Summary:
alternative solution for https://github.com/facebook/react-native/issues/33379
> when `use_frameworks!` is on, there are errors like:
> ```
> 'FBReactNativeSpec/FBReactNativeSpec.h' file not found
> #import <FBReactNativeSpec/FBReactNativeSpec.h>
> ```
> this error may come from from https://github.com/facebook/react-native/commit/f7e4c07c84b6 regression.
>
> when `use_frameworks!` is on, xcode will search headers from framework directories, the correct imports would be `#import <React_Codegen/FBReactNativeSpec/FBReactNativeSpec.h>` (xcode will transform dash to underscore, so it is `React_Codegen` but not `React-Codegen`). in the other hand, when `use_frameworks!` is off, the correct import is `#import <React-Codegen/FBReactNativeSpec/FBReactNativeSpec.h>`.
>
>
> this fix is specific for old architecture (fabric is off).
>
> when fabric is on, there are other errors from duplicated headers when copying to build folder. [the reason is that framework build would try to flatten headers](https://mkonrad.net/2015/03/29/xcode-static-libraries-preserving-header-directory-structure.html). we have `primitives.h` in different folders and they would be flattened into `React_Fabric.framework/Headers`. to be honest, i don't know how to deal with the problem in the meantime, maybe subspecs are not enough, we should separate them from subspecs to dedicated podspecs so that we can have these targets as different frameworks.
in this alternative fix, i try to add `React-Codegen/React_Codegen.framework/Headers` into header search paths and make original `#import <FBReactNativeSpec/FBReactNativeSpec.h>` reachable.
[this change](7a0398c331) in the pr is just a workaround to solve breaking in latest main branch and this is not important to the `use_frameworks!` fix at all. this breaking was coming from 1804951595.
## Changelog
[iOS] [Fixed] - Fix iOS build error when Podfile `use_frameworks!` is on and Fabric is off
Pull Request resolved: https://github.com/facebook/react-native/pull/33409
Test Plan:
verify with rn-tester
1. change `fabric_enabled` to false in `packages/rn-tester/Podfile`
2. `USE_FRAMEWORKS=1 pod install`
3. build rn-tester in xcode
Reviewed By: dmitryrykun
Differential Revision: D34817041
Pulled By: cortinico
fbshipit-source-id: 4d1a610e99a807793eb3f64461e0d735c0a9ca9c
a6c2846b37