Fix a regression I introduced back in r178147.
We don't want cast and dyn_cast to work on temporaries. They don't extend
lifetime like a direct bind to a reference would, so they can introduce
hard to find bugs.
I added tests to make sure we don't regress this. Thanks to Eli Friedman for
noticing this and for his suggestions on how to test it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186559 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Support/Casting.cpp b/unittests/Support/Casting.cpp
index 01583e4..362abee 100644
--- a/unittests/Support/Casting.cpp
+++ b/unittests/Support/Casting.cpp
@@ -10,10 +10,15 @@
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/IR/User.h"
#include "gtest/gtest.h"
#include <cstdlib>
namespace llvm {
+// Used to test illegal cast. If a cast doesn't match any of the "real" ones,
+// it will match this one.
+struct IllegalCast;
+template <typename T> IllegalCast *cast(...) { return 0; }
// set up two example classes
// with conversion facility
@@ -60,10 +65,25 @@
bar *fub();
+
+template <> struct simplify_type<foo> {
+ typedef int SimpleType;
+ static SimpleType getSimplifiedValue(foo &Val) { return 0; }
+};
+
} // End llvm namespace
using namespace llvm;
+
+// Test the peculiar behavior of Use in simplify_type.
+int Check1[is_same<simplify_type<Use>::SimpleType, Value *>::value ? 1 : -1];
+int Check2[is_same<simplify_type<Use *>::SimpleType, Value *>::value ? 1 : -1];
+
+// Test that a regular class behaves as expected.
+int Check3[is_same<simplify_type<foo>::SimpleType, int>::value ? 1 : -1];
+int Check4[is_same<simplify_type<foo *>::SimpleType, foo *>::value ? 1 : -1];
+
namespace {
const foo *null_foo = NULL;
@@ -203,3 +223,8 @@
} // end namespace inferred_upcasting
} // end anonymous namespace
+// Test that we reject casts of temporaries (and so the illegal cast gets used).
+namespace TemporaryCast {
+struct pod {};
+IllegalCast *testIllegalCast() { return cast<foo>(pod()); }
+}