8192885: Compiler in JDK 10-ea+33 misses to include entry in LineNumberTable for goto instruction of foreach loop
Reviewed-by: mcimadamore
/*
* Copyright (c) 1999, 2017, 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 com.sun.tools.javac.comp;
import java.util.*;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Kinds.KindSelector;
import com.sun.tools.javac.code.Scope.WriteableScope;
import com.sun.tools.javac.jvm.*;
import com.sun.tools.javac.main.Option.PkgInfo;
import com.sun.tools.javac.tree.*;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode;
import com.sun.tools.javac.resources.CompilerProperties.Errors;
import com.sun.tools.javac.tree.JCTree.*;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.jvm.Target;
import com.sun.tools.javac.tree.EndPosTable;
import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Flags.BLOCK;
import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
import static com.sun.tools.javac.code.TypeTag.*;
import static com.sun.tools.javac.code.Kinds.Kind.*;
import static com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode.DEREF;
import static com.sun.tools.javac.jvm.ByteCodes.*;
import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT;
import static com.sun.tools.javac.tree.JCTree.Tag.*;
/** This pass translates away some syntactic sugar: inner classes,
* class literals, assertions, foreach loops, etc.
*
* <p><b>This is NOT part of any supported API.
* 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>
*/
public class Lower extends TreeTranslator {
protected static final Context.Key<Lower> lowerKey = new Context.Key<>();
public static Lower instance(Context context) {
Lower instance = context.get(lowerKey);
if (instance == null)
instance = new Lower(context);
return instance;
}
private final Names names;
private final Log log;
private final Symtab syms;
private final Resolve rs;
private final Operators operators;
private final Check chk;
private final Attr attr;
private TreeMaker make;
private DiagnosticPosition make_pos;
private final ClassWriter writer;
private final ConstFold cfolder;
private final Target target;
private final Source source;
private final TypeEnvs typeEnvs;
private final Name dollarAssertionsDisabled;
private final Name classDollar;
private final Name dollarCloseResource;
private final Types types;
private final boolean debugLower;
private final PkgInfo pkginfoOpt;
protected Lower(Context context) {
context.put(lowerKey, this);
names = Names.instance(context);
log = Log.instance(context);
syms = Symtab.instance(context);
rs = Resolve.instance(context);
operators = Operators.instance(context);
chk = Check.instance(context);
attr = Attr.instance(context);
make = TreeMaker.instance(context);
writer = ClassWriter.instance(context);
cfolder = ConstFold.instance(context);
target = Target.instance(context);
source = Source.instance(context);
typeEnvs = TypeEnvs.instance(context);
dollarAssertionsDisabled = names.
fromString(target.syntheticNameChar() + "assertionsDisabled");
classDollar = names.
fromString("class" + target.syntheticNameChar());
dollarCloseResource = names.
fromString(target.syntheticNameChar() + "closeResource");
types = Types.instance(context);
Options options = Options.instance(context);
debugLower = options.isSet("debuglower");
pkginfoOpt = PkgInfo.get(options);
}
/** The currently enclosing class.
*/
ClassSymbol currentClass;
/** A queue of all translated classes.
*/
ListBuffer<JCTree> translated;
/** Environment for symbol lookup, set by translateTopLevelClass.
*/
Env<AttrContext> attrEnv;
/** A hash table mapping syntax trees to their ending source positions.
*/
EndPosTable endPosTable;
/**************************************************************************
* Global mappings
*************************************************************************/
/** A hash table mapping local classes to their definitions.
*/
Map<ClassSymbol, JCClassDecl> classdefs;
/** A hash table mapping local classes to a list of pruned trees.
*/
public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>();
/** A hash table mapping virtual accessed symbols in outer subclasses
* to the actually referred symbol in superclasses.
*/
Map<Symbol,Symbol> actualSymbols;
/** The current method definition.
*/
JCMethodDecl currentMethodDef;
/** The current method symbol.
*/
MethodSymbol currentMethodSym;
/** The currently enclosing outermost class definition.
*/
JCClassDecl outermostClassDef;
/** The currently enclosing outermost member definition.
*/
JCTree outermostMemberDef;
/** A map from local variable symbols to their translation (as per LambdaToMethod).
* This is required when a capturing local class is created from a lambda (in which
* case the captured symbols should be replaced with the translated lambda symbols).
*/
Map<Symbol, Symbol> lambdaTranslationMap = null;
/** A navigator class for assembling a mapping from local class symbols
* to class definition trees.
* There is only one case; all other cases simply traverse down the tree.
*/
class ClassMap extends TreeScanner {
/** All encountered class defs are entered into classdefs table.
*/
public void visitClassDef(JCClassDecl tree) {
classdefs.put(tree.sym, tree);
super.visitClassDef(tree);
}
}
ClassMap classMap = new ClassMap();
/** Map a class symbol to its definition.
* @param c The class symbol of which we want to determine the definition.
*/
JCClassDecl classDef(ClassSymbol c) {
// First lookup the class in the classdefs table.
JCClassDecl def = classdefs.get(c);
if (def == null && outermostMemberDef != null) {
// If this fails, traverse outermost member definition, entering all
// local classes into classdefs, and try again.
classMap.scan(outermostMemberDef);
def = classdefs.get(c);
}
if (def == null) {
// If this fails, traverse outermost class definition, entering all
// local classes into classdefs, and try again.
classMap.scan(outermostClassDef);
def = classdefs.get(c);
}
return def;
}
/** A hash table mapping class symbols to lists of free variables.
* accessed by them. Only free variables of the method immediately containing
* a class are associated with that class.
*/
Map<ClassSymbol,List<VarSymbol>> freevarCache;
/** A navigator class for collecting the free variables accessed
* from a local class. There is only one case; all other cases simply
* traverse down the tree. This class doesn't deal with the specific
* of Lower - it's an abstract visitor that is meant to be reused in
* order to share the local variable capture logic.
*/
abstract class BasicFreeVarCollector extends TreeScanner {
/** Add all free variables of class c to fvs list
* unless they are already there.
*/
abstract void addFreeVars(ClassSymbol c);
/** If tree refers to a variable in owner of local class, add it to
* free variables list.
*/
public void visitIdent(JCIdent tree) {
visitSymbol(tree.sym);
}
// where
abstract void visitSymbol(Symbol _sym);
/** If tree refers to a class instance creation expression
* add all free variables of the freshly created class.
*/
public void visitNewClass(JCNewClass tree) {
ClassSymbol c = (ClassSymbol)tree.constructor.owner;
addFreeVars(c);
super.visitNewClass(tree);
}
/** If tree refers to a superclass constructor call,
* add all free variables of the superclass.
*/
public void visitApply(JCMethodInvocation tree) {
if (TreeInfo.name(tree.meth) == names._super) {
addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
}
super.visitApply(tree);
}
}
/**
* Lower-specific subclass of {@code BasicFreeVarCollector}.
*/
class FreeVarCollector extends BasicFreeVarCollector {
/** The owner of the local class.
*/
Symbol owner;
/** The local class.
*/
ClassSymbol clazz;
/** The list of owner's variables accessed from within the local class,
* without any duplicates.
*/
List<VarSymbol> fvs;
FreeVarCollector(ClassSymbol clazz) {
this.clazz = clazz;
this.owner = clazz.owner;
this.fvs = List.nil();
}
/** Add free variable to fvs list unless it is already there.
*/
private void addFreeVar(VarSymbol v) {
for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail)
if (l.head == v) return;
fvs = fvs.prepend(v);
}
@Override
void addFreeVars(ClassSymbol c) {
List<VarSymbol> fvs = freevarCache.get(c);
if (fvs != null) {
for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
addFreeVar(l.head);
}
}
}
@Override
void visitSymbol(Symbol _sym) {
Symbol sym = _sym;
if (sym.kind == VAR || sym.kind == MTH) {
if (sym != null && sym.owner != owner)
sym = proxies.get(sym);
if (sym != null && sym.owner == owner) {
VarSymbol v = (VarSymbol)sym;
if (v.getConstValue() == null) {
addFreeVar(v);
}
} else {
if (outerThisStack.head != null &&
outerThisStack.head != _sym)
visitSymbol(outerThisStack.head);
}
}
}
/** If tree refers to a class instance creation expression
* add all free variables of the freshly created class.
*/
public void visitNewClass(JCNewClass tree) {
ClassSymbol c = (ClassSymbol)tree.constructor.owner;
if (tree.encl == null &&
c.hasOuterInstance() &&
outerThisStack.head != null)
visitSymbol(outerThisStack.head);
super.visitNewClass(tree);
}
/** If tree refers to a qualified this or super expression
* for anything but the current class, add the outer this
* stack as a free variable.
*/
public void visitSelect(JCFieldAccess tree) {
if ((tree.name == names._this || tree.name == names._super) &&
tree.selected.type.tsym != clazz &&
outerThisStack.head != null)
visitSymbol(outerThisStack.head);
super.visitSelect(tree);
}
/** If tree refers to a superclass constructor call,
* add all free variables of the superclass.
*/
public void visitApply(JCMethodInvocation tree) {
if (TreeInfo.name(tree.meth) == names._super) {
Symbol constructor = TreeInfo.symbol(tree.meth);
ClassSymbol c = (ClassSymbol)constructor.owner;
if (c.hasOuterInstance() &&
!tree.meth.hasTag(SELECT) &&
outerThisStack.head != null)
visitSymbol(outerThisStack.head);
}
super.visitApply(tree);
}
}
ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) {
if (!c.isLocal()) {
return null;
}
Symbol currentOwner = c.owner;
while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isLocal()) {
currentOwner = currentOwner.owner;
}
if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) {
return (ClassSymbol)currentOwner;
}
return null;
}
/** Return the variables accessed from within a local class, which
* are declared in the local class' owner.
* (in reverse order of first access).
*/
List<VarSymbol> freevars(ClassSymbol c) {
List<VarSymbol> fvs = freevarCache.get(c);
if (fvs != null) {
return fvs;
}
if (c.owner.kind.matches(KindSelector.VAL_MTH)) {
FreeVarCollector collector = new FreeVarCollector(c);
collector.scan(classDef(c));
fvs = collector.fvs;
freevarCache.put(c, fvs);
return fvs;
} else {
ClassSymbol owner = ownerToCopyFreeVarsFrom(c);
if (owner != null) {
fvs = freevarCache.get(owner);
freevarCache.put(c, fvs);
return fvs;
} else {
return List.nil();
}
}
}
Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>();
EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
EnumMapping map = enumSwitchMap.get(enumClass);
if (map == null)
enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass));
return map;
}
/** This map gives a translation table to be used for enum
* switches.
*
* <p>For each enum that appears as the type of a switch
* expression, we maintain an EnumMapping to assist in the
* translation, as exemplified by the following example:
*
* <p>we translate
* <pre>
* switch(colorExpression) {
* case red: stmt1;
* case green: stmt2;
* }
* </pre>
* into
* <pre>
* switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
* case 1: stmt1;
* case 2: stmt2
* }
* </pre>
* with the auxiliary table initialized as follows:
* <pre>
* class Outer$0 {
* synthetic final int[] $EnumMap$Color = new int[Color.values().length];
* static {
* try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
* try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
* }
* }
* </pre>
* class EnumMapping provides mapping data and support methods for this translation.
*/
class EnumMapping {
EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
this.forEnum = forEnum;
this.values = new LinkedHashMap<>();
this.pos = pos;
Name varName = names
.fromString(target.syntheticNameChar() +
"SwitchMap" +
target.syntheticNameChar() +
writer.xClassName(forEnum.type).toString()
.replace('/', '.')
.replace('.', target.syntheticNameChar()));
ClassSymbol outerCacheClass = outerCacheClass();
this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
varName,
new ArrayType(syms.intType, syms.arrayClass),
outerCacheClass);
enterSynthetic(pos, mapVar, outerCacheClass.members());
}
DiagnosticPosition pos = null;
// the next value to use
int next = 1; // 0 (unused map elements) go to the default label
// the enum for which this is a map
final TypeSymbol forEnum;
// the field containing the map
final VarSymbol mapVar;
// the mapped values
final Map<VarSymbol,Integer> values;
JCLiteral forConstant(VarSymbol v) {
Integer result = values.get(v);
if (result == null)
values.put(v, result = next++);
return make.Literal(result);
}
// generate the field initializer for the map
void translate() {
make.at(pos.getStartPosition());
JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
// synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
MethodSymbol valuesMethod = lookupMethod(pos,
names.values,
forEnum.type,
List.nil());
JCExpression size = make // Color.values().length
.Select(make.App(make.QualIdent(valuesMethod)),
syms.lengthVar);
JCExpression mapVarInit = make
.NewArray(make.Type(syms.intType), List.of(size), null)
.setType(new ArrayType(syms.intType, syms.arrayClass));
// try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
ListBuffer<JCStatement> stmts = new ListBuffer<>();
Symbol ordinalMethod = lookupMethod(pos,
names.ordinal,
forEnum.type,
List.nil());
List<JCCatch> catcher = List.<JCCatch>nil()
.prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
syms.noSuchFieldErrorType,
syms.noSymbol),
null),
make.Block(0, List.nil())));
for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
VarSymbol enumerator = e.getKey();
Integer mappedValue = e.getValue();
JCExpression assign = make
.Assign(make.Indexed(mapVar,
make.App(make.Select(make.QualIdent(enumerator),
ordinalMethod))),
make.Literal(mappedValue))
.setType(syms.intType);
JCStatement exec = make.Exec(assign);
JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
stmts.append(_try);
}
owner.defs = owner.defs
.prepend(make.Block(STATIC, stmts.toList()))
.prepend(make.VarDef(mapVar, mapVarInit));
}
}
/**************************************************************************
* Tree building blocks
*************************************************************************/
/** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
* pos as make_pos, for use in diagnostics.
