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This fixes pr13124. From the discussion at http://lists.cs.uiuc.edu/pipermail/cfe-dev/2012-June/022606.html we know that we cannot make funcions in a weak_odr vtable also weak_odr. They should remain linkonce_odr. The side effect is that we cannot emit a available_externally vtable unless we also emit a copy of the function. This also has an issue: If codegen is going to output a function, sema has to mark it used. Given llvm.org/pr9114, it looks like sema cannot be more aggressive at marking functions used because of vtables. This leaves us with a few unpleasant options: * Marking functions in vtables used if possible. This sounds a bit sloppy, so we should avoid it. * Producing available_externally vtables only when all the functions in it are already used or weak_odr. This would cover cases like -------------------- struct foo { virtual ~foo(); }; struct bar : public foo { virtual void zed(); }; void f() { foo *x(new bar); delete x; } void g(bar *x) { x->~bar(); // force the destructor to be used } -------------------------- and ---------------------------------- template<typename T> struct bar { virtual ~bar(); }; template<typename T> bar<T>::~bar() { } // make the destructor weak_odr instead of linkonce_odr extern template class bar<int>; void f() { bar<int> *x(new bar<int>); delete x; } ---------------------------- These look like corner cases, so it is unclear if it is worth it. * And finally: Just nuke this optimization. That is what this patch implements. llvm-svn: 189852
80 lines
903 B
C++
80 lines
903 B
C++
// RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -emit-llvm-only -O3
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// Check that we don't assert on this case.
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namespace Test1 {
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struct Incomplete;
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struct A {
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virtual void f();
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virtual void g(Incomplete);
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virtual void h();
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virtual void i();
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int a;
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};
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struct B {
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virtual void f();
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virtual void g(Incomplete);
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virtual void h();
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virtual void i();
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int b;
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};
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struct C : A, B {
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C();
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virtual void f();
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virtual void g(Incomplete);
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virtual void h();
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virtual void i();
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};
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void C::h() { }
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C::C() { }
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void C::i() { }
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}
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namespace Test2 {
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struct A {
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virtual void f();
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int a;
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};
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struct B {
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virtual void f();
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int b;
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};
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struct C : A, B {
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virtual void f();
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};
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static void f(B* b) {
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b->f();
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}
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}
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// Test that we don't assert.
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namespace Test3 {
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struct A {
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virtual ~A();
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int a;
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};
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struct B : A { };
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struct C : virtual B { };
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void f() {
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C c;
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}
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}
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