https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87371
Bug ID: 87371
Summary: Spurious -Wreturn-type warning with "pathological" for
Product: gcc
Version: 8.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: mwoehlke.floss at gmail dot com
Target Milestone: ---
Consider the following code:
int foo()
{
for (int y = 0; !y;)
for (/*decl*/; !y; ++y)
return 1;
}
This generates a -Wreturn-type warning, despite that the inner loop body will
*always* execute. Moreover, with optimization enabled, the compiler does (as
expected) successfully remove the loops entirely.
(This is a simplified version of a pre-C++17 `with` statement. The purpose of
this code, which is usually a macro, is to look like the opening statement of a
block, where `/*decl*/` — omitted in this example — is in scope only until the
end of the block. FWIW, the C++17 form, `if (/*decl*/; true)` does not exhibit
the problem.)
Live example: https://godbolt.org/g/5xM6C3. Possibly related to #67629 and/or
#85914.