**/
TreeMaker make_at(DiagnosticPosition pos) {
make_pos = pos;
return make.at(pos);
}
/** Make an attributed tree representing a literal. This will be an
* Ident node in the case of boolean literals, a Literal node in all
* other cases.
* @param type The literal's type.
* @param value The literal's value.
*/
JCExpression makeLit(Type type, Object value) {
return make.Literal(type.getTag(), value).setType(type.constType(value));
}
/** Make an attributed tree representing null.
*/
JCExpression makeNull() {
return makeLit(syms.botType, null);
}
/** Make an attributed class instance creation expression.
* @param ctype The class type.
* @param args The constructor arguments.
*/
JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
JCNewClass tree = make.NewClass(null,
null, make.QualIdent(ctype.tsym), args, null);
tree.constructor = rs.resolveConstructor(
make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil());
tree.type = ctype;
return tree;
}
/** Make an attributed unary expression.
* @param optag The operators tree tag.
* @param arg The operator's argument.
*/
JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
JCUnary tree = make.Unary(optag, arg);
tree.operator = operators.resolveUnary(tree, optag, arg.type);
tree.type = tree.operator.type.getReturnType();
return tree;
}
/** Make an attributed binary expression.
* @param optag The operators tree tag.
* @param lhs The operator's left argument.
* @param rhs The operator's right argument.
*/
JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
JCBinary tree = make.Binary(optag, lhs, rhs);
tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type);
tree.type = tree.operator.type.getReturnType();
return tree;
}
/** Make an attributed assignop expression.
* @param optag The operators tree tag.
* @param lhs The operator's left argument.
* @param rhs The operator's right argument.
*/
JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
JCAssignOp tree = make.Assignop(optag, lhs, rhs);
tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type);
tree.type = lhs.type;
return tree;
}
/** Convert tree into string object, unless it has already a
* reference type..
*/
JCExpression makeString(JCExpression tree) {
if (!tree.type.isPrimitiveOrVoid()) {
return tree;
} else {
Symbol valueOfSym = lookupMethod(tree.pos(),
names.valueOf,
syms.stringType,
List.of(tree.type));
return make.App(make.QualIdent(valueOfSym), List.of(tree));
}
}
/** Create an empty anonymous class definition and enter and complete
* its symbol. Return the class definition's symbol.
* and create
* @param flags The class symbol's flags
* @param owner The class symbol's owner
*/
JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
return makeEmptyClass(flags, owner, null, true);
}
JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
boolean addToDefs) {
// Create class symbol.
ClassSymbol c = syms.defineClass(names.empty, owner);
if (flatname != null) {
c.flatname = flatname;
} else {
c.flatname = chk.localClassName(c);
}
c.sourcefile = owner.sourcefile;
c.completer = Completer.NULL_COMPLETER;
c.members_field = WriteableScope.create(c);
c.flags_field = flags;
ClassType ctype = (ClassType) c.type;
ctype.supertype_field = syms.objectType;
ctype.interfaces_field = List.nil();
JCClassDecl odef = classDef(owner);
// Enter class symbol in owner scope and compiled table.
enterSynthetic(odef.pos(), c, owner.members());
chk.putCompiled(c);
// Create class definition tree.
JCClassDecl cdef = make.ClassDef(
make.Modifiers(flags), names.empty,
List.nil(),
null, List.nil(), List.nil());
cdef.sym = c;
cdef.type = c.type;
// Append class definition tree to owner's definitions.
if (addToDefs) odef.defs = odef.defs.prepend(cdef);
return cdef;
}
/**************************************************************************
* Symbol manipulation utilities
*************************************************************************/
/** Enter a synthetic symbol in a given scope, but complain if there was already one there.
* @param pos Position for error reporting.
* @param sym The symbol.
* @param s The scope.
*/
private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) {
s.enter(sym);
}
/** Create a fresh synthetic name within a given scope - the unique name is
* obtained by appending '$' chars at the end of the name until no match
* is found.
*
* @param name base name
* @param s scope in which the name has to be unique
* @return fresh synthetic name
*/
private Name makeSyntheticName(Name name, Scope s) {
do {
name = name.append(
target.syntheticNameChar(),
names.empty);
} while (lookupSynthetic(name, s) != null);
return name;
}
/** Check whether synthetic symbols generated during lowering conflict
* with user-defined symbols.
*
* @param translatedTrees lowered class trees
*/
void checkConflicts(List<JCTree> translatedTrees) {
for (JCTree t : translatedTrees) {
t.accept(conflictsChecker);
}
}
JCTree.Visitor conflictsChecker = new TreeScanner() {
TypeSymbol currentClass;
@Override
public void visitMethodDef(JCMethodDecl that) {
chk.checkConflicts(that.pos(), that.sym, currentClass);
super.visitMethodDef(that);
}
@Override
public void visitVarDef(JCVariableDecl that) {
if (that.sym.owner.kind == TYP) {
chk.checkConflicts(that.pos(), that.sym, currentClass);
}
super.visitVarDef(that);
}
@Override
public void visitClassDef(JCClassDecl that) {
TypeSymbol prevCurrentClass = currentClass;
currentClass = that.sym;
try {
super.visitClassDef(that);
}
finally {
currentClass = prevCurrentClass;
}
}
};
/** Look up a synthetic name in a given scope.
* @param s The scope.
* @param name The name.
*/
private Symbol lookupSynthetic(Name name, Scope s) {
Symbol sym = s.findFirst(name);
return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
}
/** Look up a method in a given scope.
*/
private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil());
}
/** Anon inner classes are used as access constructor tags.
* accessConstructorTag will use an existing anon class if one is available,
* and synthethise a class (with makeEmptyClass) if one is not available.
* However, there is a small possibility that an existing class will not
* be generated as expected if it is inside a conditional with a constant
* expression. If that is found to be the case, create an empty class tree here.
*/
private void checkAccessConstructorTags() {
for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
ClassSymbol c = l.head;
if (isTranslatedClassAvailable(c))
continue;
// Create class definition tree.
JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC,
c.outermostClass(), c.flatname, false);
swapAccessConstructorTag(c, cdec.sym);
translated.append(cdec);
}
}
// where
private boolean isTranslatedClassAvailable(ClassSymbol c) {
for (JCTree tree: translated) {
if (tree.hasTag(CLASSDEF)
&& ((JCClassDecl) tree).sym == c) {
return true;
}
}
return false;
}
void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
for (MethodSymbol methodSymbol : accessConstrs.values()) {
Assert.check(methodSymbol.type.hasTag(METHOD));
MethodType oldMethodType =
(MethodType)methodSymbol.type;
if (oldMethodType.argtypes.head.tsym == oldCTag)
methodSymbol.type =
types.createMethodTypeWithParameters(oldMethodType,
oldMethodType.getParameterTypes().tail
.prepend(newCTag.erasure(types)));
}
}
/**************************************************************************
* Access methods
*************************************************************************/
/** A mapping from symbols to their access numbers.
*/
private Map<Symbol,Integer> accessNums;
/** A mapping from symbols to an array of access symbols, indexed by
* access code.
*/
private Map<Symbol,MethodSymbol[]> accessSyms;
/** A mapping from (constructor) symbols to access constructor symbols.
*/
private Map<Symbol,MethodSymbol> accessConstrs;
/** A list of all class symbols used for access constructor tags.
*/
private List<ClassSymbol> accessConstrTags;
/** A queue for all accessed symbols.
*/
private ListBuffer<Symbol> accessed;
/** return access code for identifier,
* @param tree The tree representing the identifier use.
* @param enclOp The closest enclosing operation node of tree,
* null if tree is not a subtree of an operation.
*/
private static int accessCode(JCTree tree, JCTree enclOp) {
if (enclOp == null)
return AccessCode.DEREF.code;
else if (enclOp.hasTag(ASSIGN) &&
tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
return AccessCode.ASSIGN.code;
else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) &&
tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT)))
return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag());
else
return AccessCode.DEREF.code;
}
/** Return binary operator that corresponds to given access code.
*/
private OperatorSymbol binaryAccessOperator(int acode, Tag tag) {
return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode);
}
/** Return tree tag for assignment operation corresponding
* to given binary operator.
*/
private static JCTree.Tag treeTag(OperatorSymbol operator) {
switch (operator.opcode) {
case ByteCodes.ior: case ByteCodes.lor:
return BITOR_ASG;
case ByteCodes.ixor: case ByteCodes.lxor:
return BITXOR_ASG;
case ByteCodes.iand: case ByteCodes.land:
return BITAND_ASG;
case ByteCodes.ishl: case ByteCodes.lshl:
case ByteCodes.ishll: case ByteCodes.lshll:
return SL_ASG;
case ByteCodes.ishr: case ByteCodes.lshr:
case ByteCodes.ishrl: case ByteCodes.lshrl:
return SR_ASG;
case ByteCodes.iushr: case ByteCodes.lushr:
case ByteCodes.iushrl: case ByteCodes.lushrl:
return USR_ASG;
case ByteCodes.iadd: case ByteCodes.ladd:
case ByteCodes.fadd: case ByteCodes.dadd:
case ByteCodes.string_add:
return PLUS_ASG;
case ByteCodes.isub: case ByteCodes.lsub:
case ByteCodes.fsub: case ByteCodes.dsub:
return MINUS_ASG;
case ByteCodes.imul: case ByteCodes.lmul:
case ByteCodes.fmul: case ByteCodes.dmul:
return MUL_ASG;
case ByteCodes.idiv: case ByteCodes.ldiv:
case ByteCodes.fdiv: case ByteCodes.ddiv:
return DIV_ASG;
case ByteCodes.imod: case ByteCodes.lmod:
case ByteCodes.fmod: case ByteCodes.dmod:
return MOD_ASG;
default:
throw new AssertionError();
}
}
/** The name of the access method with number `anum' and access code `acode'.
*/
Name accessName(int anum, int acode) {
return names.fromString(
"access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
}
/** Return access symbol for a private or protected symbol from an inner class.
* @param sym The accessed private symbol.
* @param tree The accessing tree.
* @param enclOp The closest enclosing operation node of tree,
* null if tree is not a subtree of an operation.
* @param protAccess Is access to a protected symbol in another
* package?
* @param refSuper Is access via a (qualified) C.super?
*/
MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
boolean protAccess, boolean refSuper) {
ClassSymbol accOwner = refSuper && protAccess
// For access via qualified super (T.super.x), place the
// access symbol on T.
? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
// Otherwise pretend that the owner of an accessed
// protected symbol is the enclosing class of the current
// class which is a subclass of the symbol's owner.
: accessClass(sym, protAccess, tree);
Symbol vsym = sym;
if (sym.owner != accOwner) {
vsym = sym.clone(accOwner);
actualSymbols.put(vsym, sym);
}
Integer anum // The access number of the access method.
= accessNums.get(vsym);
if (anum == null) {
anum = accessed.length();
accessNums.put(vsym, anum);
accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]);
accessed.append(vsym);
// System.out.println("accessing " + vsym + " in " + vsym.location());
}
int acode; // The access code of the access method.
List<Type> argtypes; // The argument types of the access method.
Type restype; // The result type of the access method.
List<Type> thrown; // The thrown exceptions of the access method.
switch (vsym.kind) {
case VAR:
acode = accessCode(tree, enclOp);
if (acode >= AccessCode.FIRSTASGOP.code) {
OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag());
if (operator.opcode == string_add)
argtypes = List.of(syms.objectType);
else
argtypes = operator.type.getParameterTypes().tail;
} else if (acode == AccessCode.ASSIGN.code)
argtypes = List.of(vsym.erasure(types));
else
argtypes = List.nil();
restype = vsym.erasure(types);
thrown = List.nil();
break;
case MTH:
acode = AccessCode.DEREF.code;
argtypes = vsym.erasure(types).getParameterTypes();
restype = vsym.erasure(types).getReturnType();
thrown = vsym.type.getThrownTypes();
break;
default:
throw new AssertionError();
}
// For references via qualified super, increment acode by one,
// making it odd.
if (protAccess && refSuper) acode++;
// Instance access methods get instance as first parameter.
// For protected symbols this needs to be the instance as a member
// of the type containing the accessed symbol, not the class
// containing the access method.
if ((vsym.flags() & STATIC) == 0) {
argtypes = argtypes.prepend(vsym.owner.erasure(types));
}
MethodSymbol[] accessors = accessSyms.get(vsym);
MethodSymbol accessor = accessors[acode];
if (accessor == null) {
accessor = new MethodSymbol(
STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0),
accessName(anum.intValue(), acode),
new MethodType(argtypes, restype, thrown, syms.methodClass),
accOwner);
enterSynthetic(tree.pos(), accessor, accOwner.members());
accessors[acode] = accessor;
}
return accessor;
}
/** The qualifier to be used for accessing a symbol in an outer class.
