Fix clang-tidy warnings

[ncihnegn]

Clang-tidy gives a warning like this:
/usr/local/include/catch2/catch.hpp:5444:9: warning: Returning null reference [clang-analyzer-core.uninitialized.UndefReturn]
return *IMutableContext::currentContext;

This simple change fixes the warning and the overhead is minimal.

[codecov]

Codecov Report

Merging #1485 into master will decrease coverage by 0.03%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1485      +/-   ##
==========================================
- Coverage   80.42%   80.39%   -0.03%     
==========================================
  Files         121      121              
  Lines        3421     3426       +5     
==========================================
+ Hits         2751     2754       +3     
- Misses        670      672       +2

[codecov]

Codecov Report

Merging #1485 into master will decrease coverage by 3.28%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1485      +/-   ##
==========================================
- Coverage   83.67%   80.39%   -3.28%     
==========================================
  Files         123      121       -2     
  Lines        3380     3426      +46     
==========================================
- Hits         2828     2754      -74     
- Misses        552      672     +120

[horenmar]

Given how often people complain about this, I agree that it is time to fix it, but I really dislike this specific change, and would prefer to restructure the code differently instead.

However, I ran into some trouble reproducing the warning -- can you post what version of clang-tidy have you used, what did your compilation database look like and so on?

[ncihnegn]

➜ build git:(master) clang-tidy --version
LLVM (http://llvm.org/):
LLVM version 7.0.1
Optimized build.
Default target: x86_64-apple-darwin18.2.0
Host CPU: skylake

➜ build git:(master) cat ../.clang-tidy
Checks: '*,-bugprone-exception-escape,-clang-analyzer-cplusplus.NewDeleteLeaks,-cppcoreguidelines-pro-bounds-array-to-pointer-decay,-cppcoreguidelines-pro-type-reinterpret-cast,-fuchsia-default-arguments,-fuchsia-overloaded-operator,-fuchsia-trailing-return,-google-default-arguments,-google-runtime-references,-hicpp-no-assembler,-hicpp-no-array-decay,-misc-unused-parameters'

[horenmar]

Thanks

[yuriy-mochurad]

I have also faced this issue and would be great to have it fixed.

[poconbhui]

Adding an assertion before dereferencing the pointer should also silence the warning.

[codecov]

Codecov Report

Merging #1485 into master will decrease coverage by 6.12%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1485      +/-   ##
==========================================
- Coverage    86.5%   80.39%   -6.12%     
==========================================
  Files         136      121      -15     
  Lines        5275     3426    -1849     
==========================================
- Hits         4563     2754    -1809     
+ Misses        712      672      -40

[horenmar]

Fixed in #1735