/*
* @(#)Lint.java 1.11 07/03/21
*
* Copyright (c) 2007 Sun Microsystems, 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package com.sun.tools.javac.code;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.util.Options;
import com.sun.tools.javac.util.Pair;
import com.sun.tools.javac.util.Version;
import static com.sun.tools.javac.code.Flags.*;
/**
* A class for handling -Xlint suboptions and @SuppresssWarnings.
*
* <p><b>This is NOT part of any API supported by Sun Microsystems. If
* you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
@Version("@(#)Lint.java 1.11 07/03/21")
public class Lint
{
private static my.Debug DEBUG=new my.Debug(my.Debug.Lint);//我加上的
/** The context key for the root Lint object. */
protected static final Context.Key<Lint> lintKey = new Context.Key<Lint>();
/** Get the root Lint instance. */
public static Lint instance(Context context) {
Lint instance = context.get(lintKey);
if (instance == null)
instance = new Lint(context);
return instance;
}
/**
* Returns the result of combining the values in this object with
* the given annotation.
*/
public Lint augment(Attribute.Compound attr) {
return augmentor.augment(this, attr);
}
/**
* Returns the result of combining the values in this object with
* the given annotations.
*/
public Lint augment(List<Attribute.Compound> attrs) {
return augmentor.augment(this, attrs);
}
/**
* Returns the result of combining the values in this object with
* the given annotations and flags.
*/
public Lint augment(List<Attribute.Compound> attrs, long flags) {
DEBUG.P(this,"augment(2)");
DEBUG.P("attrs="+attrs);
DEBUG.P("flags="+Flags.toString(flags));
Lint l = augmentor.augment(this, attrs);
//如果当前对象(如方法或类等)已加了“@Deprecated”这个注释标记，
//那么在往下的程序中如果使用到了其他加了“@Deprecated”的对象，
//这时不再警告，因为当前对象本身已不赞成使用。
if ((flags & DEPRECATED) != 0) {//flags是DEPRECATED的情况
if (l == this)
l = new Lint(this);
l.values.remove(LintCategory.DEPRECATION);
l.suppressedValues.add(LintCategory.DEPRECATION);
}
DEBUG.P("return lint="+l);
DEBUG.P(0,this,"augment(2)");
return l;
}
private final AugmentVisitor augmentor;
private final EnumSet<LintCategory> values;
private final EnumSet<LintCategory> suppressedValues;
private static Map<String, LintCategory> map = new HashMap<String,LintCategory>();
protected Lint(Context context) {
DEBUG.P(this,"Lint(1)");
// initialize values according to the lint options
Options options = Options.instance(context);
DEBUG.P("options.keySet()="+options.keySet());
//建立一个空的(没有元素的)枚举类型的集合，
//集合元素的类型为“LintCategory"(LintCategory是一个枚举类，看下面)
values = EnumSet.noneOf(LintCategory.class);
//注:map是static的，它的值已在构造枚举类LintCategory时加入
DEBUG.P("map.size()="+map.size());
DEBUG.P("map="+map);
for (Map.Entry<String, LintCategory> e: map.entrySet()) {
if (options.lint(e.getKey()))
values.add(e.getValue());
}
DEBUG.P("values="+values);
/*如在javac命令行中加入“-Xlint”选项时，表示启用所有的警告(11项)
map.size()=11
map={divzero=DIVZERO, unchecked=UNCHECKED, overrides=OVERRIDES, cast=CAST, path=PATH, empty=EMPTY, deprecation=DEPRECATION, finally=FINALLY, dep-ann=DEP_ANN, serial=SERIAL, fallthrough=FALLTHROUGH}
values=[CAST, DEPRECATION, DEP_ANN, DIVZERO, EMPTY, FALLTHROUGH, FINALLY, OVERRIDES, PATH, SERIAL, UNCHECKED]
*/
/*
源代码中可以通过java.lang.SuppressWarnings类来使用警告选项
如在com.sun.tools.javac.parser.Scanner类中有如下代码:
@SuppressWarnings("fallthrough")
private void scanDocComment() {......}
*/
suppressedValues = EnumSet.noneOf(LintCategory.class);
context.put(lintKey, this);
augmentor = new AugmentVisitor(context);
DEBUG.P(0,this,"Lint(1)");
}
protected Lint(Lint other) {
this.augmentor = other.augmentor;
this.values = other.values.clone();
this.suppressedValues = other.suppressedValues.clone();
}
public String toString() {
//return "Lint:[values" + values + " suppressedValues" + suppressedValues + "]";
//我改了一下，输出有size
return "Lint:[values("+values.size()+")" + values + " suppressedValues("+suppressedValues.size()+")" + suppressedValues + "]";
}
/**
* Categories of warnings that can be generated by the compiler.
*/
public enum LintCategory { //一共11项
/**
* Warn about use of unnecessary casts.
*/
CAST("cast"),
/**
* Warn about use of deprecated items.
*/
DEPRECATION("deprecation"),
/**
* Warn about items which are documented with an {@code @deprecated} JavaDoc
* comment, but which do not have {@code @Deprecated} annotation.
