- 3a9532fb2d6ae45c3cba44c9bb0dbdfc1558b7d3 Fix the description of Span::subspan(). by Abseil Team <absl-team@google.com>

- bae1a1c21924bd31fa7315eff05ea6158d9e7947 Port the symbolizer to Windows. by Derek Mauro <dmauro@google.com>
  - 2253c04c1a4f39d9581772f1dc4491878aa3831f Support absl::Hex() and absl::Dec() as arguments to absl:... by Jorg Brown <jorg@google.com>
  - 552c3ac259e9c254fda9244755487f3423d2fe4b Internal change by Jorg Brown <jorg@google.com>

GitOrigin-RevId: 3a9532fb2d6ae45c3cba44c9bb0dbdfc1558b7d3
Change-Id: I448133c9bb6d837037c12b45a9a16a7945049453

absl/debugging/symbolize_win32.inc

@@ -0,0 +1,74 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// See "Retrieving Symbol Information by Address":
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms680578(v=vs.85).aspx
+
+#include <windows.h>
+#include <DbgHelp.h>
+#pragma comment(lib, "DbgHelp")
+
+#include <algorithm>
+#include <cstring>
+
+#include "absl/base/internal/raw_logging.h"
+
+namespace absl {
+
+static HANDLE process = NULL;
+
+void InitializeSymbolizer(const char *argv0) {
+  if (process != nullptr) {
+    return;
+  }
+  process = GetCurrentProcess();
+
+  // Symbols are not loaded until a reference is made requiring the
+  // symbols be loaded. This is the fastest, most efficient way to use
+  // the symbol handler.
+  SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME);
+  if (!SymInitialize(process, nullptr, true)) {
+    // GetLastError() returns a Win32 DWORD, but we assign to
+    // unsigned long to simplify the ABSL_RAW_LOG case below.  The uniform
+    // initialization guarantees this is not a narrowing conversion.
+    const unsigned long long error{GetLastError()};  // NOLINT(runtime/int)
+    ABSL_RAW_LOG(FATAL, "SymInitialize() failed: %llu", error);
+  }
+}
+
+bool Symbolize(const void *pc, char *out, int out_size) {
+  if (out_size <= 0) {
+    return false;
+  }
+  std::aligned_storage<sizeof(SYMBOL_INFO) + MAX_SYM_NAME,
+                       alignof(SYMBOL_INFO)>::type buf;
+  SYMBOL_INFO *symbol = reinterpret_cast<SYMBOL_INFO *>(&buf);
+  symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
+  symbol->MaxNameLen = MAX_SYM_NAME;
+  if (!SymFromAddr(process, reinterpret_cast<DWORD64>(pc), nullptr, symbol)) {
+    return false;
+  }
+  strncpy(out, symbol->Name, out_size);
+  if (out[out_size - 1] != '\0') {
+    // strncpy() does not '\0' terminate when it truncates.
+    static constexpr char kEllipsis[] = "...";
+    int ellipsis_size =
+        std::min<int>(sizeof(kEllipsis) - 1, out_size - 1);
+    memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size);
+    out[out_size - 1] = '\0';
+  }
+  return true;
+}
+
+}  // namespace absl