[clang-tidy] Invalid fixit from cppcoreguidelines-init-variables in the presence of goto

[chrchr-github]

void g(int);
int f(int i) {
    if (i == -1)
        goto end;
    int x;
    if (i > 1)
        x = 1;
    else
        x = 0;
    g(x);
end:
    return 0;
}

<source>:5:9: warning: variable 'x' is not initialized [cppcoreguidelines-init-variables]
    5 |     int x;
      |         ^
      |           = 0

Applying the fix results in

<source>:4:9: error: cannot jump from this goto statement to its label [clang-diagnostic-error]
    4 |         goto end;
      |         ^
<source>:5:9: note: jump bypasses variable initialization
    5 |     int x{};
      |         ^

https://godbolt.org/z/j43cdjYvo

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: None (chrchr-github)

~~~c++ void g(int); int f(int i) { if (i == -1) goto end; int x; if (i > 1) x = 1; else x = 0; g(x); end: return 0; } ~~~ ~~~ <source>:5:9: warning: variable 'x' is not initialized [cppcoreguidelines-init-variables] 5 | int x; | ^ | = 0 ~~~ Applying the fix results in ~~~ <source>:4:9: error: cannot jump from this goto statement to its label [clang-diagnostic-error] 4 | goto end; | ^ <source>:5:9: note: jump bypasses variable initialization 5 | int x{}; | ^ ~~~ https://godbolt.org/z/j43cdjYvo

[PiotrZSL]

This is cppcoreguidelines check, it should be used together with cppcoreguidelines-avoid-goto.
For sure no-one will be fixing check to cover such an corrner-case scenario as there are many ways to refactor code to avoid both problems.

[chrchr-github]

It's still an issue if you want to e.g. improve an old codebase step by step.