link with minimal sub-libraries
  tools/intel_display_poller: link with minimal sub-libraries
  tools/intel_gvtg_test: link with minimal sub-libraries
  lib/igt_core: move igt_load_igtrc to igt_device_scan
  tools/lsgpu: link with minimal sub-libraries

 lib/i915/intel_decode.c  |   3 +-
 lib/igt_core.c           |  47 ---------------
 lib/igt_core.h           |   2 -
 lib/igt_device_scan.c    |  48 +++++++++++++++
 lib/igt_device_scan.h    |   2 +
 lib/igt_drm_stub.c       | 125 ++++++++++++++++++++++++++++++++++++++
 lib/igt_tools_stub.c     |  83 +++++++++++++++++++++++---
 lib/meson.build          |  66 +++++++++++++++++++-
 runner/executor.c        |   1 +
 tools/intel_guc_logger.c |  21 ++++++-
 tools/intel_gvtg_test.c  |   2 +-
 tools/lsgpu.c            |   2 +-
 tools/meson.build        | 126 ++++++++++++++++++++++++++++++++-------
 13 files changed, 443 insertions(+), 85 deletions(-)
 create mode 100644 lib/igt_drm_stub.c

-- 
2.53.0