duke@1: /*
jjg@815:  * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
duke@1:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1:  *
duke@1:  * This code is free software; you can redistribute it and/or modify it
duke@1:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
duke@1:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
duke@1:  *
duke@1:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@1:  * version 2 for more details (a copy is included in the LICENSE file that
duke@1:  * accompanied this code).
duke@1:  *
duke@1:  * You should have received a copy of the GNU General Public License version
duke@1:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@1:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
duke@1:  */
duke@1: 
duke@1: package com.sun.tools.javac.jvm;
duke@1: import java.util.*;
duke@1: 
jjg@308: import javax.lang.model.element.ElementKind;
jjg@308: 
duke@1: import com.sun.tools.javac.util.*;
duke@1: import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
duke@1: import com.sun.tools.javac.util.List;
duke@1: import com.sun.tools.javac.code.*;
duke@1: import com.sun.tools.javac.comp.*;
duke@1: import com.sun.tools.javac.tree.*;
duke@1: 
duke@1: import com.sun.tools.javac.code.Symbol.*;
duke@1: import com.sun.tools.javac.code.Type.*;
duke@1: import com.sun.tools.javac.jvm.Code.*;
duke@1: import com.sun.tools.javac.jvm.Items.*;
duke@1: import com.sun.tools.javac.tree.JCTree.*;
duke@1: 
duke@1: import static com.sun.tools.javac.code.Flags.*;
duke@1: import static com.sun.tools.javac.code.Kinds.*;
duke@1: import static com.sun.tools.javac.code.TypeTags.*;
duke@1: import static com.sun.tools.javac.jvm.ByteCodes.*;
duke@1: import static com.sun.tools.javac.jvm.CRTFlags.*;
jjg@700: import static com.sun.tools.javac.main.OptionName.*;
duke@1: 
duke@1: /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
duke@1:  *
jjg@581:  *  <p><b>This is NOT part of any supported API.
jjg@581:  *  If you write code that depends on this, you do so at your own risk.
duke@1:  *  This code and its internal interfaces are subject to change or
duke@1:  *  deletion without notice.</b>
duke@1:  */
duke@1: public class Gen extends JCTree.Visitor {
duke@1:     protected static final Context.Key<Gen> genKey =
duke@1:         new Context.Key<Gen>();
duke@1: 
duke@1:     private final Log log;
duke@1:     private final Symtab syms;
duke@1:     private final Check chk;
duke@1:     private final Resolve rs;
duke@1:     private final TreeMaker make;
jjg@113:     private final Names names;
duke@1:     private final Target target;
duke@1:     private final Type stringBufferType;
duke@1:     private final Map<Type,Symbol> stringBufferAppend;
duke@1:     private Name accessDollar;
duke@1:     private final Types types;
duke@1: 
duke@1:     /** Switch: GJ mode?
duke@1:      */
duke@1:     private final boolean allowGenerics;
duke@1: 
duke@1:     /** Set when Miranda method stubs are to be generated. */
duke@1:     private final boolean generateIproxies;
duke@1: 
duke@1:     /** Format of stackmap tables to be generated. */
duke@1:     private final Code.StackMapFormat stackMap;
duke@1: 
duke@1:     /** A type that serves as the expected type for all method expressions.
duke@1:      */
duke@1:     private final Type methodType;
duke@1: 
duke@1:     public static Gen instance(Context context) {
duke@1:         Gen instance = context.get(genKey);
duke@1:         if (instance == null)
duke@1:             instance = new Gen(context);
duke@1:         return instance;
duke@1:     }
duke@1: 
duke@1:     protected Gen(Context context) {
duke@1:         context.put(genKey, this);
duke@1: 
jjg@113:         names = Names.instance(context);
duke@1:         log = Log.instance(context);
duke@1:         syms = Symtab.instance(context);
duke@1:         chk = Check.instance(context);
duke@1:         rs = Resolve.instance(context);
duke@1:         make = TreeMaker.instance(context);
duke@1:         target = Target.instance(context);
duke@1:         types = Types.instance(context);
duke@1:         methodType = new MethodType(null, null, null, syms.methodClass);
duke@1:         allowGenerics = Source.instance(context).allowGenerics();
duke@1:         stringBufferType = target.useStringBuilder()
duke@1:             ? syms.stringBuilderType
duke@1:             : syms.stringBufferType;
duke@1:         stringBufferAppend = new HashMap<Type,Symbol>();
duke@1:         accessDollar = names.
