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The Gen.java Java example source code
/*
* Copyright (c) 1999, 2013, 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.jvm;
import java.util.*;
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.*;
import com.sun.tools.javac.code.Attribute.TypeCompound;
import com.sun.tools.javac.code.Symbol.VarSymbol;
import com.sun.tools.javac.comp.*;
import com.sun.tools.javac.tree.*;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.jvm.Code.*;
import com.sun.tools.javac.jvm.Items.*;
import com.sun.tools.javac.tree.EndPosTable;
import com.sun.tools.javac.tree.JCTree.*;
import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Kinds.*;
import static com.sun.tools.javac.code.TypeTag.*;
import static com.sun.tools.javac.jvm.ByteCodes.*;
import static com.sun.tools.javac.jvm.CRTFlags.*;
import static com.sun.tools.javac.main.Option.*;
import static com.sun.tools.javac.tree.JCTree.Tag.*;
/** This pass maps flat Java (i.e. without inner classes) to bytecodes.
*
* <p>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 Gen extends JCTree.Visitor {
protected static final Context.Key<Gen> genKey =
new Context.Key<Gen>();
private final Log log;
private final Symtab syms;
private final Check chk;
private final Resolve rs;
private final TreeMaker make;
private final Names names;
private final Target target;
private final Type stringBufferType;
private final Map<Type,Symbol> stringBufferAppend;
private Name accessDollar;
private final Types types;
private final Lower lower;
/** Switch: GJ mode?
*/
private final boolean allowGenerics;
/** Set when Miranda method stubs are to be generated. */
private final boolean generateIproxies;
/** Format of stackmap tables to be generated. */
private final Code.StackMapFormat stackMap;
/** A type that serves as the expected type for all method expressions.
*/
private final Type methodType;
public static Gen instance(Context context) {
Gen instance = context.get(genKey);
if (instance == null)
instance = new Gen(context);
return instance;
}
/** Constant pool, reset by genClass.
*/
private Pool pool;
/** LVTRanges info.
*/
private LVTRanges lvtRanges;
private final boolean typeAnnoAsserts;
protected Gen(Context context) {
context.put(genKey, this);
names = Names.instance(context);
log = Log.instance(context);
syms = Symtab.instance(context);
chk = Check.instance(context);
rs = Resolve.instance(context);
make = TreeMaker.instance(context);
target = Target.instance(context);
types = Types.instance(context);
methodType = new MethodType(null, null, null, syms.methodClass);
allowGenerics = Source.instance(context).allowGenerics();
stringBufferType = target.useStringBuilder()
? syms.stringBuilderType
: syms.stringBufferType;
stringBufferAppend = new HashMap<Type,Symbol>();
accessDollar = names.
fromString("access" + target.syntheticNameChar());
lower = Lower.instance(context);
Options options = Options.instance(context);
lineDebugInfo =
options.isUnset(G_CUSTOM) ||
options.isSet(G_CUSTOM, "lines");
varDebugInfo =
options.isUnset(G_CUSTOM)
? options.isSet(G)
: options.isSet(G_CUSTOM, "vars");
if (varDebugInfo) {
lvtRanges = LVTRanges.instance(context);
}
genCrt = options.isSet(XJCOV);
debugCode = options.isSet("debugcode");
allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic");
pool = new Pool(types);
typeAnnoAsserts = options.isSet("TypeAnnotationAsserts");
generateIproxies =
target.requiresIproxy() ||
options.isSet("miranda");
if (target.generateStackMapTable()) {
// ignore cldc because we cannot have both stackmap formats
this.stackMap = StackMapFormat.JSR202;
} else {
if (target.generateCLDCStackmap()) {
this.stackMap = StackMapFormat.CLDC;
} else {
this.stackMap = StackMapFormat.NONE;
}
}
// by default, avoid jsr's for simple finalizers
int setjsrlimit = 50;
String jsrlimitString = options.get("jsrlimit");
if (jsrlimitString != null) {
try {
setjsrlimit = Integer.parseInt(jsrlimitString);
} catch (NumberFormatException ex) {
// ignore ill-formed numbers for jsrlimit
}
}
this.jsrlimit = setjsrlimit;
this.useJsrLocally = false; // reset in visitTry
}
/** Switches
*/
private final boolean lineDebugInfo;
private final boolean varDebugInfo;
private final boolean genCrt;
private final boolean debugCode;
private final boolean allowInvokedynamic;
/** Default limit of (approximate) size of finalizer to inline.
* Zero means always use jsr. 100 or greater means never use
* jsr.
*/
private final int jsrlimit;
/** True if jsr is used.
*/
private boolean useJsrLocally;
/** Code buffer, set by genMethod.
*/
private Code code;
/** Items structure, set by genMethod.
*/
private Items items;
/** Environment for symbol lookup, set by genClass
*/
private Env<AttrContext> attrEnv;
/** The top level tree.
*/
private JCCompilationUnit toplevel;
/** The number of code-gen errors in this class.
*/
private int nerrs = 0;
/** An object containing mappings of syntax trees to their
* ending source positions.
*/
EndPosTable endPosTable;
/** Generate code to load an integer constant.
* @param n The integer to be loaded.
*/
void loadIntConst(int n) {
items.makeImmediateItem(syms.intType, n).load();
}
/** The opcode that loads a zero constant of a given type code.
* @param tc The given type code (@see ByteCode).
*/
public static int zero(int tc) {
switch(tc) {
case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
return iconst_0;
case LONGcode:
return lconst_0;
case FLOATcode:
return fconst_0;
case DOUBLEcode:
return dconst_0;
default:
throw new AssertionError("zero");
}
}
/** The opcode that loads a one constant of a given type code.
* @param tc The given type code (@see ByteCode).
*/
public static int one(int tc) {
return zero(tc) + 1;
}
/** Generate code to load -1 of the given type code (either int or long).
* @param tc The given type code (@see ByteCode).
*/
void emitMinusOne(int tc) {
if (tc == LONGcode) {
items.makeImmediateItem(syms.longType, new Long(-1)).load();
} else {
code.emitop0(iconst_m1);
}
}
/** Construct a symbol to reflect the qualifying type that should
* appear in the byte code as per JLS 13.1.
*
* For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
* for those cases where we need to work around VM bugs).
*
* For {@literal target <= 1.1}: If qualified variable or method is defined in a
* non-accessible class, clone it with the qualifier class as owner.
*
* @param sym The accessed symbol
* @param site The qualifier's type.
*/
Symbol binaryQualifier(Symbol sym, Type site) {
if (site.hasTag(ARRAY)) {
if (sym == syms.lengthVar ||
sym.owner != syms.arrayClass)
return sym;
// array clone can be qualified by the array type in later targets
Symbol qualifier = target.arrayBinaryCompatibility()
? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
site, syms.noSymbol)
: syms.objectType.tsym;
return sym.clone(qualifier);
}
if (sym.owner == site.tsym ||
(sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
return sym;
}
if (!target.obeyBinaryCompatibility())
return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
? sym
: sym.clone(site.tsym);
if (!target.interfaceFieldsBinaryCompatibility()) {
if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
return sym;
}
// leave alone methods inherited from Object
// JLS 13.1.
if (sym.owner == syms.objectType.tsym)
return sym;
if (!target.interfaceObjectOverridesBinaryCompatibility()) {
if ((sym.owner.flags() & INTERFACE) != 0 &&
syms.objectType.tsym.members().lookup(sym.name).scope != null)
return sym;
}
return sym.clone(site.tsym);
}
/** Insert a reference to given type in the constant pool,
* checking for an array with too many dimensions;
* return the reference's index.
* @param type The type for which a reference is inserted.
*/
int makeRef(DiagnosticPosition pos, Type type) {
checkDimension(pos, type);
if (type.isAnnotated()) {
// Treat annotated types separately - we don't want
// to collapse all of them - at least for annotated
// exceptions.
// TODO: review this.
return pool.put((Object)type);
} else {
return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type);
}
}
/** Check if the given type is an array with too many dimensions.
*/
private void checkDimension(DiagnosticPosition pos, Type t) {
switch (t.getTag()) {
case METHOD:
checkDimension(pos, t.getReturnType());
for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
checkDimension(pos, args.head);
break;
case ARRAY:
if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
log.error(pos, "limit.dimensions");
nerrs++;
}
break;
default:
break;
}
}
/** Create a tempory variable.
* @param type The variable's type.
*/
LocalItem makeTemp(Type type) {
VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
names.empty,
type,
env.enclMethod.sym);
code.newLocal(v);
return items.makeLocalItem(v);
}
/** Generate code to call a non-private method or constructor.
* @param pos Position to be used for error reporting.
* @param site The type of which the method is a member.
* @param name The method's name.
* @param argtypes The method's argument types.
* @param isStatic A flag that indicates whether we call a
* static or instance method.
*/
void callMethod(DiagnosticPosition pos,
Type site, Name name, List<Type> argtypes,
boolean isStatic) {
Symbol msym = rs.
resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
if (isStatic) items.makeStaticItem(msym).invoke();
else items.makeMemberItem(msym, name == names.init).invoke();
}
/** Is the given method definition an access method
* resulting from a qualified super? This is signified by an odd
* access code.
*/
private boolean isAccessSuper(JCMethodDecl enclMethod) {
return
(enclMethod.mods.flags & SYNTHETIC) != 0 &&
isOddAccessName(enclMethod.name);
}
/** Does given name start with "access$" and end in an odd digit?
*/
private boolean isOddAccessName(Name name) {
return
name.startsWith(accessDollar) &&
(name.getByteAt(name.getByteLength() - 1) & 1) == 1;
}
/* ************************************************************************
* Non-local exits
*************************************************************************/
/** Generate code to invoke the finalizer associated with given
* environment.
* Any calls to finalizers are appended to the environments `cont' chain.
* Mark beginning of gap in catch all range for finalizer.
*/
void genFinalizer(Env<GenContext> env) {
if (code.isAlive() && env.info.finalize != null)
env.info.finalize.gen();
}
/** Generate code to call all finalizers of structures aborted by
* a non-local
* exit. Return target environment of the non-local exit.
* @param target The tree representing the structure that's aborted
* @param env The environment current at the non-local exit.
