On Thu, Jan 23, 2020 at 11:07:59AM -0800, Nick Desaulniers wrote: > Good thing it's the variable being modified was not declared const; I > get spooked when I see -Wdiscarded-qualifiers because of Section > 6.7.3.6 of the ISO C11 draft spec: > > ``` > If an attempt is made to modify an object defined with a > const-qualified type through use > of an lvalue with non-const-qualified type, the behavior is undefined. > If an attempt is > made to refer to an object defined with a volatile-qualified type > through use of an lvalue > with non-volatile-qualified type, the behavior is undefined.133) > > 133) This applies to those objects that behave as if they were defined > with qualified types, even if they are > never actually defined as objects in the program (such as an object at > a memory-mapped input/output > address). > ``` > > Which is about the modification of a const-declared variable (explicit > UB which Clang actively exploits), Just for curiosity's sake. What does clang actually do in that case?
