Add ModuleDescriptor.assertValid() for ensuring consistency

compiler/frontend/src/org/jetbrains/kotlin/analyzer/AnalyzerFacade.kt

@@ -96,7 +96,12 @@ class ResolverForProjectImpl<M : ModuleInfo>(
             val moduleDescriptor: ModuleDescriptorImpl,
             val modificationTracker: ModificationTracker?,
             val modificationCount: Long?
-    )
+    ) {
+        fun isOutOfDate(): Boolean {
+            val currentModCount = modificationTracker?.modificationCount
+            return currentModCount != null && currentModCount > modificationCount!!
+        }
+    }
 
     private val descriptorByModule = mutableMapOf<M, ModuleData>()
     private val moduleInfoByDescriptor = mutableMapOf<ModuleDescriptorImpl, M>()
@@ -171,8 +176,7 @@ class ResolverForProjectImpl<M : ModuleInfo>(
                 var moduleData = descriptorByModule.getOrPut(module) {
                     createModuleDescriptor(module)
                 }
-                val currentModCount = moduleData.modificationTracker?.modificationCount
+                if (moduleData.isOutOfDate()) {
-                if (currentModCount != null && currentModCount > moduleData.modificationCount!!) {
                     moduleData = recreateModuleDescriptor(module)
                 }
                 moduleData.moduleDescriptor

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/LazyDeclarationResolver.java

@@ -280,6 +280,7 @@ public class LazyDeclarationResolver {
         if (isTopLevel) { // for top level declarations we search directly in package because of possible conflicts with imports
             KtFile ktFile = (KtFile) declaration.getContainingFile();
             FqName fqName = ktFile.getPackageFqName();
+            topLevelDescriptorProvider.assertValid();
             LazyPackageDescriptor packageDescriptor = topLevelDescriptorProvider.getPackageFragment(fqName);
             if (packageDescriptor == null) {
                 if (topLevelDescriptorProvider instanceof LazyClassContext) {

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/LazyImportScope.kt

@@ -188,6 +188,7 @@ class LazyImportResolver(
     }
 
     fun getImportScope(directive: KtImportDirective): ImportingScope {
+        moduleDescriptor.assertValid()
         return importedScopesProvider(directive) ?: ImportingScope.Empty
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/ResolveSession.java

@@ -308,6 +308,7 @@ public class ResolveSession implements KotlinCodeAnalyzer, LazyClassContext {
     @Override
     @NotNull
     public DeclarationDescriptor resolveToDescriptor(@NotNull KtDeclaration declaration) {
+        assertValid();
         if (!areDescriptorsCreatedForDeclaration(declaration)) {
             throw new IllegalStateException(
                     "No descriptors are created for declarations of type " + declaration.getClass().getSimpleName()
@@ -449,4 +450,9 @@ public class ResolveSession implements KotlinCodeAnalyzer, LazyClassContext {
     public WrappedTypeFactory getWrappedTypeFactory() {
         return wrappedTypeFactory;
     }
+
+    @Override
+    public void assertValid() {
+        module.assertValid();
+    }
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/TopLevelDescriptorProvider.kt

@@ -25,6 +25,8 @@ interface TopLevelDescriptorProvider {
     fun getPackageFragment(fqName: FqName): LazyPackageDescriptor?
 
     fun getTopLevelClassifierDescriptors(fqName: FqName, location: LookupLocation): Collection<ClassifierDescriptor>
+
+    fun assertValid()
 }
 
 object NoTopLevelDescriptorProvider : TopLevelDescriptorProvider {
@@ -37,4 +39,8 @@ object NoTopLevelDescriptorProvider : TopLevelDescriptorProvider {
     override fun getTopLevelClassifierDescriptors(fqName: FqName, location: LookupLocation): Collection<ClassifierDescriptor> {
         shouldNotBeCalled()
     }
+
+    override fun assertValid() {
+        shouldNotBeCalled()
+    }
 }

core/descriptors/src/org/jetbrains/kotlin/descriptors/ModuleDescriptor.kt

@@ -50,4 +50,6 @@ interface ModuleDescriptor : DeclarationDescriptor {
     }
 
     val isValid: Boolean
+
+    fun assertValid()
 }

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt

@@ -48,8 +48,11 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
     private var packageFragmentProviderForModuleContent: PackageFragmentProvider? = null
 
     override var isValid: Boolean = true
+        set(value) {
+            field = value
+        }
 
-    private fun assertValid() {
+    override fun assertValid() {
         if (!isValid) {
             throw IllegalStateException("Accessing invalid module descriptor $this")
         }

core/descriptors/src/org/jetbrains/kotlin/types/ErrorUtils.java

@@ -127,6 +127,11 @@ public class ErrorUtils {
             public boolean isValid() {
                 return false;
             }
+
+            @Override
+            public void assertValid() {
+                throw new IllegalStateException("ERROR_MODULE is not a valid module");
+            }
         };
     }