* This is either C.sym or C.this.sym, depending on whether or not
* sym is static.
* @param sym The accessed symbol.
*/
JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
return (sym.flags() & STATIC) != 0
? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
: makeOwnerThis(pos, sym, true);
}
/** Do we need an access method to reference private symbol?
*/
boolean needsPrivateAccess(Symbol sym) {
if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
return false;
} else if (sym.name == names.init && sym.owner.isLocal()) {
// private constructor in local class: relax protection
sym.flags_field &= ~PRIVATE;
return false;
} else {
return true;
}
}
/** Do we need an access method to reference symbol in other package?
*/
boolean needsProtectedAccess(Symbol sym, JCTree tree) {
if ((sym.flags() & PROTECTED) == 0 ||
sym.owner.owner == currentClass.owner || // fast special case
sym.packge() == currentClass.packge())
return false;
if (!currentClass.isSubClass(sym.owner, types))
return true;
if ((sym.flags() & STATIC) != 0 ||
!tree.hasTag(SELECT) ||
TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
return false;
return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
}
/** The class in which an access method for given symbol goes.
* @param sym The access symbol
* @param protAccess Is access to a protected symbol in another
* package?
*/
ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
if (protAccess) {
Symbol qualifier = null;
ClassSymbol c = currentClass;
if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
qualifier = ((JCFieldAccess) tree).selected.type.tsym;
while (!qualifier.isSubClass(c, types)) {
c = c.owner.enclClass();
}
return c;
} else {
while (!c.isSubClass(sym.owner, types)) {
c = c.owner.enclClass();
}
}
return c;
} else {
// the symbol is private
return sym.owner.enclClass();
}
}
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.
* @param enclOp The closest enclosing operation node of tree,
* null if tree is not a subtree of an operation.
* @param refSuper Is access via a (qualified) C.super?
*/
JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
// Access a free variable via its proxy, or its proxy's proxy
while (sym.kind == VAR && sym.owner.kind == MTH &&
sym.owner.enclClass() != currentClass) {
// A constant is replaced by its constant value.
Object cv = ((VarSymbol)sym).getConstValue();
if (cv != null) {
make.at(tree.pos);
return makeLit(sym.type, cv);
}
// Otherwise replace the variable by its proxy.
sym = proxies.get(sym);
Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
tree = make.at(tree.pos).Ident(sym);
}
JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
switch (sym.kind) {
case TYP:
if (sym.owner.kind != PCK) {
// Convert type idents to
// <flat name> or <package name> . <flat name>
Name flatname = Convert.shortName(sym.flatName());
while (base != null &&
TreeInfo.symbol(base) != null &&
TreeInfo.symbol(base).kind != PCK) {
base = (base.hasTag(SELECT))
? ((JCFieldAccess) base).selected
: null;
}
if (tree.hasTag(IDENT)) {
((JCIdent) tree).name = flatname;
} else if (base == null) {
tree = make.at(tree.pos).Ident(sym);
((JCIdent) tree).name = flatname;
} else {
((JCFieldAccess) tree).selected = base;
((JCFieldAccess) tree).name = flatname;
}
}
break;
case MTH: case VAR:
if (sym.owner.kind == TYP) {
// Access methods are required for
// - private members,
// - protected members in a superclass of an
// enclosing class contained in another package.
// - all non-private members accessed via a qualified super.
boolean protAccess = refSuper && !needsPrivateAccess(sym)
|| needsProtectedAccess(sym, tree);
boolean accReq = protAccess || needsPrivateAccess(sym);
// A base has to be supplied for
// - simple identifiers accessing variables in outer classes.
boolean baseReq =
base == null &&
sym.owner != syms.predefClass &&
!sym.isMemberOf(currentClass, types);
if (accReq || baseReq) {
make.at(tree.pos);
// Constants are replaced by their constant value.
if (sym.kind == VAR) {
Object cv = ((VarSymbol)sym).getConstValue();
if (cv != null) {
addPrunedInfo(tree);
return makeLit(sym.type, cv);
}
}
// Private variables and methods are replaced by calls
// to their access methods.
if (accReq) {
List<JCExpression> args = List.nil();
if ((sym.flags() & STATIC) == 0) {
// Instance access methods get instance
// as first parameter.
if (base == null)
base = makeOwnerThis(tree.pos(), sym, true);
args = args.prepend(base);
base = null; // so we don't duplicate code
}
Symbol access = accessSymbol(sym, tree,
enclOp, protAccess,
refSuper);
JCExpression receiver = make.Select(
base != null ? base : make.QualIdent(access.owner),
access);
return make.App(receiver, args);
// Other accesses to members of outer classes get a
// qualifier.
} else if (baseReq) {
return make.at(tree.pos).Select(
accessBase(tree.pos(), sym), sym).setType(tree.type);
}
}
} else if (sym.owner.kind == MTH && lambdaTranslationMap != null) {
//sym is a local variable - check the lambda translation map to
//see if sym has been translated to something else in the current
//scope (by LambdaToMethod)
Symbol translatedSym = lambdaTranslationMap.get(sym);
if (translatedSym != null) {
tree = make.at(tree.pos).Ident(translatedSym);
}
}
}
return tree;
}
/** Ensure that identifier is accessible, return tree accessing the identifier.
* @param tree The identifier tree.
*/
JCExpression access(JCExpression tree) {
Symbol sym = TreeInfo.symbol(tree);
return sym == null ? tree : access(sym, tree, null, false);
}
/** Return access constructor for a private constructor,
* or the constructor itself, if no access constructor is needed.
* @param pos The position to report diagnostics, if any.
* @param constr The private constructor.
*/
Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
if (needsPrivateAccess(constr)) {
ClassSymbol accOwner = constr.owner.enclClass();
MethodSymbol aconstr = accessConstrs.get(constr);
if (aconstr == null) {
List<Type> argtypes = constr.type.getParameterTypes();
if ((accOwner.flags_field & ENUM) != 0)
argtypes = argtypes
.prepend(syms.intType)
.prepend(syms.stringType);
aconstr = new MethodSymbol(
SYNTHETIC,
names.init,
new MethodType(
argtypes.append(
accessConstructorTag().erasure(types)),
constr.type.getReturnType(),
constr.type.getThrownTypes(),
syms.methodClass),
accOwner);
enterSynthetic(pos, aconstr, accOwner.members());
accessConstrs.put(constr, aconstr);
accessed.append(constr);
}
return aconstr;
} else {
return constr;
}
}
/** Return an anonymous class nested in this toplevel class.
*/
ClassSymbol accessConstructorTag() {
ClassSymbol topClass = currentClass.outermostClass();
ModuleSymbol topModle = topClass.packge().modle;
Name flatname = names.fromString("" + topClass.getQualifiedName() +
target.syntheticNameChar() +
"1");
ClassSymbol ctag = chk.getCompiled(topModle, flatname);
if (ctag == null)
ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym;
// keep a record of all tags, to verify that all are generated as required
accessConstrTags = accessConstrTags.prepend(ctag);
return ctag;
}
/** Add all required access methods for a private symbol to enclosing class.
* @param sym The symbol.
*/
void makeAccessible(Symbol sym) {
JCClassDecl cdef = classDef(sym.owner.enclClass());
if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
if (sym.name == names.init) {
cdef.defs = cdef.defs.prepend(
accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
} else {
MethodSymbol[] accessors = accessSyms.get(sym);
for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) {
if (accessors[i] != null)
cdef.defs = cdef.defs.prepend(
accessDef(cdef.pos, sym, accessors[i], i));
}
}
}
/** Construct definition of an access method.
* @param pos The source code position of the definition.
* @param vsym The private or protected symbol.
* @param accessor The access method for the symbol.
* @param acode The access code.
*/
JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
// System.err.println("access " + vsym + " with " + accessor);//DEBUG
currentClass = vsym.owner.enclClass();
make.at(pos);
JCMethodDecl md = make.MethodDef(accessor, null);
// Find actual symbol
Symbol sym = actualSymbols.get(vsym);
if (sym == null) sym = vsym;
JCExpression ref; // The tree referencing the private symbol.
List<JCExpression> args; // Any additional arguments to be passed along.
if ((sym.flags() & STATIC) != 0) {
ref = make.Ident(sym);
args = make.Idents(md.params);
} else {
JCExpression site = make.Ident(md.params.head);
if (acode % 2 != 0) {
//odd access codes represent qualified super accesses - need to
//emit reference to the direct superclass, even if the refered
//member is from an indirect superclass (JLS 13.1)
site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
}
ref = make.Select(site, sym);
args = make.Idents(md.params.tail);
}
JCStatement stat; // The statement accessing the private symbol.
if (sym.kind == VAR) {
// Normalize out all odd access codes by taking floor modulo 2:
int acode1 = acode - (acode & 1);
JCExpression expr; // The access method's return value.
AccessCode aCode = AccessCode.getFromCode(acode1);
switch (aCode) {
case DEREF:
expr = ref;
break;
case ASSIGN:
expr = make.Assign(ref, args.head);
break;
case PREINC: case POSTINC: case PREDEC: case POSTDEC:
expr = makeUnary(aCode.tag, ref);
break;
default:
expr = make.Assignop(
treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head);
((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG);
}
stat = make.Return(expr.setType(sym.type));
} else {
stat = make.Call(make.App(ref, args));
}
md.body = make.Block(0, List.of(stat));
// Make sure all parameters, result types and thrown exceptions
// are accessible.
for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
l.head.vartype = access(l.head.vartype);
md.restype = access(md.restype);
for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
l.head = access(l.head);
return md;
}
/** Construct definition of an access constructor.
* @param pos The source code position of the definition.
* @param constr The private constructor.
* @param accessor The access method for the constructor.
*/
JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
make.at(pos);
JCMethodDecl md = make.MethodDef(accessor,
accessor.externalType(types),
null);
JCIdent callee = make.Ident(names._this);
callee.sym = constr;
callee.type = constr.type;
md.body =
make.Block(0, List.of(
make.Call(
make.App(
callee,
make.Idents(md.params.reverse().tail.reverse())))));
return md;
}
/**************************************************************************
* Free variables proxies and this$n
*************************************************************************/
/** A map which allows to retrieve the translated proxy variable for any given symbol of an
* enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol).
* Inside a constructor, the map temporarily overrides entries corresponding to proxies and any
* 'this$n' symbols, where they represent the constructor parameters.
*/
Map<Symbol, Symbol> proxies;
/** A scope containing all unnamed resource variables/saved
* exception variables for translated TWR blocks
*/
WriteableScope twrVars;
/** A stack containing the this$n field of the currently translated
* classes (if needed) in innermost first order.
* Inside a constructor, proxies and any this$n symbol are duplicated
* in an additional innermost scope, where they represent the constructor
* parameters.
*/
List<VarSymbol> outerThisStack;
/** The name of a free variable proxy.
*/
Name proxyName(Name name, int index) {
Name proxyName = names.fromString("val" + target.syntheticNameChar() + name);
if (index > 0) {
proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index));
}
return proxyName;
}
/** Proxy definitions for all free variables in given list, in reverse order.
* @param pos The source code position of the definition.
* @param freevars The free variables.
* @param owner The class in which the definitions go.
*/
List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
return freevarDefs(pos, freevars, owner, 0);
}
List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner,
long additionalFlags) {
long flags = FINAL | SYNTHETIC | additionalFlags;
List<JCVariableDecl> defs = List.nil();
Set<Name> proxyNames = new HashSet<>();
for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
VarSymbol v = l.head;
int index = 0;
Name proxyName;
do {
proxyName = proxyName(v.name, index++);
} while (!proxyNames.add(proxyName));
VarSymbol proxy = new VarSymbol(
flags, proxyName, v.erasure(types), owner);
proxies.put(v, proxy);
JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
vd.vartype = access(vd.vartype);
defs = defs.prepend(vd);
}
return defs;
}
/** The name of a this$n field
* @param type The class referenced by the this$n field
*/
Name outerThisName(Type type, Symbol owner) {
Type t = type.getEnclosingType();
int nestingLevel = 0;
while (t.hasTag(CLASS)) {
t = t.getEnclosingType();
nestingLevel++;
}
Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null)
result = names.fromString(result.toString() + target.syntheticNameChar());
return result;
}
private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) {
Type target = types.erasure(owner.enclClass().type.getEnclosingType());
VarSymbol outerThis =
new VarSymbol(flags, outerThisName(target, owner), target, owner);
outerThisStack = outerThisStack.prepend(outerThis);
return outerThis;
}
private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
JCVariableDecl vd = make.at(pos).VarDef(sym, null);
vd.vartype = access(vd.vartype);
return vd;
}
/** Definition for this$n field.
* @param pos The source code position of the definition.
* @param owner The method in which the definition goes.
*/
JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
ClassSymbol c = owner.enclClass();
boolean isMandated =
// Anonymous constructors
(owner.isConstructor() && owner.isAnonymous()) ||
// Constructors of non-private inner member classes
(owner.isConstructor() && c.isInner() &&
!c.isPrivate() && !c.isStatic());
long flags =
FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
owner.extraParams = owner.extraParams.prepend(outerThis);
return makeOuterThisVarDecl(pos, outerThis);
}
/** Definition for this$n field.
