https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82741
Bug ID: 82741
Summary: Optimisations may cause noexcept specifier to be
ignored
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: pdziepak at quarnos dot org
Target Milestone: ---
On x86_64:
gcc version 7.2.1 20170915 (Red Hat 7.2.1-2) (GCC)
The following code results in noexcept being ignored if optimisations are
enabled.
---<snip>---
volatile bool should_throw = false;
[[gnu::noinline]]
void foo() {
if (should_throw) {
throw 42;
}
}
[[gnu::noinline]]
void bar() noexcept {
should_throw = true;
foo();
}
int main() {
try {
foo();
bar();
foo();
} catch (...) { }
}
---<snip>---
When compiled with -O1 or higher exception thrown from bar() doesn't cause
std::terminate to be called.
bar() is compiled to:
0000000000400730 <bar()>:
400730: c6 05 2a 09 20 00 01 movb $0x1,0x20092a(%rip) #
601061 <should_throw>
400737: eb c7 jmp 400700 <foo()>
