[cfe-dev] Member expression returns type with wrong qualifiers

[Eli Friedman]

On Feb 4, 2008 3:06 PM, Steve Naroff <snaroff at apple.com> wrote:
> One solution is to extend Expr::isModifiableLvalue() and the
> MemberExpr AST to return the underlying base type.

That might fix this exact case, but it's not a general fix.  Try
something like the following:
int a(const struct {int a;} * x) {
int* y = &x->a;
*y = 10;
}

(Note that we actually allow this for gcc compat, but the -pedantic
warning that should show up doesn't show up.)

Or the following:
int a(volatile struct {int a;} * x) {
x->a = 10;
}

Which will silently generate wrong code because it throws out the
volatile qualifier.

Pretty much anything that depends on qualifiers would require an
independent fix for this issue, which seems like a bad idea.

-Eli