(Towards #2271, closes #2278) Generalise reference_accesses() and use to tidy KernelModuleInlineTrans.

[arporter]

I found I needed some of this in #2716 (while improving KernelModuleInlineTrans) so I thought I'd best do it as a separate PR.

[arporter]

I need to add explicit unit tests for the new reference_access() methods that I've added to Literal, CodeBlock and ScopingNode. For the moment, my implementation for ScopingNode only adds info about Symbols that appear in precision or initialisation expressions. I rely on the subsequent walk down the tree to add Symbols that are actually used (and also how they are used).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.88%. Comparing base (1e6b095) to head (4651016).

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@@           Coverage Diff           @@
##           master    #2825   +/-   ##
=======================================
  Coverage   99.88%   99.88%           
=======================================
  Files         357      357           
  Lines       49742    49765   +23     
=======================================
+ Hits        49686    49710   +24     
+ Misses         56       55    -1     

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[arporter]

This PR enhances the functionality of VariablesAccessInfo by adding reference_accesses methods to CodeBlock, Literal and ScopingNode. This then allows it to be used in KernelModuleInlineTrans() in place of the custom search for symbols that used to be performed there. We can probably use this functionality elsewhere but I've not investigated that here.

Ready for review. One for @hiker or @sergisiso.

[arporter]

(I've triggered the integration tests.)

[arporter]

Taking this back as both the NEMOv4 and LFRic integration tests failed :-(

[arporter]

LFRic ('with all transformations') test fails with:

algorithm/runtime_constants/physical_op_constants_mod_psy.f90:253:10:
41632

41633
  253 |       IF (psyclone_internal_cmp(geometry, geometry_planar)) THEN
41634
      |          1
41635
Error: Function 'psyclone_internal_cmp' at (1) has no IMPLICIT type

and the NEMO v.4 OpenACC kernels test fails at the final link stage:

NEMO/cfgs/SPITZ12_openacc_kernels/BLD/lib/lib__fcm__nemo.a(obs_oper.o): in function `obs_oper_obs_max_fpsize_':
14928
NEMO/cfgs/SPITZ12_openacc_kernels/WORK/obs_oper.f90:905: undefined reference to `obs_deg2dist_'
14929
NEMO/cfgs/SPITZ12_openacc_kernels/BLD/lib/lib__fcm__nemo.a(obs_oper.o): in function `obs_oper_obs_avg_h2d_init_':
14930
NEMO/cfgs/SPITZ12_openacc_kernels/WORK/obs_oper.f90:955: undefined reference to `obs_avg_h2d_rad_'
14931
NEMO/cfgs/SPITZ12_openacc_kernels/WORK/obs_oper.f90:959: undefined reference to `obs_avg_h2d_rec_'

I think the latter often means we've put OpenACC around a function call but the function itself hasn't been marked-up for GPU compilation?

[arporter]

In LFRic, we have an in-lined kernel that calls our PSyclone-generated routine but that routine hasn't been inlined:

      REAL(KIND=r_def), dimension(ndf_w2b,3) :: rad_vector_xyz

      ipanel = INT(panel_id(map_pid(1)), i_def)
      IF (psyclone_internal_cmp(geometry, geometry_planar)) THEN
        x_vector = (/1.0_r_def, 0.0_r_def, 0.0_r_def/)
        y_vector = (/0.0_r_def, 1.0_r_def, 0.0_r_def/)

Presumably, the symbol isn't being spotted by the transformation?