duke@1:             fromString("access" + target.syntheticNameChar());
duke@1: 
duke@1:         Options options = Options.instance(context);
duke@1:         lineDebugInfo =
jjg@700:             options.isUnset(G_CUSTOM) ||
jjg@700:             options.isSet(G_CUSTOM, "lines");
duke@1:         varDebugInfo =
jjg@700:             options.isUnset(G_CUSTOM)
jjg@700:             ? options.isSet(G)
jjg@700:             : options.isSet(G_CUSTOM, "vars");
jjg@700:         genCrt = options.isSet(XJCOV);
jjg@700:         debugCode = options.isSet("debugcode");
jjg@700:         allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic");
duke@1: 
duke@1:         generateIproxies =
duke@1:             target.requiresIproxy() ||
jjg@700:             options.isSet("miranda");
duke@1: 
duke@1:         if (target.generateStackMapTable()) {
duke@1:             // ignore cldc because we cannot have both stackmap formats
duke@1:             this.stackMap = StackMapFormat.JSR202;
duke@1:         } else {
duke@1:             if (target.generateCLDCStackmap()) {
duke@1:                 this.stackMap = StackMapFormat.CLDC;
duke@1:             } else {
duke@1:                 this.stackMap = StackMapFormat.NONE;
duke@1:             }
duke@1:         }
duke@1: 
duke@1:         // by default, avoid jsr's for simple finalizers
duke@1:         int setjsrlimit = 50;
duke@1:         String jsrlimitString = options.get("jsrlimit");
duke@1:         if (jsrlimitString != null) {
duke@1:             try {
duke@1:                 setjsrlimit = Integer.parseInt(jsrlimitString);
duke@1:             } catch (NumberFormatException ex) {
duke@1:                 // ignore ill-formed numbers for jsrlimit
duke@1:             }
duke@1:         }
duke@1:         this.jsrlimit = setjsrlimit;
duke@1:         this.useJsrLocally = false; // reset in visitTry
duke@1:     }
duke@1: 
duke@1:     /** Switches
duke@1:      */
duke@1:     private final boolean lineDebugInfo;
duke@1:     private final boolean varDebugInfo;
duke@1:     private final boolean genCrt;
duke@1:     private final boolean debugCode;
jrose@267:     private final boolean allowInvokedynamic;
duke@1: 
duke@1:     /** Default limit of (approximate) size of finalizer to inline.
duke@1:      *  Zero means always use jsr.  100 or greater means never use
duke@1:      *  jsr.
duke@1:      */
duke@1:     private final int jsrlimit;
duke@1: 
duke@1:     /** True if jsr is used.
duke@1:      */
duke@1:     private boolean useJsrLocally;
duke@1: 
duke@1:     /* Constant pool, reset by genClass.
duke@1:      */
duke@1:     private Pool pool = new Pool();
duke@1: 
duke@1:     /** Code buffer, set by genMethod.
duke@1:      */
duke@1:     private Code code;
duke@1: 
duke@1:     /** Items structure, set by genMethod.
duke@1:      */
duke@1:     private Items items;
duke@1: 
duke@1:     /** Environment for symbol lookup, set by genClass
duke@1:      */
duke@1:     private Env<AttrContext> attrEnv;
duke@1: 
duke@1:     /** The top level tree.
duke@1:      */
duke@1:     private JCCompilationUnit toplevel;
duke@1: 
duke@1:     /** The number of code-gen errors in this class.
duke@1:      */
duke@1:     private int nerrs = 0;
duke@1: 
duke@1:     /** A hash table mapping syntax trees to their ending source positions.
duke@1:      */
duke@1:     private Map<JCTree, Integer> endPositions;
duke@1: 
duke@1:     /** Generate code to load an integer constant.
duke@1:      *  @param n     The integer to be loaded.
duke@1:      */
duke@1:     void loadIntConst(int n) {
duke@1:         items.makeImmediateItem(syms.intType, n).load();
duke@1:     }
duke@1: 
duke@1:     /** The opcode that loads a zero constant of a given type code.
duke@1:      *  @param tc   The given type code (@see ByteCode).
duke@1:      */
duke@1:     public static int zero(int tc) {
duke@1:         switch(tc) {
duke@1:         case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
duke@1:             return iconst_0;
duke@1:         case LONGcode:
duke@1:             return lconst_0;
duke@1:         case FLOATcode:
duke@1:             return fconst_0;
duke@1:         case DOUBLEcode:
duke@1:             return dconst_0;
duke@1:         default:
duke@1:             throw new AssertionError("zero");
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** The opcode that loads a one constant of a given type code.
duke@1:      *  @param tc   The given type code (@see ByteCode).
duke@1:      */
duke@1:     public static int one(int tc) {
duke@1:         return zero(tc) + 1;
duke@1:     }
duke@1: 
duke@1:     /** Generate code to load -1 of the given type code (either int or long).
duke@1:      *  @param tc   The given type code (@see ByteCode).
duke@1:      */
duke@1:     void emitMinusOne(int tc) {
duke@1:         if (tc == LONGcode) {
duke@1:             items.makeImmediateItem(syms.longType, new Long(-1)).load();
duke@1:         } else {
duke@1:             code.emitop0(iconst_m1);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Construct a symbol to reflect the qualifying type that should
duke@1:      *  appear in the byte code as per JLS 13.1.
