Roman Golyshev
47aa6392bf
Here is the reasoning behind that change: Historically, all the declarations generated by compiler plugins were marked with `SYNTHESIZED` member kind in Kotlin Metadata by K1 compiler. In K1 IDE, descriptors were deserialized directly from the Kotlin Metadata, and they saw all the generated declarations from it. In the stubs, however, such declarations were not materialized at all. It caused no troubles, since K1 IDE relied on descriptors to get the essential resolution information in completion and other subsystems. So, the resolution of members from jars processed by compiler plugins (e.g. `kotlinx-serialization-json`) was mostly fine. In K2 IDE, however, we use stubs to "deserialize" FIR declarations from them, to later create `KtSymbol`s upon that FIR. If we see a library file which was processed by compiler plugins, we build stubs for it based on the Kotlin Metadata, and then use stubs to create FIR. But if stubs do not contain information about the generated declarations, then the resulting FIR will also not contain such declarations. In the end, the K2 IDE would also be blind to such declarations, since there is no other way to retrieve them from the library jar. By meterializing all the synthethic declarations in stubs (with some minor exceptions for data classes), we would avoid such problems, and the resolve of such declarations from compiler jars in K2 IDE would become possible. Important note: currently, the Kotlin Metadata format between K1 and K2 frontends is not 100% the same; most notably, in K2, the generated declarations are marked as regular declarations, not as `SYNTHESIZED` ones. Hence, if you compile a jar with the current version of K2 frontend, then all the generated declarations would have a regular `DECLARATION` origin, and there would be no such issues as described above. There are two notes here: 1. K2 IDE still has to support the jars compiled by the K1 compiler, so it still makes sense to alter the stubs and make the generated declarations visible. 2. The issue about the different stub formats has been reported (see KT-64924), and might be resolved in the future. So it is possible that K2 frontend's metadata will also start marking the generated declarations as `SYNTHESIZED`. ^KT-64808 Fixed
Kotlin Programming Language
Welcome to Kotlin!
It is an open-source, statically typed programming language supported and developed by JetBrains and open-source contributors.
Some handy links:
- Kotlin Site
- Getting Started Guide
- Try Kotlin
- Kotlin Standard Library
- Issue Tracker
- Kotlin YouTube Channel
- Forum
- Kotlin Blog
- Subscribe to Kotlin YouTube channel
- Follow Kotlin on Twitter
- Public Slack channel
- TeamCity CI build
Kotlin Multiplatform capabilities
Support for multiplatform programming is one of Kotlin’s key benefits. It reduces time spent writing and maintaining the same code for different platforms while retaining the flexibility and benefits of native programming.
- Kotlin Multiplatform Mobile for sharing code between Android and iOS
- Getting Started with Kotlin Multiplatform Mobile Guide
- Kotlin Multiplatform Benefits
- Share code on all platforms
- Share code on similar platforms
Editing Kotlin
Build environment requirements
This repository is using Gradle toolchains feature to select and auto-provision required JDKs from AdoptOpenJdk project.
Unfortunately AdoptOpenJdk project does not provide required JDK 1.6 and 1.7 images,
so you could either download them manually and provide path to installation via JDK_1_6 and JDK_1_7 environment variables or
use following SDK managers:
Alternatively, it is still possible to only provide required JDKs via environment variables
(see gradle.properties for supported variable names). To ensure Gradle uses only JDKs
from environmental variables - disable Gradle toolchain auto-detection by passing -Porg.gradle.java.installations.auto-detect=false option
(or put it into $GRADLE_USER_HOME/gradle.properties).
For local development, if you're not working on the standard library, it's OK to avoid installing JDK 1.6 and JDK 1.7.
Add kotlin.build.isObsoleteJdkOverrideEnabled=true to the local.properties file, so build will only use JDK 1.8+. Note, that in this
case, build will have Gradle remote build cache misses for some tasks.
