[Bug ipa/114784] [14 Regression] Inlining fails for always_inline inheriting constructor

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114784

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
                 CC|                            |hubicka at gcc dot gnu.org,
                   |                            |jakub at gcc dot gnu.org,
                   |                            |jason at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-04-19
   Target Milestone|---                         |14.0

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r14-2149-gabdf0b6cdff5783b97f35ad61ae31433f0569dfd
That said, if you just fix the warning (i.e. remove the UB from serenity_main
if it would ever return), then it compiles fine.  Say by adding return 0;
statement.
But adding [[gnu::cold]] attribute to serenity_main makes it error again.

Honza, I thought always_inline should have precedence over decisions if it
inlines into cold code or not etc.?
Or maybe always_inline attribute is copied over to the inheriting constructors
but DECL_DISREGARD_INLINE_LIMITS is not?

template <typename Base>
struct VariantConstructors {
  __attribute__((always_inline)) VariantConstructors(int t) {
    base().set(t, {});
  }
  __attribute__((always_inline)) VariantConstructors(long long t) {
    base().set(t, {});
  }
  Base base();
};

struct Variant : VariantConstructors<Variant> {
  using VariantConstructors<Variant>::VariantConstructors;

  __attribute__((always_inline)) Variant(long long v) : VariantConstructors(v)
{}

  template <typename T> void set(T &&, int);
  char m_data;
};

struct ErrorOr {
  ErrorOr(int v) : a(v) { }
  ErrorOr(long long v) : a(v) { }
  Variant a;
};
static ErrorOr run() {
  ErrorOr x(0); // compiles with this line removed
  ErrorOr y(0LL);
  return 0;
}
[[gnu::cold]] int serenity_main() {
    run();
    return 0;
}