duke@1:      *
duke@1:      *  For target >= 1.2: Clone a method with the qualifier as owner (except
duke@1:      *  for those cases where we need to work around VM bugs).
duke@1:      *
duke@1:      *  For target <= 1.1: If qualified variable or method is defined in a
duke@1:      *  non-accessible class, clone it with the qualifier class as owner.
duke@1:      *
duke@1:      *  @param sym    The accessed symbol
duke@1:      *  @param site   The qualifier's type.
duke@1:      */
duke@1:     Symbol binaryQualifier(Symbol sym, Type site) {
duke@1: 
duke@1:         if (site.tag == ARRAY) {
duke@1:             if (sym == syms.lengthVar ||
duke@1:                 sym.owner != syms.arrayClass)
duke@1:                 return sym;
duke@1:             // array clone can be qualified by the array type in later targets
duke@1:             Symbol qualifier = target.arrayBinaryCompatibility()
duke@1:                 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
duke@1:                                   site, syms.noSymbol)
duke@1:                 : syms.objectType.tsym;
duke@1:             return sym.clone(qualifier);
duke@1:         }
duke@1: 
duke@1:         if (sym.owner == site.tsym ||
duke@1:             (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
duke@1:             return sym;
duke@1:         }
duke@1:         if (!target.obeyBinaryCompatibility())
duke@1:             return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
duke@1:                 ? sym
duke@1:                 : sym.clone(site.tsym);
duke@1: 
duke@1:         if (!target.interfaceFieldsBinaryCompatibility()) {
duke@1:             if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
duke@1:                 return sym;
duke@1:         }
duke@1: 
duke@1:         // leave alone methods inherited from Object
duke@1:         // JLS2 13.1.
duke@1:         if (sym.owner == syms.objectType.tsym)
duke@1:             return sym;
duke@1: 
duke@1:         if (!target.interfaceObjectOverridesBinaryCompatibility()) {
duke@1:             if ((sym.owner.flags() & INTERFACE) != 0 &&
duke@1:                 syms.objectType.tsym.members().lookup(sym.name).scope != null)
duke@1:                 return sym;
duke@1:         }
duke@1: 
duke@1:         return sym.clone(site.tsym);
duke@1:     }
duke@1: 
duke@1:     /** Insert a reference to given type in the constant pool,
duke@1:      *  checking for an array with too many dimensions;
duke@1:      *  return the reference's index.
duke@1:      *  @param type   The type for which a reference is inserted.
duke@1:      */
duke@1:     int makeRef(DiagnosticPosition pos, Type type) {
duke@1:         checkDimension(pos, type);
duke@1:         return pool.put(type.tag == CLASS ? (Object)type.tsym : (Object)type);
duke@1:     }
duke@1: 
duke@1:     /** Check if the given type is an array with too many dimensions.
duke@1:      */
duke@1:     private void checkDimension(DiagnosticPosition pos, Type t) {
duke@1:         switch (t.tag) {
duke@1:         case METHOD:
duke@1:             checkDimension(pos, t.getReturnType());
duke@1:             for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
duke@1:                 checkDimension(pos, args.head);
duke@1:             break;
duke@1:         case ARRAY:
duke@1:             if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
duke@1:                 log.error(pos, "limit.dimensions");
duke@1:                 nerrs++;
duke@1:             }
duke@1:             break;
duke@1:         default:
duke@1:             break;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Create a tempory variable.
duke@1:      *  @param type   The variable's type.
duke@1:      */
duke@1:     LocalItem makeTemp(Type type) {
duke@1:         VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
duke@1:                                     names.empty,
duke@1:                                     type,
duke@1:                                     env.enclMethod.sym);
duke@1:         code.newLocal(v);
duke@1:         return items.makeLocalItem(v);
duke@1:     }
duke@1: 
duke@1:     /** Generate code to call a non-private method or constructor.
duke@1:      *  @param pos         Position to be used for error reporting.
duke@1:      *  @param site        The type of which the method is a member.
duke@1:      *  @param name        The method's name.
duke@1:      *  @param argtypes    The method's argument types.
duke@1:      *  @param isStatic    A flag that indicates whether we call a
duke@1:      *                     static or instance method.
duke@1:      */
duke@1:     void callMethod(DiagnosticPosition pos,
duke@1:                     Type site, Name name, List<Type> argtypes,
duke@1:                     boolean isStatic) {
duke@1:         Symbol msym = rs.
duke@1:             resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
duke@1:         if (isStatic) items.makeStaticItem(msym).invoke();
duke@1:         else items.makeMemberItem(msym, name == names.init).invoke();
duke@1:     }
duke@1: 
duke@1:     /** Is the given method definition an access method
duke@1:      *  resulting from a qualified super? This is signified by an odd
duke@1:      *  access code.
