7153958: add constant pool reference to class containing inlined constants

Reviewed-by: jjg, mcimadamore

langtools/src/share/classes/com/sun/tools/javac/comp/Lower.java

@@ -138,6 +138,10 @@ public class Lower extends TreeTranslator {
      */
     Map<ClassSymbol, JCClassDecl> classdefs;
 
+    /** A hash table mapping local classes to a list of pruned trees.
+     */
+    public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<ClassSymbol, List<JCTree>>();
+
     /** A hash table mapping virtual accessed symbols in outer subclasses
      *  to the actually referred symbol in superclasses.
      */
@@ -1039,6 +1043,12 @@ public class Lower extends TreeTranslator {
         }
     }
 
+    private void addPrunedInfo(JCTree tree) {
+        List<JCTree> infoList = prunedTree.get(currentClass);
+        infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
+        prunedTree.put(currentClass, infoList);
+    }
+
     /** Ensure that identifier is accessible, return tree accessing the identifier.
      *  @param sym      The accessed symbol.
      *  @param tree     The tree referring to the symbol.
@@ -1111,7 +1121,10 @@ public class Lower extends TreeTranslator {
                     // Constants are replaced by their constant value.
                     if (sym.kind == VAR) {
                         Object cv = ((VarSymbol)sym).getConstValue();
-                        if (cv != null) return makeLit(sym.type, cv);
+                        if (cv != null) {
+                            addPrunedInfo(tree);
+                            return makeLit(sym.type, cv);
+                        }
                     }
 
                     // Private variables and methods are replaced by calls
@@ -2746,12 +2759,15 @@ public class Lower extends TreeTranslator {
 
     /** Visitor method for conditional expressions.
      */
+    @Override
     public void visitConditional(JCConditional tree) {
         JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
         if (cond.type.isTrue()) {
             result = convert(translate(tree.truepart, tree.type), tree.type);
+            addPrunedInfo(cond);
         } else if (cond.type.isFalse()) {
             result = convert(translate(tree.falsepart, tree.type), tree.type);
+            addPrunedInfo(cond);
         } else {
             // Condition is not a compile-time constant.
             tree.truepart = translate(tree.truepart, tree.type);
@@ -2775,12 +2791,14 @@ public class Lower extends TreeTranslator {
         JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
         if (cond.type.isTrue()) {
             result = translate(tree.thenpart);
+            addPrunedInfo(cond);
         } else if (cond.type.isFalse()) {
             if (tree.elsepart != null) {
                 result = translate(tree.elsepart);
             } else {
                 result = make.Skip();
             }
+            addPrunedInfo(cond);
         } else {
             // Condition is not a compile-time constant.
             tree.thenpart = translate(tree.thenpart);

langtools/src/share/classes/com/sun/tools/javac/jvm/Gen.java

@@ -71,6 +71,7 @@ public class Gen extends JCTree.Visitor {
     private final Map<Type,Symbol> stringBufferAppend;
     private Name accessDollar;
     private final Types types;
+    private final Lower lower;
 
     /** Switch: GJ mode?
      */
@@ -112,6 +113,7 @@ public class Gen extends JCTree.Visitor {
         stringBufferAppend = new HashMap<Type,Symbol>();
         accessDollar = names.
             fromString("access" + target.syntheticNameChar());
+        lower = Lower.instance(context);
 
         Options options = Options.instance(context);
         lineDebugInfo =
@@ -816,6 +818,62 @@ public class Gen extends JCTree.Visitor {
         }
     }
 
+    /** Visitor class for expressions which might be constant expressions.
+     *  This class is a subset of TreeScanner. Intended to visit trees pruned by
+     *  Lower as long as constant expressions looking for references to any
+     *  ClassSymbol. Any such reference will be added to the constant pool so
+     *  automated tools can detect class dependencies better.
+     */
+    class ClassReferenceVisitor extends JCTree.Visitor {
+
+        @Override
+        public void visitTree(JCTree tree) {}
+
+        @Override
+        public void visitBinary(JCBinary tree) {
+            tree.lhs.accept(this);
+            tree.rhs.accept(this);
+        }
+
+        @Override
+        public void visitSelect(JCFieldAccess tree) {
+            if (tree.selected.type.hasTag(CLASS)) {
+                makeRef(tree.selected.pos(), tree.selected.type);
+            }
+        }
+
+        @Override
+        public void visitIdent(JCIdent tree) {
+            if (tree.sym.owner instanceof ClassSymbol) {
+                pool.put(tree.sym.owner);
+            }
+        }
+
+        @Override
+        public void visitConditional(JCConditional tree) {
+            tree.cond.accept(this);
+            tree.truepart.accept(this);
+            tree.falsepart.accept(this);
+        }
+
+        @Override
+        public void visitUnary(JCUnary tree) {
+            tree.arg.accept(this);
+        }
+
+        @Override
+        public void visitParens(JCParens tree) {
+            tree.expr.accept(this);
+        }
+
+        @Override
+        public void visitTypeCast(JCTypeCast tree) {
+            tree.expr.accept(this);
+        }
+    }
+
+    private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
+
     /** Visitor method: generate code for an expression, catching and reporting
      *  any completion failures.
      *  @param tree    The expression to be visited.
@@ -826,6 +884,7 @@ public class Gen extends JCTree.Visitor {
         try {
             if (tree.type.constValue() != null) {
                 // Short circuit any expressions which are constants
+                tree.accept(classReferenceVisitor);
                 checkStringConstant(tree.pos(), tree.type.constValue());
                 result = items.makeImmediateItem(tree.type, tree.type.constValue());
             } else {
@@ -2205,6 +2264,15 @@ public class Gen extends JCTree.Visitor {
         code.endScopes(limit);
     }
 