*/
Env<GenContext> unwind(JCTree target, Env env) {
Env<GenContext> env1 = env;
while (true) {
genFinalizer(env1);
if (env1.tree == target) break;
env1 = env1.next;
}
return env1;
}
/** Mark end of gap in catch-all range for finalizer.
* @param env the environment which might contain the finalizer
* (if it does, env.info.gaps != null).
*/
void endFinalizerGap(Env<GenContext> env) {
if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
env.info.gaps.append(code.curCP());
}
/** Mark end of all gaps in catch-all ranges for finalizers of environments
* lying between, and including to two environments.
* @param from the most deeply nested environment to mark
* @param to the least deeply nested environment to mark
*/
void endFinalizerGaps(Env<GenContext> from, Env to) {
Env<GenContext> last = null;
while (last != to) {
endFinalizerGap(from);
last = from;
from = from.next;
}
}
/** Do any of the structures aborted by a non-local exit have
* finalizers that require an empty stack?
* @param target The tree representing the structure that's aborted
* @param env The environment current at the non-local exit.
*/
boolean hasFinally(JCTree target, Env<GenContext> env) {
while (env.tree != target) {
if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
return true;
env = env.next;
}
return false;
}
/* ************************************************************************
* Normalizing class-members.
*************************************************************************/
/** Distribute member initializer code into constructors and {@code <clinit>}
* method.
* @param defs The list of class member declarations.
* @param c The enclosing class.
*/
List<JCTree> normalizeDefs(List defs, ClassSymbol c) {
ListBuffer<JCStatement> initCode = new ListBuffer();
ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer();
ListBuffer<JCStatement> clinitCode = new ListBuffer();
ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer();
ListBuffer<JCTree> methodDefs = new ListBuffer();
// Sort definitions into three listbuffers:
// - initCode for instance initializers
// - clinitCode for class initializers
// - methodDefs for method definitions
for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
JCTree def = l.head;
switch (def.getTag()) {
case BLOCK:
JCBlock block = (JCBlock)def;
if ((block.flags & STATIC) != 0)
clinitCode.append(block);
else
initCode.append(block);
break;
case METHODDEF:
methodDefs.append(def);
break;
case VARDEF:
JCVariableDecl vdef = (JCVariableDecl) def;
VarSymbol sym = vdef.sym;
checkDimension(vdef.pos(), sym.type);
if (vdef.init != null) {
if ((sym.flags() & STATIC) == 0) {
// Always initialize instance variables.
JCStatement init = make.at(vdef.pos()).
Assignment(sym, vdef.init);
initCode.append(init);
endPosTable.replaceTree(vdef, init);
initTAs.addAll(getAndRemoveNonFieldTAs(sym));
} else if (sym.getConstValue() == null) {
// Initialize class (static) variables only if
// they are not compile-time constants.
JCStatement init = make.at(vdef.pos).
Assignment(sym, vdef.init);
clinitCode.append(init);
endPosTable.replaceTree(vdef, init);
clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
} else {
checkStringConstant(vdef.init.pos(), sym.getConstValue());
}
}
break;
default:
Assert.error();
}
}
// Insert any instance initializers into all constructors.
if (initCode.length() != 0) {
List<JCStatement> inits = initCode.toList();
initTAs.addAll(c.getInitTypeAttributes());
List<Attribute.TypeCompound> initTAlist = initTAs.toList();
for (JCTree t : methodDefs) {
normalizeMethod((JCMethodDecl)t, inits, initTAlist);
}
}
// If there are class initializers, create a <clinit> method
// that contains them as its body.
if (clinitCode.length() != 0) {
MethodSymbol clinit = new MethodSymbol(
STATIC | (c.flags() & STRICTFP),
names.clinit,
new MethodType(
List.<Type>nil(), syms.voidType,
List.<Type>nil(), syms.methodClass),
c);
c.members().enter(clinit);
List<JCStatement> clinitStats = clinitCode.toList();
JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
block.endpos = TreeInfo.endPos(clinitStats.last());
methodDefs.append(make.MethodDef(clinit, block));
if (!clinitTAs.isEmpty())
clinit.appendUniqueTypeAttributes(clinitTAs.toList());
if (!c.getClassInitTypeAttributes().isEmpty())
clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
}
// Return all method definitions.
return methodDefs.toList();
}
private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
List<TypeCompound> tas = sym.getRawTypeAttributes();
ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer();
ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer();
for (TypeCompound ta : tas) {
if (ta.getPosition().type == TargetType.FIELD) {
fieldTAs.add(ta);
} else {
if (typeAnnoAsserts) {
Assert.error("Type annotation does not have a valid positior");
}
nonfieldTAs.add(ta);
}
}
sym.setTypeAttributes(fieldTAs.toList());
return nonfieldTAs.toList();
}
/** Check a constant value and report if it is a string that is
* too large.
*/
private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
if (nerrs != 0 || // only complain about a long string once
constValue == null ||
!(constValue instanceof String) ||
((String)constValue).length() < Pool.MAX_STRING_LENGTH)
return;
log.error(pos, "limit.string");
nerrs++;
}
/** Insert instance initializer code into initial constructor.
* @param md The tree potentially representing a
* constructor's definition.
* @param initCode The list of instance initializer statements.
* @param initTAs Type annotations from the initializer expression.
*/
void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List initTAs) {
if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
// We are seeing a constructor that does not call another
// constructor of the same class.
List<JCStatement> stats = md.body.stats;
ListBuffer<JCStatement> newstats = new ListBuffer();
if (stats.nonEmpty()) {
// Copy initializers of synthetic variables generated in
// the translation of inner classes.
while (TreeInfo.isSyntheticInit(stats.head)) {
newstats.append(stats.head);
stats = stats.tail;
}
// Copy superclass constructor call
newstats.append(stats.head);
stats = stats.tail;
// Copy remaining synthetic initializers.
while (stats.nonEmpty() &&
TreeInfo.isSyntheticInit(stats.head)) {
newstats.append(stats.head);
stats = stats.tail;
}
// Now insert the initializer code.
newstats.appendList(initCode);
// And copy all remaining statements.
while (stats.nonEmpty()) {
newstats.append(stats.head);
stats = stats.tail;
}
}
md.body.stats = newstats.toList();
if (md.body.endpos == Position.NOPOS)
md.body.endpos = TreeInfo.endPos(md.body.stats.last());
md.sym.appendUniqueTypeAttributes(initTAs);
}
}
/* ********************************************************************
* Adding miranda methods
*********************************************************************/
/** Add abstract methods for all methods defined in one of
* the interfaces of a given class,
* provided they are not already implemented in the class.
*
* @param c The class whose interfaces are searched for methods
* for which Miranda methods should be added.
*/
void implementInterfaceMethods(ClassSymbol c) {
implementInterfaceMethods(c, c);
}
/** Add abstract methods for all methods defined in one of
* the interfaces of a given class,
* provided they are not already implemented in the class.
*
* @param c The class whose interfaces are searched for methods
* for which Miranda methods should be added.
* @param site The class in which a definition may be needed.
*/
void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
ClassSymbol i = (ClassSymbol)l.head.tsym;
for (Scope.Entry e = i.members().elems;
e != null;
e = e.sibling)
{
if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
{
MethodSymbol absMeth = (MethodSymbol)e.sym;
MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
if (implMeth == null)
addAbstractMethod(site, absMeth);
else if ((implMeth.flags() & IPROXY) != 0)
adjustAbstractMethod(site, implMeth, absMeth);
}
}
implementInterfaceMethods(i, site);
}
}
/** Add an abstract methods to a class
* which implicitly implements a method defined in some interface
* implemented by the class. These methods are called "Miranda methods".
* Enter the newly created method into its enclosing class scope.
* Note that it is not entered into the class tree, as the emitter
* doesn't need to see it there to emit an abstract method.
*
* @param c The class to which the Miranda method is added.
* @param m The interface method symbol for which a Miranda method
* is added.
*/
private void addAbstractMethod(ClassSymbol c,
MethodSymbol m) {
MethodSymbol absMeth = new MethodSymbol(
m.flags() | IPROXY | SYNTHETIC, m.name,
m.type, // was c.type.memberType(m), but now only !generics supported
c);
c.members().enter(absMeth); // add to symbol table
}
private void adjustAbstractMethod(ClassSymbol c,
MethodSymbol pm,
MethodSymbol im) {
MethodType pmt = (MethodType)pm.type;
Type imt = types.memberType(c.type, im);
pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
}
/* ************************************************************************
* Traversal methods
*************************************************************************/
/** Visitor argument: The current environment.
*/
Env<GenContext> env;
/** Visitor argument: The expected type (prototype).
*/
Type pt;
/** Visitor result: The item representing the computed value.
*/
Item result;
/** Visitor method: generate code for a definition, catching and reporting
* any completion failures.
* @param tree The definition to be visited.
* @param env The environment current at the definition.
*/
public void genDef(JCTree tree, Env<GenContext> env) {
Env<GenContext> prevEnv = this.env;
try {
this.env = env;
tree.accept(this);
} catch (CompletionFailure ex) {
chk.completionError(tree.pos(), ex);
} finally {
this.env = prevEnv;
}
}
/** Derived visitor method: check whether CharacterRangeTable
* should be emitted, if so, put a new entry into CRTable
* and call method to generate bytecode.
* If not, just call method to generate bytecode.
* @see #genStat(JCTree, Env)
*
* @param tree The tree to be visited.
* @param env The environment to use.
* @param crtFlags The CharacterRangeTable flags
* indicating type of the entry.
*/
public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
if (!genCrt) {
genStat(tree, env);
return;
}
int startpc = code.curCP();
genStat(tree, env);
if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
code.crt.put(tree, crtFlags, startpc, code.curCP());
}
/** Derived visitor method: generate code for a statement.
*/
public void genStat(JCTree tree, Env<GenContext> env) {
if (code.isAlive()) {
code.statBegin(tree.pos);
genDef(tree, env);
} else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
// variables whose declarations are in a switch
// can be used even if the decl is unreachable.
code.newLocal(((JCVariableDecl) tree).sym);
}
}
/** Derived visitor method: check whether CharacterRangeTable
* should be emitted, if so, put a new entry into CRTable
* and call method to generate bytecode.