duke@1:      */
duke@1:     private boolean isAccessSuper(JCMethodDecl enclMethod) {
duke@1:         return
duke@1:             (enclMethod.mods.flags & SYNTHETIC) != 0 &&
duke@1:             isOddAccessName(enclMethod.name);
duke@1:     }
duke@1: 
duke@1:     /** Does given name start with "access$" and end in an odd digit?
duke@1:      */
duke@1:     private boolean isOddAccessName(Name name) {
duke@1:         return
duke@1:             name.startsWith(accessDollar) &&
jjg@113:             (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * Non-local exits
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** Generate code to invoke the finalizer associated with given
duke@1:      *  environment.
duke@1:      *  Any calls to finalizers are appended to the environments `cont' chain.
duke@1:      *  Mark beginning of gap in catch all range for finalizer.
duke@1:      */
duke@1:     void genFinalizer(Env<GenContext> env) {
duke@1:         if (code.isAlive() && env.info.finalize != null)
duke@1:             env.info.finalize.gen();
duke@1:     }
duke@1: 
duke@1:     /** Generate code to call all finalizers of structures aborted by
duke@1:      *  a non-local
duke@1:      *  exit.  Return target environment of the non-local exit.
duke@1:      *  @param target      The tree representing the structure that's aborted
duke@1:      *  @param env         The environment current at the non-local exit.
duke@1:      */
duke@1:     Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
duke@1:         Env<GenContext> env1 = env;
duke@1:         while (true) {
duke@1:             genFinalizer(env1);
duke@1:             if (env1.tree == target) break;
duke@1:             env1 = env1.next;
duke@1:         }
duke@1:         return env1;
duke@1:     }
duke@1: 
duke@1:     /** Mark end of gap in catch-all range for finalizer.
duke@1:      *  @param env   the environment which might contain the finalizer
duke@1:      *               (if it does, env.info.gaps != null).
duke@1:      */
duke@1:     void endFinalizerGap(Env<GenContext> env) {
duke@1:         if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
duke@1:             env.info.gaps.append(code.curPc());
duke@1:     }
duke@1: 
duke@1:     /** Mark end of all gaps in catch-all ranges for finalizers of environments
duke@1:      *  lying between, and including to two environments.
duke@1:      *  @param from    the most deeply nested environment to mark
duke@1:      *  @param to      the least deeply nested environment to mark
duke@1:      */
duke@1:     void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
duke@1:         Env<GenContext> last = null;
duke@1:         while (last != to) {
duke@1:             endFinalizerGap(from);
duke@1:             last = from;
duke@1:             from = from.next;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Do any of the structures aborted by a non-local exit have
duke@1:      *  finalizers that require an empty stack?
duke@1:      *  @param target      The tree representing the structure that's aborted
duke@1:      *  @param env         The environment current at the non-local exit.
duke@1:      */
duke@1:     boolean hasFinally(JCTree target, Env<GenContext> env) {
duke@1:         while (env.tree != target) {
duke@1:             if (env.tree.getTag() == JCTree.TRY && env.info.finalize.hasFinalizer())
duke@1:                 return true;
duke@1:             env = env.next;
duke@1:         }
duke@1:         return false;
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * Normalizing class-members.
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** Distribute member initializer code into constructors and <clinit>
duke@1:      *  method.
duke@1:      *  @param defs         The list of class member declarations.
duke@1:      *  @param c            The enclosing class.
duke@1:      */
duke@1:     List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
duke@1:         ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
duke@1:         ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
duke@1:         ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
duke@1:         // Sort definitions into three listbuffers:
duke@1:         //  - initCode for instance initializers
duke@1:         //  - clinitCode for class initializers
duke@1:         //  - methodDefs for method definitions
duke@1:         for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
duke@1:             JCTree def = l.head;
duke@1:             switch (def.getTag()) {
duke@1:             case JCTree.BLOCK:
duke@1:                 JCBlock block = (JCBlock)def;
duke@1:                 if ((block.flags & STATIC) != 0)
duke@1:                     clinitCode.append(block);
duke@1:                 else
duke@1:                     initCode.append(block);
duke@1:                 break;
duke@1:             case JCTree.METHODDEF:
duke@1:                 methodDefs.append(def);
duke@1:                 break;
duke@1:             case JCTree.VARDEF:
duke@1:                 JCVariableDecl vdef = (JCVariableDecl) def;
duke@1:                 VarSymbol sym = vdef.sym;
duke@1:                 checkDimension(vdef.pos(), sym.type);
duke@1:                 if (vdef.init != null) {
duke@1:                     if ((sym.flags() & STATIC) == 0) {
duke@1:                         // Always initialize instance variables.
duke@1:                         JCStatement init = make.at(vdef.pos()).
