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      1 /*
      2  *  Copyright (c) 2010 The WebRTC project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #include "webrtc/modules/audio_device/linux/latebindingsymboltable_linux.h"
     12 
     13 #ifdef WEBRTC_LINUX
     14 #include <dlfcn.h>
     15 #endif
     16 
     17 // TODO(grunell): Either put inside webrtc namespace or use webrtc:: instead.
     18 using namespace webrtc;
     19 
     20 namespace webrtc_adm_linux {
     21 
     22 inline static const char *GetDllError() {
     23 #ifdef WEBRTC_LINUX
     24   char *err = dlerror();
     25   if (err) {
     26     return err;
     27   } else {
     28     return "No error";
     29   }
     30 #else
     31 #error Not implemented
     32 #endif
     33 }
     34 
     35 DllHandle InternalLoadDll(const char dll_name[]) {
     36 #ifdef WEBRTC_LINUX
     37   DllHandle handle = dlopen(dll_name, RTLD_NOW);
     38 #else
     39 #error Not implemented
     40 #endif
     41   if (handle == kInvalidDllHandle) {
     42     WEBRTC_TRACE(kTraceWarning, kTraceAudioDevice, -1,
     43                "Can't load %s : %s", dll_name, GetDllError());
     44   }
     45   return handle;
     46 }
     47 
     48 void InternalUnloadDll(DllHandle handle) {
     49 #ifdef WEBRTC_LINUX
     50 // TODO(pbos): Remove this dlclose() exclusion when leaks and suppressions from
     51 // here are gone (or AddressSanitizer can display them properly).
     52 //
     53 // Skip dlclose() on AddressSanitizer as leaks including this module in the
     54 // stack trace gets displayed as <unknown module> instead of the actual library
     55 // -> it can not be suppressed.
     56 // https://code.google.com/p/address-sanitizer/issues/detail?id=89
     57 #if !defined(ADDRESS_SANITIZER)
     58   if (dlclose(handle) != 0) {
     59     WEBRTC_TRACE(kTraceError, kTraceAudioDevice, -1,
     60                "%s", GetDllError());
     61   }
     62 #endif  // !defined(ADDRESS_SANITIZER)
     63 #else
     64 #error Not implemented
     65 #endif
     66 }
     67 
     68 static bool LoadSymbol(DllHandle handle,
     69                        const char *symbol_name,
     70                        void **symbol) {
     71 #ifdef WEBRTC_LINUX
     72   *symbol = dlsym(handle, symbol_name);
     73   char *err = dlerror();
     74   if (err) {
     75     WEBRTC_TRACE(kTraceError, kTraceAudioDevice, -1,
     76                "Error loading symbol %s : %d", symbol_name, err);
     77     return false;
     78   } else if (!*symbol) {
     79     WEBRTC_TRACE(kTraceError, kTraceAudioDevice, -1,
     80                "Symbol %s is NULL", symbol_name);
     81     return false;
     82   }
     83   return true;
     84 #else
     85 #error Not implemented
     86 #endif
     87 }
     88 
     89 // This routine MUST assign SOME value for every symbol, even if that value is
     90 // NULL, or else some symbols may be left with uninitialized data that the
     91 // caller may later interpret as a valid address.
     92 bool InternalLoadSymbols(DllHandle handle,
     93                          int num_symbols,
     94                          const char *const symbol_names[],
     95                          void *symbols[]) {
     96 #ifdef WEBRTC_LINUX
     97   // Clear any old errors.
     98   dlerror();
     99 #endif
    100   for (int i = 0; i < num_symbols; ++i) {
    101     if (!LoadSymbol(handle, symbol_names[i], &symbols[i])) {
    102       return false;
    103     }
    104   }
    105   return true;
    106 }
    107 
    108 }  // namespace webrtc_adm_linux
    109