1 // Copyright 2018 The Abseil Authors.
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
7 // https://www.apache.org/licenses/LICENSE-2.0
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.
15 // See "Retrieving Symbol Information by Address":
16 // https://msdn.microsoft.com/en-us/library/windows/desktop/ms680578(v=vs.85).aspx
20 // MSVC header DbgHelp.h has a warning for an ignored typedef.
22 #pragma warning(disable:4091)
26 #pragma comment(lib, "dbghelp.lib")
31 #include "absl/base/internal/raw_logging.h"
35 static HANDLE process = NULL;
37 void InitializeSymbolizer(const char *argv0) {
38 if (process != nullptr) {
41 process = GetCurrentProcess();
43 // Symbols are not loaded until a reference is made requiring the
44 // symbols be loaded. This is the fastest, most efficient way to use
45 // the symbol handler.
46 SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME);
47 if (!SymInitialize(process, nullptr, true)) {
48 // GetLastError() returns a Win32 DWORD, but we assign to
49 // unsigned long long to simplify the ABSL_RAW_LOG case below. The uniform
50 // initialization guarantees this is not a narrowing conversion.
51 const unsigned long long error{GetLastError()}; // NOLINT(runtime/int)
52 ABSL_RAW_LOG(FATAL, "SymInitialize() failed: %llu", error);
56 bool Symbolize(const void *pc, char *out, int out_size) {
60 std::aligned_storage<sizeof(SYMBOL_INFO) + MAX_SYM_NAME,
61 alignof(SYMBOL_INFO)>::type buf;
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)) {
68 strncpy(out, symbol->Name, out_size);
69 if (out[out_size - 1] != '\0') {
70 // strncpy() does not '\0' terminate when it truncates.
71 static constexpr char kEllipsis[] = "...";
73 std::min<int>(sizeof(kEllipsis) - 1, out_size - 1);
74 memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size);
75 out[out_size - 1] = '\0';