8251527: CTW: C2 (Shenandoah) compilation fails with SEGV due to unhandled catchproj == NULL

Reviewed-by: chagedorn, kvn

src/hotspot/share/opto/callnode.cpp

@@ -873,8 +873,7 @@ void CallNode::extract_projections(CallProjections* projs, bool separate_io_proj
       {
         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
         projs->fallthrough_proj = pn;
-        DUIterator_Fast jmax, j = pn->fast_outs(jmax);
-        const Node *cn = pn->fast_out(j);
+        const Node *cn = pn->unique_ctrl_out();
         if (cn->is_Catch()) {
           ProjNode *cpn = NULL;
           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {

test/hotspot/jtreg/gc/shenandoah/compiler/TestLoadPinnedAfterCall.java

@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2020, Red Hat, Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8251527
+ * @summary CTW: C2 (Shenandoah) compilation fails with SEGV due to unhandled catchproj == NUL
+ * @requires vm.flavor == "server"
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled
+ *
+ * @run main/othervm -XX:+UseShenandoahGC -XX:CompileOnly=TestLoadPinnedAfterCall.test -XX:CompileCommand=dontinline,TestLoadPinnedAfterCall.not_inlined -XX:-TieredCompilation -XX:-BackgroundCompilation TestLoadPinnedAfterCall
+ *
+ */
+
+public class TestLoadPinnedAfterCall {
+    private A staticField1;
+    private static Object staticField2 = new Object();
+    private static volatile int staticField3;
+    private static int staticField4;
+    static TestLoadPinnedAfterCall object = new TestLoadPinnedAfterCall();
+
+    public static void main(String[] args) {
+        final A a = new A();
+        try {
+            throw new Exception();
+        } catch (Exception ex) {
+        }
+        for (int i = 0; i < 20_000; i++) {
+            inlined(0, 0, 0);
+            inlined(2, 0, 0);
+            inlined(2, 2, 2);
+
+            object.staticField1 = new A();
+            test(true, a, a, false, 2, 2);
+            test(false, a, a, true, 2, 2);
+            test(false, a, a, false, 2, 2);
+            object.staticField1 = a;
+            test(true, a, a, false, 2, 2);
+            test(false, a, a, true, 2, 2);
+            test(false, a, a, false, 2, 2);
+        }
+    }
+
+    private static void test(boolean flag, A a, A a2, boolean flag2, int i1, int i2) {
+
+        int ii = 1;
+        for (; ii < 2; ii *= 2) {
+
+        }
+        ii = ii / 2;
+
+        i1 = 0;
+        for (; i1 < 2; i1 += ii) {
+            for (int i = 0; i < 2; i += ii) {
+
+            }
+        }
+
+        i2 = 0;
+        for (; i2 < 2; i2 += ii) {
+            for (int i = 0; i < 2; i += ii) {
+                for (int j = 0; j < 2; j += ii) {
+
+                }
+
+            }
+        }
+
+        TestLoadPinnedAfterCall obj = object;
+        if (obj == null) {
+        }
+        counter = 10;
+        for (;;) {
+            synchronized (staticField2) {
+            }
+            int i = 0;
+            for (; i < 2; i += ii) {
+
+            }
+
+            inlined(i, i1, i2);
+
+            if (flag) {
+                staticField3 = 0x42;
+                break;
+            }
+            try {
+                not_inlined();
+                if (flag2) {
+                    break;
+                }
+            } catch (Throwable throwable) {
+                if (a == obj.staticField1) {
+                    staticField4 = 0x42;
+                }
+                break;
+            }
+        }
+        if (a2 == obj.staticField1) {
+            staticField4 = 0x42;
+        }
+    }
+
+    private static void inlined(int i, int j, int k) {
+        if (i == 2) {
+            if (j == 2) {
+                staticField3 = 0x42;
+            }
+            if (k == 2) {
+                staticField3 = 0x42;
+            }
+        }
+    }
+
+    static int counter = 0;
+    private static void not_inlined() {
+        counter--;
+        if (counter <= 0) {
+            throw new RuntimeException();
+        }
+    }
+
+    private static class A {
+    }
+}