Support for import aliases in code completion

#KT-8848 Fixed

compiler/frontend.java/src/org/jetbrains/kotlin/synthetic/JavaSyntheticPropertiesScope.kt

@@ -358,8 +358,15 @@ class JavaSyntheticPropertiesScope(storageManager: StorageManager, private val l
             }
         }
 
-        override fun createSubstitutedCopy(newOwner: DeclarationDescriptor, newModality: Modality, newVisibility: Visibility, original: PropertyDescriptor?, kind: CallableMemberDescriptor.Kind): PropertyDescriptorImpl {
-            return MyPropertyDescriptor(newOwner, this, annotations, newModality, newVisibility, isVar, name, kind, source).apply {
+        override fun createSubstitutedCopy(
+                newOwner: DeclarationDescriptor,
+                newModality: Modality,
+                newVisibility: Visibility,
+                original: PropertyDescriptor?,
+                kind: CallableMemberDescriptor.Kind,
+                newName: Name
+        ): PropertyDescriptorImpl {
+            return MyPropertyDescriptor(newOwner, this, annotations, newModality, newVisibility, isVar, newName, kind, source).apply {
                 getMethod = this@MyPropertyDescriptor.getMethod
                 setMethod = this@MyPropertyDescriptor.setMethod
             }

compiler/frontend/src/org/jetbrains/kotlin/resolve/AllUnderImportScope.kt

@@ -49,7 +49,11 @@ class AllUnderImportScope(
         excludedImportNames.mapNotNull { if (it.parent() == fqName) it.shortName() else null }.toSet()
     }
 
-    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): List<DeclarationDescriptor> {
+    override fun getContributedDescriptors(
+            kindFilter: DescriptorKindFilter,
+            nameFilter: (Name) -> Boolean,
+            changeNamesForAliased: Boolean
+    ): Collection<DeclarationDescriptor> {
         val nameFilterToUse = if (excludedNames.isEmpty()) { // optimization
             nameFilter
         }

compiler/frontend/src/org/jetbrains/kotlin/resolve/LazyExplicitImportScope.kt

@@ -57,12 +57,47 @@ class LazyExplicitImportScope(
         return collectCallableMemberDescriptors(location, MemberScope::getContributedVariables)
     }
 
-    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> {
+    override fun getContributedDescriptors(
+            kindFilter: DescriptorKindFilter,
+            nameFilter: (Name) -> Boolean,
+            changeNamesForAliased: Boolean
+    ): Collection<DeclarationDescriptor> {
         val descriptors = SmartList<DeclarationDescriptor>()
+
         descriptors.addIfNotNull(getContributedClassifier(aliasName, NoLookupLocation.WHEN_GET_ALL_DESCRIPTORS))
         descriptors.addAll(getContributedFunctions(aliasName, NoLookupLocation.WHEN_GET_ALL_DESCRIPTORS))
         descriptors.addAll(getContributedVariables(aliasName, NoLookupLocation.WHEN_GET_ALL_DESCRIPTORS))
 
+        if (changeNamesForAliased && aliasName != declaredName) {
+            for (i in descriptors.indices) {
+                val descriptor = descriptors[i]
+                val newDescriptor: DeclarationDescriptor = when (descriptor) {
+                    is ClassDescriptor -> {
+                        object : ClassDescriptor by descriptor {
+                            override fun getName() = aliasName
+                        }
+                    }
+
+                    is TypeAliasDescriptor -> {
+                        object : TypeAliasDescriptor by descriptor {
+                            override fun getName() = aliasName
+                        }
+                    }
+
+                    is CallableMemberDescriptor -> {
+                        descriptor
+                                .newCopyBuilder()
+                                .setName(aliasName)
+                                .setOriginal(descriptor)
+                                .build()!!
+                    }
+
+                    else -> error("Unknown kind of descriptor in import alias: $descriptor")
+                }
+                descriptors[i] = newDescriptor
+            }
+        }
+
         return descriptors
     }
 

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

@@ -208,7 +208,11 @@ class FileScopeFactory(
                 return scope.getContributedFunctions(name, location)
             }
 
-            override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> {
+            override fun getContributedDescriptors(
+                    kindFilter: DescriptorKindFilter,
+                    nameFilter: (Name) -> Boolean,
+                    changeNamesForAliased: Boolean
+            ): Collection<DeclarationDescriptor> {
                 // we do not perform any filtering by visibility here because all descriptors from both visible/invisible filter scopes are to be added anyway
                 if (filteringKind == FilteringKind.INVISIBLE_CLASSES) return listOf()
                 return scope.getContributedDescriptors(

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

@@ -238,7 +238,11 @@ class LazyImportScope(
         return importResolver.collectFromImports(name) { scope, name -> scope.getContributedFunctions(name, location) }
     }
 
-    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> {
+    override fun getContributedDescriptors(
+            kindFilter: DescriptorKindFilter,
+            nameFilter: (Name) -> Boolean,
+            changeNamesForAliased: Boolean
+    ): Collection<DeclarationDescriptor> {
         // we do not perform any filtering by visibility here because all descriptors from both visible/invisible filter scopes are to be added anyway
         if (filteringKind == FilteringKind.INVISIBLE_CLASSES) return listOf()
 