* @param pos The source code position of the definition.
* @param owner The class in which the definition goes.
*/
JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC);
return makeOuterThisVarDecl(pos, outerThis);
}
/** Return a list of trees that load the free variables in given list,
* in reverse order.
* @param pos The source code position to be used for the trees.
* @param freevars The list of free variables.
*/
List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
List<JCExpression> args = List.nil();
for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
args = args.prepend(loadFreevar(pos, l.head));
return args;
}
//where
JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
return access(v, make.at(pos).Ident(v), null, false);
}
/** Construct a tree simulating the expression {@code C.this}.
* @param pos The source code position to be used for the tree.
* @param c The qualifier class.
*/
JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
if (currentClass == c) {
// in this case, `this' works fine
return make.at(pos).This(c.erasure(types));
} else {
// need to go via this$n
return makeOuterThis(pos, c);
}
}
/**
* Optionally replace a try statement with the desugaring of a
* try-with-resources statement. The canonical desugaring of
*
* try ResourceSpecification
* Block
*
* is
*
* {
* final VariableModifiers_minus_final R #resource = Expression;
* Throwable #primaryException = null;
*
* try ResourceSpecificationtail
* Block
* catch (Throwable #t) {
* #primaryException = t;
* throw #t;
* } finally {
* if (#resource != null) {
* if (#primaryException != null) {
* try {
* #resource.close();
* } catch(Throwable #suppressedException) {
* #primaryException.addSuppressed(#suppressedException);
* }
* } else {
* #resource.close();
* }
* }
* }
*
* @param tree The try statement to inspect.
* @return A a desugared try-with-resources tree, or the original
* try block if there are no resources to manage.
*/
JCTree makeTwrTry(JCTry tree) {
make_at(tree.pos());
twrVars = twrVars.dup();
JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body,
tree.finallyCanCompleteNormally, 0);
if (tree.catchers.isEmpty() && tree.finalizer == null)
result = translate(twrBlock);
else
result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
twrVars = twrVars.leave();
return result;
}
private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block,
boolean finallyCanCompleteNormally, int depth) {
if (resources.isEmpty())
return block;
// Add resource declaration or expression to block statements
ListBuffer<JCStatement> stats = new ListBuffer<>();
JCTree resource = resources.head;
JCExpression expr = null;
boolean resourceNonNull;
if (resource instanceof JCVariableDecl) {
JCVariableDecl var = (JCVariableDecl) resource;
expr = make.Ident(var.sym).setType(resource.type);
resourceNonNull = var.init != null && TreeInfo.skipParens(var.init).hasTag(NEWCLASS);
stats.add(var);
} else {
Assert.check(resource instanceof JCExpression);
VarSymbol syntheticTwrVar =
new VarSymbol(SYNTHETIC | FINAL,
makeSyntheticName(names.fromString("twrVar" +
depth), twrVars),
(resource.type.hasTag(BOT)) ?
syms.autoCloseableType : resource.type,
currentMethodSym);
twrVars.enter(syntheticTwrVar);
JCVariableDecl syntheticTwrVarDecl =
make.VarDef(syntheticTwrVar, (JCExpression)resource);
expr = (JCExpression)make.Ident(syntheticTwrVar);
resourceNonNull = TreeInfo.skipParens(resource).hasTag(NEWCLASS);
stats.add(syntheticTwrVarDecl);
}
// Add primaryException declaration
VarSymbol primaryException =
new VarSymbol(SYNTHETIC,
makeSyntheticName(names.fromString("primaryException" +
depth), twrVars),
syms.throwableType,
currentMethodSym);
twrVars.enter(primaryException);
JCVariableDecl primaryExceptionTreeDecl = make.VarDef(primaryException, makeNull());
stats.add(primaryExceptionTreeDecl);
// Create catch clause that saves exception and then rethrows it
VarSymbol param =
new VarSymbol(FINAL|SYNTHETIC,
names.fromString("t" +
target.syntheticNameChar()),
syms.throwableType,
currentMethodSym);
JCVariableDecl paramTree = make.VarDef(param, null);
JCStatement assign = make.Assignment(primaryException, make.Ident(param));
JCStatement rethrowStat = make.Throw(make.Ident(param));
JCBlock catchBlock = make.Block(0L, List.of(assign, rethrowStat));
JCCatch catchClause = make.Catch(paramTree, catchBlock);
int oldPos = make.pos;
make.at(TreeInfo.endPos(block));
JCBlock finallyClause = makeTwrFinallyClause(primaryException, expr, resourceNonNull);
make.at(oldPos);
JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block,
finallyCanCompleteNormally, depth + 1),
List.of(catchClause),
finallyClause);
outerTry.finallyCanCompleteNormally = finallyCanCompleteNormally;
stats.add(outerTry);
JCBlock newBlock = make.Block(0L, stats.toList());
return newBlock;
}
/**If the estimated number of copies the close resource code in a single class is above this
* threshold, generate and use a method for the close resource code, leading to smaller code.
* As generating a method has overhead on its own, generating the method for cases below the
* threshold could lead to an increase in code size.
*/
public static final int USE_CLOSE_RESOURCE_METHOD_THRESHOLD = 4;
private JCBlock makeTwrFinallyClause(Symbol primaryException, JCExpression resource,
boolean resourceNonNull) {
MethodSymbol closeResource = (MethodSymbol)lookupSynthetic(dollarCloseResource,
currentClass.members());
if (closeResource == null && shouldUseCloseResourceMethod()) {
closeResource = new MethodSymbol(
PRIVATE | STATIC | SYNTHETIC,
dollarCloseResource,
new MethodType(
List.of(syms.throwableType, syms.autoCloseableType),
syms.voidType,
List.nil(),
syms.methodClass),
currentClass);
enterSynthetic(resource.pos(), closeResource, currentClass.members());
JCMethodDecl md = make.MethodDef(closeResource, null);
List<JCVariableDecl> params = md.getParameters();
md.body = make.Block(0, List.of(makeTwrCloseStatement(params.get(0).sym,
make.Ident(params.get(1)))));
JCClassDecl currentClassDecl = classDef(currentClass);
currentClassDecl.defs = currentClassDecl.defs.prepend(md);
}
JCStatement closeStatement;
if (closeResource != null) {
//$closeResource(#primaryException, #resource)
closeStatement = make.Exec(make.Apply(List.nil(),
make.Ident(closeResource),
List.of(make.Ident(primaryException),
resource)
).setType(syms.voidType));
} else {
closeStatement = makeTwrCloseStatement(primaryException, resource);
}
JCStatement finallyStatement;
if (resourceNonNull) {
finallyStatement = closeStatement;
} else {
// if (#resource != null) { $closeResource(...); }
finallyStatement = make.If(makeNonNullCheck(resource),
closeStatement,
null);
}
return make.Block(0L,
List.of(finallyStatement));
}
//where:
private boolean shouldUseCloseResourceMethod() {
class TryFinder extends TreeScanner {
int closeCount;
@Override
public void visitTry(JCTry tree) {
boolean empty = tree.body.stats.isEmpty();
for (JCTree r : tree.resources) {
closeCount += empty ? 1 : 2;
empty = false; //with multiple resources, only the innermost try can be empty.
}
super.visitTry(tree);
}
@Override
public void scan(JCTree tree) {
if (useCloseResourceMethod())
return;
super.scan(tree);
}
boolean useCloseResourceMethod() {
return closeCount >= USE_CLOSE_RESOURCE_METHOD_THRESHOLD;
}
}
TryFinder tryFinder = new TryFinder();
tryFinder.scan(classDef(currentClass));
return tryFinder.useCloseResourceMethod();
}
private JCStatement makeTwrCloseStatement(Symbol primaryException, JCExpression resource) {
// primaryException.addSuppressed(catchException);
VarSymbol catchException =
new VarSymbol(SYNTHETIC, make.paramName(2),
syms.throwableType,
currentMethodSym);
JCStatement addSuppressionStatement =
make.Exec(makeCall(make.Ident(primaryException),
names.addSuppressed,
List.of(make.Ident(catchException))));
// try { resource.close(); } catch (e) { primaryException.addSuppressed(e); }
JCBlock tryBlock =
make.Block(0L, List.of(makeResourceCloseInvocation(resource)));
JCVariableDecl catchExceptionDecl = make.VarDef(catchException, null);
JCBlock catchBlock = make.Block(0L, List.of(addSuppressionStatement));
List<JCCatch> catchClauses = List.of(make.Catch(catchExceptionDecl, catchBlock));
JCTry tryTree = make.Try(tryBlock, catchClauses, null);
tryTree.finallyCanCompleteNormally = true;
// if (primaryException != null) {try...} else resourceClose;
JCIf closeIfStatement = make.If(makeNonNullCheck(make.Ident(primaryException)),
tryTree,
makeResourceCloseInvocation(resource));
return closeIfStatement;
}
private JCStatement makeResourceCloseInvocation(JCExpression resource) {
// convert to AutoCloseable if needed
if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) {
resource = convert(resource, syms.autoCloseableType);
}
// create resource.close() method invocation
JCExpression resourceClose = makeCall(resource,
names.close,
List.nil());
return make.Exec(resourceClose);
}
private JCExpression makeNonNullCheck(JCExpression expression) {
return makeBinary(NE, expression, makeNull());
}
/** Construct a tree that represents the outer instance
* {@code C.this}. Never pick the current `this'.
* @param pos The source code position to be used for the tree.
* @param c The qualifier class.
*/
JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
List<VarSymbol> ots = outerThisStack;
if (ots.isEmpty()) {
log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
Assert.error();
return makeNull();
}
VarSymbol ot = ots.head;
JCExpression tree = access(make.at(pos).Ident(ot));
TypeSymbol otc = ot.type.tsym;
while (otc != c) {
do {
ots = ots.tail;
if (ots.isEmpty()) {
log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
Assert.error(); // should have been caught in Attr
return tree;
}
ot = ots.head;
} while (ot.owner != otc);
if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
chk.earlyRefError(pos, c);
Assert.error(); // should have been caught in Attr
return makeNull();
}
tree = access(make.at(pos).Select(tree, ot));
otc = ot.type.tsym;
}
return tree;
}
/** Construct a tree that represents the closest outer instance
* {@code C.this} such that the given symbol is a member of C.
* @param pos The source code position to be used for the tree.
* @param sym The accessed symbol.
* @param preciseMatch should we accept a type that is a subtype of
* sym's owner, even if it doesn't contain sym
* due to hiding, overriding, or non-inheritance
* due to protection?
*/
JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
Symbol c = sym.owner;
if (preciseMatch ? sym.isMemberOf(currentClass, types)
: currentClass.isSubClass(sym.owner, types)) {
// in this case, `this' works fine
return make.at(pos).This(c.erasure(types));
} else {
// need to go via this$n
return makeOwnerThisN(pos, sym, preciseMatch);
}
}
/**
* Similar to makeOwnerThis but will never pick "this".
*/
JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
Symbol c = sym.owner;
List<VarSymbol> ots = outerThisStack;
if (ots.isEmpty()) {
log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
Assert.error();
return makeNull();
}
VarSymbol ot = ots.head;
JCExpression tree = access(make.at(pos).Ident(ot));
TypeSymbol otc = ot.type.tsym;
while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
do {
ots = ots.tail;
if (ots.isEmpty()) {
log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
Assert.error();
return tree;
}
ot = ots.head;
} while (ot.owner != otc);
tree = access(make.at(pos).Select(tree, ot));
otc = ot.type.tsym;
}
return tree;
}
/** Return tree simulating the assignment {@code this.name = name}, where
* name is the name of a free variable.
*/
JCStatement initField(int pos, Symbol rhs, Symbol lhs) {
Assert.check(rhs.owner.kind == MTH);
Assert.check(rhs.owner.owner == lhs.owner);
make.at(pos);
return
make.Exec(
make.Assign(
make.Select(make.This(lhs.owner.erasure(types)), lhs),
make.Ident(rhs)).setType(lhs.erasure(types)));
}
/** Return tree simulating the assignment {@code this.this$n = this$n}.
*/
JCStatement initOuterThis(int pos) {
VarSymbol rhs = outerThisStack.head;
Assert.check(rhs.owner.kind == MTH);
VarSymbol lhs = outerThisStack.tail.head;
Assert.check(rhs.owner.owner == lhs.owner);
make.at(pos);
return
make.Exec(
make.Assign(
make.Select(make.This(lhs.owner.erasure(types)), lhs),
make.Ident(rhs)).setType(lhs.erasure(types)));
}
/**************************************************************************
* Code for .class
*************************************************************************/
/** Return the symbol of a class to contain a cache of
* compiler-generated statics such as class$ and the
* $assertionsDisabled flag. We create an anonymous nested class
* (unless one already exists) and return its symbol. However,
* for backward compatibility in 1.4 and earlier we use the
* top-level class itself.
*/
private ClassSymbol outerCacheClass() {
ClassSymbol clazz = outermostClassDef.sym;
Scope s = clazz.members();
for (Symbol sym : s.getSymbols(NON_RECURSIVE))
if (sym.kind == TYP &&
sym.name == names.empty &&
(sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym;
return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym;
}
/** Create an attributed tree of the form left.name(). */
private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
Assert.checkNonNull(left.type);
Symbol funcsym = lookupMethod(make_pos, name, left.type,
TreeInfo.types(args));
return make.App(make.Select(left, funcsym), args);
}
/** The tree simulating a T.class expression.
