xcode – 来自链接器(ld)的奇怪警告

我们正在构建一个主要在Obj-C/C++ocoa中编写的Mac OSX应用程序。
然后，该应用程序与一些第三方库以静态方式链接，由C/C++编写，并由我们编译(在命令行中，使用MacPorts或通常的“./configure&& make”;都是通用二进制文件)。

该应用程序正常工作，但广告编译时我们总是得到这些奇怪的链接器警告：

ld: warning: direct access in ___cxx_global_var_init17 to global weak symbol __ZGVN4i18n12phonenumbers9SingletonINS0_15PhoneNumberUtilEE8instanceE means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.
ld: warning: direct access in ___cxx_global_var_init17 to global weak symbol __ZGVN4i18n12phonenumbers9SingletonINS0_15PhoneNumberUtilEE8instanceE means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.
ld: warning: direct access in ___cxx_global_var_init17 to global weak symbol __ZN5boost10scoped_ptrIN4i18n12phonenumbers15PhoneNumberUtilEED1Ev means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.
ld: warning: direct access in ___cxx_global_var_init17 to global weak symbol __ZN4i18n12phonenumbers9SingletonINS0_15PhoneNumberUtilEE8instanceE means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.
ld: warning: direct access in ___cxx_global_var_init17 to global weak symbol __ZGVN4i18n12phonenumbers9SingletonINS0_15PhoneNumberUtilEE8instanceE means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

这来自一个C/C++库。我们正在与这些库链接：

> libphonenumber，这是导致5个警告中的4个的显然。由我们通过“cmake”编译。
boost(libboost_thread-mt)，负责1警告。与MacPorts编译。
>使用MacPorts编译的ICU(libicudata，libicuuc，libicui18n)。
> Protocol Buffers，通过“./configure&& make”编译。

请注意：

>尽管有警告，应用程序仍然运行正常，但我们希望能够摆脱这些问题，因为它们令人讨厌。
> xcode with boost : linker(Id) Warning about visibility settings提出的解决方案不起作用：“默认隐藏的符号”一直是“是”。

解决方法

The solution proposed by xcode with boost : linker(Id) Warning about
visibility settings doesn’t work: “Symbols hidden by default” has
always been “YES”.

这与设置为“YES”的更少关系，更重要的是在所有项目中设置为相同的值。依赖于其他库的Libs /项目需要具有“默认隐藏的符号”的同样设置，以便正确链接并且没有错误/警告。

我以前遇到过，所有项目的Xcode都有一个简单的改变，以确保设置匹配通常可以解决问题。由于这听起来像在编译命令行，gcc的可见性参数是你需要看的。