On Tue, 26 Jan 2021, Richard Biener wrote: > If it is an initializer from constants we gimplify to a series of > assigns it might be still useful. OTOH, I'm not sure whether > a const auto is really readonly in C or if it is safe to assume > the stack part is writable and thus casting away the const and > writing to it is fine ...
If an object is defined as const then it's undefined behavior to modify it (that's different from the case of having a pointer-to-const, where the original object might be defined as non-const and can be modified through that pointer after a cast). Note, however, that for a const object of automatic storage duration with a non-constant initializer, the initializer gets evaluated and stored in the object every time the initialization is reached in the order of execution (while the object is live for the whole block in which it is declared) - so in that case the object does get modified during execution, just not by an assignment expression. -- Joseph S. Myers jos...@codesourcery.com