* @param clazz The tree identifying type T.
*/
private JCExpression classOf(JCTree clazz) {
return classOfType(clazz.type, clazz.pos());
}
private JCExpression classOfType(Type type, DiagnosticPosition pos) {
switch (type.getTag()) {
case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
case DOUBLE: case BOOLEAN: case VOID:
// replace with <BoxedClass>.TYPE
ClassSymbol c = types.boxedClass(type);
Symbol typeSym =
rs.accessBase(
rs.findIdentInType(attrEnv, c.type, names.TYPE, KindSelector.VAR),
pos, c.type, names.TYPE, true);
if (typeSym.kind == VAR)
((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
return make.QualIdent(typeSym);
case CLASS: case ARRAY:
VarSymbol sym = new VarSymbol(
STATIC | PUBLIC | FINAL, names._class,
syms.classType, type.tsym);
return make_at(pos).Select(make.Type(type), sym);
default:
throw new AssertionError();
}
}
/**************************************************************************
* Code for enabling/disabling assertions.
*************************************************************************/
private ClassSymbol assertionsDisabledClassCache;
/**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
*/
private ClassSymbol assertionsDisabledClass() {
if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym;
return assertionsDisabledClassCache;
}
// This code is not particularly robust if the user has
// previously declared a member named '$assertionsDisabled'.
// The same faulty idiom also appears in the translation of
// class literals above. We should report an error if a
// previous declaration is not synthetic.
private JCExpression assertFlagTest(DiagnosticPosition pos) {
// Outermost class may be either true class or an interface.
ClassSymbol outermostClass = outermostClassDef.sym;
//only classes can hold a non-public field, look for a usable one:
ClassSymbol container = !currentClass.isInterface() ? currentClass :
assertionsDisabledClass();
VarSymbol assertDisabledSym =
(VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
container.members());
if (assertDisabledSym == null) {
assertDisabledSym =
new VarSymbol(STATIC | FINAL | SYNTHETIC,
dollarAssertionsDisabled,
syms.booleanType,
container);
enterSynthetic(pos, assertDisabledSym, container.members());
Symbol desiredAssertionStatusSym = lookupMethod(pos,
names.desiredAssertionStatus,
types.erasure(syms.classType),
List.nil());
JCClassDecl containerDef = classDef(container);
make_at(containerDef.pos());
JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
classOfType(types.erasure(outermostClass.type),
containerDef.pos()),
desiredAssertionStatusSym)));
JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
notStatus);
containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
if (currentClass.isInterface()) {
//need to load the assertions enabled/disabled state while
//initializing the interface:
JCClassDecl currentClassDef = classDef(currentClass);
make_at(currentClassDef.pos());
JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
JCBlock clinit = make.Block(STATIC, List.of(dummy));
currentClassDef.defs = currentClassDef.defs.prepend(clinit);
}
}
make_at(pos);
return makeUnary(NOT, make.Ident(assertDisabledSym));
}
/**************************************************************************
* Building blocks for let expressions
*************************************************************************/
interface TreeBuilder {
JCExpression build(JCExpression arg);
}
/** Construct an expression using the builder, with the given rval
* expression as an argument to the builder. However, the rval
* expression must be computed only once, even if used multiple
* times in the result of the builder. We do that by
* constructing a "let" expression that saves the rvalue into a
* temporary variable and then uses the temporary variable in
* place of the expression built by the builder. The complete
* resulting expression is of the form
* <pre>
* (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
* in (<b>BUILDER</b>(<b>TEMP</b>)))
* </pre>
* where <code><b>TEMP</b></code> is a newly declared variable
* in the let expression.
*/
JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) {
rval = TreeInfo.skipParens(rval);
switch (rval.getTag()) {
case LITERAL:
return builder.build(rval);
case IDENT:
JCIdent id = (JCIdent) rval;
if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
return builder.build(rval);
}
Name name = TreeInfo.name(rval);
if (name == names._super || name == names._this)
return builder.build(rval);
VarSymbol var =
new VarSymbol(FINAL|SYNTHETIC,
names.fromString(
target.syntheticNameChar()
+ "" + rval.hashCode()),
type,
currentMethodSym);
rval = convert(rval,type);
JCVariableDecl def = make.VarDef(var, rval); // XXX cast
JCExpression built = builder.build(make.Ident(var));
JCExpression res = make.LetExpr(def, built);
res.type = built.type;
return res;
}
// same as above, with the type of the temporary variable computed
JCExpression abstractRval(JCExpression rval, TreeBuilder builder) {
return abstractRval(rval, rval.type, builder);
}
// same as above, but for an expression that may be used as either
// an rvalue or an lvalue. This requires special handling for
// Select expressions, where we place the left-hand-side of the
// select in a temporary, and for Indexed expressions, where we
// place both the indexed expression and the index value in temps.
JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) {
lval = TreeInfo.skipParens(lval);
switch (lval.getTag()) {
case IDENT:
return builder.build(lval);
case SELECT: {
final JCFieldAccess s = (JCFieldAccess)lval;
Symbol lid = TreeInfo.symbol(s.selected);
if (lid != null && lid.kind == TYP) return builder.build(lval);
return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym)));
}
case INDEXED: {
final JCArrayAccess i = (JCArrayAccess)lval;
return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> {
JCExpression newLval = make.Indexed(indexed, index);
newLval.setType(i.type);
return builder.build(newLval);
}));
}
case TYPECAST: {
return abstractLval(((JCTypeCast)lval).expr, builder);
}
}
throw new AssertionError(lval);
}
// evaluate and discard the first expression, then evaluate the second.
JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
return abstractRval(expr1, discarded -> expr2);
}
/**************************************************************************
* Translation methods
*************************************************************************/
/** Visitor argument: enclosing operator node.
*/
private JCExpression enclOp;
/** Visitor method: Translate a single node.
* Attach the source position from the old tree to its replacement tree.
*/
@Override
public <T extends JCTree> T translate(T tree) {
if (tree == null) {
return null;
} else {
make_at(tree.pos());
T result = super.translate(tree);
if (endPosTable != null && result != tree) {
endPosTable.replaceTree(tree, result);
}
return result;
}
}
/** Visitor method: Translate a single node, boxing or unboxing if needed.
*/
public <T extends JCExpression> T translate(T tree, Type type) {
return (tree == null) ? null : boxIfNeeded(translate(tree), type);
}
/** Visitor method: Translate tree.
*/
public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
JCExpression prevEnclOp = this.enclOp;
this.enclOp = enclOp;
T res = translate(tree);
this.enclOp = prevEnclOp;
return res;
}
/** Visitor method: Translate list of trees.
*/
public <T extends JCExpression> List<T> translate(List<T> trees, Type type) {
if (trees == null) return null;
for (List<T> l = trees; l.nonEmpty(); l = l.tail)
l.head = translate(l.head, type);
return trees;
}
public void visitPackageDef(JCPackageDecl tree) {
if (!needPackageInfoClass(tree))
return;
long flags = Flags.ABSTRACT | Flags.INTERFACE;
// package-info is marked SYNTHETIC in JDK 1.6 and later releases
flags = flags | Flags.SYNTHETIC;
ClassSymbol c = tree.packge.package_info;
c.setAttributes(tree.packge);
c.flags_field |= flags;
ClassType ctype = (ClassType) c.type;
ctype.supertype_field = syms.objectType;
ctype.interfaces_field = List.nil();
createInfoClass(tree.annotations, c);
}
// where
private boolean needPackageInfoClass(JCPackageDecl pd) {
switch (pkginfoOpt) {
case ALWAYS:
return true;
case LEGACY:
return pd.getAnnotations().nonEmpty();
case NONEMPTY:
for (Attribute.Compound a :
pd.packge.getDeclarationAttributes()) {
Attribute.RetentionPolicy p = types.getRetention(a);
if (p != Attribute.RetentionPolicy.SOURCE)
return true;
}
return false;
}
throw new AssertionError();
}
public void visitModuleDef(JCModuleDecl tree) {
ModuleSymbol msym = tree.sym;
ClassSymbol c = msym.module_info;
c.setAttributes(msym);
c.flags_field |= Flags.MODULE;
createInfoClass(List.nil(), tree.sym.module_info);
}
private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) {
long flags = Flags.ABSTRACT | Flags.INTERFACE;
JCClassDecl infoClass =
make.ClassDef(make.Modifiers(flags, annots),
c.name, List.nil(),
null, List.nil(), List.nil());
infoClass.sym = c;
translated.append(infoClass);
}
public void visitClassDef(JCClassDecl tree) {
Env<AttrContext> prevEnv = attrEnv;
ClassSymbol currentClassPrev = currentClass;
MethodSymbol currentMethodSymPrev = currentMethodSym;
currentClass = tree.sym;
currentMethodSym = null;
attrEnv = typeEnvs.remove(currentClass);
if (attrEnv == null)
attrEnv = prevEnv;
classdefs.put(currentClass, tree);
Map<Symbol, Symbol> prevProxies = proxies;
proxies = new HashMap<>(proxies);
List<VarSymbol> prevOuterThisStack = outerThisStack;
// If this is an enum definition
if ((tree.mods.flags & ENUM) != 0 &&
(types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
visitEnumDef(tree);
// If this is a nested class, define a this$n field for
// it and add to proxies.
JCVariableDecl otdef = null;
if (currentClass.hasOuterInstance())
otdef = outerThisDef(tree.pos, currentClass);
// If this is a local class, define proxies for all its free variables.
List<JCVariableDecl> fvdefs = freevarDefs(
tree.pos, freevars(currentClass), currentClass);
// Recursively translate superclass, interfaces.
tree.extending = translate(tree.extending);
tree.implementing = translate(tree.implementing);
if (currentClass.isLocal()) {
ClassSymbol encl = currentClass.owner.enclClass();
if (encl.trans_local == null) {
encl.trans_local = List.nil();
}
encl.trans_local = encl.trans_local.prepend(currentClass);
}
// Recursively translate members, taking into account that new members
// might be created during the translation and prepended to the member
// list `tree.defs'.
List<JCTree> seen = List.nil();
while (tree.defs != seen) {
List<JCTree> unseen = tree.defs;
for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
JCTree outermostMemberDefPrev = outermostMemberDef;
if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
l.head = translate(l.head);
outermostMemberDef = outermostMemberDefPrev;
}
seen = unseen;
}
// Convert a protected modifier to public, mask static modifier.
if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
tree.mods.flags &= ClassFlags;
// Convert name to flat representation, replacing '.' by '$'.
tree.name = Convert.shortName(currentClass.flatName());
// Add this$n and free variables proxy definitions to class.
for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
tree.defs = tree.defs.prepend(l.head);
enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
}
if (currentClass.hasOuterInstance()) {
tree.defs = tree.defs.prepend(otdef);
enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
}
proxies = prevProxies;
outerThisStack = prevOuterThisStack;
// Append translated tree to `translated' queue.
translated.append(tree);
attrEnv = prevEnv;
currentClass = currentClassPrev;
currentMethodSym = currentMethodSymPrev;
// Return empty block {} as a placeholder for an inner class.
