ios 为什么 Xcode 7 显示 *.tbd 而不是 *.dylib？

Why Xcode 7 shows *.tbd instead of *.dylib?

提问by Ted

Xcode 7 In Target > BuildPhases > Link Binary With Libraries > tap + button

Xcode 7 在 Target > BuildPhases > Link Binary With Libraries > 点击 + 按钮

When choosing frameworks to add, you cannot find *.dylib, you'll see *.tbd instead.

在选择要添加的框架时，您找不到 *.dylib，而是会看到 *.tbd。

What is the reason for this?

这是什么原因？

**For people who need dylib, follow from this post

**对于需要dylib的人，请关注这篇文章

1. Choose "Add other"
2. Once in the file selection window do "CMD"+Shift+G (Go to folder) & type /usr/lib/
3. From /user/lib you can find the *.dylib files

1. 选择“添加其他”
2. 进入文件选择窗口后，执行“CMD”+Shift+G（转到文件夹）并输入 /usr/lib/
3. 从 /user/lib 你可以找到 *.dylib 文件

回答by Suragch

I've scoured Google but the only thing I can find so far is the following quote from the Apple developer forums:

我已经搜索过谷歌，但到目前为止我唯一能找到的是来自 Apple 开发者论坛的以下引用：

For those who are curious, the .tbd files are new "text-based stub libraries", that provide a much more compact version of the stub libraries for use in the SDK, and help to significantly reduce its download size.

对于那些好奇的人来说，.tbd 文件是新的“基于文本的存根库”，它提供了一个更紧凑的存根库版本以供在 SDK 中使用，并有助于显着减少其下载大小。

Hopefully more documentation will be coming soon.

希望更多的文档很快就会出现。

Update

更新

As an example, here is the entire contents of libsqlite3.tbd. It is just a text file. Note that the install-name is libsqlite3.dylib.

