https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96215
Bug ID: 96215
Summary: Wrong mangling for non-dependent return type involving
decltype(g.x) or decltype(p->x)
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: arthur.j.odwyer at gmail dot com
Target Milestone: ---
// https://godbolt.org/z/z4rjjq
struct S { int x; int operator*() const; };
extern const S g;
extern const S *p;
extern int S::*m;
template<class T>
decltype(g.x) foo() { return 0; }
template<class T>
decltype(p->x) bar() { return 0; }
template int foo<int>();
template int bar<int>();
Clang mangles these instantiations as
_Z3fooIiEiv
_Z3barIiEiv
GCC mangles them as
_Z3fooIiEDtdtL_Z1gE1xEv
_Z3barIiEDtptL_Z1pE1xEv
Weirdly, GCC doesn't seem to have this issue with any other operators --
decltype(g+1), decltype(g.*m), etc. are all handled as synonyms for `int`. Only
dot and arrow are handled as-if-they-were-dependent-even-though-they-aren't.
