Why doesn't LLVM compile typedeffed C blocks in pch file with Xcode?

Question

I have typedeffed a C block type that I use commonly, in my project's PCH file:

typedef void (^UserBlock)(PFUser* user);

When I try to define an Objective C method in a header like this:

+(void)ensureUserWithID:(NSString *)userID withCompletion:(UserBlock)completionHandler

I am getting Expected a type error on UserBlock. However, if I move the typedef from PCH to beginning of that header file, it compiles (with the warning Redefinition of typedef 'UserBlock' is a C11 feature. I've cleaned the build folder, deleted derived data, restarted Xcode, but I'm still getting the same error. I've got other definitions in my PCH too, and they are compiling just file. All I'm having trouble is the C block types defined in my PCH. Why am I encountering such behavior? I am on Xcode 5.1.1 and LLVM 5.1.

I don't see why that wouldn't work. Can you show the whole prefix file please? — trojanfoe, Aug 29 '14 at 10:43
@trojanfoe http://pastebin.com/m5WLMcsS (just commented out the line, temporarily. it's not commented out normally obviously) — Can Poyrazoğlu, Aug 29 '14 at 10:50
And what happens if you move those `typedef`s inside the `#ifdef __OBJC__` block? — trojanfoe, Aug 29 '14 at 10:52
@trojanfoe nothing changes. by the way, I am using those block types everywhere else in my app. it's just one place that I'm getting this weird behavior. — Can Poyrazoğlu, Aug 29 '14 at 11:42

score 0 · Accepted Answer · answered Aug 29 '14 at 12:12

0

Found the problem. The header file that I was getting errors on was imported to the PCH file, before the typedefs. I've moved the typedefs above the header import, and the problem was gone.

answered Aug 29 '14 at 12:12

Can Poyrazoğlu

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interesting to see that I've run onto the exact same problem again, googled it, and found my own question and answer :) – Can Poyrazoğlu Oct 27 '14 at 20:39

Why doesn't LLVM compile typedeffed C blocks in pch file with Xcode?

1 Answers1