001: /*
002: * Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved.
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004: *
005: * This code is free software; you can redistribute it and/or modify it
006: * under the terms of the GNU General Public License version 2 only, as
007: * published by the Free Software Foundation. Sun designates this
008: * particular file as subject to the "Classpath" exception as provided
009: * by Sun in the LICENSE file that accompanied this code.
010: *
011: * This code is distributed in the hope that it will be useful, but WITHOUT
012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014: * version 2 for more details (a copy is included in the LICENSE file that
015: * accompanied this code).
016: *
017: * You should have received a copy of the GNU General Public License version
018: * 2 along with this work; if not, write to the Free Software Foundation,
019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022: * CA 95054 USA or visit www.sun.com if you need additional information or
023: * have any questions.
024: */
025:
026: package java.lang;
027:
028: /**
029: * The {@code Compiler} class is provided to support Java-to-native-code
030: * compilers and related services. By design, the {@code Compiler} class does
031: * nothing; it serves as a placeholder for a JIT compiler implementation.
032: *
033: * <p> When the Java Virtual Machine first starts, it determines if the system
034: * property {@code java.compiler} exists. (System properties are accessible
035: * through {@link System#getProperty(String)} and {@link
036: * System#getProperty(String, String)}. If so, it is assumed to be the name of
037: * a library (with a platform-dependent exact location and type); {@link
038: * System#loadLibrary} is called to load that library. If this loading
039: * succeeds, the function named {@code java_lang_Compiler_start()} in that
040: * library is called.
041: *
042: * <p> If no compiler is available, these methods do nothing.
043: *
044: * @author Frank Yellin
045: * @version 1.29, 05/05/07
046: * @since JDK1.0
047: */
048: public final class Compiler {
049: private Compiler() {
050: } // don't make instances
051:
052: private static native void initialize();
053:
054: private static native void registerNatives();
055:
056: static {
057: registerNatives();
058: java.security.AccessController
059: .doPrivileged(new java.security.PrivilegedAction() {
060: public Object run() {
061: boolean loaded = false;
062: String jit = System
063: .getProperty("java.compiler");
064: if ((jit != null) && (!jit.equals("NONE"))
065: && (!jit.equals(""))) {
066: try {
067: System.loadLibrary(jit);
068: initialize();
069: loaded = true;
070: } catch (UnsatisfiedLinkError e) {
071: System.err
072: .println("Warning: JIT compiler \""
073: + jit
074: + "\" not found. Will use interpreter.");
075: }
076: }
077: String info = System
078: .getProperty("java.vm.info");
079: if (loaded) {
080: System.setProperty("java.vm.info", info
081: + ", " + jit);
082: } else {
083: System.setProperty("java.vm.info", info
084: + ", nojit");
085: }
086: return null;
087: }
088: });
089: }
090:
091: /**
092: * Compiles the specified class.
093: *
094: * @param clazz
095: * A class
096: *
097: * @return {@code true} if the compilation succeeded; {@code false} if the
098: * compilation failed or no compiler is available
099: *
100: * @throws NullPointerException
101: * If {@code clazz} is {@code null}
102: */
103: public static native boolean compileClass(Class<?> clazz);
104:
105: /**
106: * Compiles all classes whose name matches the specified string.
107: *
108: * @param string
109: * The name of the classes to compile
110: *
111: * @return {@code true} if the compilation succeeded; {@code false} if the
112: * compilation failed or no compiler is available
113: *
114: * @throws NullPointerException
115: * If {@code string} is {@code null}
116: */
117: public static native boolean compileClasses(String string);
118:
119: /**
120: * Examines the argument type and its fields and perform some documented
121: * operation. No specific operations are required.
122: *
123: * @param any
124: * An argument
125: *
126: * @return A compiler-specific value, or {@code null} if no compiler is
127: * available
128: *
129: * @throws NullPointerException
130: * If {@code any} is {@code null}
131: */
132: public static native Object command(Object any);
133:
134: /**
135: * Cause the Compiler to resume operation.
136: */
137: public static native void enable();
138:
139: /**
140: * Cause the Compiler to cease operation.
141: */
142: public static native void disable();
143: }
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