* If not, just call method to generate bytecode.
* @see #genStats(List, Env)
*
* @param trees The list of trees to be visited.
* @param env The environment to use.
* @param crtFlags The CharacterRangeTable flags
* indicating type of the entry.
*/
public void genStats(List<JCStatement> trees, Env env, int crtFlags) {
if (!genCrt) {
genStats(trees, env);
return;
}
if (trees.length() == 1) { // mark one statement with the flags
genStat(trees.head, env, crtFlags | CRT_STATEMENT);
} else {
int startpc = code.curCP();
genStats(trees, env);
code.crt.put(trees, crtFlags, startpc, code.curCP());
}
}
/** Derived visitor method: generate code for a list of statements.
*/
public void genStats(List<? extends JCTree> trees, Env env) {
for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
genStat(l.head, env, CRT_STATEMENT);
}
/** Derived visitor method: check whether CharacterRangeTable
* should be emitted, if so, put a new entry into CRTable
* and call method to generate bytecode.
* If not, just call method to generate bytecode.
* @see #genCond(JCTree,boolean)
*
* @param tree The tree to be visited.
* @param crtFlags The CharacterRangeTable flags
* indicating type of the entry.
*/
public CondItem genCond(JCTree tree, int crtFlags) {
if (!genCrt) return genCond(tree, false);
int startpc = code.curCP();
CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
code.crt.put(tree, crtFlags, startpc, code.curCP());
return item;
}
/** Derived visitor method: generate code for a boolean
* expression in a control-flow context.
* @param _tree The expression to be visited.
* @param markBranches The flag to indicate that the condition is
* a flow controller so produced conditions
* should contain a proper tree to generate
* CharacterRangeTable branches for them.
*/
public CondItem genCond(JCTree _tree, boolean markBranches) {
JCTree inner_tree = TreeInfo.skipParens(_tree);
if (inner_tree.hasTag(CONDEXPR)) {
JCConditional tree = (JCConditional)inner_tree;
CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
if (cond.isTrue()) {
code.resolve(cond.trueJumps);
CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
if (markBranches) result.tree = tree.truepart;
return result;
}
if (cond.isFalse()) {
code.resolve(cond.falseJumps);
CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
if (markBranches) result.tree = tree.falsepart;
return result;
}
Chain secondJumps = cond.jumpFalse();
code.resolve(cond.trueJumps);
CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
if (markBranches) first.tree = tree.truepart;
Chain falseJumps = first.jumpFalse();
code.resolve(first.trueJumps);
Chain trueJumps = code.branch(goto_);
code.resolve(secondJumps);
CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
CondItem result = items.makeCondItem(second.opcode,
Code.mergeChains(trueJumps, second.trueJumps),
Code.mergeChains(falseJumps, second.falseJumps));
if (markBranches) result.tree = tree.falsepart;
return result;
} else {
CondItem result = genExpr(_tree, syms.booleanType).mkCond();
if (markBranches) result.tree = _tree;
return result;
}
}
/** Visitor class for expressions which might be constant expressions.
* This class is a subset of TreeScanner. Intended to visit trees pruned by
* Lower as long as constant expressions looking for references to any
* ClassSymbol. Any such reference will be added to the constant pool so
* automated tools can detect class dependencies better.
*/
class ClassReferenceVisitor extends JCTree.Visitor {
@Override
public void visitTree(JCTree tree) {}
@Override
public void visitBinary(JCBinary tree) {
tree.lhs.accept(this);
tree.rhs.accept(this);
}
@Override
public void visitSelect(JCFieldAccess tree) {
if (tree.selected.type.hasTag(CLASS)) {
makeRef(tree.selected.pos(), tree.selected.type);
}
}
@Override
public void visitIdent(JCIdent tree) {
if (tree.sym.owner instanceof ClassSymbol) {
pool.put(tree.sym.owner);
}
}
@Override
public void visitConditional(JCConditional tree) {
tree.cond.accept(this);
tree.truepart.accept(this);
tree.falsepart.accept(this);
}
@Override
public void visitUnary(JCUnary tree) {
tree.arg.accept(this);
}
@Override
public void visitParens(JCParens tree) {
tree.expr.accept(this);
}
@Override
public void visitTypeCast(JCTypeCast tree) {
tree.expr.accept(this);
}
}
private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
/** Visitor method: generate code for an expression, catching and reporting
* any completion failures.
* @param tree The expression to be visited.
* @param pt The expression's expected type (proto-type).
*/
public Item genExpr(JCTree tree, Type pt) {
Type prevPt = this.pt;
try {
if (tree.type.constValue() != null) {
// Short circuit any expressions which are constants
tree.accept(classReferenceVisitor);
checkStringConstant(tree.pos(), tree.type.constValue());
result = items.makeImmediateItem(tree.type, tree.type.constValue());
} else {
this.pt = pt;
tree.accept(this);
}
return result.coerce(pt);
} catch (CompletionFailure ex) {
chk.completionError(tree.pos(), ex);
code.state.stacksize = 1;
return items.makeStackItem(pt);
} finally {
this.pt = prevPt;
}
}
/** Derived visitor method: generate code for a list of method arguments.
* @param trees The argument expressions to be visited.
* @param pts The expression's expected types (i.e. the formal parameter
* types of the invoked method).
*/
public void genArgs(List<JCExpression> trees, List pts) {
for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
genExpr(l.head, pts.head).load();
pts = pts.tail;
}
// require lists be of same length
Assert.check(pts.isEmpty());
}
/* ************************************************************************
* Visitor methods for statements and definitions
*************************************************************************/
/** Thrown when the byte code size exceeds limit.
*/
public static class CodeSizeOverflow extends RuntimeException {
private static final long serialVersionUID = 0;
public CodeSizeOverflow() {}
}
public void visitMethodDef(JCMethodDecl tree) {
// Create a new local environment that points pack at method
// definition.
Env<GenContext> localEnv = env.dup(tree);
localEnv.enclMethod = tree;
// The expected type of every return statement in this method
// is the method's return type.
this.pt = tree.sym.erasure(types).getReturnType();
checkDimension(tree.pos(), tree.sym.erasure(types));
genMethod(tree, localEnv, false);
}
//where
/** Generate code for a method.
* @param tree The tree representing the method definition.
* @param env The environment current for the method body.
* @param fatcode A flag that indicates whether all jumps are
* within 32K. We first invoke this method under
* the assumption that fatcode == false, i.e. all
* jumps are within 32K. If this fails, fatcode
* is set to true and we try again.
*/
void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
MethodSymbol meth = tree.sym;
int extras = 0;
// Count up extra parameters
if (meth.isConstructor()) {
extras++;
if (meth.enclClass().isInner() &&
!meth.enclClass().isStatic()) {
extras++;
}
} else if ((tree.mods.flags & STATIC) == 0) {
extras++;
}
// System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
ClassFile.MAX_PARAMETERS) {
log.error(tree.pos(), "limit.parameters");
nerrs++;
}
else if (tree.body != null) {
// Create a new code structure and initialize it.
int startpcCrt = initCode(tree, env, fatcode);
try {
genStat(tree.body, env);
} catch (CodeSizeOverflow e) {
// Failed due to code limit, try again with jsr/ret
startpcCrt = initCode(tree, env, fatcode);
genStat(tree.body, env);
}
if (code.state.stacksize != 0) {
log.error(tree.body.pos(), "stack.sim.error", tree);
throw new AssertionError();
}
// If last statement could complete normally, insert a
// return at the end.
if (code.isAlive()) {
code.statBegin(TreeInfo.endPos(tree.body));
if (env.enclMethod == null ||
env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
code.emitop0(return_);
} else {
// sometime dead code seems alive (4415991);
// generate a small loop instead
int startpc = code.entryPoint();
CondItem c = items.makeCondItem(goto_);
code.resolve(c.jumpTrue(), startpc);
}
}
if (genCrt)
code.crt.put(tree.body,
CRT_BLOCK,
startpcCrt,
code.curCP());
code.endScopes(0);
// If we exceeded limits, panic
if (code.checkLimits(tree.pos(), log)) {
nerrs++;
return;
}
// If we generated short code but got a long jump, do it again
// with fatCode = true.
if (!fatcode && code.fatcode) genMethod(tree, env, true);
// Clean up
if(stackMap == StackMapFormat.JSR202) {
code.lastFrame = null;
code.frameBeforeLast = null;
}
// Compress exception table
code.compressCatchTable();
// Fill in type annotation positions for exception parameters
code.fillExceptionParameterPositions();
}
}
private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
MethodSymbol meth = tree.sym;
// Create a new code structure.
meth.code = code = new Code(meth,
fatcode,
lineDebugInfo ? toplevel.lineMap : null,
varDebugInfo,
stackMap,
debugCode,
genCrt ? new CRTable(tree, env.toplevel.endPositions)
: null,
syms,
types,
pool,
varDebugInfo ? lvtRanges : null);
items = new Items(pool, code, syms, types);
if (code.debugCode) {
System.err.println(meth + " for body " + tree);
}
// If method is not static, create a new local variable address
// for `this'.
if ((tree.mods.flags & STATIC) == 0) {
Type selfType = meth.owner.type;
if (meth.isConstructor() && selfType != syms.objectType)
selfType = UninitializedType.uninitializedThis(selfType);
code.setDefined(
code.newLocal(
new VarSymbol(FINAL, names._this, selfType, meth.owner)));
}
// Mark all parameters as defined from the beginning of
// the method.
for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
checkDimension(l.head.pos(), l.head.sym.type);
code.setDefined(code.newLocal(l.head.sym));
}
// Get ready to generate code for method body.
int startpcCrt = genCrt ? code.curCP() : 0;
code.entryPoint();
// Suppress initial stackmap
code.pendingStackMap = false;
return startpcCrt;
}
public void visitVarDef(JCVariableDecl tree) {
VarSymbol v = tree.sym;
code.newLocal(v);
if (tree.init != null) {
checkStringConstant(tree.init.pos(), v.getConstValue());
if (v.getConstValue() == null || varDebugInfo) {
genExpr(tree.init, v.erasure(types)).load();
items.makeLocalItem(v).store();
}
}
checkDimension(tree.pos(), v.type);
}
public void visitSkip(JCSkip tree) {
}
public void visitBlock(JCBlock tree) {
int limit = code.nextreg;
Env<GenContext> localEnv = env.dup(tree, new GenContext());
genStats(tree.stats, localEnv);
// End the scope of all block-local variables in variable info.
if (!env.tree.hasTag(METHODDEF)) {
code.statBegin(tree.endpos);
code.endScopes(limit);
code.pendingStatPos = Position.NOPOS;
}
}
public void visitDoLoop(JCDoWhileLoop tree) {
genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
}
public void visitWhileLoop(JCWhileLoop tree) {
genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
}
public void visitForLoop(JCForLoop tree) {
int limit = code.nextreg;
genStats(tree.init, env);
genLoop(tree, tree.body, tree.cond, tree.step, true);
code.endScopes(limit);
}
//where
/** Generate code for a loop.