duke@1:                             Assignment(sym, vdef.init);
duke@1:                         initCode.append(init);
duke@1:                         if (endPositions != null) {
duke@1:                             Integer endPos = endPositions.remove(vdef);
duke@1:                             if (endPos != null) endPositions.put(init, endPos);
duke@1:                         }
duke@1:                     } else if (sym.getConstValue() == null) {
duke@1:                         // Initialize class (static) variables only if
duke@1:                         // they are not compile-time constants.
duke@1:                         JCStatement init = make.at(vdef.pos).
duke@1:                             Assignment(sym, vdef.init);
duke@1:                         clinitCode.append(init);
duke@1:                         if (endPositions != null) {
duke@1:                             Integer endPos = endPositions.remove(vdef);
duke@1:                             if (endPos != null) endPositions.put(init, endPos);
duke@1:                         }
duke@1:                     } else {
duke@1:                         checkStringConstant(vdef.init.pos(), sym.getConstValue());
duke@1:                     }
duke@1:                 }
duke@1:                 break;
duke@1:             default:
jjg@816:                 Assert.error();
duke@1:             }
duke@1:         }
duke@1:         // Insert any instance initializers into all constructors.
duke@1:         if (initCode.length() != 0) {
duke@1:             List<JCStatement> inits = initCode.toList();
duke@1:             for (JCTree t : methodDefs) {
duke@1:                 normalizeMethod((JCMethodDecl)t, inits);
duke@1:             }
duke@1:         }
duke@1:         // If there are class initializers, create a <clinit> method
duke@1:         // that contains them as its body.
duke@1:         if (clinitCode.length() != 0) {
duke@1:             MethodSymbol clinit = new MethodSymbol(
duke@1:                 STATIC, names.clinit,
duke@1:                 new MethodType(
duke@1:                     List.<Type>nil(), syms.voidType,
duke@1:                     List.<Type>nil(), syms.methodClass),
duke@1:                 c);
duke@1:             c.members().enter(clinit);
duke@1:             List<JCStatement> clinitStats = clinitCode.toList();
duke@1:             JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
duke@1:             block.endpos = TreeInfo.endPos(clinitStats.last());
duke@1:             methodDefs.append(make.MethodDef(clinit, block));
duke@1:         }
duke@1:         // Return all method definitions.
duke@1:         return methodDefs.toList();
duke@1:     }
duke@1: 
duke@1:     /** Check a constant value and report if it is a string that is
duke@1:      *  too large.
duke@1:      */
duke@1:     private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
duke@1:         if (nerrs != 0 || // only complain about a long string once
duke@1:             constValue == null ||
duke@1:             !(constValue instanceof String) ||
duke@1:             ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
duke@1:             return;
duke@1:         log.error(pos, "limit.string");
duke@1:         nerrs++;
duke@1:     }
duke@1: 
duke@1:     /** Insert instance initializer code into initial constructor.
duke@1:      *  @param md        The tree potentially representing a
duke@1:      *                   constructor's definition.
duke@1:      *  @param initCode  The list of instance initializer statements.
duke@1:      */
duke@1:     void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode) {
duke@1:         if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
duke@1:             // We are seeing a constructor that does not call another
duke@1:             // constructor of the same class.
duke@1:             List<JCStatement> stats = md.body.stats;
duke@1:             ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
duke@1: 
duke@1:             if (stats.nonEmpty()) {
duke@1:                 // Copy initializers of synthetic variables generated in
duke@1:                 // the translation of inner classes.
duke@1:                 while (TreeInfo.isSyntheticInit(stats.head)) {
duke@1:                     newstats.append(stats.head);
duke@1:                     stats = stats.tail;
duke@1:                 }
duke@1:                 // Copy superclass constructor call
duke@1:                 newstats.append(stats.head);
duke@1:                 stats = stats.tail;
duke@1:                 // Copy remaining synthetic initializers.
duke@1:                 while (stats.nonEmpty() &&
duke@1:                        TreeInfo.isSyntheticInit(stats.head)) {
duke@1:                     newstats.append(stats.head);
duke@1:                     stats = stats.tail;
duke@1:                 }
duke@1:                 // Now insert the initializer code.
duke@1:                 newstats.appendList(initCode);
duke@1:                 // And copy all remaining statements.
duke@1:                 while (stats.nonEmpty()) {
duke@1:                     newstats.append(stats.head);
duke@1:                     stats = stats.tail;
duke@1:                 }
duke@1:             }
duke@1:             md.body.stats = newstats.toList();
duke@1:             if (md.body.endpos == Position.NOPOS)
duke@1:                 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* ********************************************************************
duke@1:  * Adding miranda methods
duke@1:  *********************************************************************/
duke@1: 
duke@1:     /** Add abstract methods for all methods defined in one of
duke@1:      *  the interfaces of a given class,
duke@1:      *  provided they are not already implemented in the class.
duke@1:      *
duke@1:      *  @param c      The class whose interfaces are searched for methods
duke@1:      *                for which Miranda methods should be added.
