Target Preprocessor Macros are ignored by the preprocessor in Xcode

Question

I added TEST=1 in the Preprocessor Macros section of the project target's Build Settings, and whenever I use it in code, the preprocessor thinks it's not defined.

alt + click on it shows a question mark
The syntax coloring doesn't work well
The syntax autocomplete doesn't work well

For example, having:

#if TEST

// a

#else

// b

#endif

has this behavior:

Syntax coloring only works for // b
Syntax autocomplete only works for // b

This is because the preprocessor can't find TEST (even if it's defined as 1, as I previously stated) so it treats it as being false.

Is there any way to solve these problems?

Edit:

My use case is related to multiple Project Targets. So, say that the initial target is named First, which has the TEST preprocessor macro defined with value 1.

If I create another project target named Second with no preprocessor macros defined and want to add some code for it only if TEST is 0 (false/not defined), I'll put it in the #else block (// b).

Knowing that syntax coloring and autocomplete works for // b, it looks like it works ok, but if I change the current target to the First one (pun intended) and even build it, it still works as Second is selected.

if you build the project, preprocessor will detect the compile time flags and will show coloring and autocomplete. have you tried that? — manishg
– manishg, Commented Mar 9, 2017 at 3:56
Did you do it for both debug and release? It works at my end. — manishg
– manishg, Commented Mar 9, 2017 at 12:18
This has nothing to do with Build Configurations. I updated my question. — Iulian Onofrei
– Iulian Onofrei, Commented Mar 9, 2017 at 13:04

Iulian Onofrei · Accepted Answer · 2020-03-11 07:20:00Z

19

If you want to do it like this in Swift, you should add a User-Defined setting named OTHER_SWIFT_FLAGS in your Build Settings like this:

And then in your code you type:

#if TEST1

// Debug

#endif

#if TEST2

// Release

#endif

I don't know why you need this, but it may be interesting to look into native Xcode Target, to use specific behavior for multiple apps with same root project. If this is what you want, you should look into an article this: AppCoda using Targets with Xcode.

edited Mar 11, 2020 at 7:20

Iulian Onofrei

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answered Mar 15, 2017 at 15:49

cdescours

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Comments

Harish Gupta · Accepted Answer · 2017-03-10 02:57:49Z

5

Just go to target->Edit Scheme -> Run -> Info and check the Build Configuration. Now while adding the Preprocessor Macros in build setting just make sure you are adding the macro for correct build configuration and correct target.

I tried by adding for both debug and release build as above for my target App (Test-ObjectiveC). So when i tried below code with this setting, u can see the syntax color accordingly.

answered Mar 10, 2017 at 2:57

Harish Gupta

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3 Comments

Iulian Onofrei Over a year ago

And what happens when you cmd + click it?

Harish Gupta Over a year ago

@lulian not sure what you want to check there with cmd + click.

Iulian Onofrei Over a year ago

I was just wondering if it knows to open the Build Settings or if it's showing the question mark as in my example. There might be other settings of my big project that interfere with this. I'll try testing it myself in a new project and try to find if the problem is caused by one of my settings.

MartinZ · Accepted Answer · 2021-03-20 07:05:12Z

4

I was able to make it work by setting "Target->Build Settings->All->Swift Compiler - Custom Flags -> Active Compilation Conditions".

XCode version 12.3

edited Mar 20, 2021 at 7:05

answered Mar 11, 2021 at 14:57

MartinZ

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