8236697: Stack overflow with cyclic hierarchy in class file
Implemented minimal necessary cycle detection to avoid stack overflow in c.s.t.j.code.Types::asSuper
Reviewed-by: vromero
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java
index 97df186..e1a57e8 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java
@@ -2124,22 +2124,31 @@
if (t.tsym == sym)
return t;
- Type st = supertype(t);
- if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) {
- Type x = asSuper(st, sym);
- if (x != null)
- return x;
+ Symbol c = t.tsym;
+ if ((c.flags_field & LOCKED) != 0) {
+ return null;
}
- if ((sym.flags() & INTERFACE) != 0) {
- for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
- if (!l.head.hasTag(ERROR)) {
- Type x = asSuper(l.head, sym);
- if (x != null)
- return x;
+ try {
+ c.flags_field |= LOCKED;
+ Type st = supertype(t);
+ if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) {
+ Type x = asSuper(st, sym);
+ if (x != null)
+ return x;
+ }
+ if ((sym.flags() & INTERFACE) != 0) {
+ for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
+ if (!l.head.hasTag(ERROR)) {
+ Type x = asSuper(l.head, sym);
+ if (x != null)
+ return x;
+ }
}
}
+ return null;
+ } finally {
+ c.flags_field &= ~LOCKED;
}
- return null;
}
@Override
diff --git a/test/langtools/tools/javac/8236697/Cyclic.jcod b/test/langtools/tools/javac/8236697/Cyclic.jcod
new file mode 100644
index 0000000..def57c1
--- /dev/null
+++ b/test/langtools/tools/javac/8236697/Cyclic.jcod
@@ -0,0 +1,29 @@
+class Cyclic {
+ 0xCAFEBABE;
+ 0; // minor version
+ 57; // version
+ [] { // Constant Pool
+ ; // first element is empty
+ class #2; // #1
+ Utf8 "Cyclic"; // #2
+ class #4; // #3
+ Utf8 "java/lang/Object"; // #4
+ } // Constant Pool
+
+ 0x0600; // access
+ #1;// this_cpx
+ #3;// super_cpx
+
+ [] { // Interfaces
+ #1;
+ } // Interfaces
+
+ [] { // fields
+ } // fields
+
+ [] { // methods
+ } // methods
+
+ [] { // Attributes
+ } // Attributes
+} // end class Cyclic
diff --git a/test/langtools/tools/javac/8236697/T8236697.java b/test/langtools/tools/javac/8236697/T8236697.java
new file mode 100644
index 0000000..ecf2205
--- /dev/null
+++ b/test/langtools/tools/javac/8236697/T8236697.java
@@ -0,0 +1,12 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8236697
+ * @summary Stack overflow with cyclic hierarchy in class file
+ * @build Cyclic
+ * @compile/fail/ref=T8236697.out -XDrawDiagnostics T8236697.java
+ */
+interface T8236697 extends Iterable {
+
+ public Cyclic iterator();
+
+}
diff --git a/test/langtools/tools/javac/8236697/T8236697.out b/test/langtools/tools/javac/8236697/T8236697.out
new file mode 100644
index 0000000..eb2d4ed
--- /dev/null
+++ b/test/langtools/tools/javac/8236697/T8236697.out
@@ -0,0 +1,2 @@
+T8236697.java:10:19: compiler.err.override.incompatible.ret: (compiler.misc.clashes.with: iterator(), T8236697, iterator(), java.lang.Iterable), Cyclic, java.util.Iterator
+1 error
\ No newline at end of file