例如，这里是libsqlite3.tbd的全部内容。它只是一个文本文件。请注意，安装名称是libsqlite3.dylib。

---
archs:           [ armv7, armv7s, arm64 ]
platform:        ios
install-name:    /usr/lib/libsqlite3.dylib
current-version: 216.4
compatibility-version: 9.0
exports:         
  - archs:           [ armv7, armv7s, arm64 ]
    symbols:         [ __sqlite3_lockstate, __sqlite3_purgeEligiblePagerCacheMemory, 
                       __sqlite3_system_busy_handler, __sqlite_auto_profile, 
                       __sqlite_auto_profile_syslog, __sqlite_auto_trace, 
                       __sqlite_auto_trace_syslog, _sqlite3OsShmHasMultipleLinks, 
                       _sqlite3OsShmRenamedWhileOpen, _sqlite3OsShmWasTruncated, 
                       _sqlite3OsShmWasUnlinkedWhileOpen, _sqlite3VersionNumber, 
                       _sqlite3VersionString, _sqlite3_aggregate_context, 
                       _sqlite3_aggregate_count, _sqlite3_auto_extension, 
                       _sqlite3_backup_finish, _sqlite3_backup_init, _sqlite3_backup_pagecount, 
                       _sqlite3_backup_remaining, _sqlite3_backup_step, 
                       _sqlite3_bind_blob, _sqlite3_bind_blob64, _sqlite3_bind_double, 
                       _sqlite3_bind_int, _sqlite3_bind_int64, _sqlite3_bind_null, 
                       _sqlite3_bind_parameter_count, _sqlite3_bind_parameter_index, 
                       _sqlite3_bind_parameter_name, _sqlite3_bind_text, 
                       _sqlite3_bind_text16, _sqlite3_bind_text64, _sqlite3_bind_value, 
                       _sqlite3_bind_zeroblob, _sqlite3_blob_bytes, _sqlite3_blob_close, 
                       _sqlite3_blob_open, _sqlite3_blob_read, _sqlite3_blob_reopen, 
                       _sqlite3_blob_write, _sqlite3_busy_handler, _sqlite3_busy_timeout, 
                       _sqlite3_cancel_auto_extension, _sqlite3_changes, 
                       _sqlite3_clear_bindings, _sqlite3_close, _sqlite3_close_v2, 
                       _sqlite3_collation_needed, _sqlite3_collation_needed16, 
                       _sqlite3_column_blob, _sqlite3_column_bytes, _sqlite3_column_bytes16, 
                       _sqlite3_column_count, _sqlite3_column_decltype, 
                       _sqlite3_column_decltype16, _sqlite3_column_double, 
                       _sqlite3_column_int, _sqlite3_column_int64, _sqlite3_column_name, 
                       _sqlite3_column_name16, _sqlite3_column_text, _sqlite3_column_text16, 
                       _sqlite3_column_type, _sqlite3_column_value, _sqlite3_commit_hook, 
                       _sqlite3_compileoption_get, _sqlite3_compileoption_used, 
                       _sqlite3_complete, _sqlite3_complete16, _sqlite3_config, 
                       _sqlite3_context_db_handle, _sqlite3_create_collation, 
                       _sqlite3_create_collation16, _sqlite3_create_collation_v2, 
                       _sqlite3_create_function, _sqlite3_create_function16, 
                       _sqlite3_create_function_v2, _sqlite3_create_module, 
                       _sqlite3_create_module_v2, _sqlite3_data_count, 
                       _sqlite3_data_directory, _sqlite3_db_config, _sqlite3_db_filename, 
                       _sqlite3_db_handle, _sqlite3_db_mutex, _sqlite3_db_readonly, 
                       _sqlite3_db_release_memory, _sqlite3_db_status, 
                       _sqlite3_declare_vtab, _sqlite3_enable_shared_cache, 
                       _sqlite3_errcode, _sqlite3_errmsg, _sqlite3_errmsg16, 
                       _sqlite3_errstr, _sqlite3_exec, _sqlite3_expired, 
                       _sqlite3_extended_errcode, _sqlite3_extended_result_codes, 
                       _sqlite3_file_control, _sqlite3_finalize, _sqlite3_free, 
                       _sqlite3_free_table, _sqlite3_get_autocommit, _sqlite3_get_auxdata, 
                       _sqlite3_get_table, _sqlite3_global_recover, _sqlite3_initialize, 
                       _sqlite3_intarray_bind, _sqlite3_intarray_create, 
                       _sqlite3_interrupt, _sqlite3_last_insert_rowid, 
                       _sqlite3_libversion, _sqlite3_libversion_number, 
                       _sqlite3_limit, _sqlite3_log, _sqlite3_malloc, _sqlite3_malloc64, 
                       _sqlite3_memory_alarm, _sqlite3_memory_highwater, 
                       _sqlite3_memory_used, _sqlite3_mprintf, _sqlite3_msize, 
                       _sqlite3_mutex_alloc, _sqlite3_mutex_enter, _sqlite3_mutex_free, 
                       _sqlite3_mutex_leave, _sqlite3_mutex_try, _sqlite3_next_stmt, 
                       _sqlite3_open, _sqlite3_open16, _sqlite3_open_v2, 
                       _sqlite3_os_end, _sqlite3_os_init, _sqlite3_overload_function, 
                       _sqlite3_prepare, _sqlite3_prepare16, _sqlite3_prepare16_v2, 
                       _sqlite3_prepare_v2, _sqlite3_profile, _sqlite3_progress_handler, 
                       _sqlite3_randomness, _sqlite3_realloc, _sqlite3_realloc64, 
                       _sqlite3_release_memory, _sqlite3_reset, _sqlite3_reset_auto_extension, 
                       _sqlite3_result_blob, _sqlite3_result_blob64, _sqlite3_result_double, 
                       _sqlite3_result_error, _sqlite3_result_error16, 
                       _sqlite3_result_error_code, _sqlite3_result_error_nomem, 
                       _sqlite3_result_error_toobig, _sqlite3_result_int, 
                       _sqlite3_result_int64, _sqlite3_result_null, _sqlite3_result_text, 
                       _sqlite3_result_text16, _sqlite3_result_text16be, 
                       _sqlite3_result_text16le, _sqlite3_result_text64, 
                       _sqlite3_result_value, _sqlite3_result_zeroblob, 
                       _sqlite3_rollback_hook, _sqlite3_rtree_geometry_callback, 
                       _sqlite3_rtree_query_callback, _sqlite3_set_authorizer, 
                       _sqlite3_set_auxdata, _sqlite3_shutdown, _sqlite3_sleep, 
                       _sqlite3_snprintf, _sqlite3_soft_heap_limit, _sqlite3_soft_heap_limit64, 
                       _sqlite3_sourceid, _sqlite3_sql, _sqlite3_status, 
                       _sqlite3_status64, _sqlite3_step, _sqlite3_stmt_busy, 
                       _sqlite3_stmt_readonly, _sqlite3_stmt_status, _sqlite3_strglob, 
                       _sqlite3_stricmp, _sqlite3_strnicmp, _sqlite3_table_column_metadata, 
                       _sqlite3_temp_directory, _sqlite3_test_control, 
                       _sqlite3_thread_cleanup, _sqlite3_threadsafe, _sqlite3_total_changes, 
                       _sqlite3_trace, _sqlite3_transfer_bindings, _sqlite3_update_hook, 
                       _sqlite3_uri_boolean, _sqlite3_uri_int64, _sqlite3_uri_parameter, 
                       _sqlite3_user_data, _sqlite3_value_blob, _sqlite3_value_bytes, 
                       _sqlite3_value_bytes16, _sqlite3_value_double, _sqlite3_value_int, 
                       _sqlite3_value_int64, _sqlite3_value_numeric_type, 
                       _sqlite3_value_text, _sqlite3_value_text16, _sqlite3_value_text16be, 
                       _sqlite3_value_text16le, _sqlite3_value_type, _sqlite3_version, 
                       _sqlite3_vfs_find, _sqlite3_vfs_register, _sqlite3_vfs_unregister, 
                       _sqlite3_vmprintf, _sqlite3_vsnprintf, _sqlite3_vtab_config, 
                       _sqlite3_vtab_on_conflict, _sqlite3_wal_autocheckpoint, 
                       _sqlite3_wal_checkpoint, _sqlite3_wal_checkpoint_v2, 
                       _sqlite3_wal_hook ]
...

