Check and Fix Warnings during Compiling

[XZTian64]

Description

The MFC code include many warnings during compiling, include unnecessary variables, dummy variables, subroutines and so on. This branch aims to solve these warnings.

A partial fix of #845

Type of change

Please delete options that are not relevant.

• Redundant variables
• Redundant dummy variables
• Unused subroutines
• Something else

Scope

• This PR comprises a set of related changes with a common goal

If you cannot check the above box, please split your PR into multiple PRs that each have a common goal.

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.
Provide instructions so we can reproduce.
Please also list any relevant details for your test configuration

• Test A
• Test B

Test Configuration:

• What computers and compilers did you use to test this:
  Phoenix cluster with both CPU and GPU computing nodes.

Checklist

• I have added comments for the new code
• I added Doxygen docstrings to the new code
• I have made corresponding changes to the documentation (docs/)
• I have added regression tests to the test suite so that people can verify in the future that the feature is behaving as expected
• I have added example cases in examples/ that demonstrate my new feature performing as expected.
  They run to completion and demonstrate "interesting physics"
• I ran ./mfc.sh format before committing my code
• New and existing tests pass locally with my changes, including with GPU capability enabled (both NVIDIA hardware with NVHPC compilers and AMD hardware with CRAY compilers) and disabled
• This PR does not introduce any repeated code (it follows the DRY principle)
• I cannot think of a way to condense this code and reduce any introduced additional line count

If your code changes any code source files (anything in src/simulation)

To make sure the code is performing as expected on GPU devices, I have:

• Checked that the code compiles using NVHPC compilers
• Checked that the code compiles using CRAY compilers
• Ran the code on either V100, A100, or H100 GPUs and ensured the new feature performed as expected (the GPU results match the CPU results)
• Ran the code on MI200+ GPUs and ensure the new features performed as expected (the GPU results match the CPU results)
• Enclosed the new feature via nvtx ranges so that they can be identified in profiles
• Ran a Nsight Systems profile using ./mfc.sh run XXXX --gpu -t simulation --nsys, and have attached the output file (.nsys-rep) and plain text results to this PR
• Ran a Rocprof Systems profile using ./mfc.sh run XXXX --gpu -t simulation --rsys --hip-trace, and have attached the output file and plain text results to this PR.
• Ran my code using various numbers of different GPUs (1, 2, and 8, for example) in parallel and made sure that the results scale similarly to what happens if you run without the new code/feature

[codecov]

Codecov Report

Attention: Patch coverage is 20.00000% with 8 lines in your changes missing coverage. Please review.

Project coverage is 43.24%. Comparing base (8a24386) to head (4ceee02).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
src/common/m_boundary_common.fpp	12.50%	7 Missing ⚠️
src/post_process/m_data_output.fpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #843      +/-   ##
==========================================
- Coverage   43.24%   43.24%   -0.01%     
==========================================
  Files          68       68              
  Lines       20182    20183       +1     
  Branches     2401     2402       +1     
==========================================
  Hits         8728     8728              
- Misses       9985     9986       +1     
  Partials     1469     1469              

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[sbryngelson]

hi @XZTian64 - you need to run ./mfc.sh format -j X where X is the number of threads it runs in parallel (just a few is fine). This reformats the code to a standardized form so everything is consistent.

[sbryngelson]

Very small/easy PR, thanks! Next time, make it a bit clearer what your PR does and why it does it. Since smaller PRs are easy to review and merge, I will merge this one now, and you can fix additional things in a new PR.