8231826: Implement javac changes for pattern matching for instanceof
Reviewed-by: mcimadamore
Contributed-by: brian.goetz@oracle.com, gavin.bierman@oracle.com, maurizio.cimadamore@oracle.com, srikanth.adayapalam@oracle.com, vicente.romero@oracle.com, jan.lahoda@oracle.com
/*
* Copyright (c) 1999, 2019, 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 com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
import com.sun.tools.javac.tree.TreeInfo.PosKind;
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.resources.CompilerProperties.Errors;
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.Kind.*;
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><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 Gen extends JCTree.Visitor {
protected static final Context.Key<Gen> genKey = new Context.Key<>();
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 Name accessDollar;
private final Types types;
private final Lower lower;
private final Annotate annotate;
private final StringConcat concat;
/** 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 writer, set by genClass.
*/
final PoolWriter poolWriter;
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);
concat = StringConcat.instance(context);
methodType = new MethodType(null, null, null, syms.methodClass);
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");
genCrt = options.isSet(XJCOV);
debugCode = options.isSet("debug.code");
disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
poolWriter = new PoolWriter(types, names);
// ignore cldc because we cannot have both stackmap formats
this.stackMap = StackMapFormat.JSR202;
annotate = Annotate.instance(context);
}
/** Switches
*/
private final boolean lineDebugInfo;
private final boolean varDebugInfo;
private final boolean genCrt;
private final boolean debugCode;
private boolean disableVirtualizedPrivateInvoke;
/** 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;
boolean inCondSwitchExpression;
Chain switchExpressionTrueChain;
Chain switchExpressionFalseChain;
List<LocalItem> stackBeforeSwitchExpression;
LocalItem switchResult;
/** 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, Long.valueOf(-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 = new ClassSymbol(Flags.PUBLIC, site.tsym.name,
site, syms.noSymbol);
return sym.clone(qualifier);
}
if (sym.owner == site.tsym ||
(sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
return sym;
}
// leave alone methods inherited from Object
// JLS 13.1.
if (sym.owner == syms.objectType.tsym)
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) {
return poolWriter.putClass(checkDimension(pos, type));
}
/** Check if the given type is an array with too many dimensions.
*/
private Type checkDimension(DiagnosticPosition pos, Type t) {
checkDimensionInternal(pos, t);
return t;
}
private void checkDimensionInternal(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, Errors.LimitDimensions);
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<GenContext> 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<GenContext> 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<JCTree> 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 if ((block.flags & SYNTHETIC) == 0)
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());
/* if the init contains a reference to an external class, add it to the
* constant's pool
*/
vdef.init.accept(classReferenceVisitor);
}
}
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.nil(), syms.voidType,
List.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) {
Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
if (ta.getPosition().type == TargetType.FIELD) {
fieldTAs.add(ta);
} else {
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() < PoolWriter.MAX_STRING_LENGTH)
return;
log.error(pos, Errors.LimitString);
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<TypeCompound> 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);
}
}
/* ************************************************************************
* 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<GenContext> 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<GenContext> 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 if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
boolean prevInCondSwitchExpression = inCondSwitchExpression;
Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
try {
inCondSwitchExpression = true;
switchExpressionTrueChain = null;
switchExpressionFalseChain = null;
try {
doHandleSwitchExpression((JCSwitchExpression) inner_tree);
} catch (CompletionFailure ex) {
chk.completionError(_tree.pos(), ex);
code.state.stacksize = 1;
}
CondItem result = items.makeCondItem(goto_,
switchExpressionTrueChain,
switchExpressionFalseChain);
if (markBranches) result.tree = _tree;
return result;
} finally {
inCondSwitchExpression = prevInCondSwitchExpression;
switchExpressionTrueChain = prevSwitchExpressionTrueChain;
switchExpressionFalseChain = prevSwitchExpressionFalseChain;
}
} else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
LetExpr tree = (LetExpr) inner_tree;
int limit = code.nextreg;
int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
try {
genStats(tree.defs, env);
} finally {
code.setLetExprStackPos(prevLetExprStart);
}
CondItem result = genCond(tree.expr, markBranches);
code.endScopes(limit);
return result;
} else {
