vendor/compiler-rt/compiler-rt-trunk-r366426

1 files changed, 64 insertions, 0 deletions

diff --git a/lib/gwp_asan/optional/backtrace_linux_libc.cpp b/lib/gwp_asan/optional/backtrace_linux_libc.cpp
new file mode 100644
index 000000000000..f20a3100927e
--- /dev/null
+++ b/lib/gwp_asan/optional/backtrace_linux_libc.cpp
@@ -0,0 +1,64 @@
+//===-- backtrace_linux_libc.cpp --------------------------------*- 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 <assert.h>
+#include <execinfo.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "gwp_asan/optional/backtrace.h"
+#include "gwp_asan/options.h"
+
+namespace {
+void Backtrace(uintptr_t *TraceBuffer, size_t Size) {
+  // Grab (what seems to be) one more trace than we need. TraceBuffer needs to
+  // be null-terminated, but we wish to remove the frame of this function call.
+  static_assert(sizeof(uintptr_t) == sizeof(void *), "uintptr_t is not void*");
+  int NumTraces =
+      backtrace(reinterpret_cast<void **>(TraceBuffer), Size);
+
+  // Now shift the entire trace one place to the left and null-terminate.
+  memmove(TraceBuffer, TraceBuffer + 1, NumTraces * sizeof(void *));
+  TraceBuffer[NumTraces - 1] = 0;
+}
+
+static void PrintBacktrace(uintptr_t *Trace,
+                           gwp_asan::options::Printf_t Printf) {
+  size_t NumTraces = 0;
+  for (; Trace[NumTraces] != 0; ++NumTraces) {
+  }
+
+  if (NumTraces == 0) {
+    Printf("  <not found (does your allocator support backtracing?)>\n\n");
+    return;
+  }
+
+  char **BacktraceSymbols =
+      backtrace_symbols(reinterpret_cast<void **>(Trace), NumTraces);
+
+  for (size_t i = 0; i < NumTraces; ++i) {
+    if (!BacktraceSymbols)
+      Printf("  #%zu %p\n", i, Trace[i]);
+    else
+      Printf("  #%zu %s\n", i, BacktraceSymbols[i]);
+  }
+
+  Printf("\n");
+  if (BacktraceSymbols)
+    free(BacktraceSymbols);
+}
+} // anonymous namespace
+
+namespace gwp_asan {
+namespace options {
+Backtrace_t getBacktraceFunction() { return Backtrace; }
+PrintBacktrace_t getPrintBacktraceFunction() { return PrintBacktrace; }
+} // namespace options
+} // namespace gwp_asan