* @param loop The tree representing the loop.
* @param body The loop's body.
* @param cond The loop's controling condition.
* @param step "Step" statements to be inserted at end of
* each iteration.
* @param testFirst True if the loop test belongs before the body.
*/
private void genLoop(JCStatement loop,
JCStatement body,
JCExpression cond,
List<JCExpressionStatement> step,
boolean testFirst) {
Env<GenContext> loopEnv = env.dup(loop, new GenContext());
int startpc = code.entryPoint();
if (testFirst) {
CondItem c;
if (cond != null) {
code.statBegin(cond.pos);
c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
} else {
c = items.makeCondItem(goto_);
}
Chain loopDone = c.jumpFalse();
code.resolve(c.trueJumps);
genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
if (varDebugInfo) {
checkLoopLocalVarRangeEnding(loop, body,
LoopLocalVarRangeEndingPoint.BEFORE_STEPS);
}
code.resolve(loopEnv.info.cont);
genStats(step, loopEnv);
if (varDebugInfo) {
checkLoopLocalVarRangeEnding(loop, body,
LoopLocalVarRangeEndingPoint.AFTER_STEPS);
}
code.resolve(code.branch(goto_), startpc);
code.resolve(loopDone);
} else {
genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
if (varDebugInfo) {
checkLoopLocalVarRangeEnding(loop, body,
LoopLocalVarRangeEndingPoint.BEFORE_STEPS);
}
code.resolve(loopEnv.info.cont);
genStats(step, loopEnv);
if (varDebugInfo) {
checkLoopLocalVarRangeEnding(loop, body,
LoopLocalVarRangeEndingPoint.AFTER_STEPS);
}
CondItem c;
if (cond != null) {
code.statBegin(cond.pos);
c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
} else {
c = items.makeCondItem(goto_);
}
code.resolve(c.jumpTrue(), startpc);
code.resolve(c.falseJumps);
}
code.resolve(loopEnv.info.exit);
}
private enum LoopLocalVarRangeEndingPoint {
BEFORE_STEPS,
AFTER_STEPS,
}
/**
* Checks whether we have reached an alive range ending point for local
* variables after a loop.
*
* Local variables alive range ending point for loops varies depending
* on the loop type. The range can be closed before or after the code
* for the steps sentences has been generated.
*
* - While loops has no steps so in that case the range is closed just
* after the body of the loop.
*
* - For-like loops may have steps so as long as the steps sentences
* can possibly contain non-synthetic local variables, the alive range
* for local variables must be closed after the steps in this case.
*/
private void checkLoopLocalVarRangeEnding(JCTree loop, JCTree body,
LoopLocalVarRangeEndingPoint endingPoint) {
if (varDebugInfo && lvtRanges.containsKey(code.meth, body)) {
switch (endingPoint) {
case BEFORE_STEPS:
if (!loop.hasTag(FORLOOP)) {
code.closeAliveRanges(body);
}
break;
case AFTER_STEPS:
if (loop.hasTag(FORLOOP)) {
code.closeAliveRanges(body);
}
break;
}
}
}
public void visitForeachLoop(JCEnhancedForLoop tree) {
throw new AssertionError(); // should have been removed by Lower.
}
public void visitLabelled(JCLabeledStatement tree) {
Env<GenContext> localEnv = env.dup(tree, new GenContext());
genStat(tree.body, localEnv, CRT_STATEMENT);
code.resolve(localEnv.info.exit);
}
public void visitSwitch(JCSwitch tree) {
int limit = code.nextreg;
Assert.check(!tree.selector.type.hasTag(CLASS));
int startpcCrt = genCrt ? code.curCP() : 0;
Item sel = genExpr(tree.selector, syms.intType);
List<JCCase> cases = tree.cases;
if (cases.isEmpty()) {
// We are seeing: switch <sel> {}
sel.load().drop();
if (genCrt)
code.crt.put(TreeInfo.skipParens(tree.selector),
CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
} else {
// We are seeing a nonempty switch.
sel.load();
if (genCrt)
code.crt.put(TreeInfo.skipParens(tree.selector),
CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
Env<GenContext> switchEnv = env.dup(tree, new GenContext());
switchEnv.info.isSwitch = true;
// Compute number of labels and minimum and maximum label values.
// For each case, store its label in an array.
int lo = Integer.MAX_VALUE; // minimum label.
int hi = Integer.MIN_VALUE; // maximum label.
int nlabels = 0; // number of labels.
int[] labels = new int[cases.length()]; // the label array.
int defaultIndex = -1; // the index of the default clause.
List<JCCase> l = cases;
for (int i = 0; i < labels.length; i++) {
if (l.head.pat != null) {
int val = ((Number)l.head.pat.type.constValue()).intValue();
labels[i] = val;
if (val < lo) lo = val;
if (hi < val) hi = val;
nlabels++;
} else {
Assert.check(defaultIndex == -1);
defaultIndex = i;
}
l = l.tail;
}
// Determine whether to issue a tableswitch or a lookupswitch
// instruction.
long table_space_cost = 4 + ((long) hi - lo + 1); // words
long table_time_cost = 3; // comparisons
long lookup_space_cost = 3 + 2 * (long) nlabels;
long lookup_time_cost = nlabels;
int opcode =
nlabels > 0 &&
table_space_cost + 3 * table_time_cost <=
lookup_space_cost + 3 * lookup_time_cost
?
tableswitch : lookupswitch;
int startpc = code.curCP(); // the position of the selector operation
code.emitop0(opcode);
code.align(4);
int tableBase = code.curCP(); // the start of the jump table
int[] offsets = null; // a table of offsets for a lookupswitch
code.emit4(-1); // leave space for default offset
if (opcode == tableswitch) {
code.emit4(lo); // minimum label
code.emit4(hi); // maximum label
for (long i = lo; i <= hi; i++) { // leave space for jump table
code.emit4(-1);
}
} else {
code.emit4(nlabels); // number of labels
for (int i = 0; i < nlabels; i++) {
code.emit4(-1); code.emit4(-1); // leave space for lookup table
}
offsets = new int[labels.length];
}
Code.State stateSwitch = code.state.dup();
code.markDead();
// For each case do:
l = cases;
for (int i = 0; i < labels.length; i++) {
JCCase c = l.head;
l = l.tail;
int pc = code.entryPoint(stateSwitch);
// Insert offset directly into code or else into the
// offsets table.
if (i != defaultIndex) {
if (opcode == tableswitch) {
code.put4(
tableBase + 4 * (labels[i] - lo + 3),
pc - startpc);
} else {
offsets[i] = pc - startpc;
}
} else {
code.put4(tableBase, pc - startpc);
}
// Generate code for the statements in this case.
genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
if (varDebugInfo && lvtRanges.containsKey(code.meth, c.stats.last())) {
code.closeAliveRanges(c.stats.last());
}
}
// Resolve all breaks.
code.resolve(switchEnv.info.exit);
// If we have not set the default offset, we do so now.
if (code.get4(tableBase) == -1) {
code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
}
if (opcode == tableswitch) {
// Let any unfilled slots point to the default case.
int defaultOffset = code.get4(tableBase);
for (long i = lo; i <= hi; i++) {
int t = (int)(tableBase + 4 * (i - lo + 3));
if (code.get4(t) == -1)
code.put4(t, defaultOffset);
}
} else {
// Sort non-default offsets and copy into lookup table.
if (defaultIndex >= 0)
for (int i = defaultIndex; i < labels.length - 1; i++) {
labels[i] = labels[i+1];
offsets[i] = offsets[i+1];
}
if (nlabels > 0)
qsort2(labels, offsets, 0, nlabels - 1);
for (int i = 0; i < nlabels; i++) {
int caseidx = tableBase + 8 * (i + 1);
code.put4(caseidx, labels[i]);
code.put4(caseidx + 4, offsets[i]);
}
}
}
code.endScopes(limit);
}
//where
/** Sort (int) arrays of keys and values
*/
static void qsort2(int[] keys, int[] values, int lo, int hi) {
int i = lo;
int j = hi;
int pivot = keys[(i+j)/2];
do {
while (keys[i] < pivot) i++;
while (pivot < keys[j]) j--;
if (i <= j) {
int temp1 = keys[i];
keys[i] = keys[j];
keys[j] = temp1;
int temp2 = values[i];
values[i] = values[j];
values[j] = temp2;
i++;
j--;
}
} while (i <= j);
if (lo < j) qsort2(keys, values, lo, j);
if (i < hi) qsort2(keys, values, i, hi);
}
public void visitSynchronized(JCSynchronized tree) {
int limit = code.nextreg;
// Generate code to evaluate lock and save in temporary variable.
final LocalItem lockVar = makeTemp(syms.objectType);
genExpr(tree.lock, tree.lock.type).load().duplicate();
lockVar.store();
// Generate code to enter monitor.
code.emitop0(monitorenter);
code.state.lock(lockVar.reg);
// Generate code for a try statement with given body, no catch clauses
// in a new environment with the "exit-monitor" operation as finalizer.
