https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106696
Bug ID: 106696
Summary: Fallthrough between functions without proper return
statement when optimizing
Product: gcc
Version: 12.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ipa
Assignee: unassigned at gcc dot gnu.org
Reporter: stefan.kneifel at bluewin dot ch
CC: marxin at gcc dot gnu.org
Target Milestone: ---
Host: x86_64
Target: x86_64, aarch64
Consider the following incorrect code:
----------------------
void* foo (void)
{
}
int bar (void)
{
return 42;
}
----------------------
Compiling this as either plain C or without optimization gives the proper
warning (no return statement in function returning non-void), but returns from
foo. However, compiling this as C++ with optimization on (-O1 is sufficient),
the warning is emitted anyway, but the function body of foo is now eliminated
entirely (even the ret statement!) and a call to foo() falls through to a call
to bar(). For security reasons, I don't think this should be the case, even
when the input code is faulty.
