Xcode 4中没有GCC 4.2编译器选项？

Question

在我的Xcode 4安装中，我只有两个编译器选项：

1. Apple LLVM编译器3.0
2. GCC LLVM 4.2

在许多Xcode示例中，我看到GCC 4.2被显示为第三个选项，但实际上并不存在。我有意进行了干净的XCode 4安装。如果没有GCC 4.2，是否有添加它的标准方法？我的一个项目需要使用GCC（而不是GCC LLVM），其他项目我很满意使用GCC LLVM，所以这只是针对那一个项目的问题。

- MOK9

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感谢 @Bavarious，这正是正确的答案。问题还为时过早。 - MOK9

Answer 1

以下是使用gcc 4.2在xcode 4.2中进行编译的方法。大部分操作都是通过命令行完成的，所以当您看到以[ 15:30 jon@MacBookPro / ]$开头的行时，需要打开Terminal.app并运行以$开始的命令。

在此过程中不会删除任何文件或目录，因此如果将来需要使用LLVM进行编译，则可以轻松撤销。

1. Download - but do not install yet - xcode_4.1_for_lion.dmg or xcode_4.1_for_snow_leopard.dmg

2. Now, follow these steps to install Xcode 4.1 into /Developer-4.1:

   1. Backup the working /Developer directory (where Xcode 4.2 is installed)

   [ 15:30 jon@MacBookPro / ]$ sudo mv -v /Developer /Developer-4.2
   

3. Run the Xcode 4.1 installer using the default install location (/Developer)

4. Move the new Xcode 4.1 installation to /Developer-4.1:

   [ 15:30 jon@MacBookPro / ]$ sudo mv -v /Developer /Developer-4.1
   

5. Move the Xcode 4.2 developer directory back to /Developer:

   [ 15:30 jon@MacBookPro / ]$ sudo mv -v /Developer-4.2 /Developer
   

Edit the Xcode 4.2 GCC 4.2.xcspec file to get gcc 4.2 to show in the list of compiler options ^[1]:

[ 15:30 jon@MacBookPro / ]$ sudo vi "/Developer/Library/Xcode/PrivatePlugIns/Xcode3Core.ideplugin/Contents/SharedSupport/Developer/Library/Xcode/Plug-ins/GCC 4.2 (Plausible Blocks).xcplugin/Contents/Resources/GCC 4.2.xcspec"

• Change lines 41 and 42 from this:

  ShowInCompilerSelectionPopup = NO;
  IsNoLongerSupported = YES;
  

• To This:

  ShowInCompilerSelectionPopup = YES; 
  IsNoLongerSupported = NO;
  

Backup the Xcode 4.2 iOS/Simulator Framework usr directories:

[ 15:30 jon@MacBookPro / ]$ sudo mv -v /Developer/Platforms/iPhoneOS.platform/Developer/usr /Developer/Platforms/iPhoneOS.platform/Developer/usr.backup
[ 15:30 jon@MacBookPro / ]$ sudo mv -v /Developer/Platforms/iPhoneSimulator.platform/Developer/usr /Developer/Platforms/iPhoneSimulator.platform/Developer/usr.backup

Copy Xcode 4.1 iOS/Simulator Framework usr directories to Xcode 4.2:

[ 15:30 jon@MacBookPro / ]$ sudo cp -rv /Developer-4.1/Platforms/iPhoneOS.platform/Developer/usr /Developer/Platforms/iPhoneOS.platform/Developer/usr
[ 15:30 jon@MacBookPro / ]$ sudo cp -rv /Developer-4.1/usr /Developer/Platforms/iPhoneSimulator.platform/Developer/usr

Copy the gcc and info iOS SDK library directories from Xcode 4.1 to Xcode 4.2 ^[2]:

[ 15:30 jon@MacBookPro / ]$ sudo cp -rv /Developer-4.1/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/usr/lib/gcc /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/usr/lib/gcc
[ 15:30 jon@MacBookPro / ]$ sudo cp -rv /Developer-4.1/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/usr/lib/info /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/usr/lib/info

使用gcc-4.2进行编译！

这是我撰写的一篇博客文章，更详细地介绍了这个过程。如果遇到任何问题或有任何疑问，请随时在博客上留言。

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^[1] 如果从命令行打开（使用类似vi、emacs、nano等），请确保将路径用引号括起来"/long path/with spaces/in it/file.xcspec"，或转义空格/some/long\ path/with\ spaces/in\ it/file.xcspec

^[2] 这是必要的，因为iPhoneOS.platform SDK有自己单独的/usr/lib目录，而iPhoneSimulator.platform SDK没有

- chown

Answer 2

Xcode 4.3有一个特定的文件夹/Applications/Xcode.app/Contents/Developer/Toolchains。

是否有办法添加其他的工具链，比如AVR-gcc和PIC32-gcc？

- Rei Vilo