final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
syncEnv.info.finalize = new GenFinalizer() {
void gen() {
genLast();
Assert.check(syncEnv.info.gaps.length() % 2 == 0);
syncEnv.info.gaps.append(code.curCP());
}
void genLast() {
if (code.isAlive()) {
lockVar.load();
code.emitop0(monitorexit);
code.state.unlock(lockVar.reg);
}
}
};
syncEnv.info.gaps = new ListBuffer<Integer>();
genTry(tree.body, List.<JCCatch>nil(), syncEnv);
code.endScopes(limit);
}
public void visitTry(final JCTry tree) {
// Generate code for a try statement with given body and catch clauses,
// in a new environment which calls the finally block if there is one.
final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
final Env<GenContext> oldEnv = env;
if (!useJsrLocally) {
useJsrLocally =
(stackMap == StackMapFormat.NONE) &&
(jsrlimit <= 0 ||
jsrlimit < 100 &&
estimateCodeComplexity(tree.finalizer)>jsrlimit);
}
tryEnv.info.finalize = new GenFinalizer() {
void gen() {
if (useJsrLocally) {
if (tree.finalizer != null) {
Code.State jsrState = code.state.dup();
jsrState.push(Code.jsrReturnValue);
tryEnv.info.cont =
new Chain(code.emitJump(jsr),
tryEnv.info.cont,
jsrState);
}
Assert.check(tryEnv.info.gaps.length() % 2 == 0);
tryEnv.info.gaps.append(code.curCP());
} else {
Assert.check(tryEnv.info.gaps.length() % 2 == 0);
tryEnv.info.gaps.append(code.curCP());
genLast();
}
}
void genLast() {
if (tree.finalizer != null)
genStat(tree.finalizer, oldEnv, CRT_BLOCK);
}
boolean hasFinalizer() {
return tree.finalizer != null;
}
};
tryEnv.info.gaps = new ListBuffer<Integer>();
genTry(tree.body, tree.catchers, tryEnv);
}
//where
/** Generate code for a try or synchronized statement
* @param body The body of the try or synchronized statement.
* @param catchers The lis of catch clauses.
* @param env the environment current for the body.
*/
void genTry(JCTree body, List<JCCatch> catchers, Env env) {
int limit = code.nextreg;
int startpc = code.curCP();
Code.State stateTry = code.state.dup();
genStat(body, env, CRT_BLOCK);
int endpc = code.curCP();
boolean hasFinalizer =
env.info.finalize != null &&
env.info.finalize.hasFinalizer();
List<Integer> gaps = env.info.gaps.toList();
code.statBegin(TreeInfo.endPos(body));
genFinalizer(env);
code.statBegin(TreeInfo.endPos(env.tree));
Chain exitChain = code.branch(goto_);
if (varDebugInfo && lvtRanges.containsKey(code.meth, body)) {
code.closeAliveRanges(body);
}
endFinalizerGap(env);
if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
// start off with exception on stack
code.entryPoint(stateTry, l.head.param.sym.type);
genCatch(l.head, env, startpc, endpc, gaps);
genFinalizer(env);
if (hasFinalizer || l.tail.nonEmpty()) {
code.statBegin(TreeInfo.endPos(env.tree));
exitChain = Code.mergeChains(exitChain,
code.branch(goto_));
}
endFinalizerGap(env);
}
if (hasFinalizer) {
// Create a new register segement to avoid allocating
// the same variables in finalizers and other statements.
code.newRegSegment();
// Add a catch-all clause.
// start off with exception on stack
int catchallpc = code.entryPoint(stateTry, syms.throwableType);
// Register all exception ranges for catch all clause.
// The range of the catch all clause is from the beginning
// of the try or synchronized block until the present
// code pointer excluding all gaps in the current
// environment's GenContext.
int startseg = startpc;
while (env.info.gaps.nonEmpty()) {
int endseg = env.info.gaps.next().intValue();
registerCatch(body.pos(), startseg, endseg,
catchallpc, 0);
startseg = env.info.gaps.next().intValue();
}
code.statBegin(TreeInfo.finalizerPos(env.tree));
code.markStatBegin();
Item excVar = makeTemp(syms.throwableType);
excVar.store();
genFinalizer(env);
excVar.load();
registerCatch(body.pos(), startseg,
env.info.gaps.next().intValue(),
catchallpc, 0);
code.emitop0(athrow);
code.markDead();
// If there are jsr's to this finalizer, ...
if (env.info.cont != null) {
// Resolve all jsr's.
code.resolve(env.info.cont);
// Mark statement line number
code.statBegin(TreeInfo.finalizerPos(env.tree));
code.markStatBegin();
// Save return address.
LocalItem retVar = makeTemp(syms.throwableType);
retVar.store();
// Generate finalizer code.
env.info.finalize.genLast();
// Return.
code.emitop1w(ret, retVar.reg);
code.markDead();
}
}
// Resolve all breaks.
code.resolve(exitChain);
code.endScopes(limit);
}
/** Generate code for a catch clause.
* @param tree The catch clause.
* @param env The environment current in the enclosing try.
* @param startpc Start pc of try-block.
* @param endpc End pc of try-block.
*/
void genCatch(JCCatch tree,
Env<GenContext> env,
int startpc, int endpc,
List<Integer> gaps) {
if (startpc != endpc) {
List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
((JCTypeUnion)tree.param.vartype).alternatives :
List.of(tree.param.vartype);
while (gaps.nonEmpty()) {
for (JCExpression subCatch : subClauses) {
int catchType = makeRef(tree.pos(), subCatch.type);
int end = gaps.head.intValue();
registerCatch(tree.pos(),
startpc, end, code.curCP(),
catchType);
if (subCatch.type.isAnnotated()) {
for (Attribute.TypeCompound tc :
subCatch.type.getAnnotationMirrors()) {
tc.position.type_index = catchType;
}
}
}
gaps = gaps.tail;
startpc = gaps.head.intValue();
gaps = gaps.tail;
}
if (startpc < endpc) {
for (JCExpression subCatch : subClauses) {
int catchType = makeRef(tree.pos(), subCatch.type);
registerCatch(tree.pos(),
startpc, endpc, code.curCP(),
catchType);
if (subCatch.type.isAnnotated()) {
for (Attribute.TypeCompound tc :
subCatch.type.getAnnotationMirrors()) {
tc.position.type_index = catchType;
}
}
}
}
VarSymbol exparam = tree.param.sym;
code.statBegin(tree.pos);
code.markStatBegin();
int limit = code.nextreg;
int exlocal = code.newLocal(exparam);
items.makeLocalItem(exparam).store();
code.statBegin(TreeInfo.firstStatPos(tree.body));
genStat(tree.body, env, CRT_BLOCK);
code.endScopes(limit);
code.statBegin(TreeInfo.endPos(tree.body));
}
}
/** Register a catch clause in the "Exceptions" code-attribute.
*/
void registerCatch(DiagnosticPosition pos,
int startpc, int endpc,
int handler_pc, int catch_type) {
char startpc1 = (char)startpc;
char endpc1 = (char)endpc;
char handler_pc1 = (char)handler_pc;
if (startpc1 == startpc &&
endpc1 == endpc &&
handler_pc1 == handler_pc) {
code.addCatch(startpc1, endpc1, handler_pc1,
(char)catch_type);
} else {
if (!useJsrLocally && !target.generateStackMapTable()) {
useJsrLocally = true;
throw new CodeSizeOverflow();
} else {
log.error(pos, "limit.code.too.large.for.try.stmt");
nerrs++;
}
}
}
/** Very roughly estimate the number of instructions needed for
* the given tree.
*/
int estimateCodeComplexity(JCTree tree) {
if (tree == null) return 0;
class ComplexityScanner extends TreeScanner {
int complexity = 0;
public void scan(JCTree tree) {
if (complexity > jsrlimit) return;
super.scan(tree);
}
public void visitClassDef(JCClassDecl tree) {}
public void visitDoLoop(JCDoWhileLoop tree)
{ super.visitDoLoop(tree); complexity++; }
public void visitWhileLoop(JCWhileLoop tree)
{ super.visitWhileLoop(tree); complexity++; }
public void visitForLoop(JCForLoop tree)
{ super.visitForLoop(tree); complexity++; }
public void visitSwitch(JCSwitch tree)
{ super.visitSwitch(tree); complexity+=5; }
public void visitCase(JCCase tree)
{ super.visitCase(tree); complexity++; }
public void visitSynchronized(JCSynchronized tree)
{ super.visitSynchronized(tree); complexity+=6; }
public void visitTry(JCTry tree)
{ super.visitTry(tree);
if (tree.finalizer != null) complexity+=6; }
public void visitCatch(JCCatch tree)
{ super.visitCatch(tree); complexity+=2; }
public void visitConditional(JCConditional tree)
{ super.visitConditional(tree); complexity+=2; }
public void visitIf(JCIf tree)
{ super.visitIf(tree); complexity+=2; }
// note: for break, continue, and return we don't take unwind() into account.