duke@1:      */
duke@1:     void implementInterfaceMethods(ClassSymbol c) {
duke@1:         implementInterfaceMethods(c, c);
duke@1:     }
duke@1: 
duke@1:     /** Add abstract methods for all methods defined in one of
duke@1:      *  the interfaces of a given class,
duke@1:      *  provided they are not already implemented in the class.
duke@1:      *
duke@1:      *  @param c      The class whose interfaces are searched for methods
duke@1:      *                for which Miranda methods should be added.
duke@1:      *  @param site   The class in which a definition may be needed.
duke@1:      */
duke@1:     void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
duke@1:         for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
duke@1:             ClassSymbol i = (ClassSymbol)l.head.tsym;
duke@1:             for (Scope.Entry e = i.members().elems;
duke@1:                  e != null;
duke@1:                  e = e.sibling)
duke@1:             {
duke@1:                 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
duke@1:                 {
duke@1:                     MethodSymbol absMeth = (MethodSymbol)e.sym;
duke@1:                     MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
duke@1:                     if (implMeth == null)
duke@1:                         addAbstractMethod(site, absMeth);
duke@1:                     else if ((implMeth.flags() & IPROXY) != 0)
duke@1:                         adjustAbstractMethod(site, implMeth, absMeth);
duke@1:                 }
duke@1:             }
duke@1:             implementInterfaceMethods(i, site);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Add an abstract methods to a class
duke@1:      *  which implicitly implements a method defined in some interface
duke@1:      *  implemented by the class. These methods are called "Miranda methods".
duke@1:      *  Enter the newly created method into its enclosing class scope.
duke@1:      *  Note that it is not entered into the class tree, as the emitter
duke@1:      *  doesn't need to see it there to emit an abstract method.
duke@1:      *
duke@1:      *  @param c      The class to which the Miranda method is added.
duke@1:      *  @param m      The interface method symbol for which a Miranda method
duke@1:      *                is added.
duke@1:      */
duke@1:     private void addAbstractMethod(ClassSymbol c,
duke@1:                                    MethodSymbol m) {
duke@1:         MethodSymbol absMeth = new MethodSymbol(
duke@1:             m.flags() | IPROXY | SYNTHETIC, m.name,
duke@1:             m.type, // was c.type.memberType(m), but now only !generics supported
duke@1:             c);
duke@1:         c.members().enter(absMeth); // add to symbol table
duke@1:     }
duke@1: 
duke@1:     private void adjustAbstractMethod(ClassSymbol c,
duke@1:                                       MethodSymbol pm,
duke@1:                                       MethodSymbol im) {
duke@1:         MethodType pmt = (MethodType)pm.type;
duke@1:         Type imt = types.memberType(c.type, im);
duke@1:         pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * Traversal methods
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** Visitor argument: The current environment.
duke@1:      */
duke@1:     Env<GenContext> env;
duke@1: 
duke@1:     /** Visitor argument: The expected type (prototype).
duke@1:      */
duke@1:     Type pt;
duke@1: 
duke@1:     /** Visitor result: The item representing the computed value.
duke@1:      */
duke@1:     Item result;
duke@1: 
duke@1:     /** Visitor method: generate code for a definition, catching and reporting
duke@1:      *  any completion failures.
duke@1:      *  @param tree    The definition to be visited.
duke@1:      *  @param env     The environment current at the definition.
duke@1:      */
duke@1:     public void genDef(JCTree tree, Env<GenContext> env) {
duke@1:         Env<GenContext> prevEnv = this.env;
duke@1:         try {
duke@1:             this.env = env;
duke@1:             tree.accept(this);
duke@1:         } catch (CompletionFailure ex) {
duke@1:             chk.completionError(tree.pos(), ex);
duke@1:         } finally {
duke@1:             this.env = prevEnv;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: check whether CharacterRangeTable
duke@1:      *  should be emitted, if so, put a new entry into CRTable
duke@1:      *  and call method to generate bytecode.
duke@1:      *  If not, just call method to generate bytecode.
duke@1:      *  @see    #genStat(Tree, Env)
duke@1:      *
duke@1:      *  @param  tree     The tree to be visited.
duke@1:      *  @param  env      The environment to use.
duke@1:      *  @param  crtFlags The CharacterRangeTable flags
duke@1:      *                   indicating type of the entry.
duke@1:      */
duke@1:     public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
duke@1:         if (!genCrt) {
duke@1:             genStat(tree, env);
duke@1:             return;
duke@1:         }
duke@1:         int startpc = code.curPc();
duke@1:         genStat(tree, env);
duke@1:         if (tree.getTag() == JCTree.BLOCK) crtFlags |= CRT_BLOCK;
duke@1:         code.crt.put(tree, crtFlags, startpc, code.curPc());
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: generate code for a statement.
