Always treat all sources as parts of the module being compiled

If a path to the module-info.java file is passed as an argument, we
should treat all other source files passed as arguments (either as
individual source files or inside a source directory) as members of that
module. Previously we treated other source files as members of the
unnamed module, and this resulted in incorrect errors when using a
member exported with a qualification from another named module, for
example

 #KT-18598 In Fixed

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/modules/CliJavaModuleResolver.kt

@@ -17,8 +17,10 @@
 package org.jetbrains.kotlin.cli.jvm.modules
 
 import com.intellij.ide.highlighter.JavaClassFileType
+import com.intellij.ide.highlighter.JavaFileType
 import com.intellij.openapi.vfs.VfsUtilCore
 import com.intellij.openapi.vfs.VirtualFile
+import org.jetbrains.kotlin.idea.KotlinFileType
 import org.jetbrains.kotlin.resolve.jvm.modules.JavaModule
 import org.jetbrains.kotlin.resolve.jvm.modules.JavaModuleGraph
 import org.jetbrains.kotlin.resolve.jvm.modules.JavaModuleResolver
@@ -27,10 +29,20 @@ class CliJavaModuleResolver(
         override val moduleGraph: JavaModuleGraph,
         private val javaModules: List<JavaModule>
 ) : JavaModuleResolver {
-    override fun findJavaModule(file: VirtualFile): JavaModule? {
-        val isBinary = file.fileType == JavaClassFileType.INSTANCE
-        return javaModules.firstOrNull { module ->
-            module.isBinary == isBinary && VfsUtilCore.isAncestor(module.moduleRoot, file, false)
+    init {
+        assert(javaModules.count { !it.isBinary } <= 1) {
+            "Modules computed by ClasspathRootsResolver cannot have more than one source module: $javaModules"
         }
     }
+
+    private val sourceModule = javaModules.firstOrNull { !it.isBinary }
+
+    override fun findJavaModule(file: VirtualFile): JavaModule? =
+            when (file.fileType) {
+                KotlinFileType.INSTANCE, JavaFileType.INSTANCE -> sourceModule
+                JavaClassFileType.INSTANCE -> javaModules.firstOrNull { module ->
+                    module.isBinary && VfsUtilCore.isAncestor(module.moduleRoot, file, false)
+                }
+                else -> null
+            }
 }

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/modules/JavaModule.kt

@@ -28,8 +28,9 @@ interface JavaModule {
     val name: String
 
     /**
-     * A directory or the root of a .jar file on the module path. In case of an explicit module,
-     * module-info.class file can be found in its children.
+     * A directory or the root of a .jar file on the module path. Can also be the path to the `module-info.java` file if that path
+     * was passed as an explicit argument to the compiler.
+     * In case of an explicit module, module-info.class file can be found in its children.
      */
     val moduleRoot: VirtualFile
 

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleA/foo/Foo.java

@@ -0,0 +1,3 @@
+package foo;
+
+public class Foo {}

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleA/module-info.java

@@ -0,0 +1,3 @@
+module moduleA {
+    exports foo to moduleB;
+}

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleA/unexported/Unexported.java

@@ -0,0 +1,3 @@
+package unexported;
+
+public class Unexported {}

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleB.txt

@@ -0,0 +1,10 @@
+compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleB/usage.kt:2:19: error: symbol is declared in module 'moduleA' which does not export package 'unexported'
+import unexported.Unexported
+                  ^
+compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleB/usage.kt:9:5: error: symbol is declared in module 'moduleA' which does not export package 'unexported'
+    Unexported()
+    ^
+compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleB/usage.kt:13:5: error: unresolved reference: Unrelated
+    Unrelated()
+    ^
+COMPILATION_ERROR

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/moduleB/usage.kt

@@ -0,0 +1,14 @@
+import foo.Foo
+import unexported.Unexported
+
+fun usage() {
+    // Should be OK
+    Foo()
+
+    // Should be error
+    Unexported()
+
+    // Should be error: if we're passing the path to a particular module-info.java to the compiler,
+    // we should not treat its location as a root
+    Unrelated()
+}

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/someOtherDirectoryWithTheActualModuleInfo/Unrelated.java

@@ -0,0 +1 @@
+public class Unrelated {}

compiler/testData/javaModules/specifyPathToModuleInfoInArguments/someOtherDirectoryWithTheActualModuleInfo/module-info.java

@@ -0,0 +1,3 @@
+module moduleB {
+    requires moduleA;
+}

compiler/tests/org/jetbrains/kotlin/jvm/compiler/Java9ModulesIntegrationTest.kt

@@ -54,12 +54,14 @@ class Java9ModulesIntegrationTest : AbstractKotlinCompilerIntegrationTest() {
                     }
                     KotlinTestUtils.compileJavaFilesExternallyWithJava9(javaFiles, javaOptions)
                 },
-                checkKotlinOutput = { actual ->
-                    KotlinTestUtils.assertEqualsToFile(File(testDataDirectory, "$name.txt"), actual)
-                }
+                checkKotlinOutput = checkKotlinOutput(name)
         )
     }
 
+    private fun checkKotlinOutput(moduleName: String): (String) -> Unit = { actual ->
+        KotlinTestUtils.assertEqualsToFile(File(testDataDirectory, "$moduleName.txt"), actual)
+    }
+
     fun testSimple() {
         val a = module("moduleA")
         module("moduleB", listOf(a))
@@ -130,4 +132,21 @@ class Java9ModulesIntegrationTest : AbstractKotlinCompilerIntegrationTest() {
         val c = module("moduleC", listOf(a, b))
         module("moduleD", listOf(c, b, a))
     }
+
+    fun testSpecifyPathToModuleInfoInArguments() {
+        val a = module("moduleA")
+
+        val jdk9Home = KotlinTestUtils.getJdk9HomeIfPossible() ?: return
+        val kotlinOptions = mutableListOf(
+                "$testDataDirectory/someOtherDirectoryWithTheActualModuleInfo/module-info.java",
+                "-jdk-home", jdk9Home.path,
+                "-Xmodule-path=${a.path}"
+        )
+        compileLibrary(
+                "moduleB",
+                additionalOptions = kotlinOptions,
+                compileJava = { _, _, _ -> error("No .java files in moduleB in this test") },
+                checkKotlinOutput = checkKotlinOutput("moduleB")
+        )
+    }
 }