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  • /*
     * Copyright (C) 2017 The Android Open Source Project
     *
     * 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.
     */
    
    #include <getopt.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>
    
    #include <cctype>
    #include <string>
    
    #include <demangle.h>
    
    extern "C" char* __cxa_demangle(const char*, char*, size_t*, int*);
    
    static void Usage(const char* prog_name) {
      printf("usage: %s [-c] [NAME_TO_DEMANGLE...]\n", prog_name);
      printf("\n");
      printf("Demangles C++ mangled names if supplied on the command-line, or found\n");
      printf("reading from stdin otherwise.\n");
      printf("\n");
      printf("-c\tCompare against __cxa_demangle\n");
      printf("\n");
    }
    
    static std::string DemangleWithCxa(const char* name) {
      const char* cxa_demangle = __cxa_demangle(name, nullptr, nullptr, nullptr);
      if (cxa_demangle == nullptr) {
        return name;
      }
    
      // The format of our demangler is slightly different from the cxa demangler
      // so modify the cxa demangler output. Specifically, for templates, remove
      // the spaces between '>' and '>'.
      std::string demangled_str;
      for (size_t i = 0; i < strlen(cxa_demangle); i++) {
        if (i > 2 && cxa_demangle[i] == '>' && std::isspace(cxa_demangle[i - 1]) &&
            cxa_demangle[i - 2] == '>') {
          demangled_str.resize(demangled_str.size() - 1);
        }
        demangled_str += cxa_demangle[i];
      }
      return demangled_str;
    }
    
    static void Compare(const char* name, const std::string& demangled_name) {
      std::string cxa_demangled_name(DemangleWithCxa(name));
      if (cxa_demangled_name != demangled_name) {
        printf("\nMismatch!\n");
        printf("\tmangled name: %s\n", name);
        printf("\tour demangle: %s\n", demangled_name.c_str());
        printf("\tcxa demangle: %s\n", cxa_demangled_name.c_str());
        exit(1);
      }
    }
    
    static int Filter(bool compare) {
      char* line = nullptr;
      size_t line_length = 0;
    
      while ((getline(&line, &line_length, stdin)) != -1) {
        char* p = line;
        char* name;
        while ((name = strstr(p, "_Z")) != nullptr) {
          // Output anything before the identifier.
          *name = 0;
          printf("%s", p);
          *name = '_';
    
          // Extract the identifier.
          p = name;
          while (*p && (std::isalnum(*p) || *p == '_' || *p == '.' || *p == '$')) ++p;
    
          // Demangle and output.
          std::string identifier(name, p);
          std::string demangled_name = demangle(identifier.c_str());
          printf("%s", demangled_name.c_str());
    
          if (compare) Compare(identifier.c_str(), demangled_name);
        }
        // Output anything after the last identifier.
        printf("%s", p);
      }
    
      free(line);
      return 0;
    }
    
    int main(int argc, char** argv) {
    #ifdef __BIONIC__
      const char* prog_name = getprogname();
    #else
      const char* prog_name = argv[0];
    #endif
    
      bool compare = false;
      int opt_char;
      while ((opt_char = getopt(argc, argv, "c")) != -1) {
        if (opt_char == 'c') {
          compare = true;
        } else {
          Usage(prog_name);
          return 1;
        }
      }
    
      // With no arguments, act as a filter.
      if (optind == argc) return Filter(compare);
    
      // Otherwise demangle each argument.
      while (optind < argc) {
        const char* name = argv[optind++];
        std::string demangled_name = demangle(name);
        printf("%s\n", demangled_name.c_str());
    
        if (compare) Compare(name, demangled_name);
      }
      return 0;
    }