symbolize_emscripten.inc (2181B)
1 // Copyright 2020 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 #include <cxxabi.h> 16 #include <emscripten.h> 17 18 #include <algorithm> 19 #include <cstring> 20 21 #include "absl/base/internal/raw_logging.h" 22 #include "absl/debugging/internal/demangle.h" 23 #include "absl/strings/numbers.h" 24 #include "absl/strings/str_cat.h" 25 #include "absl/strings/string_view.h" 26 27 extern "C" { 28 const char* emscripten_pc_get_function(const void* pc); 29 } 30 31 // clang-format off 32 EM_JS(bool, HaveOffsetConverter, (), 33 { return typeof wasmOffsetConverter !== 'undefined'; }); 34 // clang-format on 35 36 namespace absl { 37 ABSL_NAMESPACE_BEGIN 38 39 void InitializeSymbolizer(const char*) { 40 if (!HaveOffsetConverter()) { 41 ABSL_RAW_LOG(INFO, 42 "Symbolization unavailable. Rebuild with -sWASM=1 " 43 "and -sUSE_OFFSET_CONVERTER=1."); 44 } 45 } 46 47 bool Symbolize(const void* pc, char* out, int out_size) { 48 // Check if we have the offset converter necessary for pc_get_function. 49 // Without it, the program will abort(). 50 if (!HaveOffsetConverter()) { 51 return false; 52 } 53 if (pc == nullptr || out_size <= 0) { 54 return false; 55 } 56 const char* func_name = emscripten_pc_get_function(pc); 57 if (func_name == nullptr) { 58 return false; 59 } 60 61 strncpy(out, func_name, out_size); 62 63 if (out[out_size - 1] != '\0') { 64 // strncpy() does not '\0' terminate when it truncates. 65 static constexpr char kEllipsis[] = "..."; 66 int ellipsis_size = std::min<int>(sizeof(kEllipsis) - 1, out_size - 1); 67 memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size); 68 out[out_size - 1] = '\0'; 69 } 70 71 return true; 72 } 73 74 ABSL_NAMESPACE_END 75 } // namespace absl