8058542: Devise scheme for better diagnostic creation

Add support for generating (at build-time) an enum-like class containing all javac diagnostics, which allows for safe diagnostic creation.

Reviewed-by: jlahoda, jjg, vromero, erikj, jfranck

langtools/make/tools/propertiesparser/parser/MessageInfo.java

@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ * 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 propertiesparser.parser;
+
+import propertiesparser.parser.MessageType.CompoundType;
+import propertiesparser.parser.MessageType.OrType;
+import propertiesparser.parser.MessageType.SimpleType;
+import propertiesparser.parser.MessageType.UnionType;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * An object to represent the comment that may precede the property
+ * specification in a Message.
+ * The comment is modelled as a list of fields, where the fields correspond
+ * to the placeholder values (e.g. {0}, {1}, etc) within the message value.
+ */
+public final class MessageInfo {
+
+    /** The fields of the Info object. */
+    List<MessageType> types = new ArrayList<>();
+
+    MessageInfo(String text) throws IllegalArgumentException {
+        if (text != null) {
+            if (!text.startsWith("# "))
+                throw new IllegalArgumentException();
+            String[] segs = text.substring(2).split(", ");
+            types = new ArrayList<>();
+            for (String seg : segs) {
+                types.add(parseType(seg));
+            }
+        }
+    }
+
+    public List<MessageType> getTypes() {
+        return types;
+    }
+
+    boolean isEmpty() {
+        return types.isEmpty();
+    }
+
+    @Override
+    public String toString() {
+        return types.toString();
+    }
+
+    /**
+     * Split the type comment into multiple alternatives (separated by 'or') - then parse each of them
+     * individually and form an 'or' type.
+     */
+    MessageType parseType(String text) {
+        int commentStart = text.indexOf("(");
+        if (commentStart != -1) {
+            //remove optional comment
+            text = text.substring(0, commentStart);
+        }
+        text = text.substring(text.indexOf(": ") + 2);
+        String[] alternatives = text.split(" " + OrType.OR_NAME + " ");
+        MessageType[] types = new MessageType[alternatives.length];
+        for (int i = 0 ; i < alternatives.length ; i++) {
+            types[i] = parseAlternative(alternatives[i].trim());
+        }
+        return types.length > 1 ?
+                new OrType(types) : types[0];
+    }
+
+    /**
+     * Parse a subset of the type comment; valid matches are simple types, compound types,
+     * union types and custom types.
+     */
+    MessageType parseAlternative(String text) {
+        //try with custom types
+        if (text.charAt(0) == '\'') {
+            int end = text.indexOf('\'', 1);
+            return new MessageType.CustomType(text.substring(1, end));
+        }
+        //try with simple types
+        for (SimpleType st : SimpleType.values()) {
+            if (text.equals(st.kindName())) {
+                return st;
+            }
+        }
+        //try with compound types
+        for (CompoundType.Kind ck : CompoundType.Kind.values()) {
+            if (text.startsWith(ck.kindName)) {
+                MessageType elemtype = parseAlternative(text.substring(ck.kindName.length() + 1).trim());
+                return new CompoundType(ck, elemtype);
+            }
+        }
+        //try with union types
+        for (UnionType.Kind uk : UnionType.Kind.values()) {
+            if (text.startsWith(uk.kindName)) {
+                return new UnionType(uk);
+            }
+        }
+        //no match - report a warning
+        System.err.println("WARNING - unrecognized type: " + text);
+        return SimpleType.UNKNOWN;
+    }
+
+    /** Dummy message info to be used when no resource key comment is available. */
+    static final MessageInfo dummyInfo = new MessageInfo(null);
+}