Sergej Jaskiewicz
3713d95bb1
tl;dr the current design of klibs does not allow to properly deserialize the list of sealed subclasses in a sound way. It is possible that a subclass of a sealed class is declared in a different file, AND is private in that file. A more detailed explanation: Right now we don't serialize file signatures at all. However, a private declaration's signature must necessarily include the file signature. How do we serialize a private declaration's signature into a klib and deserialize it later? **Serialization** is simple: we just serialize the file signature as an empty protobuf message. When we are **deserializing** a private declaration, we look at the file that is being deserialized right now, and construct the file signature based on that. This logic, however, doesn't always work. An example is KT-54028. Basically, if we have a sealed interface with a private implementor declared in a different file, this breaks: 1. We are deserializing the sealed interface. The deserializer knows that we are now in the file in which the sealed interface is declared. 2. As part of deserializing the interface, we deserialize its sealed subclasses. 3. Naturally, we come to deserializing the private implementor that is declared in another file, but the deserializer still thinks that we are in the file in which the interface is declared. A wrong signature is created, which leads to linkage failure. We *could* fix this by properly serializing the file signature, i.e. instead of an empty protobuf message we could write the file path and its package to the klib. However, there a problems with this approach: - The current design of signatures allows a situation where two different files can have the same relative path (for example, with the help of the `-Xklib-relative-path-base` compiler flag) *and* the same package, which would introduce ambiguity during linkage. - Most importantly, this appoach won't work well with incremental compilation of klibs. Currently we rely on the assumption that all cross-file references are handled with public signatures, and private signatures are only used inside a single file. This allows to move declarations across files without recompiling it's use sites. It has been decided to apply the following hacky solution: we just don't deserialize the list of sealed subclasses from klibs. The list of sealed subclasses is not used in lowerings, so it should be safe. #KT-54028 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.
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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
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- Share code on all platforms
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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:
- Use auto-generation for getting an initial list of new hashes (verify updates relate to you changes).
./gradlew -i --write-verification-metadata sha256,md5 -Pkotlin.native.enabled=true help
(any other task may be used instead of help)
- Consider removing old versions from the file if you are updating dependencies.
- Leave meaningful
originattribute (instead ofGenerated by Gradle) if you did some manual verification of the artifact. - Always do manual verification if several hashes are needed, and a new
also-trusttag has to be added. - If you’re adding a dependency with OS mentioning in an artifact name (
darwin,mac,osx,linux,windows), remember to add counterparts for other platforms.
Using -dev and -SNAPSHOT versions
We publish -dev and -SNAPSHOT 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")
For -SNAPSHOT versions that are updated daily, you can use the list of available versions and include this maven repository:
maven("https://oss.sonatype.org/content/repositories/snapshots/")
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.