+    private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
+        List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
+        if (prunedInfo != null) {
+            for (JCTree prunedTree: prunedInfo) {
+                prunedTree.accept(classReferenceVisitor);
+            }
+        }
+    }
+
 /* ************************************************************************
  * main method
  *************************************************************************/
@@ -2232,6 +2300,7 @@ public class Gen extends JCTree.Visitor {
             cdef.defs = normalizeDefs(cdef.defs, c);
             c.pool = pool;
             pool.reset();
+            generateReferencesToPrunedTree(c, pool);
             Env<GenContext> localEnv =
                 new Env<GenContext>(cdef, new GenContext());
             localEnv.toplevel = env.toplevel;

langtools/test/tools/javac/7153958/CPoolRefClassContainingInlinedCts.java

@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 7153958
+ * @summary add constant pool reference to class containing inlined constants
+ * @compile pkg/ClassToBeStaticallyImported.java
+ * @run main CPoolRefClassContainingInlinedCts
+ */
+
+import com.sun.tools.classfile.ClassFile;
+import com.sun.tools.classfile.ConstantPool.CONSTANT_Class_info;
+import com.sun.tools.classfile.ConstantPool.CPInfo;
+import com.sun.tools.classfile.ConstantPoolException;
+import java.io.File;
+import java.io.IOException;
+
+import static pkg.ClassToBeStaticallyImported.staticField;
+
+public class CPoolRefClassContainingInlinedCts {
+
+    public static void main(String args[]) throws Exception {
+        new CPoolRefClassContainingInlinedCts().run();
+    }
+
+    void run() throws Exception {
+        checkReferences();
+    }
+
+    int numberOfReferencedClassesToBeChecked = 0;
+
+    void checkClassName(String className) {
+        switch (className) {
+            case "SimpleAssignClass" : case "BinaryExpClass":
+            case "UnaryExpClass" : case "CastClass":
+            case "ParensClass" : case "CondClass":
+            case "IfClass" : case "pkg/ClassToBeStaticallyImported":
+                numberOfReferencedClassesToBeChecked++;
+        }
+    }
+
+    void checkReferences() throws IOException, ConstantPoolException {
+        File testClasses = new File(System.getProperty("test.classes"));
+        File file = new File(testClasses,
+                CPoolRefClassContainingInlinedCts.class.getName() + ".class");
+        ClassFile classFile = ClassFile.read(file);
+        int i = 1;
+        CPInfo cpInfo;
+        while (i < classFile.constant_pool.size()) {
+            cpInfo = classFile.constant_pool.get(i);
+            if (cpInfo instanceof CONSTANT_Class_info) {
+                checkClassName(((CONSTANT_Class_info)cpInfo).getName());
+            }
+            i += cpInfo.size();
+        }
+        if (numberOfReferencedClassesToBeChecked != 8) {
+            throw new AssertionError("Class reference missing in the constant pool");
+        }
+    }
+
+    private int assign = SimpleAssignClass.x;
+    private int binary = BinaryExpClass.x + 1;
+    private int unary = -UnaryExpClass.x;
+    private int cast = (int)CastClass.x;
+    private int parens = (ParensClass.x);
+    private int cond = (CondClass.x == 1) ? 1 : 2;
+    private static int ifConstant;
+    private static int importStatic;
+    static {
+        if (IfClass.x == 1) {
+            ifConstant = 1;
+        } else {
+            ifConstant = 2;
+        }
+    }
+    static {
+        if (staticField == 1) {
+            importStatic = 1;
+        } else {
+            importStatic = 2;
+        }
+    }
+}
+
+class SimpleAssignClass {
+    public static final int x = 1;
+}
+
+class BinaryExpClass {
+    public static final int x = 1;
+}
+
+class UnaryExpClass {
+    public static final int x = 1;
+}
+
+class CastClass {
+    public static final int x = 1;
+}
+
+class ParensClass {
+    public static final int x = 1;
+}
+
+class CondClass {
+    public static final int x = 1;
+}
+
+class IfClass {
+    public static final int x = 1;
+}

langtools/test/tools/javac/7153958/pkg/ClassToBeStaticallyImported.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package pkg;
+
+public class ClassToBeStaticallyImported {
+    public static final int staticField = 1;
+}