public void visitBreak(JCBreak tree)
{ super.visitBreak(tree); complexity+=1; }
public void visitContinue(JCContinue tree)
{ super.visitContinue(tree); complexity+=1; }
public void visitReturn(JCReturn tree)
{ super.visitReturn(tree); complexity+=1; }
public void visitThrow(JCThrow tree)
{ super.visitThrow(tree); complexity+=1; }
public void visitAssert(JCAssert tree)
{ super.visitAssert(tree); complexity+=5; }
public void visitApply(JCMethodInvocation tree)
{ super.visitApply(tree); complexity+=2; }
public void visitNewClass(JCNewClass tree)
{ scan(tree.encl); scan(tree.args); complexity+=2; }
public void visitNewArray(JCNewArray tree)
{ super.visitNewArray(tree); complexity+=5; }
public void visitAssign(JCAssign tree)
{ super.visitAssign(tree); complexity+=1; }
public void visitAssignop(JCAssignOp tree)
{ super.visitAssignop(tree); complexity+=2; }
public void visitUnary(JCUnary tree)
{ complexity+=1;
if (tree.type.constValue() == null) super.visitUnary(tree); }
public void visitBinary(JCBinary tree)
{ complexity+=1;
if (tree.type.constValue() == null) super.visitBinary(tree); }
public void visitTypeTest(JCInstanceOf tree)
{ super.visitTypeTest(tree); complexity+=1; }
public void visitIndexed(JCArrayAccess tree)
{ super.visitIndexed(tree); complexity+=1; }
public void visitSelect(JCFieldAccess tree)
{ super.visitSelect(tree);
if (tree.sym.kind == VAR) complexity+=1; }
public void visitIdent(JCIdent tree) {
if (tree.sym.kind == VAR) {
complexity+=1;
if (tree.type.constValue() == null &&
tree.sym.owner.kind == TYP)
complexity+=1;
}
}
public void visitLiteral(JCLiteral tree)
{ complexity+=1; }
public void visitTree(JCTree tree) {}
public void visitWildcard(JCWildcard tree) {
throw new AssertionError(this.getClass().getName());
}
}
ComplexityScanner scanner = new ComplexityScanner();
tree.accept(scanner);
return scanner.complexity;
}
public void visitIf(JCIf tree) {
int limit = code.nextreg;
Chain thenExit = null;
CondItem c = genCond(TreeInfo.skipParens(tree.cond),
CRT_FLOW_CONTROLLER);
Chain elseChain = c.jumpFalse();
if (!c.isFalse()) {
code.resolve(c.trueJumps);
genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
thenExit = code.branch(goto_);
if (varDebugInfo && lvtRanges.containsKey(code.meth, tree.thenpart)) {
code.closeAliveRanges(tree.thenpart,
thenExit != null && tree.elsepart == null ? thenExit.pc : code.cp);
}
}
if (elseChain != null) {
code.resolve(elseChain);
if (tree.elsepart != null) {
genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
if (varDebugInfo && lvtRanges.containsKey(code.meth, tree.elsepart)) {
code.closeAliveRanges(tree.elsepart);
}
}
}
code.resolve(thenExit);
code.endScopes(limit);
}
public void visitExec(JCExpressionStatement tree) {
// Optimize x++ to ++x and x-- to --x.
JCExpression e = tree.expr;
switch (e.getTag()) {
case POSTINC:
((JCUnary) e).setTag(PREINC);
break;
case POSTDEC:
((JCUnary) e).setTag(PREDEC);
break;
}
genExpr(tree.expr, tree.expr.type).drop();
}
public void visitBreak(JCBreak tree) {
Env<GenContext> targetEnv = unwind(tree.target, env);
Assert.check(code.state.stacksize == 0);
targetEnv.info.addExit(code.branch(goto_));
endFinalizerGaps(env, targetEnv);
}
public void visitContinue(JCContinue tree) {
Env<GenContext> targetEnv = unwind(tree.target, env);
Assert.check(code.state.stacksize == 0);
targetEnv.info.addCont(code.branch(goto_));
endFinalizerGaps(env, targetEnv);
}
public void visitReturn(JCReturn tree) {
int limit = code.nextreg;
final Env<GenContext> targetEnv;
if (tree.expr != null) {
Item r = genExpr(tree.expr, pt).load();
if (hasFinally(env.enclMethod, env)) {
r = makeTemp(pt);
r.store();
}
targetEnv = unwind(env.enclMethod, env);
r.load();
code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
} else {
/* If we have a statement like:
*
* return;
*
* we need to store the code.pendingStatPos value before generating
* the finalizer.
*/
int tmpPos = code.pendingStatPos;
targetEnv = unwind(env.enclMethod, env);
code.pendingStatPos = tmpPos;
code.emitop0(return_);
}
endFinalizerGaps(env, targetEnv);
code.endScopes(limit);
}
public void visitThrow(JCThrow tree) {
genExpr(tree.expr, tree.expr.type).load();
code.emitop0(athrow);
}
/* ************************************************************************
* Visitor methods for expressions
*************************************************************************/
public void visitApply(JCMethodInvocation tree) {
setTypeAnnotationPositions(tree.pos);
// Generate code for method.
Item m = genExpr(tree.meth, methodType);
// Generate code for all arguments, where the expected types are
// the parameters of the method's external type (that is, any implicit
// outer instance of a super(...) call appears as first parameter).
MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
genArgs(tree.args,
msym.externalType(types).getParameterTypes());
if (!msym.isDynamic()) {
code.statBegin(tree.pos);
}
result = m.invoke();
}
public void visitConditional(JCConditional tree) {
Chain thenExit = null;
CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
Chain elseChain = c.jumpFalse();
if (!c.isFalse()) {
code.resolve(c.trueJumps);
int startpc = genCrt ? code.curCP() : 0;
genExpr(tree.truepart, pt).load();
code.state.forceStackTop(tree.type);
if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
startpc, code.curCP());
thenExit = code.branch(goto_);
}
if (elseChain != null) {
code.resolve(elseChain);
int startpc = genCrt ? code.curCP() : 0;
genExpr(tree.falsepart, pt).load();
code.state.forceStackTop(tree.type);
if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
startpc, code.curCP());
}
code.resolve(thenExit);
result = items.makeStackItem(pt);
}
private void setTypeAnnotationPositions(int treePos) {
MethodSymbol meth = code.meth;
boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
|| code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
if (ta.hasUnknownPosition())
ta.tryFixPosition();
if (ta.position.matchesPos(treePos))
ta.position.updatePosOffset(code.cp);
}
if (!initOrClinit)
return;
for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
if (ta.hasUnknownPosition())
ta.tryFixPosition();
if (ta.position.matchesPos(treePos))
ta.position.updatePosOffset(code.cp);
}
ClassSymbol clazz = meth.enclClass();
for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
if (!s.getKind().isField())
continue;
for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
if (ta.hasUnknownPosition())
ta.tryFixPosition();
if (ta.position.matchesPos(treePos))
ta.position.updatePosOffset(code.cp);
}
}
}
public void visitNewClass(JCNewClass tree) {
// Enclosing instances or anonymous classes should have been eliminated
// by now.
Assert.check(tree.encl == null && tree.def == null);
setTypeAnnotationPositions(tree.pos);
code.emitop2(new_, makeRef(tree.pos(), tree.type));
code.emitop0(dup);
// Generate code for all arguments, where the expected types are
// the parameters of the constructor's external type (that is,
// any implicit outer instance appears as first parameter).
genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
items.makeMemberItem(tree.constructor, true).invoke();
result = items.makeStackItem(tree.type);
}
public void visitNewArray(JCNewArray tree) {
setTypeAnnotationPositions(tree.pos);
if (tree.elems != null) {
Type elemtype = types.elemtype(tree.type);
loadIntConst(tree.elems.length());
Item arr = makeNewArray(tree.pos(), tree.type, 1);
int i = 0;
for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
arr.duplicate();
loadIntConst(i);
i++;
genExpr(l.head, elemtype).load();
items.makeIndexedItem(elemtype).store();
}
result = arr;
} else {
for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
genExpr(l.head, syms.intType).load();
}
result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
}
}
//where
/** Generate code to create an array with given element type and number
* of dimensions.
*/
Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
Type elemtype = types.elemtype(type);
if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
log.error(pos, "limit.dimensions");
nerrs++;
}
int elemcode = Code.arraycode(elemtype);
if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
code.emitAnewarray(makeRef(pos, elemtype), type);
} else if (elemcode == 1) {
code.emitMultianewarray(ndims, makeRef(pos, type), type);
} else {
code.emitNewarray(elemcode, type);
}
return items.makeStackItem(type);
}
public void visitParens(JCParens tree) {
result = genExpr(tree.expr, tree.expr.type);
}
public void visitAssign(JCAssign tree) {
Item l = genExpr(tree.lhs, tree.lhs.type);
genExpr(tree.rhs, tree.lhs.type).load();
result = items.makeAssignItem(l);
}
public void visitAssignop(JCAssignOp tree) {
OperatorSymbol operator = (OperatorSymbol) tree.operator;
Item l;
if (operator.opcode == string_add) {
// Generate code to make a string buffer
makeStringBuffer(tree.pos());
// Generate code for first string, possibly save one
// copy under buffer
l = genExpr(tree.lhs, tree.lhs.type);
if (l.width() > 0) {
code.emitop0(dup_x1 + 3 * (l.width() - 1));
}
// Load first string and append to buffer.
l.load();
appendString(tree.lhs);
// Append all other strings to buffer.
appendStrings(tree.rhs);
// Convert buffer to string.
bufferToString(tree.pos());
} else {
// Generate code for first expression
l = genExpr(tree.lhs, tree.lhs.type);
// If we have an increment of -32768 to +32767 of a local
// int variable we can use an incr instruction instead of
// proceeding further.
if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
l instanceof LocalItem &&
tree.lhs.type.getTag().isSubRangeOf(INT) &&
tree.rhs.type.getTag().isSubRangeOf(INT) &&
tree.rhs.type.constValue() != null) {
int ival = ((Number) tree.rhs.type.constValue()).intValue();
if (tree.hasTag(MINUS_ASG)) ival = -ival;
((LocalItem)l).incr(ival);
result = l;
return;
}
// Otherwise, duplicate expression, load one copy
// and complete binary operation.
l.duplicate();
l.coerce(operator.type.getParameterTypes().head).load();
completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
}
result = items.makeAssignItem(l);
}
public void visitUnary(JCUnary tree) {
OperatorSymbol operator = (OperatorSymbol)tree.operator;
if (tree.hasTag(NOT)) {
CondItem od = genCond(tree.arg, false);
result = od.negate();
} else {
Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
switch (tree.getTag()) {
case POS:
result = od.load();
break;
case NEG:
result = od.load();
code.emitop0(operator.opcode);
break;
case COMPL:
result = od.load();
emitMinusOne(od.typecode);
code.emitop0(operator.opcode);
break;
case PREINC: case PREDEC:
od.duplicate();
if (od instanceof LocalItem &&
(operator.opcode == iadd || operator.opcode == isub)) {
((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
result = od;
} else {
od.load();
code.emitop0(one(od.typecode));
code.emitop0(operator.opcode);
// Perform narrowing primitive conversion if byte,
// char, or short. Fix for 4304655.
if (od.typecode != INTcode &&
Code.truncate(od.typecode) == INTcode)
code.emitop0(int2byte + od.typecode - BYTEcode);
result = items.makeAssignItem(od);
}
break;
case POSTINC: case POSTDEC:
od.duplicate();
if (od instanceof LocalItem &&
(operator.opcode == iadd || operator.opcode == isub)) {
Item res = od.load();
((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
result = res;
} else {
Item res = od.load();
od.stash(od.typecode);
code.emitop0(one(od.typecode));
code.emitop0(operator.opcode);
// Perform narrowing primitive conversion if byte,
// char, or short. Fix for 4304655.
