Provide a forced compiler version compatibility -X control.

backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2Native.kt

@@ -175,6 +175,9 @@ class K2Native : CLICompiler<K2NativeCompilerArguments>() {
                 put(LIST_PHASES, arguments.listPhases)
                 put(TIME_PHASES, arguments.timePhases)
 
+                put(COMPATIBLE_COMPILER_VERSIONS,
+                    arguments.compatibleCompilerVersions.toNonNullList())
+
                 put(ENABLE_ASSERTIONS, arguments.enableAssertions)
 
                 put(GENERATE_TEST_RUNNER, arguments.generateTestRunner)

backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2NativeCompilerArguments.kt

@@ -81,12 +81,15 @@ class K2NativeCompilerArguments : CommonCompilerArguments() {
     var target: String? = null
 
     // The rest of the options are only interesting to the developers.
-    // Make sure to prepend them with a double dash.
+    // Make sure to prepend them with -X.
     // Keep the list lexically sorted.
 
     @Argument(value="-Xcheck-dependencies", deprecatedName = "--check_dependencies", description = "Check dependencies and download the missing ones")
     var checkDependencies: Boolean = false
 
+    @Argument(value="-Xcompatible-compiler-version", valueDescription = "<version>", description = "Assume the given compiler version to be binary compatible")
+    var compatibleCompilerVersions: Array<String>? = null
+
     @Argument(value = "-Xdisable", deprecatedName = "--disable", valueDescription = "<Phase>", description = "Disable backend phase")
     var disablePhases: Array<String>? = null
 

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanConfig.kt

@@ -21,7 +21,9 @@ import org.jetbrains.kotlin.konan.library.libraryResolver
 import org.jetbrains.kotlin.konan.properties.loadProperties
 import org.jetbrains.kotlin.konan.target.*
 import org.jetbrains.kotlin.konan.KonanAbiVersion
+import org.jetbrains.kotlin.konan.KonanVersion
 import org.jetbrains.kotlin.konan.library.toUnresolvedLibraries
+import org.jetbrains.kotlin.konan.parseKonanVersion
 
 class KonanConfig(val project: Project, val configuration: CompilerConfiguration) {
 
@@ -76,12 +78,16 @@ class KonanConfig(val project: Project, val configuration: CompilerConfiguration
     private val repositories = configuration.getList(KonanConfigKeys.REPOSITORIES)
     private fun resolverLogger(msg: String) = configuration.report(STRONG_WARNING, msg)
 
+    private val compatibleCompilerVersions: List<KonanVersion> =
+        configuration.getList(KonanConfigKeys.COMPATIBLE_COMPILER_VERSIONS).map { it.parseKonanVersion() }
+
     private val resolver = defaultResolver(
         repositories,
         libraryNames.filter { it.contains(File.separator) },
         target,
         distribution,
-        ::resolverLogger
+        ::resolverLogger,
+        compatibleCompilerVersions = compatibleCompilerVersions 
     ).libraryResolver()
 
     internal val resolvedLibraries by lazy {

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanConfigurationKeys.kt

@@ -14,6 +14,8 @@ class KonanConfigKeys {
         // Keep the list lexically sorted.
         val CHECK_DEPENDENCIES: CompilerConfigurationKey<Boolean>
                 = CompilerConfigurationKey.create("check dependencies and download the missing ones")
+        val COMPATIBLE_COMPILER_VERSIONS: CompilerConfigurationKey<List<String>>
+                = CompilerConfigurationKey.create("compatible compiler versions")
         val DEBUG: CompilerConfigurationKey<Boolean>
                 = CompilerConfigurationKey.create("add debug information")
         val DISABLED_PHASES: CompilerConfigurationKey<List<String>> 

shared/src/library/kotlin/org/jetbrains/kotlin/konan/library/SearchPathResolver.kt

@@ -39,13 +39,14 @@ fun defaultResolver(
         target: KonanTarget,
         distribution: Distribution,
         logger: Logger = ::dummyLogger,
-        skipCurrentDir: Boolean = false
+        skipCurrentDir: Boolean = false,
+        compatibleCompilerVersions: List<KonanVersion> = emptyList()
 ): SearchPathResolverWithTarget = KonanLibraryProperResolver(
         repositories,
         directLibs,
         target,
         listOf(KonanAbiVersion.CURRENT),
-        listOf(KonanVersion.CURRENT),
+        listOf(KonanVersion.CURRENT) + compatibleCompilerVersions,
         distribution.klib,
         distribution.localKonanDir.absolutePath,
         skipCurrentDir,