tor-browser

The Tor Browser
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symbolize_win32.inc (2769B)


      1 // Copyright 2018 The Abseil Authors.
      2 //
      3 // Licensed under the Apache License, Version 2.0 (the "License");
      4 // you may not use this file except in compliance with the License.
      5 // You may obtain a copy of the License at
      6 //
      7 //      https://www.apache.org/licenses/LICENSE-2.0
      8 //
      9 // Unless required by applicable law or agreed to in writing, software
     10 // distributed under the License is distributed on an "AS IS" BASIS,
     11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12 // See the License for the specific language governing permissions and
     13 // limitations under the License.
     14 
     15 // See "Retrieving Symbol Information by Address":
     16 // https://msdn.microsoft.com/en-us/library/windows/desktop/ms680578(v=vs.85).aspx
     17 
     18 #include <windows.h>
     19 
     20 // MSVC header dbghelp.h has a warning for an ignored typedef.
     21 #pragma warning(push)
     22 #pragma warning(disable:4091)
     23 #include <dbghelp.h>
     24 #pragma warning(pop)
     25 
     26 #pragma comment(lib, "dbghelp.lib")
     27 
     28 #include <algorithm>
     29 #include <cstring>
     30 
     31 #include "absl/base/internal/raw_logging.h"
     32 
     33 namespace absl {
     34 ABSL_NAMESPACE_BEGIN
     35 
     36 static HANDLE process = NULL;
     37 
     38 void InitializeSymbolizer(const char*) {
     39  if (process != nullptr) {
     40    return;
     41  }
     42  process = GetCurrentProcess();
     43 
     44  // Symbols are not loaded until a reference is made requiring the
     45  // symbols be loaded. This is the fastest, most efficient way to use
     46  // the symbol handler.
     47  SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME);
     48  if (!SymInitialize(process, nullptr, true)) {
     49    // GetLastError() returns a Win32 DWORD, but we assign to
     50    // unsigned long long to simplify the ABSL_RAW_LOG case below.  The uniform
     51    // initialization guarantees this is not a narrowing conversion.
     52    const unsigned long long error{GetLastError()};  // NOLINT(runtime/int)
     53    ABSL_RAW_LOG(FATAL, "SymInitialize() failed: %llu", error);
     54  }
     55 }
     56 
     57 bool Symbolize(const void* pc, char* out, int out_size) {
     58  if (out_size <= 0) {
     59    return false;
     60  }
     61  alignas(SYMBOL_INFO) char buf[sizeof(SYMBOL_INFO) + MAX_SYM_NAME];
     62  SYMBOL_INFO* symbol = reinterpret_cast<SYMBOL_INFO*>(buf);
     63  symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
     64  symbol->MaxNameLen = MAX_SYM_NAME;
     65  if (!SymFromAddr(process, reinterpret_cast<DWORD64>(pc), nullptr, symbol)) {
     66    return false;
     67  }
     68  const size_t out_size_t = static_cast<size_t>(out_size);
     69  strncpy(out, symbol->Name, out_size_t);
     70  if (out[out_size_t - 1] != '\0') {
     71    // strncpy() does not '\0' terminate when it truncates.
     72    static constexpr char kEllipsis[] = "...";
     73    size_t ellipsis_size =
     74        std::min(sizeof(kEllipsis) - 1, out_size_t - 1);
     75    memcpy(out + out_size_t - ellipsis_size - 1, kEllipsis, ellipsis_size);
     76    out[out_size_t - 1] = '\0';
     77  }
     78  return true;
     79 }
     80 
     81 ABSL_NAMESPACE_END
     82 }  // namespace absl