if (od.typecode != INTcode &&
Code.truncate(od.typecode) == INTcode)
code.emitop0(int2byte + od.typecode - BYTEcode);
od.store();
result = res;
}
break;
case NULLCHK:
result = od.load();
code.emitop0(dup);
genNullCheck(tree.pos());
break;
default:
Assert.error();
}
}
}
/** Generate a null check from the object value at stack top. */
private void genNullCheck(DiagnosticPosition pos) {
callMethod(pos, syms.objectType, names.getClass,
List.<Type>nil(), false);
code.emitop0(pop);
}
public void visitBinary(JCBinary tree) {
OperatorSymbol operator = (OperatorSymbol)tree.operator;
if (operator.opcode == string_add) {
// Create a string buffer.
makeStringBuffer(tree.pos());
// Append all strings to buffer.
appendStrings(tree);
// Convert buffer to string.
bufferToString(tree.pos());
result = items.makeStackItem(syms.stringType);
} else if (tree.hasTag(AND)) {
CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
if (!lcond.isFalse()) {
Chain falseJumps = lcond.jumpFalse();
code.resolve(lcond.trueJumps);
CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
result = items.
makeCondItem(rcond.opcode,
rcond.trueJumps,
Code.mergeChains(falseJumps,
rcond.falseJumps));
} else {
result = lcond;
}
} else if (tree.hasTag(OR)) {
CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
if (!lcond.isTrue()) {
Chain trueJumps = lcond.jumpTrue();
code.resolve(lcond.falseJumps);
CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
result = items.
makeCondItem(rcond.opcode,
Code.mergeChains(trueJumps, rcond.trueJumps),
rcond.falseJumps);
} else {
result = lcond;
}
} else {
Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
od.load();
result = completeBinop(tree.lhs, tree.rhs, operator);
}
}
//where
/** Make a new string buffer.
*/
void makeStringBuffer(DiagnosticPosition pos) {
code.emitop2(new_, makeRef(pos, stringBufferType));
code.emitop0(dup);
callMethod(
pos, stringBufferType, names.init, List.<Type>nil(), false);
}
/** Append value (on tos) to string buffer (on tos - 1).
*/
void appendString(JCTree tree) {
Type t = tree.type.baseType();
if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) {
t = syms.objectType;
}
items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
}
Symbol getStringBufferAppend(JCTree tree, Type t) {
Assert.checkNull(t.constValue());
Symbol method = stringBufferAppend.get(t);
if (method == null) {
method = rs.resolveInternalMethod(tree.pos(),
attrEnv,
stringBufferType,
names.append,
List.of(t),
null);
stringBufferAppend.put(t, method);
}
return method;
}
/** Add all strings in tree to string buffer.
*/
void appendStrings(JCTree tree) {
tree = TreeInfo.skipParens(tree);
if (tree.hasTag(PLUS) && tree.type.constValue() == null) {
JCBinary op = (JCBinary) tree;
if (op.operator.kind == MTH &&
((OperatorSymbol) op.operator).opcode == string_add) {
appendStrings(op.lhs);
appendStrings(op.rhs);
return;
}
}
genExpr(tree, tree.type).load();
appendString(tree);
}
/** Convert string buffer on tos to string.
*/
void bufferToString(DiagnosticPosition pos) {
callMethod(
pos,
stringBufferType,
names.toString,
List.<Type>nil(),
false);
}
/** Complete generating code for operation, with left operand
* already on stack.
* @param lhs The tree representing the left operand.
* @param rhs The tree representing the right operand.
* @param operator The operator symbol.
*/
Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
MethodType optype = (MethodType)operator.type;
int opcode = operator.opcode;
if (opcode >= if_icmpeq && opcode <= if_icmple &&
rhs.type.constValue() instanceof Number &&
((Number) rhs.type.constValue()).intValue() == 0) {
opcode = opcode + (ifeq - if_icmpeq);
} else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
TreeInfo.isNull(rhs)) {
opcode = opcode + (if_acmp_null - if_acmpeq);
} else {
// The expected type of the right operand is
// the second parameter type of the operator, except for
// shifts with long shiftcount, where we convert the opcode
// to a short shift and the expected type to int.
Type rtype = operator.erasure(types).getParameterTypes().tail.head;
if (opcode >= ishll && opcode <= lushrl) {
opcode = opcode + (ishl - ishll);
rtype = syms.intType;
}
// Generate code for right operand and load.
genExpr(rhs, rtype).load();
// If there are two consecutive opcode instructions,
// emit the first now.
if (opcode >= (1 << preShift)) {
code.emitop0(opcode >> preShift);
opcode = opcode & 0xFF;
}
}
if (opcode >= ifeq && opcode <= if_acmpne ||
opcode == if_acmp_null || opcode == if_acmp_nonnull) {
return items.makeCondItem(opcode);
} else {
code.emitop0(opcode);
return items.makeStackItem(optype.restype);
}
}
public void visitTypeCast(JCTypeCast tree) {
setTypeAnnotationPositions(tree.pos);
result = genExpr(tree.expr, tree.clazz.type).load();
// Additional code is only needed if we cast to a reference type
// which is not statically a supertype of the expression's type.
// For basic types, the coerce(...) in genExpr(...) will do
// the conversion.
if (!tree.clazz.type.isPrimitive() &&
types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
}
}
public void visitWildcard(JCWildcard tree) {
throw new AssertionError(this.getClass().getName());
}
public void visitTypeTest(JCInstanceOf tree) {
setTypeAnnotationPositions(tree.pos);
genExpr(tree.expr, tree.expr.type).load();
code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
result = items.makeStackItem(syms.booleanType);
}
public void visitIndexed(JCArrayAccess tree) {
genExpr(tree.indexed, tree.indexed.type).load();
genExpr(tree.index, syms.intType).load();
result = items.makeIndexedItem(tree.type);
}
public void visitIdent(JCIdent tree) {
Symbol sym = tree.sym;
if (tree.name == names._this || tree.name == names._super) {
Item res = tree.name == names._this
? items.makeThisItem()
: items.makeSuperItem();
if (sym.kind == MTH) {
// Generate code to address the constructor.
res.load();
res = items.makeMemberItem(sym, true);
}
result = res;
} else if (sym.kind == VAR && sym.owner.kind == MTH) {
result = items.makeLocalItem((VarSymbol)sym);
} else if (isInvokeDynamic(sym)) {
result = items.makeDynamicItem(sym);
} else if ((sym.flags() & STATIC) != 0) {
if (!isAccessSuper(env.enclMethod))
sym = binaryQualifier(sym, env.enclClass.type);
result = items.makeStaticItem(sym);
} else {
items.makeThisItem().load();
sym = binaryQualifier(sym, env.enclClass.type);
result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
}
}
public void visitSelect(JCFieldAccess tree) {
Symbol sym = tree.sym;
if (tree.name == names._class) {
Assert.check(target.hasClassLiterals());
code.emitLdc(makeRef(tree.pos(), tree.selected.type));
result = items.makeStackItem(pt);
return;
}
Symbol ssym = TreeInfo.symbol(tree.selected);
// Are we selecting via super?
boolean selectSuper =
ssym != null && (ssym.kind == TYP || ssym.name == names._super);
// Are we accessing a member of the superclass in an access method
// resulting from a qualified super?
boolean accessSuper = isAccessSuper(env.enclMethod);
Item base = (selectSuper)
? items.makeSuperItem()
: genExpr(tree.selected, tree.selected.type);
if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
// We are seeing a variable that is constant but its selecting
// expression is not.
if ((sym.flags() & STATIC) != 0) {
if (!selectSuper && (ssym == null || ssym.kind != TYP))
base = base.load();
base.drop();
} else {
base.load();
genNullCheck(tree.selected.pos());
}
result = items.
makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
} else {
if (isInvokeDynamic(sym)) {
result = items.makeDynamicItem(sym);
return;
} else {
sym = binaryQualifier(sym, tree.selected.type);
}
if ((sym.flags() & STATIC) != 0) {
if (!selectSuper && (ssym == null || ssym.kind != TYP))
base = base.load();
base.drop();
result = items.makeStaticItem(sym);
} else {
base.load();
if (sym == syms.lengthVar) {
code.emitop0(arraylength);
result = items.makeStackItem(syms.intType);
} else {
result = items.
makeMemberItem(sym,
(sym.flags() & PRIVATE) != 0 ||
selectSuper || accessSuper);
}
}
}
}
public boolean isInvokeDynamic(Symbol sym) {
return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
}
public void visitLiteral(JCLiteral tree) {
if (tree.type.hasTag(BOT)) {
code.emitop0(aconst_null);
if (types.dimensions(pt) > 1) {
code.emitop2(checkcast, makeRef(tree.pos(), pt));
result = items.makeStackItem(pt);
} else {
result = items.makeStackItem(tree.type);
}
}
else
result = items.makeImmediateItem(tree.type, tree.value);
}
public void visitLetExpr(LetExpr tree) {
int limit = code.nextreg;
genStats(tree.defs, env);
result = genExpr(tree.expr, tree.expr.type).load();
code.endScopes(limit);
}
private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
if (prunedInfo != null) {
for (JCTree prunedTree: prunedInfo) {
prunedTree.accept(classReferenceVisitor);
}
}
}
/* ************************************************************************
* main method
*************************************************************************/
/** Generate code for a class definition.
* @param env The attribution environment that belongs to the
* outermost class containing this class definition.
* We need this for resolving some additional symbols.
* @param cdef The tree representing the class definition.
* @return True if code is generated with no errors.