CondItem result = genExpr(_tree, syms.booleanType).mkCond();
if (markBranches) result.tree = _tree;
return result;
}
}
public Code getCode() {
return code;
}
public Items getItems() {
return items;
}
public Env<AttrContext> getAttrEnv() {
return attrEnv;
}
/** 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) {
poolWriter.putClass((ClassSymbol)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());
Symbol sym = TreeInfo.symbol(tree);
if (sym != null && isConstantDynamic(sym)) {
result = items.makeDynamicItem(sym);
} else {
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;
}
}
public boolean isConstantDynamic(Symbol sym) {
return sym.kind == VAR &&
sym instanceof DynamicVarSymbol &&
((DynamicVarSymbol)sym).isDynamic();
}
/** 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<Type> 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(), Errors.LimitParameters);
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(), Errors.StackSimError(tree.sym));
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,
poolWriter);
items = new Items(poolWriter, 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;
if (tree.init != null) {
checkStringConstant(tree.init.pos(), v.getConstValue());
if (v.getConstValue() == null || varDebugInfo) {
Assert.check(code.isStatementStart());
code.newLocal(v);
genExpr(tree.init, v.erasure(types)).load();
items.makeLocalItem(v).store();
Assert.check(code.isStatementStart());
}
} else {
code.newLocal(v);
}
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.nil(), false);
}
public void visitWhileLoop(JCWhileLoop tree) {
genLoop(tree, tree.body, tree.cond, List.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) { //while or for loop
CondItem c;
if (cond != null) {
code.statBegin(cond.pos);
Assert.check(code.isStatementStart());
c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
} else {
c = items.makeCondItem(goto_);
}
Chain loopDone = c.jumpFalse();
code.resolve(c.trueJumps);
Assert.check(code.isStatementStart());
genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
code.resolve(loopEnv.info.cont);
genStats(step, loopEnv);
code.resolve(code.branch(goto_), startpc);
code.resolve(loopDone);
} else {
genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
code.resolve(loopEnv.info.cont);
genStats(step, loopEnv);
if (code.isAlive()) {
CondItem c;
if (cond != null) {
code.statBegin(cond.pos);
Assert.check(code.isStatementStart());
c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
} else {
c = items.makeCondItem(goto_);
}
code.resolve(c.jumpTrue(), startpc);
Assert.check(code.isStatementStart());
code.resolve(c.falseJumps);
}
}
Chain exit = loopEnv.info.exit;
if (exit != null) {
code.resolve(exit);
exit.state.defined.excludeFrom(code.nextreg);
}
}
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);
Chain exit = localEnv.info.exit;
if (exit != null) {
code.resolve(exit);
exit.state.defined.excludeFrom(code.nextreg);
}
}
public void visitSwitch(JCSwitch tree) {
handleSwitch(tree, tree.selector, tree.cases);
}
@Override
public void visitSwitchExpression(JCSwitchExpression tree) {
code.resolvePending();
boolean prevInCondSwitchExpression = inCondSwitchExpression;
try {
inCondSwitchExpression = false;
doHandleSwitchExpression(tree);
} finally {
inCondSwitchExpression = prevInCondSwitchExpression;
}
result = items.makeStackItem(pt);
}
private void doHandleSwitchExpression(JCSwitchExpression tree) {
List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
LocalItem prevSwitchResult = switchResult;
int limit = code.nextreg;
try {
stackBeforeSwitchExpression = List.nil();
switchResult = null;
if (hasTry(tree)) {
//if the switch expression contains try-catch, the catch handlers need to have
//an empty stack. So stash whole stack to local variables, and restore it before
//breaks:
while (code.state.stacksize > 0) {
Type type = code.state.peek();
Name varName = names.fromString(target.syntheticNameChar() +
"stack" +
target.syntheticNameChar() +
tree.pos +
target.syntheticNameChar() +
code.state.stacksize);
VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
this.env.enclMethod.sym);
LocalItem item = items.new LocalItem(type, code.newLocal(var));
stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
item.store();
}
switchResult = makeTemp(tree.type);
}
int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
try {
handleSwitch(tree, tree.selector, tree.cases);
} finally {
code.setLetExprStackPos(prevLetExprStart);
}
} finally {
stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
switchResult = prevSwitchResult;
code.endScopes(limit);
}
}
//where:
private boolean hasTry(JCSwitchExpression tree) {
boolean[] hasTry = new boolean[1];
new TreeScanner() {
@Override
public void visitTry(JCTry tree) {
hasTry[0] = true;
}
@Override
public void visitClassDef(JCClassDecl tree) {
}
@Override
public void visitLambda(JCLambda tree) {
}
}.scan(tree);
return hasTry[0];
}
private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases) {
int limit = code.nextreg;
Assert.check(!selector.type.hasTag(CLASS));
int startpcCrt = genCrt ? code.curCP() : 0;
Assert.check(code.isStatementStart());
Item sel = genExpr(selector, syms.intType);
if (cases.isEmpty()) {
// We are seeing: switch <sel> {}
sel.load().drop();
if (genCrt)
code.crt.put(TreeInfo.skipParens(selector),
CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
} else {
// We are seeing a nonempty switch.
