Catch classes inheriting from themselves in the class linker.
(cherry picked from commit 90328ac545f65759a8e4fb217a75332906795518)
Bug: 28685551
Bug: 27682580
Bug: 28830038
Change-Id: If568013bf3c82c1df9b282522712d9af5ca5945d
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 1835c72..8fcb6b2 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -5316,6 +5316,19 @@
const DexFile::ClassDef& class_def = dex_file.GetClassDef(klass->GetDexClassDefIndex());
uint16_t super_class_idx = class_def.superclass_idx_;
if (super_class_idx != DexFile::kDexNoIndex16) {
+ // Check that a class does not inherit from itself directly.
+ //
+ // TODO: This is a cheap check to detect the straightforward case
+ // of a class extending itself (b/28685551), but we should do a
+ // proper cycle detection on loaded classes, to detect all cases
+ // of class circularity errors (b/28830038).
+ if (super_class_idx == class_def.class_idx_) {
+ ThrowClassCircularityError(klass.Get(),
+ "Class %s extends itself",
+ PrettyDescriptor(klass.Get()).c_str());
+ return false;
+ }
+
mirror::Class* super_class = ResolveType(dex_file, super_class_idx, klass.Get());
if (super_class == nullptr) {
DCHECK(Thread::Current()->IsExceptionPending());