result = make_at(tree.pos()).Block(SYNTHETIC, List.nil());
}
/** Translate an enum class. */
private void visitEnumDef(JCClassDecl tree) {
make_at(tree.pos());
// add the supertype, if needed
if (tree.extending == null)
tree.extending = make.Type(types.supertype(tree.type));
// classOfType adds a cache field to tree.defs
JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
setType(types.erasure(syms.classType));
// process each enumeration constant, adding implicit constructor parameters
int nextOrdinal = 0;
ListBuffer<JCExpression> values = new ListBuffer<>();
ListBuffer<JCTree> enumDefs = new ListBuffer<>();
ListBuffer<JCTree> otherDefs = new ListBuffer<>();
for (List<JCTree> defs = tree.defs;
defs.nonEmpty();
defs=defs.tail) {
if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
JCVariableDecl var = (JCVariableDecl)defs.head;
visitEnumConstantDef(var, nextOrdinal++);
values.append(make.QualIdent(var.sym));
enumDefs.append(var);
} else {
otherDefs.append(defs.head);
}
}
// private static final T[] #VALUES = { a, b, c };
Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES");
while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash
valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
valuesName,
arrayType,
tree.type.tsym);
JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
List.nil(),
values.toList());
newArray.type = arrayType;
enumDefs.append(make.VarDef(valuesVar, newArray));
tree.sym.members().enter(valuesVar);
Symbol valuesSym = lookupMethod(tree.pos(), names.values,
tree.type, List.nil());
List<JCStatement> valuesBody;
if (useClone()) {
// return (T[]) $VALUES.clone();
JCTypeCast valuesResult =
make.TypeCast(valuesSym.type.getReturnType(),
make.App(make.Select(make.Ident(valuesVar),
syms.arrayCloneMethod)));
valuesBody = List.of(make.Return(valuesResult));
} else {
// template: T[] $result = new T[$values.length];
Name resultName = names.fromString(target.syntheticNameChar() + "result");
while (tree.sym.members().findFirst(resultName) != null) // avoid name clash
resultName = names.fromString(resultName + "" + target.syntheticNameChar());
VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
resultName,
arrayType,
valuesSym);
JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
null);
resultArray.type = arrayType;
JCVariableDecl decl = make.VarDef(resultVar, resultArray);
// template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
if (systemArraycopyMethod == null) {
systemArraycopyMethod =
new MethodSymbol(PUBLIC | STATIC,
names.fromString("arraycopy"),
new MethodType(List.of(syms.objectType,
syms.intType,
syms.objectType,
syms.intType,
syms.intType),
syms.voidType,
List.nil(),
syms.methodClass),
syms.systemType.tsym);
}
JCStatement copy =
make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
systemArraycopyMethod),
List.of(make.Ident(valuesVar), make.Literal(0),
make.Ident(resultVar), make.Literal(0),
make.Select(make.Ident(valuesVar), syms.lengthVar))));
// template: return $result;
JCStatement ret = make.Return(make.Ident(resultVar));
valuesBody = List.of(decl, copy, ret);
}
JCMethodDecl valuesDef =
make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody));
enumDefs.append(valuesDef);
if (debugLower)
System.err.println(tree.sym + ".valuesDef = " + valuesDef);
/** The template for the following code is:
*
* public static E valueOf(String name) {
* return (E)Enum.valueOf(E.class, name);
* }
*
* where E is tree.sym
*/
MethodSymbol valueOfSym = lookupMethod(tree.pos(),
names.valueOf,
tree.sym.type,
List.of(syms.stringType));
Assert.check((valueOfSym.flags() & STATIC) != 0);
VarSymbol nameArgSym = valueOfSym.params.head;
JCIdent nameVal = make.Ident(nameArgSym);
JCStatement enum_ValueOf =
make.Return(make.TypeCast(tree.sym.type,
makeCall(make.Ident(syms.enumSym),
names.valueOf,
List.of(e_class, nameVal))));
JCMethodDecl valueOf = make.MethodDef(valueOfSym,
make.Block(0, List.of(enum_ValueOf)));
nameVal.sym = valueOf.params.head.sym;
if (debugLower)
System.err.println(tree.sym + ".valueOf = " + valueOf);
enumDefs.append(valueOf);
enumDefs.appendList(otherDefs.toList());
tree.defs = enumDefs.toList();
}
// where
private MethodSymbol systemArraycopyMethod;
private boolean useClone() {
try {
return syms.objectType.tsym.members().findFirst(names.clone) != null;
}
catch (CompletionFailure e) {
return false;
}
}
/** Translate an enumeration constant and its initializer. */
private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
JCNewClass varDef = (JCNewClass)var.init;
varDef.args = varDef.args.
prepend(makeLit(syms.intType, ordinal)).
prepend(makeLit(syms.stringType, var.name.toString()));
}
public void visitMethodDef(JCMethodDecl tree) {
if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
// Add "String $enum$name, int $enum$ordinal" to the beginning of the
// argument list for each constructor of an enum.
JCVariableDecl nameParam = make_at(tree.pos()).
Param(names.fromString(target.syntheticNameChar() +
"enum" + target.syntheticNameChar() + "name"),
syms.stringType, tree.sym);
nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
JCVariableDecl ordParam = make.
Param(names.fromString(target.syntheticNameChar() +
"enum" + target.syntheticNameChar() +
"ordinal"),
syms.intType, tree.sym);
ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
MethodSymbol m = tree.sym;
tree.params = tree.params.prepend(ordParam).prepend(nameParam);
m.extraParams = m.extraParams.prepend(ordParam.sym);
m.extraParams = m.extraParams.prepend(nameParam.sym);
Type olderasure = m.erasure(types);
m.erasure_field = new MethodType(
olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
olderasure.getReturnType(),
olderasure.getThrownTypes(),
syms.methodClass);
}
JCMethodDecl prevMethodDef = currentMethodDef;
MethodSymbol prevMethodSym = currentMethodSym;
try {
currentMethodDef = tree;
currentMethodSym = tree.sym;
visitMethodDefInternal(tree);
} finally {
currentMethodDef = prevMethodDef;
currentMethodSym = prevMethodSym;
}
}
private void visitMethodDefInternal(JCMethodDecl tree) {
if (tree.name == names.init &&
(currentClass.isInner() || currentClass.isLocal())) {
// We are seeing a constructor of an inner class.
MethodSymbol m = tree.sym;
// Push a new proxy scope for constructor parameters.
// and create definitions for any this$n and proxy parameters.
Map<Symbol, Symbol> prevProxies = proxies;
proxies = new HashMap<>(proxies);
List<VarSymbol> prevOuterThisStack = outerThisStack;
List<VarSymbol> fvs = freevars(currentClass);
JCVariableDecl otdef = null;
if (currentClass.hasOuterInstance())
otdef = outerThisDef(tree.pos, m);
List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
// Recursively translate result type, parameters and thrown list.
tree.restype = translate(tree.restype);
tree.params = translateVarDefs(tree.params);
tree.thrown = translate(tree.thrown);
// when compiling stubs, don't process body
if (tree.body == null) {
result = tree;
return;
}
// Add this$n (if needed) in front of and free variables behind
// constructor parameter list.
tree.params = tree.params.appendList(fvdefs);
if (currentClass.hasOuterInstance()) {
tree.params = tree.params.prepend(otdef);
}
// If this is an initial constructor, i.e., it does not start with
// this(...), insert initializers for this$n and proxies
// before (pre-1.4, after) the call to superclass constructor.
JCStatement selfCall = translate(tree.body.stats.head);
List<JCStatement> added = List.nil();
if (fvs.nonEmpty()) {
List<Type> addedargtypes = List.nil();
for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
m.capturedLocals =
m.capturedLocals.prepend((VarSymbol)
(proxies.get(l.head)));
if (TreeInfo.isInitialConstructor(tree)) {
added = added.prepend(
initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head)));
}
addedargtypes = addedargtypes.prepend(l.head.erasure(types));
}
Type olderasure = m.erasure(types);
m.erasure_field = new MethodType(
olderasure.getParameterTypes().appendList(addedargtypes),
olderasure.getReturnType(),
olderasure.getThrownTypes(),
syms.methodClass);
}
if (currentClass.hasOuterInstance() &&
TreeInfo.isInitialConstructor(tree))
{
added = added.prepend(initOuterThis(tree.body.pos));
}
// pop local variables from proxy stack
proxies = prevProxies;
// recursively translate following local statements and
// combine with this- or super-call
List<JCStatement> stats = translate(tree.body.stats.tail);
tree.body.stats = stats.prepend(selfCall).prependList(added);
outerThisStack = prevOuterThisStack;
} else {
Map<Symbol, Symbol> prevLambdaTranslationMap =
lambdaTranslationMap;
try {
lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 &&
tree.sym.name.startsWith(names.lambda) ?
makeTranslationMap(tree) : null;
super.visitMethodDef(tree);
} finally {
lambdaTranslationMap = prevLambdaTranslationMap;
}
}
result = tree;
}
//where
private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) {
Map<Symbol, Symbol> translationMap = new HashMap<>();
for (JCVariableDecl vd : tree.params) {
Symbol p = vd.sym;
if (p != p.baseSymbol()) {
translationMap.put(p.baseSymbol(), p);
}
}
return translationMap;
}
public void visitTypeCast(JCTypeCast tree) {
tree.clazz = translate(tree.clazz);
if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
tree.expr = translate(tree.expr, tree.type);
else
tree.expr = translate(tree.expr);
result = tree;
}
public void visitNewClass(JCNewClass tree) {
ClassSymbol c = (ClassSymbol)tree.constructor.owner;
// Box arguments, if necessary
boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
List<Type> argTypes = tree.constructor.type.getParameterTypes();
if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
tree.varargsElement = null;
// If created class is local, add free variables after
// explicit constructor arguments.
if (c.isLocal()) {
tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
}
// If an access constructor is used, append null as a last argument.
Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
if (constructor != tree.constructor) {
tree.args = tree.args.append(makeNull());
tree.constructor = constructor;
}
// If created class has an outer instance, and new is qualified, pass
// qualifier as first argument. If new is not qualified, pass the
// correct outer instance as first argument.
if (c.hasOuterInstance()) {
JCExpression thisArg;
if (tree.encl != null) {
thisArg = attr.makeNullCheck(translate(tree.encl));
thisArg.type = tree.encl.type;
} else if (c.isLocal()) {
// local class
thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym);
} else {
// nested class
thisArg = makeOwnerThis(tree.pos(), c, false);
}
tree.args = tree.args.prepend(thisArg);
}
tree.encl = null;
// If we have an anonymous class, create its flat version, rather
// than the class or interface following new.
if (tree.def != null) {
translate(tree.def);
tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
tree.def = null;
} else {
tree.clazz = access(c, tree.clazz, enclOp, false);
}
result = tree;
}
// Simplify conditionals with known constant controlling expressions.
// This allows us to avoid generating supporting declarations for
// the dead code, which will not be eliminated during code generation.
// Note that Flow.isFalse and Flow.isTrue only return true
// for constant expressions in the sense of JLS 15.27, which
// are guaranteed to have no side-effects. More aggressive
// constant propagation would require that we take care to
// preserve possible side-effects in the condition expression.
// One common case is equality expressions involving a constant and null.
// Since null is not a constant expression (because null cannot be
// represented in the constant pool), equality checks involving null are
// not captured by Flow.isTrue/isFalse.
// Equality checks involving a constant and null, e.g.
// "" == null
// are safe to simplify as no side-effects can occur.
private boolean isTrue(JCTree exp) {
if (exp.type.isTrue())
return true;
Boolean b = expValue(exp);
return b == null ? false : b;
}
private boolean isFalse(JCTree exp) {
if (exp.type.isFalse())
return true;
Boolean b = expValue(exp);
return b == null ? false : !b;
}
/* look for (in)equality relations involving null.
* return true - if expression is always true
* false - if expression is always false
* null - if expression cannot be eliminated
*/
private Boolean expValue(JCTree exp) {
while (exp.hasTag(PARENS))
exp = ((JCParens)exp).expr;
boolean eq;
switch (exp.getTag()) {
case EQ: eq = true; break;
case NE: eq = false; break;
default:
return null;
}
// we have a JCBinary(EQ|NE)
// check if we have two literals (constants or null)
JCBinary b = (JCBinary)exp;
if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs);
if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs);
return null;
}
private Boolean expValueIsNull(boolean eq, JCTree t) {
if (t.type.hasTag(BOT)) return Boolean.valueOf(eq);
if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq);
return null;
}
/** Visitor method for conditional expressions.
*/
@Override
public void visitConditional(JCConditional tree) {
JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
if (isTrue(cond)) {
result = convert(translate(tree.truepart, tree.type), tree.type);
addPrunedInfo(cond);
} else if (isFalse(cond)) {
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);
tree.falsepart = translate(tree.falsepart, tree.type);
result = tree;
}
}
//where
private JCExpression convert(JCExpression tree, Type pt) {
if (tree.type == pt || tree.type.hasTag(BOT))
return tree;
JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree);
result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
: pt;
return result;
}
/** Visitor method for if statements.
*/
public void visitIf(JCIf tree) {
JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
if (isTrue(cond)) {
result = translate(tree.thenpart);
addPrunedInfo(cond);
} else if (isFalse(cond)) {
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);
tree.elsepart = translate(tree.elsepart);
result = tree;
}
}
/** Visitor method for assert statements. Translate them away.
*/
public void visitAssert(JCAssert tree) {
tree.cond = translate(tree.cond, syms.booleanType);
if (!tree.cond.type.isTrue()) {
JCExpression cond = assertFlagTest(tree.pos());
List<JCExpression> exnArgs = (tree.detail == null) ?
List.nil() : List.of(translate(tree.detail));
if (!tree.cond.type.isFalse()) {
cond = makeBinary
(AND,
cond,
makeUnary(NOT, tree.cond));
}
result =
make.If(cond,
make_at(tree).
Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
null);
} else {
result = make.Skip();
}
}
public void visitApply(JCMethodInvocation tree) {
Symbol meth = TreeInfo.symbol(tree.meth);
List<Type> argtypes = meth.type.getParameterTypes();
if (meth.name == names.init && meth.owner == syms.enumSym)
argtypes = argtypes.tail.tail;
tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
tree.varargsElement = null;
Name methName = TreeInfo.name(tree.meth);
if (meth.name==names.init) {
// We are seeing a this(...) or super(...) constructor call.
// If an access constructor is used, append null as a last argument.
Symbol constructor = accessConstructor(tree.pos(), meth);
if (constructor != meth) {
tree.args = tree.args.append(makeNull());
TreeInfo.setSymbol(tree.meth, constructor);
}
// If we are calling a constructor of a local class, add
// free variables after explicit constructor arguments.