sel.load();
if (genCrt)
code.crt.put(TreeInfo.skipParens(selector),
CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
Env<GenContext> switchEnv = env.dup(swtch, 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.pats.nonEmpty()) {
Assert.check(l.head.pats.size() == 1);
int val = ((Number)l.head.pats.head.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);
}
// Resolve all breaks.
Chain exit = switchEnv.info.exit;
if (exit != null) {
code.resolve(exit);
exit.state.defined.excludeFrom(limit);
}
// 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);
Assert.check(code.isStatementStart());
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<>();
genTry(tree.body, List.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;
tryEnv.info.finalize = new GenFinalizer() {
void gen() {
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;
}
@Override
void afterBody() {
if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
//for body-only finally, remove the GenFinalizer after try body
//so that the finally is not generated to catch bodies:
tryEnv.info.finalize = null;
}
}
};
tryEnv.info.gaps = new ListBuffer<>();
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<GenContext> env) {
int limit = code.nextreg;
int startpc = code.curCP();
Code.State stateTry = code.state.dup();
genStat(body, env, CRT_BLOCK);
int endpc = code.curCP();
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_);
endFinalizerGap(env);
env.info.finalize.afterBody();
boolean hasFinalizer =
env.info.finalize != null &&
env.info.finalize.hasFinalizer();
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, PosKind.FIRST_STAT_POS));
code.markStatBegin();
Item excVar = makeTemp(syms.throwableType);
excVar.store();
genFinalizer(env);
code.resolvePending();
code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
code.markStatBegin();
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, PosKind.FIRST_STAT_POS));
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<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
= catchTypesWithAnnotations(tree);
while (gaps.nonEmpty()) {
for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
JCExpression subCatch = subCatch1.snd;
int catchType = makeRef(tree.pos(), subCatch.type);
int end = gaps.head.intValue();
registerCatch(tree.pos(),
startpc, end, code.curCP(),
catchType);
for (Attribute.TypeCompound tc : subCatch1.fst) {
tc.position.setCatchInfo(catchType, startpc);
}
}
gaps = gaps.tail;
startpc = gaps.head.intValue();
gaps = gaps.tail;
}
if (startpc < endpc) {
for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
JCExpression subCatch = subCatch1.snd;
int catchType = makeRef(tree.pos(), subCatch.type);
registerCatch(tree.pos(),
startpc, endpc, code.curCP(),
catchType);
for (Attribute.TypeCompound tc : subCatch1.fst) {
tc.position.setCatchInfo(catchType, startpc);
}
}
}
VarSymbol exparam = tree.param.sym;
code.statBegin(tree.pos);
code.markStatBegin();
int limit = code.nextreg;
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));
}
}
// where
List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
return TreeInfo.isMultiCatch(tree) ?
catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
}
// where
List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
List<JCExpression> alts = tree.alternatives;
List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
alts = alts.tail;
while(alts != null && alts.head != null) {
JCExpression alt = alts.head;
if (alt instanceof JCAnnotatedType) {
JCAnnotatedType a = (JCAnnotatedType)alt;
res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt));
} else {
res = res.prepend(new Pair<>(List.nil(), alt));
}
alts = alts.tail;
}
return res.reverse();
}
/** 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 {
log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
nerrs++;
}
}
public void visitIf(JCIf tree) {
int limit = code.nextreg;
Chain thenExit = null;
Assert.check(code.isStatementStart());
CondItem c = genCond(TreeInfo.skipParens(tree.cond),
CRT_FLOW_CONTROLLER);
Chain elseChain = c.jumpFalse();
Assert.check(code.isStatementStart());
if (!c.isFalse()) {
code.resolve(c.trueJumps);
genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
thenExit = code.branch(goto_);
}
if (elseChain != null) {
code.resolve(elseChain);
if (tree.elsepart != null) {
genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
}
}
code.resolve(thenExit);
code.endScopes(limit);
Assert.check(code.isStatementStart());
}
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;
}
Assert.check(code.isStatementStart());
genExpr(tree.expr, tree.expr.type).drop();
Assert.check(code.isStatementStart());
}
public void visitBreak(JCBreak tree) {
Assert.check(code.isStatementStart());
final Env<GenContext> targetEnv = unwindBreak(tree.target);
targetEnv.info.addExit(code.branch(goto_));
endFinalizerGaps(env, targetEnv);
}
public void visitYield(JCYield tree) {
Assert.check(code.isStatementStart());
final Env<GenContext> targetEnv;
if (inCondSwitchExpression) {
CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
Chain falseJumps = value.jumpFalse();
code.resolve(value.trueJumps);
Env<GenContext> localEnv = unwindBreak(tree.target);
reloadStackBeforeSwitchExpr();
Chain trueJumps = code.branch(goto_);
endFinalizerGaps(env, localEnv);
code.resolve(falseJumps);
targetEnv = unwindBreak(tree.target);
reloadStackBeforeSwitchExpr();
falseJumps = code.branch(goto_);
if (switchExpressionTrueChain == null) {
switchExpressionTrueChain = trueJumps;
} else {
switchExpressionTrueChain =
Code.mergeChains(switchExpressionTrueChain, trueJumps);
}
if (switchExpressionFalseChain == null) {
switchExpressionFalseChain = falseJumps;
} else {
switchExpressionFalseChain =
Code.mergeChains(switchExpressionFalseChain, falseJumps);
}
} else {
genExpr(tree.value, pt).load();
if (switchResult != null)
switchResult.store();
targetEnv = unwindBreak(tree.target);
if (code.isAlive()) {
reloadStackBeforeSwitchExpr();
if (switchResult != null)
switchResult.load();
code.state.forceStackTop(tree.target.type);
targetEnv.info.addExit(code.branch(goto_));
code.markDead();
}
}
endFinalizerGaps(env, targetEnv);
}
//where:
/** As side-effect, might mark code as dead disabling any further emission.
*/
private Env<GenContext> unwindBreak(JCTree target) {
int tmpPos = code.pendingStatPos;
Env<GenContext> targetEnv = unwind(target, env);
code.pendingStatPos = tmpPos;
return targetEnv;
}
private void reloadStackBeforeSwitchExpr() {
for (LocalItem li : stackBeforeSwitchExpression)
li.load();
}
public void visitContinue(JCContinue tree) {
int tmpPos = code.pendingStatPos;
Env<GenContext> targetEnv = unwind(tree.target, env);
code.pendingStatPos = tmpPos;
Assert.check(code.isStatementStart());
targetEnv.info.addCont(code.branch(goto_));
endFinalizerGaps(env, targetEnv);
}
public void visitReturn(JCReturn tree) {
int limit = code.nextreg;
final Env<GenContext> targetEnv;
/* Save and then restore the location of the return in case a finally
* is expanded (with unwind()) in the middle of our bytecodes.