I found this and other .tbd files in

我发现这个和其他 .tbd 文件

Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib/

You can also see a .tbd file if you go to the General tab of your Xcode project and then add a library under Linked Frameworks and Libraries. The .tbd file will be copied to your project.

如果您转到 Xcode 项目的 General 选项卡，然后在 Linked Frameworks and Libraries 下添加库，您还可以看到 .tbd 文件。.tbd 文件将复制到您的项目中。

So it appears that the .dylib file is the actual library of binary code that your project is using and is located in the /usr/lib/ directory on the user's device. The .tbd file, on the other hand, is just a text file that is included in your project and serves as a link to the required .dylib binary. Since this text file is much smaller than the binary library, it makes the SDK's download size smaller.

因此，.dylib 文件似乎是您的项目正在使用的实际二进制代码库，位于用户设备上的 /usr/lib/ 目录中。另一方面，.tbd 文件只是一个包含在您的项目中的文本文件，用作指向所需 .dylib 二进制文件的链接。由于此文本文件比二进制库小得多，因此使 SDK 的下载大小更小。

At this point I am only surmising from the information given, so please correct me if I am wrong.

在这一点上，我只是根据所提供的信息进行推测，所以如果我错了，请纠正我。

回答by Peter Lapisu

.dylib is the compiled binary that contains the machine code. .tbd is a smaller text file, similar to a cross-platform module map.

.dylib 是包含机器代码的编译后的二进制文件。.tbd 是一个较小的文本文件，类似于跨平台模块映射。

回答by yoAlex5

.tbd- Text Based dylib stubs. It is a kind of optimization that means you do not have to copy a .dylibfile (which exists on a target) into your bundle (e.g. application). This file does not contain the binary code which has a major impact on the file size.

.tbd- Text Based dylib stubs. 这是一种优化，意味着您不必将.dylib文件（存在于目标上）复制到您的包（例如应用程序）中。此文件不包含对文件大小有重大影响的二进制代码。

It is applicable only for:

它仅适用于：

1. Dynamic librariesbecause they are runtime-linked
2. File should have a relevant path on the target. As a result it is the best place for standard system libraries.

1. Dynamic libraries因为它们是运行时链接的
2. 文件应该在目标上有一个相关的路径。因此，它是最好的地方standard system libraries。

For iOS development you can find .tbd files which you can use here

对于 iOS 开发，您可以找到可以在此处使用的 .tbd 文件

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib

For example libiconv.tbdlooks like

例如libiconv.tbd看起来像

This file contains some meta information like:

该文件包含一些元信息，例如：

• .dyliblocation
• symbols(class's properties, methods)
• architecture
• platform

• .dylib地点
• 符号（类的属性、方法）
• 建筑学
• 平台