7034585: Adjust fillInStackTrace filtering to assist 6998871

Allow for one or more fillInStackTrace frames to be skipped

Reviewed-by: mchung, kvn

hotspot/src/share/vm/classfile/javaClasses.cpp

@@ -1453,23 +1453,32 @@ void java_lang_Throwable::fill_in_stack_trace(Handle throwable, TRAPS) {
       st_method = st.method();
     }
 #endif
+
+    // the format of the stacktrace will be:
+    // - 1 or more fillInStackTrace frames for the exception class (skipped)
+    // - 0 or more <init> methods for the exception class (skipped)
+    // - rest of the stack
+
     if (!skip_fillInStackTrace_check) {
-      // check "fillInStackTrace" only once, so we negate the flag
+      if ((method->name() == vmSymbols::fillInStackTrace_name() ||
-      // after the first time check.
+           method->name() == vmSymbols::fillInStackTrace0_name()) &&
-      skip_fillInStackTrace_check = true;
+          throwable->is_a(method->method_holder())) {
-      if (method->name() == vmSymbols::fillInStackTrace_name()) {
         continue;
       }
+      else {
+        skip_fillInStackTrace_check = true; // gone past them all
+      }
     }
-    // skip <init> methods of the exceptions klass. If there is <init> methods
-    // that belongs to a superclass of the exception  we are going to skipping
-    // them in stack trace. This is simlar to classic VM.
     if (!skip_throwableInit_check) {
+      assert(skip_fillInStackTrace_check, "logic error in backtrace filtering");
+
+      // skip <init> methods of the exception class and superclasses
+      // This is simlar to classic VM.
       if (method->name() == vmSymbols::object_initializer_name() &&
           throwable->is_a(method->method_holder())) {
         continue;
       } else {
-        // if no "Throwable.init()" method found, we stop checking it next time.
+        // there are none or we've seen them all - either way stop checking
         skip_throwableInit_check = true;
       }
     }

hotspot/src/share/vm/classfile/vmSymbols.hpp

@@ -330,6 +330,7 @@
   template(dispatch_name,                             "dispatch")                                 \
   template(getSystemClassLoader_name,                 "getSystemClassLoader")                     \
   template(fillInStackTrace_name,                     "fillInStackTrace")                         \
+  template(fillInStackTrace0_name,                    "fillInStackTrace0")                        \
   template(getCause_name,                             "getCause")                                 \
   template(initCause_name,                            "initCause")                                \
   template(setProperty_name,                          "setProperty")                              \