duke@1:      */
duke@1:     public void genStat(JCTree tree, Env<GenContext> env) {
duke@1:         if (code.isAlive()) {
duke@1:             code.statBegin(tree.pos);
duke@1:             genDef(tree, env);
duke@1:         } else if (env.info.isSwitch && tree.getTag() == JCTree.VARDEF) {
duke@1:             // variables whose declarations are in a switch
duke@1:             // can be used even if the decl is unreachable.
duke@1:             code.newLocal(((JCVariableDecl) tree).sym);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: check whether CharacterRangeTable
duke@1:      *  should be emitted, if so, put a new entry into CRTable
duke@1:      *  and call method to generate bytecode.
duke@1:      *  If not, just call method to generate bytecode.
duke@1:      *  @see    #genStats(List, Env)
duke@1:      *
duke@1:      *  @param  trees    The list of trees to be visited.
duke@1:      *  @param  env      The environment to use.
duke@1:      *  @param  crtFlags The CharacterRangeTable flags
duke@1:      *                   indicating type of the entry.
duke@1:      */
duke@1:     public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
duke@1:         if (!genCrt) {
duke@1:             genStats(trees, env);
duke@1:             return;
duke@1:         }
duke@1:         if (trees.length() == 1) {        // mark one statement with the flags
duke@1:             genStat(trees.head, env, crtFlags | CRT_STATEMENT);
duke@1:         } else {
duke@1:             int startpc = code.curPc();
duke@1:             genStats(trees, env);
duke@1:             code.crt.put(trees, crtFlags, startpc, code.curPc());
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: generate code for a list of statements.
duke@1:      */
duke@1:     public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
duke@1:         for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
duke@1:             genStat(l.head, env, CRT_STATEMENT);
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: check whether CharacterRangeTable
duke@1:      *  should be emitted, if so, put a new entry into CRTable
duke@1:      *  and call method to generate bytecode.
duke@1:      *  If not, just call method to generate bytecode.
duke@1:      *  @see    #genCond(Tree,boolean)
duke@1:      *
duke@1:      *  @param  tree     The tree to be visited.
duke@1:      *  @param  crtFlags The CharacterRangeTable flags
duke@1:      *                   indicating type of the entry.
duke@1:      */
duke@1:     public CondItem genCond(JCTree tree, int crtFlags) {
duke@1:         if (!genCrt) return genCond(tree, false);
duke@1:         int startpc = code.curPc();
duke@1:         CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
duke@1:         code.crt.put(tree, crtFlags, startpc, code.curPc());
duke@1:         return item;
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: generate code for a boolean
duke@1:      *  expression in a control-flow context.
duke@1:      *  @param _tree         The expression to be visited.
duke@1:      *  @param markBranches The flag to indicate that the condition is
duke@1:      *                      a flow controller so produced conditions
duke@1:      *                      should contain a proper tree to generate
duke@1:      *                      CharacterRangeTable branches for them.
duke@1:      */
duke@1:     public CondItem genCond(JCTree _tree, boolean markBranches) {
duke@1:         JCTree inner_tree = TreeInfo.skipParens(_tree);
duke@1:         if (inner_tree.getTag() == JCTree.CONDEXPR) {
duke@1:             JCConditional tree = (JCConditional)inner_tree;
duke@1:             CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
duke@1:             if (cond.isTrue()) {
duke@1:                 code.resolve(cond.trueJumps);
duke@1:                 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
duke@1:                 if (markBranches) result.tree = tree.truepart;
duke@1:                 return result;
duke@1:             }
duke@1:             if (cond.isFalse()) {
duke@1:                 code.resolve(cond.falseJumps);
duke@1:                 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
duke@1:                 if (markBranches) result.tree = tree.falsepart;
duke@1:                 return result;
duke@1:             }
duke@1:             Chain secondJumps = cond.jumpFalse();
duke@1:             code.resolve(cond.trueJumps);
duke@1:             CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
duke@1:             if (markBranches) first.tree = tree.truepart;
duke@1:             Chain falseJumps = first.jumpFalse();
duke@1:             code.resolve(first.trueJumps);
duke@1:             Chain trueJumps = code.branch(goto_);
duke@1:             code.resolve(secondJumps);
duke@1:             CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
duke@1:             CondItem result = items.makeCondItem(second.opcode,
jjg@507:                                       Code.mergeChains(trueJumps, second.trueJumps),
jjg@507:                                       Code.mergeChains(falseJumps, second.falseJumps));
duke@1:             if (markBranches) result.tree = tree.falsepart;
duke@1:             return result;
duke@1:         } else {
duke@1:             CondItem result = genExpr(_tree, syms.booleanType).mkCond();
duke@1:             if (markBranches) result.tree = _tree;
duke@1:             return result;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Visitor method: generate code for an expression, catching and reporting
duke@1:      *  any completion failures.
duke@1:      *  @param tree    The expression to be visited.
duke@1:      *  @param pt      The expression's expected type (proto-type).
