Manually add PCH precompiled files for iOS development Xcode6

Reference Document http://blog.csdn.net/crazyzhang1990/article/details/44243343

The red part is my own supplementary notice

Before Xcode6, create a new project Xcode automatically creates a "project name-prefix.pch" file under the supporting Files folder, which is also a header file, and the contents of the PCH header file can be shared and accessed by all other source files in the project. is a precompiled file.

First, let's talk about the role of PCH:

1. Store some global macros (macros that are used throughout the project)

2. Used to include all header files (header files that are used throughout the project)

3. Can automatically turn on or off the log output function

Although it took a long time to Xcode6 but the project was created before XCODE5, the PCH file was not found to be missing from the beginning. Why should Apple do this, perhaps because people put a lot of header files and macro definitions into the PCH, resulting in a long compilation time. Apple to get rid of him may be to speed up the compilation time to increase the user experience. Although the convenience of programming has been lost. Have to admire Apple's user-centric approach to thinking. A more detailed discussion can go up to StackOverflow and see http://stackoverflow.com/questions/24158648/. Why-isnt-projectname-prefix-pch-created-automatically-in-xcode-6.

How to add a PCH file in Xcode:

Command+n, open the new File window: ios->other->pch file, create a PCH

2. Add the path to the precompile header option in building setting: Add "$ (srcroot)/project name/PCH filename"

Add the PCH file you built before show in Finder to see where your PCH file is located

$ (srcroot) This representative navigates to your project file, the trailing slash is (PREFIXPCHTEST/PREFIXHEADER.PCH) sub- file/pch file

For example: $ (srcroot)/prefixpchtest/prefixheader.pch (prefixheader.pch under the project file under a folder named Prefixpchtest)

(or $ (srcroot)/prefixheader.pch (and prefixheader.pch below the project file)

Yes, compile the program, if you have an error check the path you added is correct.

3, precompile Prefix header is yes, pre-compiled PCH file will be cached, can improve the speed of compilation

Manually add PCH precompiled files for iOS development Xcode6