@@ -248,7 +252,7 @@ class LazyImportScope(
                 val importPath = directive.importPath ?: continue
                 val importedName = importPath.importedName
                 if (importedName == null || nameFilter(importedName)) {
-                    descriptors.addAll(importResolver.getImportScope(directive).getContributedDescriptors(kindFilter, nameFilter))
+                    descriptors.addAll(importResolver.getImportScope(directive).getContributedDescriptors(kindFilter, nameFilter, changeNamesForAliased))
                 }
             }
             descriptors

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDescriptorWithExtraFlags.kt

@@ -51,10 +51,11 @@ class JvmPropertyDescriptorImpl private constructor(
             newModality: Modality,
             newVisibility: Visibility,
             original: PropertyDescriptor?,
-            kind: CallableMemberDescriptor.Kind
+            kind: CallableMemberDescriptor.Kind,
+            newName: Name
     ): PropertyDescriptorImpl =
             JvmPropertyDescriptorImpl(
-                    newOwner, original, annotations, newModality, newVisibility, extraFlags, isVar, name, kind,
+                    newOwner, original, annotations, newModality, newVisibility, extraFlags, isVar, newName, kind,
                     SourceElement.NO_SOURCE, isLateInit, isConst, isHeader, isImpl
             )
 

compiler/resolution/src/org/jetbrains/kotlin/resolve/scopes/Scopes.kt

@@ -109,6 +109,16 @@ interface ImportingScope : HierarchicalScope {
 
     fun getContributedPackage(name: Name): PackageViewDescriptor?
 
+    fun getContributedDescriptors(
+            kindFilter: DescriptorKindFilter = DescriptorKindFilter.ALL,
+            nameFilter: (Name) -> Boolean = MemberScope.ALL_NAME_FILTER,
+            changeNamesForAliased: Boolean
+    ): Collection<DeclarationDescriptor>
+
+    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> {
+        return getContributedDescriptors(kindFilter, nameFilter, changeNamesForAliased = false)
+    }
+
     object Empty : BaseImportingScope(null) {
         override fun printStructure(p: Printer) {
             p.println("ImportingScope.Empty")
@@ -131,4 +141,11 @@ abstract class BaseImportingScope(parent: ImportingScope?) : BaseHierarchicalSco
         get() = super.parent as ImportingScope?
 
     override fun getContributedPackage(name: Name): PackageViewDescriptor? = null
+
+    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> {
+        return getContributedDescriptors(kindFilter, nameFilter, changeNamesForAliased = false)
+    }
+
+    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean, changeNamesForAliased: Boolean): Collection<DeclarationDescriptor>
+            = emptyList()
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/scopes/SubpackagesImportingScope.kt

@@ -40,12 +40,12 @@ class SubpackagesImportingScope(
     override fun getContributedFunctions(name: Name, location: LookupLocation) = super.getContributedFunctions(name, location)
 
     //TODO: kept old behavior, but it seems very strange (super call seems more applicable)
-    override fun getContributedClassifier(name: Name, location: LookupLocation): ClassifierDescriptor? {
-        return ImportingScope.Empty.getContributedClassifier(name, location)
-    }
+    override fun getContributedClassifier(name: Name, location: LookupLocation): ClassifierDescriptor? = null
+
+    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> =
+            emptyList()
 
     //TODO: kept old behavior, but it seems very strange (super call seems more applicable)
-    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean): Collection<DeclarationDescriptor> {
-        return ImportingScope.Empty.getContributedDescriptors(kindFilter, nameFilter)
-    }
+    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean, changeNamesForAliased: Boolean): Collection<DeclarationDescriptor>
+            = emptyList()
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/scopes/utils/ScopeUtils.kt

@@ -50,14 +50,18 @@ fun LexicalScope.getDeclarationsByLabel(labelName: Name): Collection<Declaration
 // Result is guaranteed to be filtered by kind and name.
 fun HierarchicalScope.collectDescriptorsFiltered(
         kindFilter: DescriptorKindFilter = DescriptorKindFilter.ALL,
-        nameFilter: (Name) -> Boolean = { true }
+        nameFilter: (Name) -> Boolean = { true },
+        changeNamesForAliased: Boolean = false
 ): Collection<DeclarationDescriptor> {
     if (kindFilter.kindMask == 0) return listOf()
-    return collectAllFromMeAndParent { it.getContributedDescriptors(kindFilter, nameFilter) }
-            .filter { kindFilter.accepts(it) && nameFilter(it.name) }
+    return collectAllFromMeAndParent {
+        if (it is ImportingScope)
+            it.getContributedDescriptors(kindFilter, nameFilter, changeNamesForAliased)
+        else
+            it.getContributedDescriptors(kindFilter, nameFilter)
+    }.filter { kindFilter.accepts(it) && nameFilter(it.name) }
 }
 
-
 @Deprecated("Use getContributedProperties instead") fun LexicalScope.findLocalVariable(name: Name): VariableDescriptor? {
     return findFirstFromMeAndParent {
         when {
@@ -103,7 +107,7 @@ fun HierarchicalScope.takeSnapshot(): HierarchicalScope = if (this is LexicalWri
 private class MemberScopeToImportingScopeAdapter(override val parent: ImportingScope?, val memberScope: MemberScope) : ImportingScope {
     override fun getContributedPackage(name: Name): PackageViewDescriptor? = null
 
-    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean)
+    override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean, changeNamesForAliased: Boolean)
             = memberScope.getContributedDescriptors(kindFilter, nameFilter)
 
     override fun getContributedClassifier(name: Name, location: LookupLocation) = memberScope.getContributedClassifier(name, location)