ClassSymbol c = (ClassSymbol)constructor.owner;
if (c.isLocal()) {
tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
}
// If we are calling a constructor of an enum class, pass
// along the name and ordinal arguments
if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
List<JCVariableDecl> params = currentMethodDef.params;
if (currentMethodSym.owner.hasOuterInstance())
params = params.tail; // drop this$n
tree.args = tree.args
.prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
.prepend(make.Ident(params.head.sym)); // name
}
// If we are calling a constructor of a class with an outer
// instance, and the call
// is qualified, pass qualifier as first argument in front of
// the explicit constructor arguments. If the call
// is not qualified, pass the correct outer instance as
// first argument.
if (c.hasOuterInstance()) {
JCExpression thisArg;
if (tree.meth.hasTag(SELECT)) {
thisArg = attr.
makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
tree.meth = make.Ident(constructor);
((JCIdent) tree.meth).name = methName;
} else if (c.isLocal() || methName == names._this){
// local class or this() call
thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym);
} else {
// super() call of nested class - never pick 'this'
thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
}
tree.args = tree.args.prepend(thisArg);
}
} else {
// We are seeing a normal method invocation; translate this as usual.
tree.meth = translate(tree.meth);
// If the translated method itself is an Apply tree, we are
// seeing an access method invocation. In this case, append
// the method arguments to the arguments of the access method.
if (tree.meth.hasTag(APPLY)) {
JCMethodInvocation app = (JCMethodInvocation)tree.meth;
app.args = tree.args.prependList(app.args);
result = app;
return;
}
}
result = tree;
}
List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
List<JCExpression> args = _args;
if (parameters.isEmpty()) return args;
boolean anyChanges = false;
ListBuffer<JCExpression> result = new ListBuffer<>();
while (parameters.tail.nonEmpty()) {
JCExpression arg = translate(args.head, parameters.head);
anyChanges |= (arg != args.head);
result.append(arg);
args = args.tail;
parameters = parameters.tail;
}
Type parameter = parameters.head;
if (varargsElement != null) {
anyChanges = true;
ListBuffer<JCExpression> elems = new ListBuffer<>();
while (args.nonEmpty()) {
JCExpression arg = translate(args.head, varargsElement);
elems.append(arg);
args = args.tail;
}
JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
List.nil(),
elems.toList());
boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
result.append(boxedArgs);
} else {
if (args.length() != 1) throw new AssertionError(args);
JCExpression arg = translate(args.head, parameter);
anyChanges |= (arg != args.head);
result.append(arg);
if (!anyChanges) return _args;
}
return result.toList();
}
/** Expand a boxing or unboxing conversion if needed. */
@SuppressWarnings("unchecked") // XXX unchecked
<T extends JCExpression> T boxIfNeeded(T tree, Type type) {
boolean havePrimitive = tree.type.isPrimitive();
if (havePrimitive == type.isPrimitive())
return tree;
if (havePrimitive) {
Type unboxedTarget = types.unboxedType(type);
if (!unboxedTarget.hasTag(NONE)) {
if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
tree.type = unboxedTarget.constType(tree.type.constValue());
return (T)boxPrimitive(tree, types.erasure(type));
} else {
tree = (T)boxPrimitive(tree);
}
} else {
tree = (T)unbox(tree, type);
}
return tree;
}
/** Box up a single primitive expression. */
JCExpression boxPrimitive(JCExpression tree) {
return boxPrimitive(tree, types.boxedClass(tree.type).type);
}
/** Box up a single primitive expression. */
JCExpression boxPrimitive(JCExpression tree, Type box) {
make_at(tree.pos());
Symbol valueOfSym = lookupMethod(tree.pos(),
names.valueOf,
box,
List.<Type>nil()
.prepend(tree.type));
return make.App(make.QualIdent(valueOfSym), List.of(tree));
}
/** Unbox an object to a primitive value. */
JCExpression unbox(JCExpression tree, Type primitive) {
Type unboxedType = types.unboxedType(tree.type);
if (unboxedType.hasTag(NONE)) {
unboxedType = primitive;
if (!unboxedType.isPrimitive())
throw new AssertionError(unboxedType);
make_at(tree.pos());
tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
} else {
// There must be a conversion from unboxedType to primitive.
if (!types.isSubtype(unboxedType, primitive))
throw new AssertionError(tree);
}
make_at(tree.pos());
Symbol valueSym = lookupMethod(tree.pos(),
unboxedType.tsym.name.append(names.Value), // x.intValue()
tree.type,
List.nil());
return make.App(make.Select(tree, valueSym));
}
/** Visitor method for parenthesized expressions.
* If the subexpression has changed, omit the parens.
*/
public void visitParens(JCParens tree) {
JCTree expr = translate(tree.expr);
result = ((expr == tree.expr) ? tree : expr);
}
public void visitIndexed(JCArrayAccess tree) {
tree.indexed = translate(tree.indexed);
tree.index = translate(tree.index, syms.intType);
result = tree;
}
public void visitAssign(JCAssign tree) {
tree.lhs = translate(tree.lhs, tree);
tree.rhs = translate(tree.rhs, tree.lhs.type);
// If translated left hand side is an Apply, we are
// seeing an access method invocation. In this case, append
// right hand side as last argument of the access method.
if (tree.lhs.hasTag(APPLY)) {
JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
app.args = List.of(tree.rhs).prependList(app.args);
result = app;
} else {
result = tree;
}
}
public void visitAssignop(final JCAssignOp tree) {
final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
tree.operator.type.getReturnType().isPrimitive();
AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree);
depScanner.scan(tree.rhs);
if (boxingReq || depScanner.dependencyFound) {
// boxing required; need to rewrite as x = (unbox typeof x)(x op y);
// or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
// (but without recomputing x)
JCTree newTree = abstractLval(tree.lhs, lhs -> {
Tag newTag = tree.getTag().noAssignOp();
// Erasure (TransTypes) can change the type of
// tree.lhs. However, we can still get the
// unerased type of tree.lhs as it is stored
// in tree.type in Attr.
OperatorSymbol newOperator = operators.resolveBinary(tree,
newTag,
tree.type,
tree.rhs.type);
//Need to use the "lhs" at two places, once on the future left hand side
//and once in the future binary operator. But further processing may change
//the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>),
//so cloning the tree to avoid interference between the uses:
JCExpression expr = (JCExpression) lhs.clone();
if (expr.type != tree.type)
expr = make.TypeCast(tree.type, expr);
JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
opResult.operator = newOperator;
opResult.type = newOperator.type.getReturnType();
JCExpression newRhs = boxingReq ?
make.TypeCast(types.unboxedType(tree.type), opResult) :
opResult;
return make.Assign(lhs, newRhs).setType(tree.type);
});
result = translate(newTree);
return;
}
tree.lhs = translate(tree.lhs, tree);
tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
// If translated left hand side is an Apply, we are
// seeing an access method invocation. In this case, append
// right hand side as last argument of the access method.
if (tree.lhs.hasTag(APPLY)) {
JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
// if operation is a += on strings,
// make sure to convert argument to string
JCExpression rhs = tree.operator.opcode == string_add
? makeString(tree.rhs)
: tree.rhs;
app.args = List.of(rhs).prependList(app.args);
result = app;
} else {
result = tree;
}
}
class AssignopDependencyScanner extends TreeScanner {
Symbol sym;
boolean dependencyFound = false;
AssignopDependencyScanner(JCAssignOp tree) {
this.sym = TreeInfo.symbol(tree.lhs);
}
@Override
public void scan(JCTree tree) {
if (tree != null && sym != null) {
tree.accept(this);
}
}
@Override
public void visitAssignop(JCAssignOp tree) {
if (TreeInfo.symbol(tree.lhs) == sym) {
dependencyFound = true;
return;
}
super.visitAssignop(tree);
}
@Override
public void visitUnary(JCUnary tree) {
if (TreeInfo.symbol(tree.arg) == sym) {
dependencyFound = true;
return;
}
super.visitUnary(tree);
}
}
/** Lower a tree of the form e++ or e-- where e is an object type */
JCExpression lowerBoxedPostop(final JCUnary tree) {
// translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
// or
// translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
// where OP is += or -=
final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> {
Tag opcode = (tree.hasTag(POSTINC))
? PLUS_ASG : MINUS_ASG;
//"tmp1" and "tmp2" may refer to the same instance
//(for e.g. <Class>.super.<ident>). But further processing may
//change the components of the tree in place (see visitSelect),
//so cloning the tree to avoid interference between the two uses:
JCExpression lhs = (JCExpression)tmp1.clone();
lhs = cast
? make.TypeCast(tree.arg.type, lhs)
: lhs;
JCExpression update = makeAssignop(opcode,
lhs,
make.Literal(1));
return makeComma(update, tmp2);
}));
}
public void visitUnary(JCUnary tree) {
boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
switch(tree.getTag()) {
case PREINC: // ++ e
// translate to e += 1
case PREDEC: // -- e
// translate to e -= 1
{
JCTree.Tag opcode = (tree.hasTag(PREINC))
? PLUS_ASG : MINUS_ASG;
JCAssignOp newTree = makeAssignop(opcode,
tree.arg,
make.Literal(1));
result = translate(newTree, tree.type);
return;
}
case POSTINC: // e ++
case POSTDEC: // e --
{
result = translate(lowerBoxedPostop(tree), tree.type);
return;
}
}
throw new AssertionError(tree);
}
tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
tree.type = cfolder.fold1(bool_not, tree.arg.type);
}
// If translated left hand side is an Apply, we are
// seeing an access method invocation. In this case, return
// that access method invocation as result.
if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
result = tree.arg;
} else {
result = tree;
}
}
public void visitBinary(JCBinary tree) {
List<Type> formals = tree.operator.type.getParameterTypes();
JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
switch (tree.getTag()) {
case OR:
if (isTrue(lhs)) {
result = lhs;
return;
}
if (isFalse(lhs)) {
result = translate(tree.rhs, formals.tail.head);
return;
}
break;
case AND:
if (isFalse(lhs)) {
result = lhs;
return;
}
if (isTrue(lhs)) {
result = translate(tree.rhs, formals.tail.head);
return;
}
break;
}
tree.rhs = translate(tree.rhs, formals.tail.head);
result = tree;
}
public void visitIdent(JCIdent tree) {
result = access(tree.sym, tree, enclOp, false);
}
/** Translate away the foreach loop. */
public void visitForeachLoop(JCEnhancedForLoop tree) {
if (types.elemtype(tree.expr.type) == null)
visitIterableForeachLoop(tree);
else
visitArrayForeachLoop(tree);
}
// where
/**
* A statement of the form
*
* <pre>
* for ( T v : arrayexpr ) stmt;
* </pre>
*
* (where arrayexpr is of an array type) gets translated to
*
* <pre>{@code
* for ( { arraytype #arr = arrayexpr;
* int #len = array.length;
* int #i = 0; };
* #i < #len; i$++ ) {
* T v = arr$[#i];
* stmt;
* }
* }</pre>
*
* where #arr, #len, and #i are freshly named synthetic local variables.
*/
private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
make_at(tree.expr.pos());
VarSymbol arraycache = new VarSymbol(SYNTHETIC,
names.fromString("arr" + target.syntheticNameChar()),
tree.expr.type,
currentMethodSym);
JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
VarSymbol lencache = new VarSymbol(SYNTHETIC,
names.fromString("len" + target.syntheticNameChar()),
syms.intType,
currentMethodSym);
JCStatement lencachedef = make.
VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
VarSymbol index = new VarSymbol(SYNTHETIC,
names.fromString("i" + target.syntheticNameChar()),
syms.intType,
currentMethodSym);
JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
indexdef.init.type = indexdef.type = syms.intType.constType(0);
List<JCStatement> loopinit = List.of(lencachedef, indexdef);
JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
Type elemtype = types.elemtype(tree.expr.type);
JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
make.Ident(index)).setType(elemtype);
JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
tree.var.name,
tree.var.vartype, loopvarinit).setType(tree.var.type);
loopvardef.sym = tree.var.sym;
JCBlock body = make.Block(0, List.of(loopvardef, tree.body));
arraycachedef = translate(arraycachedef);
result = translate(make.
ForLoop(loopinit,
cond,
List.of(step),
body));
patchTargets(body, tree, result);
JCStatement nullAssignToArr = make.Assignment(arraycache, make.Literal(BOT, null).setType(syms.botType));
result = make.Block(0, List.of(arraycachedef, (JCStatement)result, nullAssignToArr));
}
/** Patch up break and continue targets. */
private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
class Patcher extends TreeScanner {
public void visitBreak(JCBreak tree) {
if (tree.target == src)
tree.target = dest;
}
public void visitContinue(JCContinue tree) {
if (tree.target == src)
tree.target = dest;
}
public void visitClassDef(JCClassDecl tree) {}
}
new Patcher().scan(body);
}
/**
* A statement of the form
*
* <pre>
* for ( T v : coll ) stmt ;
* </pre>
*
* (where coll implements {@code Iterable<? extends T>}) gets translated to
*
* <pre>{@code
* for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
* T v = (T) #i.next();
* stmt;
* }
* }</pre>
*
* where #i is a freshly named synthetic local variable.
*/
private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
make_at(tree.expr.pos());
Type iteratorTarget = syms.objectType;
Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type),
syms.iterableType.tsym);
if (iterableType.getTypeArguments().nonEmpty())
iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
Type eType = types.skipTypeVars(tree.expr.type, false);
tree.expr.type = types.erasure(eType);
if (eType.isCompound())
tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr);
Symbol iterator = lookupMethod(tree.expr.pos(),
names.iterator,
eType,
List.nil());
VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)),
currentMethodSym);
JCStatement init = make.
