Kotlin Fuzzer

Fuzzer for Kotlin compiler. Found > 65 unique bugs in kotlinc v1.1.4-3.

Fuzzer produced .kt files by mutating kotlinc test suite. If, when compiling the file, kotlinc threw an exception, we considered this a compiler bug.
All files that crash the compiler are presented here.

List of bugs

Full list of bugs can be found here. Currently, it starts as follows:

66
1, KotlinTypeMapper.java:130,	at org.jetbrains.kotlin.codegen.ExpressionCodegen.genQualified(ExpressionCodegen.java:323),	at org.jetbrains.kotlin.codegen.ExpressionCodegen.genQualified(ExpressionCodegen.java:289),	at org.jetbrains.kotlin.codegen.ExpressionCodegen.gen(ExpressionCodegen.java:329),	Caused by: java.lang.IllegalStateException: Error type encountered: [ERROR : <ERROR FUNCTION RETURN TYPE>] (ErrorType).,	at org.jetbrains.kotlin.codegen.state.KotlinTypeMapper$1.processErrorType(KotlinTypeMapper.java:130),	at org.jetbrains.kotlin.load.kotlin.TypeSignatureMappingKt.mapType(typeSignatureMapping.kt:111),	at org.jetbrains.kotlin.codegen.state.KotlinTypeMapper.mapType(KotlinTypeMapper.java:454)
	kt6990.kt-1463450686.kt
1, KotlinTypeMapper.java:130,	at org.jetbrains.kotlin.codegen.ExpressionCodegen.genQualified(ExpressionCodegen.java:323),	at org.jetbrains.kotlin.codegen.ExpressionCodegen.genQualified(ExpressionCodegen.java:289),	at org.jetbrains.kotlin.codegen.ExpressionCodegen.visitParenthesizedExpression(ExpressionCodegen.java:445),	Caused by: java.lang.IllegalStateException: Error type encountered: [ERROR : Unsubstituted type for <ERROR CLASS>] (ErrorType).,	at org.jetbrains.kotlin.codegen.state.KotlinTypeMapper$1.processErrorType(KotlinTypeMapper.java:130),	at org.jetbrains.kotlin.load.kotlin.TypeSignatureMappingKt.mapType(typeSignatureMapping.kt:111),	at org.jetbrains.kotlin.codegen.state.KotlinTypeMapper.mapType(KotlinTypeMapper.java:454)
	equalsHashCodeToString.kt-1975246039.kt

The list is organized so:

• first comes the number of unique bugs
• then, each bug is described
  • N, the number of files that trigger the bug, is written
  • then, some description of the bug is shown. It is a snippet from full kotlinc stacktrace (with some parts possibly omitted, so that source-specific information is deleted)
  • the following N lines show names of files that trigger this bug, in ascending order of size

How to run

From the fuzzer folder, run run_current_main.sh to start fuzzing.
To update the list of bugs, run update_all.sh.
To run minimization of verified tests, run

git checkout minimization
cd fuzzer
./minimize_verified.sh

Authors

Mike Koltsov
Marat Akhin