https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64181
Bug ID: 64181
Summary: 'noexcept' on a lambda sometimes appears to get
optimised away at -O2 (or above).
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: rogero at howzatt dot demon.co.uk
Created attachment 34188
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34188&action=edit
Demonstration of the problem
In some cases a program containing noexcept on a lambda allows exceptions
thrown inside the body of the lambda to propagate out of the lambda.
We have managed to simplify the problem down to a small test case (attached as
noexcept_optimisation_bug.cpp) - the issue seems to occur when the lambda is
called inside a virtual function and in turns calls a virtual function.
The example contains a 'volatile' pointer -- the original code used a shared
pointer here, it seems that you just need "enough" here to prevent the
optimiser remove the function completely.