VarDef(itvar, make.App(make.Select(tree.expr, iterator)
.setType(types.erasure(iterator.type))));
Symbol hasNext = lookupMethod(tree.expr.pos(),
names.hasNext,
itvar.type,
List.nil());
JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
Symbol next = lookupMethod(tree.expr.pos(),
names.next,
itvar.type,
List.nil());
JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
if (tree.var.type.isPrimitive())
vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
else
vardefinit = make.TypeCast(tree.var.type, vardefinit);
JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
tree.var.name,
tree.var.vartype,
vardefinit).setType(tree.var.type);
indexDef.sym = tree.var.sym;
JCBlock body = make.Block(0, List.of(indexDef, tree.body));
body.endpos = TreeInfo.endPos(tree.body);
init = translate(init);
result = translate(make.
ForLoop(List.nil(),
cond,
List.nil(),
body));
patchTargets(body, tree, result);
JCStatement nullAssignToIterator = make.Assignment(itvar, make.Literal(BOT, null).setType(syms.botType));
result = make.Block(0, List.of(init, (JCStatement)result, nullAssignToIterator));
}
public void visitVarDef(JCVariableDecl tree) {
MethodSymbol oldMethodSym = currentMethodSym;
tree.mods = translate(tree.mods);
tree.vartype = translate(tree.vartype);
if (currentMethodSym == null) {
// A class or instance field initializer.
currentMethodSym =
new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
names.empty, null,
currentClass);
}
if (tree.init != null) tree.init = translate(tree.init, tree.type);
result = tree;
currentMethodSym = oldMethodSym;
}
public void visitBlock(JCBlock tree) {
MethodSymbol oldMethodSym = currentMethodSym;
if (currentMethodSym == null) {
// Block is a static or instance initializer.
currentMethodSym =
new MethodSymbol(tree.flags | BLOCK,
names.empty, null,
currentClass);
}
super.visitBlock(tree);
currentMethodSym = oldMethodSym;
}
public void visitDoLoop(JCDoWhileLoop tree) {
tree.body = translate(tree.body);
tree.cond = translate(tree.cond, syms.booleanType);
result = tree;
}
public void visitWhileLoop(JCWhileLoop tree) {
tree.cond = translate(tree.cond, syms.booleanType);
tree.body = translate(tree.body);
result = tree;
}
public void visitForLoop(JCForLoop tree) {
tree.init = translate(tree.init);
if (tree.cond != null)
tree.cond = translate(tree.cond, syms.booleanType);
tree.step = translate(tree.step);
tree.body = translate(tree.body);
result = tree;
}
public void visitReturn(JCReturn tree) {
if (tree.expr != null)
tree.expr = translate(tree.expr,
types.erasure(currentMethodDef
.restype.type));
result = tree;
}
public void visitSwitch(JCSwitch tree) {
Type selsuper = types.supertype(tree.selector.type);
boolean enumSwitch = selsuper != null &&
(tree.selector.type.tsym.flags() & ENUM) != 0;
boolean stringSwitch = selsuper != null &&
types.isSameType(tree.selector.type, syms.stringType);
Type target = enumSwitch ? tree.selector.type :
(stringSwitch? syms.stringType : syms.intType);
tree.selector = translate(tree.selector, target);
tree.cases = translateCases(tree.cases);
if (enumSwitch) {
result = visitEnumSwitch(tree);
} else if (stringSwitch) {
result = visitStringSwitch(tree);
} else {
result = tree;
}
}
public JCTree visitEnumSwitch(JCSwitch tree) {
TypeSymbol enumSym = tree.selector.type.tsym;
EnumMapping map = mapForEnum(tree.pos(), enumSym);
make_at(tree.pos());
Symbol ordinalMethod = lookupMethod(tree.pos(),
names.ordinal,
tree.selector.type,
List.nil());
JCArrayAccess selector = make.Indexed(map.mapVar,
make.App(make.Select(tree.selector,
ordinalMethod)));
ListBuffer<JCCase> cases = new ListBuffer<>();
for (JCCase c : tree.cases) {
if (c.pat != null) {
VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat);
JCLiteral pat = map.forConstant(label);
cases.append(make.Case(pat, c.stats));
} else {
cases.append(c);
}
}
JCSwitch enumSwitch = make.Switch(selector, cases.toList());
patchTargets(enumSwitch, tree, enumSwitch);
return enumSwitch;
}
public JCTree visitStringSwitch(JCSwitch tree) {
List<JCCase> caseList = tree.getCases();
int alternatives = caseList.size();
if (alternatives == 0) { // Strange but legal possibility
return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression()));
} else {
/*
* The general approach used is to translate a single
* string switch statement into a series of two chained
* switch statements: the first a synthesized statement
* switching on the argument string's hash value and
* computing a string's position in the list of original
* case labels, if any, followed by a second switch on the
* computed integer value. The second switch has the same
* code structure as the original string switch statement
* except that the string case labels are replaced with
* positional integer constants starting at 0.
*
* The first switch statement can be thought of as an
* inlined map from strings to their position in the case
* label list. An alternate implementation would use an
* actual Map for this purpose, as done for enum switches.
*
* With some additional effort, it would be possible to
* use a single switch statement on the hash code of the
* argument, but care would need to be taken to preserve
* the proper control flow in the presence of hash
* collisions and other complications, such as
* fallthroughs. Switch statements with one or two
* alternatives could also be specially translated into
* if-then statements to omit the computation of the hash
* code.
*
* The generated code assumes that the hashing algorithm
* of String is the same in the compilation environment as
* in the environment the code will run in. The string
* hashing algorithm in the SE JDK has been unchanged
* since at least JDK 1.2. Since the algorithm has been
* specified since that release as well, it is very
* unlikely to be changed in the future.
*
* Different hashing algorithms, such as the length of the
* strings or a perfect hashing algorithm over the
* particular set of case labels, could potentially be
* used instead of String.hashCode.
*/
ListBuffer<JCStatement> stmtList = new ListBuffer<>();
// Map from String case labels to their original position in
// the list of case labels.
Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f);
// Map of hash codes to the string case labels having that hashCode.
Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f);
int casePosition = 0;
for(JCCase oneCase : caseList) {
JCExpression expression = oneCase.getExpression();
if (expression != null) { // expression for a "default" case is null
String labelExpr = (String) expression.type.constValue();
Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
Assert.checkNull(mapping);
int hashCode = labelExpr.hashCode();
Set<String> stringSet = hashToString.get(hashCode);
if (stringSet == null) {
stringSet = new LinkedHashSet<>(1, 1.0f);
stringSet.add(labelExpr);
hashToString.put(hashCode, stringSet);
} else {
boolean added = stringSet.add(labelExpr);
Assert.check(added);
}
}
casePosition++;
}
// Synthesize a switch statement that has the effect of
// mapping from a string to the integer position of that
// string in the list of case labels. This is done by
// switching on the hashCode of the string followed by an
// if-then-else chain comparing the input for equality
// with all the case labels having that hash value.
/*
* s$ = top of stack;
* tmp$ = -1;
* switch($s.hashCode()) {
* case caseLabel.hashCode:
* if (s$.equals("caseLabel_1")
* tmp$ = caseLabelToPosition("caseLabel_1");
* else if (s$.equals("caseLabel_2"))
* tmp$ = caseLabelToPosition("caseLabel_2");
* ...
* break;
* ...
* }
*/
VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
names.fromString("s" + tree.pos + target.syntheticNameChar()),
syms.stringType,
currentMethodSym);
stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type));
VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
names.fromString("tmp" + tree.pos + target.syntheticNameChar()),
syms.intType,
currentMethodSym);
JCVariableDecl dollar_tmp_def =
(JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
stmtList.append(dollar_tmp_def);
ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
// hashCode will trigger nullcheck on original switch expression
JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
names.hashCode,
List.nil()).setType(syms.intType);
JCSwitch switch1 = make.Switch(hashCodeCall,
caseBuffer.toList());
for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
int hashCode = entry.getKey();
Set<String> stringsWithHashCode = entry.getValue();
Assert.check(stringsWithHashCode.size() >= 1);
JCStatement elsepart = null;
for(String caseLabel : stringsWithHashCode ) {
JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
names.equals,
List.of(make.Literal(caseLabel)));
elsepart = make.If(stringEqualsCall,
make.Exec(make.Assign(make.Ident(dollar_tmp),
make.Literal(caseLabelToPosition.get(caseLabel))).
setType(dollar_tmp.type)),
elsepart);
}
ListBuffer<JCStatement> lb = new ListBuffer<>();
JCBreak breakStmt = make.Break(null);
breakStmt.target = switch1;
lb.append(elsepart).append(breakStmt);
caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList()));
}
switch1.cases = caseBuffer.toList();
stmtList.append(switch1);
// Make isomorphic switch tree replacing string labels
// with corresponding integer ones from the label to
// position map.
ListBuffer<JCCase> lb = new ListBuffer<>();
JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
for(JCCase oneCase : caseList ) {
// Rewire up old unlabeled break statements to the
// replacement switch being created.
patchTargets(oneCase, tree, switch2);
boolean isDefault = (oneCase.getExpression() == null);
JCExpression caseExpr;
if (isDefault)
caseExpr = null;
else {
caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens(oneCase.
getExpression()).
type.constValue()));
}
lb.append(make.Case(caseExpr,
oneCase.getStatements()));
}
switch2.cases = lb.toList();
stmtList.append(switch2);
return make.Block(0L, stmtList.toList());
}
}
public void visitNewArray(JCNewArray tree) {
tree.elemtype = translate(tree.elemtype);
for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
if (t.head != null) t.head = translate(t.head, syms.intType);
tree.elems = translate(tree.elems, types.elemtype(tree.type));
result = tree;
}
public void visitSelect(JCFieldAccess tree) {
// need to special case-access of the form C.super.x
// these will always need an access method, unless C
// is a default interface subclassed by the current class.
boolean qualifiedSuperAccess =
tree.selected.hasTag(SELECT) &&
TreeInfo.name(tree.selected) == names._super &&
!types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
tree.selected = translate(tree.selected);
if (tree.name == names._class) {
result = classOf(tree.selected);
}
else if (tree.name == names._super &&
types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
//default super call!! Not a classic qualified super call
TypeSymbol supSym = tree.selected.type.tsym;
Assert.checkNonNull(types.asSuper(currentClass.type, supSym));
result = tree;
}
else if (tree.name == names._this || tree.name == names._super) {
result = makeThis(tree.pos(), tree.selected.type.tsym);
}
else
result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
}
public void visitLetExpr(LetExpr tree) {
tree.defs = translateVarDefs(tree.defs);
tree.expr = translate(tree.expr, tree.type);
result = tree;
}
// There ought to be nothing to rewrite here;
// we don't generate code.
public void visitAnnotation(JCAnnotation tree) {
result = tree;
}
@Override
public void visitTry(JCTry tree) {
if (tree.resources.nonEmpty()) {
result = makeTwrTry(tree);
return;
}
boolean hasBody = tree.body.getStatements().nonEmpty();
boolean hasCatchers = tree.catchers.nonEmpty();
boolean hasFinally = tree.finalizer != null &&
tree.finalizer.getStatements().nonEmpty();
if (!hasCatchers && !hasFinally) {
result = translate(tree.body);
return;
}
if (!hasBody) {
if (hasFinally) {
result = translate(tree.finalizer);
} else {
result = translate(tree.body);
}
return;
}
// no optimizations possible
super.visitTry(tree);
}
/**************************************************************************
* main method
*************************************************************************/
/** Translate a toplevel class and return a list consisting of
* the translated class and translated versions of all inner classes.
* @param env The attribution environment current at the class definition.
* We need this for resolving some additional symbols.
* @param cdef The tree representing the class definition.
*/
public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
ListBuffer<JCTree> translated = null;
try {
attrEnv = env;
this.make = make;
endPosTable = env.toplevel.endPositions;
currentClass = null;
currentMethodDef = null;
outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
outermostMemberDef = null;
this.translated = new ListBuffer<>();
classdefs = new HashMap<>();
actualSymbols = new HashMap<>();
freevarCache = new HashMap<>();
proxies = new HashMap<>();
twrVars = WriteableScope.create(syms.noSymbol);
outerThisStack = List.nil();
accessNums = new HashMap<>();
accessSyms = new HashMap<>();
accessConstrs = new HashMap<>();
accessConstrTags = List.nil();
accessed = new ListBuffer<>();
translate(cdef, (JCExpression)null);
for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
makeAccessible(l.head);
for (EnumMapping map : enumSwitchMap.values())
map.translate();
checkConflicts(this.translated.toList());
checkAccessConstructorTags();
translated = this.translated;
} finally {
// note that recursive invocations of this method fail hard
attrEnv = null;
this.make = null;
endPosTable = null;
currentClass = null;
currentMethodDef = null;
outermostClassDef = null;
outermostMemberDef = null;
this.translated = null;
classdefs = null;
actualSymbols = null;
freevarCache = null;
proxies = null;
outerThisStack = null;
accessNums = null;
accessSyms = null;
accessConstrs = null;
accessConstrTags = null;
accessed = null;
enumSwitchMap.clear();
assertionsDisabledClassCache = null;
}
return translated.toList();
}
}