[llvm-branch-commits] [compiler-rt] [compiler-rt] Add 'csan' library for the concurrency sanitizer (PR #225782)

[Yaxun Liu via llvm-branch-commits]

================
@@ -0,0 +1,456 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Watchpoint-based data race detector for GPU targets.
+///
+//===----------------------------------------------------------------------===//
+
+#include <gpuintrin.h>
+
+#include "csan_offload_packet.h"
+#include "csan_watch.h"
+#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "shared/rpc.h"
+
+using namespace __sanitizer;
+
+#define INTERFACE extern "C" SANITIZER_INTERFACE_ATTRIBUTE
+
+extern "C" {
+// Externally initialized by the sanitizer, keeps one table per active device.
+[[gnu::visibility("protected")]] u64 *__csan_watchpoint_table = nullptr;
+}
+
+static constexpr u64 SAMPLE_DELAY_MIN_NS = 1000;
+static constexpr u64 SAMPLE_DELAY_MAX_NS = 10000;
+static constexpr u32 WP_CHANCE = 8;
+static_assert((CSAN_WATCHPOINT_TABLE_ENTRIES &
+               (CSAN_WATCHPOINT_TABLE_ENTRIES - 1)) == 0,
+              "watchpoint table size must be a power of two");
+static_assert(WP_CHANCE >= 2 && (WP_CHANCE & (WP_CHANCE - 1)) == 0,
+              "WP_CHANCE must be a power of two");
+
+// The GPU case does
----------------
yxsamliu wrote:

This comment and `Using ... ignored on the device` below look incomplete. Could you finish or remove them?

https://github.com/llvm/llvm-project/pull/225782