[clang] [compiler-rt] [compiler-rt] Realtime Sanitizer: Introduce Realtime Sanitizer (RTSan) backend (PR #92460)

[Fangrui Song via cfe-commits]

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@@ -0,0 +1,50 @@
+//===--- rtsan_stack.cpp - Realtime Sanitizer -------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+//===----------------------------------------------------------------------===//
+
+#include "rtsan_stack.h"
+
+#include <sanitizer_common/sanitizer_flags.h>
+#include <sanitizer_common/sanitizer_stacktrace.h>
+
+using namespace __sanitizer;
+
+// We must define our own implementation of this method for our runtime.
+// This one is just copied from UBSan.
+namespace __sanitizer {
+void BufferedStackTrace::UnwindImpl(uptr pc, uptr bp, void *context,
+                                    bool request_fast, u32 max_depth) {
+  uptr top = 0;
+  uptr bottom = 0;
+  GetThreadStackTopAndBottom(false, &top, &bottom);
+  bool fast = StackTrace::WillUseFastUnwind(request_fast);
+  Unwind(max_depth, pc, bp, context, top, bottom, fast);
+}
+} // namespace __sanitizer
+
+static void SetGlobalStackTraceFormat() {
+  SetCommonFlagsDefaults();
+  CommonFlags cf;
+  cf.CopyFrom(*common_flags());
+  cf.stack_trace_format = "DEFAULT";
+  cf.external_symbolizer_path = GetEnv("RTSAN_SYMBOLIZER_PATH");
+  OverrideCommonFlags(cf);
+}
+
+using namespace __rtsan;
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MaskRay wrote:

should be moved up, beside `using namespace __sanitizer;`

https://github.com/llvm/llvm-project/pull/92460