*/
public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
try {
attrEnv = env;
ClassSymbol c = cdef.sym;
this.toplevel = env.toplevel;
this.endPosTable = toplevel.endPositions;
// If this is a class definition requiring Miranda methods,
// add them.
if (generateIproxies &&
(c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
&& !allowGenerics // no Miranda methods available with generics
)
implementInterfaceMethods(c);
cdef.defs = normalizeDefs(cdef.defs, c);
c.pool = pool;
pool.reset();
generateReferencesToPrunedTree(c, pool);
Env<GenContext> localEnv =
new Env<GenContext>(cdef, new GenContext());
localEnv.toplevel = env.toplevel;
localEnv.enclClass = cdef;
/* We must not analyze synthetic methods
*/
if (varDebugInfo && (cdef.sym.flags() & SYNTHETIC) == 0) {
try {
LVTAssignAnalyzer lvtAssignAnalyzer = LVTAssignAnalyzer.make(
lvtRanges, syms, names);
lvtAssignAnalyzer.analyzeTree(localEnv);
} catch (Throwable e) {
throw e;
}
}
for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
genDef(l.head, localEnv);
}
if (pool.numEntries() > Pool.MAX_ENTRIES) {
log.error(cdef.pos(), "limit.pool");
nerrs++;
}
if (nerrs != 0) {
// if errors, discard code
for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
if (l.head.hasTag(METHODDEF))
((JCMethodDecl) l.head).sym.code = null;
}
}
cdef.defs = List.nil(); // discard trees
return nerrs == 0;
} finally {
// note: this method does NOT support recursion.
attrEnv = null;
this.env = null;
toplevel = null;
endPosTable = null;
nerrs = 0;
}
}
/* ************************************************************************
* Auxiliary classes
*************************************************************************/
/** An abstract class for finalizer generation.
*/
abstract class GenFinalizer {
/** Generate code to clean up when unwinding. */
abstract void gen();
/** Generate code to clean up at last. */
abstract void genLast();
/** Does this finalizer have some nontrivial cleanup to perform? */
boolean hasFinalizer() { return true; }
}
/** code generation contexts,
* to be used as type parameter for environments.
*/
static class GenContext {
/** A chain for all unresolved jumps that exit the current environment.
*/
Chain exit = null;
/** A chain for all unresolved jumps that continue in the
* current environment.
*/
Chain cont = null;
/** A closure that generates the finalizer of the current environment.
* Only set for Synchronized and Try contexts.
*/
GenFinalizer finalize = null;
/** Is this a switch statement? If so, allocate registers
* even when the variable declaration is unreachable.
*/
boolean isSwitch = false;
/** A list buffer containing all gaps in the finalizer range,
* where a catch all exception should not apply.
*/
ListBuffer<Integer> gaps = null;
/** Add given chain to exit chain.
*/
void addExit(Chain c) {
exit = Code.mergeChains(c, exit);
}
/** Add given chain to cont chain.
*/
void addCont(Chain c) {
cont = Code.mergeChains(c, cont);
}
}
static class LVTAssignAnalyzer
extends Flow.AbstractAssignAnalyzer<LVTAssignAnalyzer.LVTAssignPendingExit> {
final LVTBits lvtInits;
final LVTRanges lvtRanges;
/* This class is anchored to a context dependent tree. The tree can
* vary inside the same instruction for example in the switch instruction
* the same FlowBits instance can be anchored to the whole tree, or
* to a given case. The aim is to always anchor the bits to the tree
* capable of closing a DA range.
*/
static class LVTBits extends Bits {
enum BitsOpKind {
INIT,
CLEAR,
INCL_BIT,
EXCL_BIT,
ASSIGN,
AND_SET,
OR_SET,
DIFF_SET,
XOR_SET,
INCL_RANGE,
EXCL_RANGE,
}
JCTree currentTree;
LVTAssignAnalyzer analyzer;
private int[] oldBits = null;
BitsState stateBeforeOp;
LVTBits() {
super(false);
}
LVTBits(int[] bits, BitsState initState) {
super(bits, initState);
}
@Override
public void clear() {
generalOp(null, -1, BitsOpKind.CLEAR);
}
@Override
protected void internalReset() {
super.internalReset();
oldBits = null;
}
@Override
public Bits assign(Bits someBits) {
// bits can be null
oldBits = bits;
stateBeforeOp = currentState;
super.assign(someBits);
changed();
return this;
}
@Override
public void excludeFrom(int start) {
generalOp(null, start, BitsOpKind.EXCL_RANGE);
}
@Override
public void excl(int x) {
Assert.check(x >= 0);
generalOp(null, x, BitsOpKind.EXCL_BIT);
}
@Override
public Bits andSet(Bits xs) {
return generalOp(xs, -1, BitsOpKind.AND_SET);
}
@Override
public Bits orSet(Bits xs) {
return generalOp(xs, -1, BitsOpKind.OR_SET);
}
@Override
public Bits diffSet(Bits xs) {
return generalOp(xs, -1, BitsOpKind.DIFF_SET);
}
@Override
public Bits xorSet(Bits xs) {
return generalOp(xs, -1, BitsOpKind.XOR_SET);
}
private Bits generalOp(Bits xs, int i, BitsOpKind opKind) {
Assert.check(currentState != BitsState.UNKNOWN);
oldBits = dupBits();
stateBeforeOp = currentState;
switch (opKind) {
case AND_SET:
super.andSet(xs);
break;
case OR_SET:
super.orSet(xs);
break;
case XOR_SET:
super.xorSet(xs);
break;
case DIFF_SET:
super.diffSet(xs);
break;
case CLEAR:
super.clear();
break;
case EXCL_BIT:
super.excl(i);
break;
case EXCL_RANGE:
super.excludeFrom(i);
break;
}
changed();
return this;
}
/* The tree we need to anchor the bits instance to.
*/
LVTBits at(JCTree tree) {
this.currentTree = tree;
return this;
}
/* If the instance should be changed but the tree is not a closing
* tree then a reset is needed or the former tree can mistakingly be
* used.
*/
LVTBits resetTree() {
this.currentTree = null;
return this;
}
/** This method will be called after any operation that causes a change to
* the bits. Subclasses can thus override it in order to extract information
* from the changes produced to the bits by the given operation.
*/
public void changed() {
if (currentTree != null &&
stateBeforeOp != BitsState.UNKNOWN &&
trackTree(currentTree)) {
List<VarSymbol> locals =
analyzer.lvtRanges
.getVars(analyzer.currentMethod, currentTree);
locals = locals != null ?
locals : List.<VarSymbol>nil();
for (JCVariableDecl vardecl : analyzer.vardecls) {
//once the first is null, the rest will be so.
if (vardecl == null) {
break;
}
if (trackVar(vardecl.sym) && bitChanged(vardecl.sym.adr)) {
locals = locals.prepend(vardecl.sym);
}
}
if (!locals.isEmpty()) {
analyzer.lvtRanges.setEntry(analyzer.currentMethod,
currentTree, locals);
}
}
}
boolean bitChanged(int x) {
boolean isMemberOfBits = isMember(x);
int[] tmp = bits;
bits = oldBits;
boolean isMemberOfOldBits = isMember(x);
bits = tmp;
return (!isMemberOfBits && isMemberOfOldBits);
}
boolean trackVar(VarSymbol var) {
return (var.owner.kind == MTH &&
(var.flags() & (PARAMETER | HASINIT)) == 0 &&
analyzer.trackable(var));
}
boolean trackTree(JCTree tree) {
switch (tree.getTag()) {
// of course a method closes the alive range of a local variable.
case METHODDEF:
// for while loops we want only the body
case WHILELOOP:
return false;
}
return true;
}
}
public class LVTAssignPendingExit extends Flow.AssignAnalyzer.AssignPendingExit {
LVTAssignPendingExit(JCTree tree, final Bits inits, final Bits uninits) {
super(tree, inits, uninits);
}
@Override
public void resolveJump(JCTree tree) {
lvtInits.at(tree);
super.resolveJump(tree);
}
}
private LVTAssignAnalyzer(LVTRanges lvtRanges, Symtab syms, Names names) {
super(new LVTBits(), syms, names);
lvtInits = (LVTBits)inits;
this.lvtRanges = lvtRanges;
}
public static LVTAssignAnalyzer make(LVTRanges lvtRanges, Symtab syms, Names names) {
LVTAssignAnalyzer result = new LVTAssignAnalyzer(lvtRanges, syms, names);
result.lvtInits.analyzer = result;
return result;
}
@Override
protected void markDead(JCTree tree) {
lvtInits.at(tree).inclRange(returnadr, nextadr);
super.markDead(tree);
}
@Override
protected void merge(JCTree tree) {
lvtInits.at(tree);
super.merge(tree);
}
boolean isSyntheticOrMandated(Symbol sym) {
return (sym.flags() & (SYNTHETIC | MANDATED)) != 0;
}
@Override
protected boolean trackable(VarSymbol sym) {
if (isSyntheticOrMandated(sym)) {
//fast check to avoid tracking synthetic or mandated variables
return false;
}
return super.trackable(sym);
}
@Override
protected void initParam(JCVariableDecl def) {
if (!isSyntheticOrMandated(def.sym)) {
super.initParam(def);
}
}
@Override
protected void assignToInits(JCTree tree, Bits bits) {
lvtInits.at(tree);
lvtInits.assign(bits);
}
@Override
protected void andSetInits(JCTree tree, Bits bits) {
lvtInits.at(tree);
lvtInits.andSet(bits);
}
@Override
protected void orSetInits(JCTree tree, Bits bits) {
lvtInits.at(tree);
lvtInits.orSet(bits);
}
@Override
protected void exclVarFromInits(JCTree tree, int adr) {
lvtInits.at(tree);
lvtInits.excl(adr);
}
@Override
protected LVTAssignPendingExit createNewPendingExit(JCTree tree, Bits inits, Bits uninits) {
return new LVTAssignPendingExit(tree, inits, uninits);
}
MethodSymbol currentMethod;
@Override
public void visitMethodDef(JCMethodDecl tree) {
if ((tree.sym.flags() & (SYNTHETIC | GENERATEDCONSTR)) != 0
&& (tree.sym.flags() & LAMBDA_METHOD) == 0) {
return;
}
if (tree.name.equals(names.clinit)) {
return;
}
boolean enumClass = (tree.sym.owner.flags() & ENUM) != 0;
if (enumClass &&
(tree.name.equals(names.valueOf) ||
tree.name.equals(names.values) ||
tree.name.equals(names.init))) {
return;
}
currentMethod = tree.sym;
super.visitMethodDef(tree);
}
}
}
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