1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "base/native_library.h"
6 
7 #include <dlfcn.h>
8 
9 #include "base/files/file_path.h"
10 #include "base/logging.h"
11 #include "base/strings/string_util.h"
12 #include "base/strings/utf_string_conversions.h"
13 #include "base/threading/thread_restrictions.h"
14 
15 namespace base {
16 
ToString() const17 std::string NativeLibraryLoadError::ToString() const {
18   return message;
19 }
20 
21 // static
LoadNativeLibraryWithOptions(const FilePath & library_path,const NativeLibraryOptions & options,NativeLibraryLoadError * error)22 NativeLibrary LoadNativeLibraryWithOptions(const FilePath& library_path,
23                                            const NativeLibraryOptions& options,
24                                            NativeLibraryLoadError* error) {
25   // dlopen() opens the file off disk.
26   ThreadRestrictions::AssertIOAllowed();
27 
28   // We deliberately do not use RTLD_DEEPBIND by default.  For the history why,
29   // please refer to the bug tracker.  Some useful bug reports to read include:
30   // http://crbug.com/17943, http://crbug.com/17557, http://crbug.com/36892,
31   // and http://crbug.com/40794.
32   int flags = RTLD_LAZY;
33 #if defined(OS_ANDROID) || !defined(RTLD_DEEPBIND)
34   // Certain platforms don't define RTLD_DEEPBIND. Android dlopen() requires
35   // further investigation, as it might vary across versions. Crash here to
36   // warn developers that they're trying to rely on uncertain behavior.
37   CHECK(!options.prefer_own_symbols);
38 #else
39   if (options.prefer_own_symbols)
40     flags |= RTLD_DEEPBIND;
41 #endif
42   void* dl = dlopen(library_path.value().c_str(), flags);
43   if (!dl && error)
44     error->message = dlerror();
45 
46   return dl;
47 }
48 
49 // static
UnloadNativeLibrary(NativeLibrary library)50 void UnloadNativeLibrary(NativeLibrary library) {
51   int ret = dlclose(library);
52   if (ret < 0) {
53     DLOG(ERROR) << "dlclose failed: " << dlerror();
54     NOTREACHED();
55   }
56 }
57 
58 // static
GetFunctionPointerFromNativeLibrary(NativeLibrary library,StringPiece name)59 void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
60                                           StringPiece name) {
61   return dlsym(library, name.data());
62 }
63 
64 // static
GetNativeLibraryName(StringPiece name)65 std::string GetNativeLibraryName(StringPiece name) {
66   DCHECK(IsStringASCII(name));
67   return "lib" + name.as_string() + ".so";
68 }
69 
70 }  // namespace base
71