*/
int tmpPos = code.pendingStatPos;
if (tree.expr != null) {
Assert.check(code.isStatementStart());
Item r = genExpr(tree.expr, pt).load();
if (hasFinally(env.enclMethod, env)) {
r = makeTemp(pt);
r.store();
}
targetEnv = unwind(env.enclMethod, env);
code.pendingStatPos = tmpPos;
r.load();
code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
} else {
targetEnv = unwind(env.enclMethod, env);
code.pendingStatPos = tmpPos;
code.emitop0(return_);
}
endFinalizerGaps(env, targetEnv);
code.endScopes(limit);
}
public void visitThrow(JCThrow tree) {
Assert.check(code.isStatementStart());
genExpr(tree.expr, tree.expr.type).load();
code.emitop0(athrow);
Assert.check(code.isStatementStart());
}
/* ************************************************************************
* 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;
code.statBegin(tree.cond.pos);
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;
code.statBegin(tree.truepart.pos);
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;
code.statBegin(tree.falsepart.pos);
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_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
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, Errors.LimitDimensions);
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();
if (tree.rhs.type.hasTag(BOT)) {
/* This is just a case of widening reference conversion that per 5.1.5 simply calls
for "regarding a reference as having some other type in a manner that can be proved
correct at compile time."
*/
code.state.forceStackTop(tree.lhs.type);
}
result = items.makeAssignItem(l);
}
public void visitAssignop(JCAssignOp tree) {
OperatorSymbol operator = tree.operator;
Item l;
if (operator.opcode == string_add) {
l = concat.makeConcat(tree);
} 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 = 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);
break;
default:
Assert.error();
}
}
}
/** Generate a null check from the object value at stack top. */
private void genNullCheck(JCTree tree) {
code.statBegin(tree.pos);
callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
List.of(syms.objectType), true);
code.emitop0(pop);
}
public void visitBinary(JCBinary tree) {
OperatorSymbol operator = tree.operator;
if (operator.opcode == string_add) {
result = concat.makeConcat(tree);
} 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);
}
}
/** 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) {
result = genExpr(tree.expr, tree.clazz.type).load();
setTypeAnnotationPositions(tree.pos);
// 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.isSameType(tree.expr.type, tree.clazz.type) &&
types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
}
}
public void visitWildcard(JCWildcard tree) {
throw new AssertionError(this.getClass().getName());
}
public void visitTypeTest(JCInstanceOf tree) {
genExpr(tree.expr, tree.expr.type).load();
setTypeAnnotationPositions(tree.pos);
code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.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 (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
if (isConstantDynamic(sym)) {
setTypeAnnotationPositions(tree.pos);
}
result = items.makeDynamicItem(sym);
} else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
result = items.makeLocalItem((VarSymbol)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, nonVirtualForPrivateAccess(sym));
}
}
//where
private boolean nonVirtualForPrivateAccess(Symbol sym) {
boolean useVirtual = target.hasVirtualPrivateInvoke() &&
!disableVirtualizedPrivateInvoke;
return !useVirtual && ((sym.flags() & PRIVATE) != 0);
}
public void visitSelect(JCFieldAccess tree) {
Symbol sym = tree.sym;
if (tree.name == names._class) {
code.emitLdc((LoadableConstant)checkDimension(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);
}
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,
nonVirtualForPrivateAccess(sym) ||
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);
result = items.makeStackItem(tree.type);
}
else
result = items.makeImmediateItem(tree.type, tree.value);
}
public void visitLetExpr(LetExpr tree) {
code.resolvePending();
int limit = code.nextreg;
int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
try {
genStats(tree.defs, env);
} finally {
code.setLetExprStackPos(prevLetExprStart);
}
result = genExpr(tree.expr, tree.expr.type).load();
code.endScopes(limit);
}
private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
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;
/* method normalizeDefs() can add references to external classes into the constant pool
*/
cdef.defs = normalizeDefs(cdef.defs, c);
generateReferencesToPrunedTree(c);
Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
localEnv.toplevel = env.toplevel;
localEnv.enclClass = cdef;
for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
genDef(l.head, localEnv);
}
if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
log.error(cdef.pos(), Errors.LimitPool);
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; }
/** Should be invoked after the try's body has been visited. */
void afterBody() {}
}
/** 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);
}
}
}