Let Gradle handle KMP build caching on Xcode builds

[cartland]

This resolves an Xcode build warning:

Run script build phase 'Compile Kotlin Multiplatform' will be run during every build because it does not specify any outputs. To address this issue, either add output dependencies to the script phase, or configure it to run in every build by unchecking "Based on dependency analysis" in the script phase.

[gemini-code-assist]

Summary of Changes

Hello @cartland, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an Xcode build warning related to the Kotlin Multiplatform compilation script. By marking the script phase as always needing to run, we ensure it executes consistently and eliminate the warning, improving the build process clarity.

Highlights

• Xcode Build Warning Fix: Explicitly configured the 'Compile Kotlin Multiplatform' build phase in the Xcode project to always run, resolving a build warning about the script not specifying outputs.

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[gemini-code-assist]

Code Review

The pull request updates the Xcode project to ensure the shared Kotlin Multiplatform module is built on every Xcode build. This resolves a build warning. The review highlights a potential trade-off: while the warning is fixed, this change might increase incremental build times. It suggests exploring the alternative of specifying input/output files for the build script phase to allow Xcode's dependency analysis to optimize rebuilds, or documenting the decision if the current approach is preferred after consideration.

[gemini-code-assist]

This change effectively silences the Xcode warning by forcing the 'Compile Kotlin Multiplatform' script to run on every build.

While this addresses the warning, it might lead to longer incremental build times because the shared module will recompile even if its source files or dependencies haven't changed. This could particularly impact developer productivity on larger projects or during frequent build cycles.

Have you considered the alternative approach of specifying input and output files for this script phase? This would allow Xcode to leverage its dependency analysis and potentially skip unnecessary recompilations. For instance:

• Output Files: The path to the generated shared.framework (e.g., $(CONFIGURATION_BUILD_DIR)/$(FRAMEWORKS_FOLDER_PATH)/shared.framework).
• Input Files: Key source directories of the shared module (e.g., $(SRCROOT)/../shared/src), the build.gradle.kts of the shared module, or a specific marker file that changes upon successful KMP compilation.

Defining these accurately can significantly optimize build times. If this approach was considered and deemed too complex or problematic for the current setup, it might be beneficial to document the rationale behind choosing alwaysOutOfDate = 1 for future maintainers, perhaps in a project README or a wiki page discussing build configurations.

[cartland]

Xcode has a warning because the Build Phase "Compile Kotlin Multiplatform" is only supposed to run "Based on dependency analysis", but then the rest of the configuration doesn't specify any Input Files or Output Files. Xcode doesn't like that we tell it to conditionally run the script, but we don't give it any conditions.

Options:

• Abandon this PR: Leave the warning as-is so developers can handle it on their own.
• Accept this PR: Silence the warning. Declare that the XCFramework is expected to build every time (as it already does).
• Add dependency detection logic: We could do something like this: main...cartland:github-android-kotlin-multiplatform-samples:ios-outputs
  • Adding the extra logic has several risks: Correctness (we might introduce a bug) & Complexity (increased mental load) & Limited Value (this sample code doesn't take long to build). This is why I think we should either decide to silence the warning or leave the warning as-is so developers can decide how to optimize on their own.