[PATCH] D155659: [WPD][LLD] Add option to validate RTTI is enabled on all native types and prevent devirtualization on types with native RTTI

[Di Mo via Phabricator via llvm-commits]

modimo marked an inline comment as not done.
modimo added inline comments.


================
Comment at: lld/test/ELF/lto/devirt_validate_vtable_typeinfos.ll:163
+
+%struct.A = type { ptr }
+%struct.B = type { %struct.A }
----------------
MaskRay wrote:
> Consider pasting the source code as well for readability and upgradability?
> 
> I haven't carefully studied the tests yet...
I pulled the base IR from lld/test/ELF/lto/devirt_vcall_vis_export_dynamic.ll and modified it so no direct source.

The test case is effectively:
```
struct A {
  virtual void f(int) = 0;
  virtual void n(int) { return 0; }
};

struct B {
  virtual void f(int) { return 0; }
};

struct C {
  virtual void f(int) { return 0; }
};

namespace {
  struct D {
    virtual void int m(int) { return 0; }
  };
}

int _start(A *obj, D* obj2, int a) {
  call = obj->n(a); // single implementation in A, devirtualize unless a native type derives from A
  call2 = obj->f(call); // multiple implementation in B and C, never devirtualize
  call3 = obj2->m(call2); // local type, always devirtualize
  return call3;
}
```



Repository:
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  https://reviews.llvm.org/D155659/new/

https://reviews.llvm.org/D155659