[MacPorts] #71548: gtk-osx-application-gtk2 build error: cannot find protocol declaration for 'NSString'

[MacPorts]

#71548: gtk-osx-application-gtk2 build error: cannot find protocol declaration for
'NSString'
---------------------------------------+----------------------
  Reporter:  barracuda156              |      Owner:  mascguy
      Type:  defect                    |     Status:  assigned
  Priority:  Normal                    |  Milestone:
 Component:  ports                     |    Version:  2.10.5
Resolution:                            |   Keywords:
      Port:  gtk-osx-application-gtk2  |
---------------------------------------+----------------------

Comment (by kencu):

 I find chatgpt is really great for these kinds of build errors.

 Here’s what it says:


 The errors and warnings you're seeing during the compilation process
 appear to stem from a mix of deprecated API usage and syntax issues in the
 code. I'll break down the issues for you:

 ### 1. **Deprecation Warning** (`GTimeVal` is deprecated)
 {{{
 /opt/local/include/gtk-2.0/gtk/gtktooltips.h:73:3: warning: 'GTimeVal' is
 deprecated: Use 'GDateTime' instead [-Wdeprecated-declarations]
    73 |   GTimeVal last_popdown;
 }}}

 **Explanation**: The code is using `GTimeVal`, which is a deprecated
 structure in the GLib library. The warning suggests using `GDateTime`
 instead, which is the recommended modern API for date and time handling.

 **Solution**:
 - To fix this warning, you'll need to update the code to replace
 `GTimeVal` with `GDateTime`. This requires modifying how the time is
 handled in the code.
 - Check the parts of the codebase that deal with `GTimeVal` and refactor
 them to use `GDateTime` instead. For example, `g_time_val_to_timeval()`
 and similar functions are deprecated in favor of `g_date_time_*`
 functions.

 ### 2. **Syntax Error** (`expected '>' before '*' token`)

 {{{
 GtkApplicationDelegate.c:76:83: error: expected '>' before '*' token
    76 | -(void) application: (NSApplication*)theApplication openFiless:
 (NSArray<NSString *> *) files
       |
 ^
 }}}

 **Explanation**: This error is likely due to incorrect Objective-C syntax.
 Specifically, the `<NSString *>` is incorrectly placed in the method
 declaration.

 **Solution**:
 - In Objective-C, you can't use generics syntax (like `<NSString *>`)
 directly in method signatures unless you're using a specific compiler that
 supports it (like Clang). The correct syntax would be to use `NSArray *`
 and cast it to `NSArray<NSString *> *` if needed.

 **Fixed declaration**:
 {{{objective-c
 -(void) application: (NSApplication *)theApplication openFiles: (NSArray
 *)files;
 }}}
 If you need type safety for `NSString`, you can cast it inside the method
 body, or use `NSArray<NSString *> *` in a context where it’s valid (e.g.,
 in the class definition or with modern compilers).

 ### 3. **Protocol Declaration Not Found** (`cannot find protocol
 declaration for 'NSString'`)

 ```
 GtkApplicationDelegate.c:76:1: error: cannot find protocol declaration for
 'NSString'
 ```

 **Explanation**: This error suggests that the compiler cannot find the
 definition for `NSString`, which is part of the Foundation framework in
 macOS.

 **Solution**: Ensure that the proper headers are included in your file. In
 Objective-C, you typically need to import the Foundation framework.

 **Add this at the top of your file**:
 ```objective-c
 #import <Foundation/Foundation.h>
 ```

 ### Putting it All Together:
 - Refactor your code to avoid using deprecated types like `GTimeVal` in
 favor of `GDateTime`.
 - Fix the Objective-C method declaration for `openFiles` to avoid using
 invalid generic syntax.
 - Ensure the `Foundation` framework is imported so that `NSString` and
 other Foundation types are recognized.

 ### Final Considerations:
 - If you're working with GTK 2 and Objective-C, ensure that your build
 environment is set up correctly with the necessary headers and libraries.
 - If you need further help refactoring the code or if this is part of a
 larger project, feel free to provide more context!

-- 
Ticket URL: <https://trac.macports.org/ticket/71548#comment:2>
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