Note: The JDK 6 for MacOS is not available on Oracle's site. You can install it by
$ brew tap homebrew/cask-versions
$ brew install --cask java6
On Windows you might need to add long paths setting to the repo:
git config core.longpaths true
Building
The project is built with Gradle. Run Gradle to build the project and to run the tests using the following command on Unix/macOS:
./gradlew <tasks-and-options>
or the following command on Windows:
gradlew <tasks-and-options>
On the first project configuration gradle will download and setup the dependencies on
intellij-coreis a part of command line compiler and contains only necessary APIs.idea-fullis a full blown IntelliJ IDEA Community Edition to be used in the plugin module.
These dependencies are quite large, so depending on the quality of your internet connection you might face timeouts getting them. In this case, you can increase timeout by specifying the following command line parameters on the first run:
./gradlew -Dhttp.socketTimeout=60000 -Dhttp.connectionTimeout=60000
Important gradle tasks
clean- clean build resultsdist- assembles the compiler distribution intodist/kotlinc/folderinstall- build and install all public artifacts into local maven repositorycoreLibsTest- build and run stdlib, reflect and kotlin-test testsgradlePluginTest- build and run gradle plugin testscompilerTest- build and run all compiler tests
To reproduce TeamCity build use -Pteamcity=true flag. Local builds don't run proguard and have jar compression disabled by default.
OPTIONAL: Some artifacts, mainly Maven plugin ones, are built separately with Maven. Refer to libraries/ReadMe.md for details.
To build Kotlin/Native, see kotlin-native/README.md.
Working with the project in IntelliJ IDEA
It is recommended to use the latest released version of Intellij IDEA (Community or Ultimate Edition). You can download IntelliJ IDEA here.
After cloning the project, import the project in IntelliJ by choosing the project directory in the Open project dialog.
For handy work with compiler tests it's recommended to use Kotlin Compiler Test Helper
Dependency verification
We have a dependencies verification feature enabled in the
repository for all Gradle builds. Gradle will check hashes (md5 and sha256) of used dependencies and will fail builds with
Dependency verification failed errors when local artifacts are absent or have different hashes listed in the
verification-metadata.xml file.
It's expected that verification-metadata.xml should only be updated with the commits that modify the build. There are some tips how
to perform such updates:
- Delete
componentssection ofverification-metadata.xmlto avoid stockpiling of old unused dependencies. You may use the following command:
#macOS
sed -i '' -e '/<components>/,/<\/components>/d' gradle/verification-metadata.xml
#Linux & Git for Windows
sed -i -e '/<components>/,/<\/components>/d' gradle/verification-metadata.xml
- Re-generate dependencies with Gradle's
--write-verification-metadatacommand (verify update relates to your changes)
./gradlew -i --write-verification-metadata sha256,md5 -Pkotlin.native.enabled=true resolveDependencies
resolveDependencies task resolves dependencies for all platforms including dependencies downloaded by plugins.
Keep in mind:
- If you’re adding a dependency with OS mentioned in an artifact name (
darwin,mac,osx,linux,windows), remember to add them toimplicitDependenciesconfiguration or updateresolveDependenciestask if needed.resolveDependenciesshould resolve all dependencies including dependencies for different platforms. - If you have a
local.propertiesfile in your Kotlin project folder, make sure that it doesn't containkotlin.native.enabled=false. Otherwise, native-only dependencies may not be added to the verification metadata. This is becauselocal.propertieshas higher precedence than the-Pkotlin.native.enabled=truespecified in the Gradle command.
Using -dev versions
We publish -dev versions frequently.
For -dev versions you can use the list of available versions and include this maven repository:
maven("https://maven.pkg.jetbrains.space/kotlin/p/kotlin/bootstrap")
License
Kotlin is distributed under the terms of the Apache License (Version 2.0). See license folder for details.
Contributing
Please be sure to review Kotlin's contributing guidelines to learn how to help the project.