[Bug c++/52477] Wrong initialization order? __attribute__((constructor)) vs static data access

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52477

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |NEW
   Last reconfirmed|                            |2017-03-16
                 CC|                            |jason at gcc dot gnu.org
         Resolution|INVALID                     |---
     Ever confirmed|0                           |1

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
I don't think this is undefined; it seems natural for these functions to be
ordered with a translation unit along with dynamic initialization of non-local
variables.  So for

---
extern "C" int printf (const char *, ...);

struct A { A() { printf ("A\n"); } } a;

static void B() __attribute__((constructor));
static void B()
{
  printf ("B\n");
}

struct C { C() { printf ("C\n"); } } c;

int main() {}
---

I would expect A B C, and gcc currently outputs B A C.  Instead of emitting
constructor functions directly into .init_array as we do now, we should
remember them and call them from __static_initialization_and_destruction_0.

Note that 4.6 gave the differently wrong A C B, due to running .init_array in
the opposite order, so this isn't really a regression.