https://github.com/lacasseio/sample-multiple-public-header-directories

Demonstrate how to allow multiple public header directories using native core Gradle plugins
https://github.com/lacasseio/sample-multiple-public-header-directories

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Demonstrate how to allow multiple public header directories using native core Gradle plugins

• Host: GitHub
• URL: https://github.com/lacasseio/sample-multiple-public-header-directories
• Owner: lacasseio
• Created: 2024-02-15T16:55:20.000Z (11 months ago)
• Default Branch: main
• Last Pushed: 2024-02-15T17:47:26.000Z (11 months ago)
• Last Synced: 2024-11-11T21:42:32.518Z (2 months ago)
• Language: C++
• Size: 59.6 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.adoc

Awesome Lists containing this project

README

        
= Allow multiple public headers in `cpp-library` plugin

== Problem

Gradle only allows exporting a single public header from `CppLibrary`.

Thus, the following is invalid out of the box:

```groovy

library {

    publicHeaders.from('includes')

    publicHeaders.from('my-other-includes')

}

```

== Solution

We can use a `Sync` task to assemble the outgoing headers and export that single location in `cppApiElements`.

Why not simply list all the `publicHeaders` and export them individually?

Unfortunately, the `FileCollection` public API doesn't allow access to the raw content; thus, there is no way of reliably knowing how many locations we have to export.

Exporting generated headers becomes especially impossible because the outgoing `Configuration` is processed immediately after the project evaluation.

As part of the process, Gradle eagerly realizes the `outgoing.artifacts` collection, disallowing `addLater`/`addAllLater`.

As we are still part of the configuration phase, we have two additional issues:

1. Realizing the task output before the task executes.

2. All non-generated paths will be ignored, as they are unknown.

Using a Sync task as padding is a great and only solution.

== Demonstration (script)

```

library {

    publicHeaders.from('inc')

    publicHeaders.from('includes')

}

```

== Demonstration (build)

```

$ ./gradlew :app:assembleRelease --console=verbose

> Task :lib2:syncCppApiElements    // <1>

> Task :lib1:syncCppApiElements    // <1>

> Task :lib2:compileReleaseCpp

> Task :lib1:compileReleaseCpp

> Task :lib2:linkRelease

> Task :lib2:stripSymbolsRelease

> Task :lib1:linkRelease

> Task :lib1:stripSymbolsRelease

> Task :app:compileReleaseCpp

> Task :app:linkRelease

> Task :app:extractSymbolsRelease

> Task :app:stripSymbolsRelease

> Task :app:installRelease

> Task :app:assembleRelease

BUILD SUCCESSFUL

```

<1>: Notice the sync task.

The performance impact of the `Sync` is negligible thanks to Gradle's work avoidance features.

== Demonstration (publish)

```

$ ./gradlew :lib1:publishAllPublicationsToMavenRepository

BUILD SUCCESSFUL

$ unzip -l repo/com/example/lib1/1.0/lib1-1.0-cpp-api-headers.zip

Archive:  repo/com/example/lib1/1.0/lib1-1.0-cpp-api-headers.zip

  Length      Date    Time    Name

---------  ---------- -----   ----

        0  02-15-2024 09:11   one.h

        0  02-15-2024 09:11   three/

        0  02-15-2024 09:11   three/four.h

        0  02-15-2024 09:11   two.h

---------                     -------

        0                     4 files

```