[Bug c++/110263] New: Bogos Warning [-Wreturn-type] for unreachable code

[Bug c++/110263] New: Bogos Warning [-Wreturn-type] for unreachable code

[gerstner.thomas at siemens dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110263

            Bug ID: 110263
           Summary: Bogos Warning [-Wreturn-type] for unreachable code
           Product: gcc
           Version: 13.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gerstner.thomas at siemens dot com
  Target Milestone: ---

The following example (see https://gcc.godbolt.org/z/4477zajnj) produces
Warning [-Wreturn-type]:


bool foo();
int instrumentation = 0;

struct S { ~S(); };

int func() {
    S s;  // if commented out there is no warning [-Wreturn-type]
    while(true) {  // "endless loop"
        if (foo()) return 42;
    }
    instrumentation++; // if commented out there is no warning [-Wreturn-type]
}

Our original code is without the line "instrumentation++;", because this line
is an additional instrumentation by a tool (Squish Coco).

We made [-Wreturn-type] an error and therefor our build fails.

If this example is build with "-O2" the warning is gone.

This problem is very similar to
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67693 which seems to be fixed but
it's not identical.