[BTA tests] Get BTA implementation version via the API

^KT-61860 In Progress

compiler/build-tools/kotlin-build-tools-api-tests/build.gradle.kts

@@ -91,10 +91,6 @@ testing {
                 targets.all {
                     projectTest(taskName = testTask.name, jUnitMode = JUnitMode.JUnit5) {
                         ensureExecutedAgainstExpectedBuildToolsImplVersion(implVersion)
-                        systemProperty(
-                            "kotlin.build-tools-api.impl-version",
-                            implVersion.toString()
-                        ) // TODO: remove after KT-63862
                     }
                 }
             }
@@ -119,12 +115,6 @@ testing {
             targets.all {
                 projectTest(taskName = testTask.name, jUnitMode = JUnitMode.JUnit5) {
                     systemProperty("kotlin.build-tools-api.log.level", "DEBUG")
-                    if (isRegular) {
-                        systemProperty(
-                            "kotlin.build-tools-api.impl-version",
-                            project.version.toString()
-                        ) // TODO: remove after KT-63862
-                    }
                 }
             }
         }

compiler/build-tools/kotlin-build-tools-api-tests/src/main/kotlin/buildToolsVersion.kt

@@ -1,14 +0,0 @@
-/*
- * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.buildtools.api.tests
-
-import org.jetbrains.kotlin.tooling.core.KotlinToolingVersion
-
-// TODO: remove after KT-63862
-const val IMPL_VERSION_SYSTEM_PROPERTY = "kotlin.build-tools-api.impl-version"
-val buildToolsVersion = System.getProperty(IMPL_VERSION_SYSTEM_PROPERTY)
-    ?.let { KotlinToolingVersion(it) }
-    ?: error("The build tools implementation version must be passed via the `$IMPL_VERSION_SYSTEM_PROPERTY` system property to the tests")

compiler/build-tools/kotlin-build-tools-api-tests/src/main/kotlin/compilation/model/BaseTest.kt

@@ -6,11 +6,22 @@
 package org.jetbrains.kotlin.buildtools.api.tests.compilation.model
 
 import org.jetbrains.kotlin.buildtools.api.CompilationService
+import org.jetbrains.kotlin.tooling.core.KotlinToolingVersion
 
 abstract class BaseTest {
     companion object {
         val compilationService: CompilationService by lazy {
             CompilationService.loadImplementation(BaseTest::class.java.classLoader)
         }
+        private val _compilerVersion by lazy {
+            try {
+                compilationService.getCompilerVersion()
+            } catch (_: NoSuchMethodError) {
+                "1.9.20" // getCompilerVersion is introduced since 2.0.0
+            }
+        }
+        val compilerVersion: KotlinToolingVersion by lazy {
+            KotlinToolingVersion(_compilerVersion)
+        }
     }
 }

compiler/build-tools/kotlin-build-tools-api-tests/src/main/kotlin/compilation/model/JvmModule.kt

@@ -9,7 +9,6 @@ import org.jetbrains.kotlin.buildtools.api.CompilationResult
 import org.jetbrains.kotlin.buildtools.api.CompilerExecutionStrategyConfiguration
 import org.jetbrains.kotlin.buildtools.api.SourcesChanges
 import org.jetbrains.kotlin.buildtools.api.jvm.*
-import org.jetbrains.kotlin.buildtools.api.tests.buildToolsVersion
 import org.jetbrains.kotlin.buildtools.api.tests.compilation.model.Module
 import org.jetbrains.kotlin.tooling.core.KotlinToolingVersion
 import java.io.File
@@ -98,7 +97,7 @@ class JvmModule(
             options.setBuildDir(buildDirectory.toFile())
             options.setRootProjectDir(project.projectDirectory.toFile())
 
-            if (buildToolsVersion < KotlinToolingVersion(2, 0, 0, "Beta2")) {
+            if (BaseTest.compilerVersion < KotlinToolingVersion(2, 0, 0, "Beta2")) {
                 // workaround for the incorrect default value
                 options.useOutputDirs(setOf(icCachesDir.toFile(), outputDirectory.toFile()))
             }