Add a runtime diagnostics library for Clang's -fcatch-undefined-behavior.

llvm-svn: 165533

1 files changed, 26 insertions, 0 deletions

diff --git a/compiler-rt/lib/ubsan/lit_tests/Integer/sub-overflow.cpp b/compiler-rt/lib/ubsan/lit_tests/Integer/sub-overflow.cpp
new file mode 100644
index 00000000000..71925c9bde8
--- /dev/null
+++ b/compiler-rt/lib/ubsan/lit_tests/Integer/sub-overflow.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang -DSUB_I32 -fcatch-undefined-behavior %s -o %t && %t 2>&1 | FileCheck %s --check-prefix=SUB_I32
+// RUN: %clang -DSUB_I64 -fcatch-undefined-behavior %s -o %t && %t 2>&1 | FileCheck %s --check-prefix=SUB_I64
+// RUN: %clang -DSUB_I128 -fcatch-undefined-behavior %s -o %t && %t 2>&1 | FileCheck %s --check-prefix=SUB_I128
+
+#include <stdint.h>
+
+int main() {
+  // These promote to 'int'.
+  (void)(int8_t(-2) - int8_t(0x7f));
+  (void)(int16_t(-2) - int16_t(0x7fff));
+
+#ifdef SUB_I32
+  (void)(int32_t(-2) - int32_t(0x7fffffff));
+  // CHECK-SUB_I32: sub-overflow.cpp:13:22: fatal error: signed integer overflow: -2 - 2147483647 cannot be represented in type 'int'
+#endif
+
+#ifdef SUB_I64
+  (void)(int64_t(-8000000000000000000ll) - int64_t(2000000000000000000ll));
+  // CHECK-SUB_I64: -8000000000000000000 - 2000000000000000000 cannot be represented in type 'long'
+#endif
+
+#ifdef SUB_I128
+  (void)(-(__int128_t(1) << 126) - (__int128_t(1) << 126) - 1);
+  // CHECK-SUB_I128: 0x80000000000000000000000000000000 - 1 cannot be represented in type '__int128'
+#endif
+}