*/
DEP_ANN("dep-ann"),//这一选项在jdk1.6中没找到,com.sun.tools.javac.main.OptionName中也没有
/**
* Warn about division by constant integer 0.
*/
DIVZERO("divzero"),
/**
* Warn about empty statement after if.
*/
EMPTY("empty"),//如:if(true);
/**
* Warn about falling through from one case of a switch statement to the next.
*/
FALLTHROUGH("fallthrough"),
/**
* Warn about finally clauses that do not terminate normally.
*/
FINALLY("finally"),
/**
* Warn about issues regarding method overrides.
*/
OVERRIDES("overrides"),
/**
* Warn about invalid path elements on the command line.
* Such warnings cannot be suppressed with the SuppressWarnings
* annotation.
*/
PATH("path"),
/**
* Warn about Serializable classes that do not provide a serial version ID.
*/
SERIAL("serial"),
/**
* Warn about unchecked operations on raw types.
*/
UNCHECKED("unchecked");
LintCategory(String option) {
this.option = option;
map.put(option, this);
}
static LintCategory get(String option) {
return map.get(option);
}
private final String option;
};
/**
* Checks if a warning category is enabled. A warning category may be enabled
* on the command line, or by default, and can be temporarily disabled with
* the SuppressWarnings annotation.
*/
public boolean isEnabled(LintCategory lc) {
return values.contains(lc);
}
/**
* Checks is a warning category has been specifically suppressed, by means
* of the SuppressWarnings annotation, or, in the case of the deprecated
* category, whether it has been implicitly suppressed by virtue of the
* current entity being itself deprecated.
*/
public boolean isSuppressed(LintCategory lc) {
return suppressedValues.contains(lc);
}
protected static class AugmentVisitor implements Attribute.Visitor {
private final Context context;
private Symtab syms;
private Lint parent;
private Lint lint;
AugmentVisitor(Context context) {
// to break an ugly sequence of initialization dependencies,
// we defer the initialization of syms until it is needed
this.context = context;
}
Lint augment(Lint parent, Attribute.Compound attr) {
initSyms();
this.parent = parent;
lint = null;
attr.accept(this);
return (lint == null ? parent : lint);
}
Lint augment(Lint parent, List<Attribute.Compound> attrs) {
try {//我加上的
DEBUG.P(this,"augment(2)");
DEBUG.P("attrs="+attrs);
DEBUG.P("lint ="+lint);
DEBUG.P("parent="+parent);
initSyms();
this.parent = parent;
lint = null;
for (Attribute.Compound a: attrs) {
a.accept(this);
}
return (lint == null ? parent : lint);
}finally{//我加上的
DEBUG.P("");
DEBUG.P("lint ="+lint);
DEBUG.P("parent="+parent);
DEBUG.P(0,this,"augment(2)");
}
}
private void initSyms() {
if (syms == null)
syms = Symtab.instance(context);
}
private void suppress(LintCategory lc) {
DEBUG.P(this,"suppress(1)");
DEBUG.P("lc="+lc);
DEBUG.P("lint="+lint);
if (lint == null)
lint = new Lint(parent);
lint.suppressedValues.add(lc);
lint.values.remove(lc);
DEBUG.P("");
DEBUG.P("lint="+lint);
DEBUG.P(0,this,"suppress(1)");
}
public void visitConstant(Attribute.Constant value) {
DEBUG.P(this,"visitConstant(1)");
DEBUG.P("value="+value);
if (value.type.tsym == syms.stringType.tsym) {
LintCategory lc = LintCategory.get((String) (value.value));
if (lc != null)
suppress(lc);
}
DEBUG.P(0,this,"visitConstant(1)");
}
public void visitClass(Attribute.Class clazz) {
}
// If we find a @SuppressWarnings annotation, then we continue
// walking the tree, in order to suppress the individual warnings
// specified in the @SuppressWarnings annotation.
public void visitCompound(Attribute.Compound compound) {
DEBUG.P(this,"visitCompound(1)");
DEBUG.P("compound="+compound);
DEBUG.P("compound.type.tsym="+compound.type.tsym);
DEBUG.P("syms.suppressWarningsType.tsym="+syms.suppressWarningsType.tsym);
if (compound.type.tsym == syms.suppressWarningsType.tsym) {
for (List<Pair<MethodSymbol,Attribute>> v = compound.values;
v.nonEmpty(); v = v.tail) {
Pair<MethodSymbol,Attribute> value = v.head;
DEBUG.P("value="+value);
if (value.fst.name.toString().equals("value"))
value.snd.accept(this);
}
}
DEBUG.P(0,this,"visitCompound(1)");
}
public void visitArray(Attribute.Array array) {
DEBUG.P(this,"visitArray(1)");
for (Attribute value : array.values)
value.accept(this);
DEBUG.P(0,this,"visitArray(1)");
}
public void visitEnum(Attribute.Enum e) {
}
public void visitError(Attribute.Error e) {
}
};
}