Restore heuristic to compute inner class names in ClassifierResolutionContext

This commit restores the heuristic removed in 9df02b2366, but only enables it in case the class wasn't found with the name mapped initially according to the InnerClasses attribute values. This helps to support class files which do not have the InnerClasses attribute for all nested referenced classes, such as those generated by Groovy. Note that in theory it's still possible for this code to behave incorrectly, for example a reference to a class `C` nested in a _top-level_ class named `A$B` will not be loaded by this code correctly. This is a lower-priority issue and it will need to be fixed later. #KT-27874 Fixed
2018-10-31 16:53:27 +01:00
parent a3231e561c
commit 61d3b6ee1f
11 changed files with 64 additions and 7 deletions
@@ -33,7 +33,7 @@ import java.text.StringCharacterIterator
 class BinaryJavaClass(
        override val virtualFile: VirtualFile,
        override val fqName: FqName,
-        private val context: ClassifierResolutionContext,
+        internal val context: ClassifierResolutionContext,
        private val signatureParser: BinaryClassSignatureParser,
        override var access: Int = 0,
        override val outerClass: JavaClass?,
@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.util.javaslang.ImmutableHashMap
 import org.jetbrains.kotlin.util.javaslang.ImmutableMap
 import org.jetbrains.kotlin.util.javaslang.getOrNull
+import org.jetbrains.kotlin.utils.SmartList

 typealias ClassIdToJavaClass = (ClassId) -> JavaClass?

@@ -73,5 +74,49 @@ class ClassifierResolutionContext private constructor(
        return ClassId.topLevel(FqName(internalName.replace('/', '.')))
    }

-    internal fun resolveByInternalName(c: String): Result = resolveClass(mapInternalNameToClassId(c))
+    // See com.intellij.psi.impl.compiled.StubBuildingVisitor.GUESSING_MAPPER
+    private fun convertNestedClassInternalNameWithSimpleHeuristic(internalName: String): ClassId? {
+        val splitPoints = SmartList<Int>()
+        for (p in 0 until internalName.length) {
+            val c = internalName[p]
+            if (c == '$' && p > 0 && internalName[p - 1] != '/' && p < internalName.length - 1 && internalName[p + 1] != '$') {
+                splitPoints.add(p)
+            }
+        }
+
+        if (splitPoints.isEmpty()) return null
+
+        val substrings = (listOf(-1) + splitPoints).zip(splitPoints + internalName.length).map { (from, to) ->
+            internalName.substring(from + 1, to)
+        }
+
+        val outerFqName = FqName(substrings[0].replace('/', '.'))
+        val packageFqName = outerFqName.parent()
+        val relativeName = FqName(outerFqName.shortName().asString() + "." + substrings.subList(1, substrings.size).joinToString("."))
+
+        return ClassId(packageFqName, relativeName, false)
+    }
+
+    internal fun resolveByInternalName(internalName: String): Result {
+        val result = resolveClass(mapInternalNameToClassId(internalName))
+        if (result.classifier == null && '$' in internalName) {
+            // Class files generated by some (non-javac) compilers lack the InnerClasses attribute which would make it possible to
+            // unambiguously determine how to parse a particular internal name found in the class file. For example, see
+            // https://issues.apache.org/jira/browse/GROOVY-8863. In this case, we're trying to treat all dollar characters in the class
+            // name as nested class separators, lookup the class with that ClassId, and see if its InnerClasses attribute confirms our
+            // suspicion that this class was in fact nested.
+            val heuristicName = convertNestedClassInternalNameWithSimpleHeuristic(internalName)
+            if (heuristicName != null) {
+                val heuristicResult = resolveClass(heuristicName)
+                if (heuristicResult.classifier is BinaryJavaClass) {
+                    val realName = heuristicResult.classifier.context.mapInternalNameToClassId(internalName)
+                    if (heuristicName == realName) {
+                        return heuristicResult
+                    }
+                }
+            }
+        }
+
+        return result
+    }
 }