1 files changed, 158 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/ubsan/ubsan_value.cpp b/contrib/llvm-project/compiler-rt/lib/ubsan/ubsan_value.cpp
new file mode 100644
index 000000000000..dc61e5b939d9
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/ubsan/ubsan_value.cpp
@@ -0,0 +1,158 @@
+//===-- ubsan_value.cpp ---------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Representation of a runtime value, as marshaled from the generated code to
+// the ubsan runtime.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ubsan_platform.h"
+#if CAN_SANITIZE_UB
+#include "ubsan_value.h"
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_libc.h"
+#include "sanitizer_common/sanitizer_mutex.h"
+
+#if SANITIZER_APPLE
+#include <dlfcn.h>
+#endif
+
+using namespace __ubsan;
+
+typedef const char *(*ObjCGetClassNameTy)(void *);
+
+const char *__ubsan::getObjCClassName(ValueHandle Pointer) {
+#if SANITIZER_APPLE
+  // We need to query the ObjC runtime for some information, but do not want
+  // to introduce a static dependency from the ubsan runtime onto ObjC. Try to
+  // grab a handle to the ObjC runtime used by the process.
+  static bool AttemptedDlopen = false;
+  static void *ObjCHandle = nullptr;
+  static void *ObjCObjectGetClassName = nullptr;
+
+  // Prevent threads from racing to dlopen().
+  static __sanitizer::StaticSpinMutex Lock;
+  {
+    __sanitizer::SpinMutexLock Guard(&Lock);
+
+    if (!AttemptedDlopen) {
+      ObjCHandle = dlopen(
+          "/usr/lib/libobjc.A.dylib",
+          RTLD_LAZY         // Only bind symbols when used.
+              | RTLD_LOCAL  // Only make symbols available via the handle.
+              | RTLD_NOLOAD // Do not load the dylib, just grab a handle if the
+                            // image is already loaded.
+              | RTLD_FIRST  // Only search the image pointed-to by the handle.
+      );
+      AttemptedDlopen = true;
+      if (!ObjCHandle)
+        return nullptr;
+      ObjCObjectGetClassName = dlsym(ObjCHandle, "object_getClassName");
+    }
+  }
+
+  if (!ObjCObjectGetClassName)
+    return nullptr;
+
+  return ObjCGetClassNameTy(ObjCObjectGetClassName)((void *)Pointer);
+#else
+  return nullptr;
+#endif
+}
+
+SIntMax Value::getSIntValue() const {
+  CHECK(getType().isSignedIntegerTy());
+  if (isInlineInt()) {
+    // Val was zero-extended to ValueHandle. Sign-extend from original width
+    // to SIntMax.
+    const unsigned ExtraBits =
+      sizeof(SIntMax) * 8 - getType().getIntegerBitWidth();
+    return SIntMax(UIntMax(Val) << ExtraBits) >> ExtraBits;
+  }
+  if (getType().getIntegerBitWidth() == 64)
+    return *reinterpret_cast<s64*>(Val);
+#if HAVE_INT128_T
+  if (getType().getIntegerBitWidth() == 128)
+    return *reinterpret_cast<s128*>(Val);
+#else
+  if (getType().getIntegerBitWidth() == 128)
+    UNREACHABLE("libclang_rt.ubsan was built without __int128 support");
+#endif
+  UNREACHABLE("unexpected bit width");
+}
+
+UIntMax Value::getUIntValue() const {
+  CHECK(getType().isUnsignedIntegerTy());
+  if (isInlineInt())
+    return Val;
+  if (getType().getIntegerBitWidth() == 64)
+    return *reinterpret_cast<u64*>(Val);
+#if HAVE_INT128_T
+  if (getType().getIntegerBitWidth() == 128)
+    return *reinterpret_cast<u128*>(Val);
+#else
+  if (getType().getIntegerBitWidth() == 128)
+    UNREACHABLE("libclang_rt.ubsan was built without __int128 support");
+#endif
+  UNREACHABLE("unexpected bit width");
+}
+
+UIntMax Value::getPositiveIntValue() const {
+  if (getType().isUnsignedIntegerTy())
+    return getUIntValue();
+  SIntMax Val = getSIntValue();
+  CHECK(Val >= 0);
+  return Val;
+}
+
+/// Get the floating-point value of this object, extended to a long double.
+/// These are always passed by address (our calling convention doesn't allow
+/// them to be passed in floating-point registers, so this has little cost).
+FloatMax Value::getFloatValue() const {
+  CHECK(getType().isFloatTy());
+  if (isInlineFloat()) {
+    switch (getType().getFloatBitWidth()) {
+#if 0
+      // FIXME: OpenCL / NEON 'half' type. LLVM can't lower the conversion
+      //        from '__fp16' to 'long double'.
+      case 16: {
+        __fp16 Value;
+        internal_memcpy(&Value, &Val, 4);
+        return Value;
+      }
+#endif
+      case 32: {
+        float Value;
+#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+       // For big endian the float value is in the last 4 bytes.
+       // On some targets we may only have 4 bytes so we count backwards from
+       // the end of Val to account for both the 32-bit and 64-bit cases.
+       internal_memcpy(&Value, ((const char*)(&Val + 1)) - 4, 4);
+#else
+       internal_memcpy(&Value, &Val, 4);
+#endif
+        return Value;
+      }
+      case 64: {
+        double Value;
+        internal_memcpy(&Value, &Val, 8);
+        return Value;
+      }
+    }
+  } else {
+    switch (getType().getFloatBitWidth()) {
+    case 64: return *reinterpret_cast<double*>(Val);
+    case 80: return *reinterpret_cast<long double*>(Val);
+    case 96: return *reinterpret_cast<long double*>(Val);
+    case 128: return *reinterpret_cast<long double*>(Val);
+    }
+  }
+  UNREACHABLE("unexpected floating point bit width");
+}
+
+#endif  // CAN_SANITIZE_UB