1 files changed, 54 insertions, 40 deletions
diff --git a/test/cfi/utils.h b/test/cfi/utils.h
index 5c290d151069..430359d8c50c 100644
--- a/test/cfi/utils.h
+++ b/test/cfi/utils.h
@@ -5,49 +5,63 @@ inline void break_optimization(void *arg) {
   __asm__ __volatile__("" : : "r" (arg) : "memory");
 }
 
-// Tests will instantiate this class to pad out bit sets to test out the various
-// ways we can represent the bit set (32-bit inline, 64-bit inline, memory).
-// This class has 37 virtual member functions, which forces us to use a
-// pointer-aligned bitset.
+// Tests will instantiate this class to pad out bit sets to test out the
+// various ways we can represent the bit set (32-bit inline, 64-bit inline,
+// memory). Instantiating this class will trigger the instantiation of I
+// templates with I virtual tables for classes deriving from T, I-2 of which
+// will be of size sizeof(void*) * 5, 1 of which will be of size sizeof(void*)
+// * 3, and 1 of which will be of size sizeof(void*) * 9. (Under the MS ABI
+// each virtual table will be sizeof(void*) bytes smaller). Each category
+// of virtual tables is aligned to a different power of 2, precluding the
+// all-ones optimization. As a result, the bit vector for the base class will
+// need to contain at least I*2 entries to accommodate all the derived virtual
+// tables.
 template <typename T, unsigned I>
-class Deriver : T {
+struct Deriver : T {
+  Deriver() {
+    break_optimization(new Deriver<T, I-1>);
+  }
   virtual void f() {}
   virtual void g() {}
-  virtual void f1() {}
-  virtual void f2() {}
-  virtual void f3() {}
-  virtual void f4() {}
-  virtual void f5() {}
-  virtual void f6() {}
-  virtual void f7() {}
-  virtual void f8() {}
-  virtual void f9() {}
-  virtual void f10() {}
-  virtual void f11() {}
-  virtual void f12() {}
-  virtual void f13() {}
-  virtual void f14() {}
-  virtual void f15() {}
-  virtual void f16() {}
-  virtual void f17() {}
-  virtual void f18() {}
-  virtual void f19() {}
-  virtual void f20() {}
-  virtual void f21() {}
-  virtual void f22() {}
-  virtual void f23() {}
-  virtual void f24() {}
-  virtual void f25() {}
-  virtual void f26() {}
-  virtual void f27() {}
-  virtual void f28() {}
-  virtual void f29() {}
-  virtual void f30() {}
-  virtual void f31() {}
-  virtual void f32() {}
-  virtual void f33() {}
-  virtual void f34() {}
-  virtual void f35() {}
+  virtual void h() {}
 };
 
+template <typename T>
+struct Deriver<T, 0> : T {
+  virtual void f() {}
+  void g() {}
+};
+
+template <typename T>
+struct Deriver<T, 1> : T {
+  Deriver() {
+    break_optimization(new Deriver<T, 0>);
+  }
+  virtual void f() {}
+  virtual void g() {}
+  virtual void h() {}
+  virtual void i() {}
+  virtual void j() {}
+  virtual void k() {}
+  virtual void l() {}
+};
+
+// Instantiate enough classes to force CFI checks for type T to use bit
+// vectors of size 32 (if B32 defined), 64 (if B64 defined) or >64 (if BM
+// defined).
+template <typename T>
+void create_derivers() {
+#ifdef B32
+  break_optimization(new Deriver<T, 10>);
+#endif
+
+#ifdef B64
+  break_optimization(new Deriver<T, 25>);
+#endif
+
+#ifdef BM
+  break_optimization(new Deriver<T, 40>);
+#endif
+}
+
 #endif