[compiler-rt][ubsan] Split Implicit Integer Truncation Sanitizer into unsigned and signed checks

Summary:
This is compiler-rt part.
clang part is D50901.

Reviewers: rsmith, vsk, filcab, Sanitizers

Reviewed by: filcab

Differential Revision: https://reviews.llvm.org/D50902

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@344231 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 0 deletions

diff --git a/test/ubsan_minimal/TestCases/implicit-signed-integer-truncation.c b/test/ubsan_minimal/TestCases/implicit-signed-integer-truncation.c
new file mode 100644
index 000000000..9677407e0
--- /dev/null
+++ b/test/ubsan_minimal/TestCases/implicit-signed-integer-truncation.c
@@ -0,0 +1,25 @@
+// RUN: %clang -fsanitize=implicit-signed-integer-truncation %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+
+#include <stdint.h>
+
+int main() {
+// CHECK-NOT: implicit-conversion
+
+  // Negative tests. Even if they produce unexpected results, this sanitizer does not care.
+  int8_t n0 = (~((uint32_t)(0))); // ~0 -> -1, but do not warn.
+  uint8_t n2 = 128;
+  uint8_t n3 = 255;
+  // Bools do not count
+  _Bool b0 = (~((uint32_t)(0)));
+  _Bool b1 = 255;
+
+  // Explicit and-ing of bits will silence it.
+  uint8_t nc0 = ((int32_t)(-1)) & 255;
+
+  // Positive tests.
+  uint8_t t0 = (int32_t)(-1);
+// CHECK: implicit-conversion
+// CHECK-NOT: implicit-conversion
+
+  return 0;
+}