duke@1:      */
duke@1:     public Item genExpr(JCTree tree, Type pt) {
duke@1:         Type prevPt = this.pt;
duke@1:         try {
duke@1:             if (tree.type.constValue() != null) {
duke@1:                 // Short circuit any expressions which are constants
duke@1:                 checkStringConstant(tree.pos(), tree.type.constValue());
duke@1:                 result = items.makeImmediateItem(tree.type, tree.type.constValue());
duke@1:             } else {
duke@1:                 this.pt = pt;
duke@1:                 tree.accept(this);
duke@1:             }
duke@1:             return result.coerce(pt);
duke@1:         } catch (CompletionFailure ex) {
duke@1:             chk.completionError(tree.pos(), ex);
duke@1:             code.state.stacksize = 1;
duke@1:             return items.makeStackItem(pt);
duke@1:         } finally {
duke@1:             this.pt = prevPt;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Derived visitor method: generate code for a list of method arguments.
duke@1:      *  @param trees    The argument expressions to be visited.
duke@1:      *  @param pts      The expression's expected types (i.e. the formal parameter
duke@1:      *                  types of the invoked method).
duke@1:      */
duke@1:     public void genArgs(List<JCExpression> trees, List<Type> pts) {
duke@1:         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
duke@1:             genExpr(l.head, pts.head).load();
duke@1:             pts = pts.tail;
duke@1:         }
duke@1:         // require lists be of same length
jjg@816:         Assert.check(pts.isEmpty());
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * Visitor methods for statements and definitions
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** Thrown when the byte code size exceeds limit.
duke@1:      */
duke@1:     public static class CodeSizeOverflow extends RuntimeException {
duke@1:         private static final long serialVersionUID = 0;
duke@1:         public CodeSizeOverflow() {}
duke@1:     }
duke@1: 
duke@1:     public void visitMethodDef(JCMethodDecl tree) {
duke@1:         // Create a new local environment that points pack at method
duke@1:         // definition.
duke@1:         Env<GenContext> localEnv = env.dup(tree);
duke@1:         localEnv.enclMethod = tree;
duke@1: 
duke@1:         // The expected type of every return statement in this method
duke@1:         // is the method's return type.
duke@1:         this.pt = tree.sym.erasure(types).getReturnType();
duke@1: 
duke@1:         checkDimension(tree.pos(), tree.sym.erasure(types));
duke@1:         genMethod(tree, localEnv, false);
duke@1:     }
duke@1: //where
duke@1:         /** Generate code for a method.
duke@1:          *  @param tree     The tree representing the method definition.
duke@1:          *  @param env      The environment current for the method body.
duke@1:          *  @param fatcode  A flag that indicates whether all jumps are
duke@1:          *                  within 32K.  We first invoke this method under
duke@1:          *                  the assumption that fatcode == false, i.e. all
duke@1:          *                  jumps are within 32K.  If this fails, fatcode
duke@1:          *                  is set to true and we try again.
duke@1:          */
duke@1:         void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
duke@1:             MethodSymbol meth = tree.sym;
duke@1: //      System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
duke@1:             if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes())  +
duke@1:                 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
duke@1:                 ClassFile.MAX_PARAMETERS) {
duke@1:                 log.error(tree.pos(), "limit.parameters");
duke@1:                 nerrs++;
duke@1:             }
duke@1: 
duke@1:             else if (tree.body != null) {
duke@1:                 // Create a new code structure and initialize it.
duke@1:                 int startpcCrt = initCode(tree, env, fatcode);
duke@1: 
duke@1:                 try {
duke@1:                     genStat(tree.body, env);
duke@1:                 } catch (CodeSizeOverflow e) {
duke@1:                     // Failed due to code limit, try again with jsr/ret
duke@1:                     startpcCrt = initCode(tree, env, fatcode);
duke@1:                     genStat(tree.body, env);
duke@1:                 }
duke@1: 
duke@1:                 if (code.state.stacksize != 0) {
duke@1:                     log.error(tree.body.pos(), "stack.sim.error", tree);
duke@1:                     throw new AssertionError();
duke@1:                 }
duke@1: 
duke@1:                 // If last statement could complete normally, insert a
duke@1:                 // return at the end.
duke@1:                 if (code.isAlive()) {
duke@1:                     code.statBegin(TreeInfo.endPos(tree.body));
duke@1:                     if (env.enclMethod == null ||
duke@1:                         env.enclMethod.sym.type.getReturnType().tag == VOID) {
duke@1:                         code.emitop0(return_);
duke@1:                     } else {
duke@1:                         // sometime dead code seems alive (4415991);
duke@1:                         // generate a small loop instead
duke@1:                         int startpc = code.entryPoint();
duke@1:                         CondItem c = items.makeCondItem(goto_);
duke@1:                         code.resolve(c.jumpTrue(), startpc);
duke@1:                     }
duke@1:                 }
duke@1:                 if (genCrt)
duke@1:                     code.crt.put(tree.body,
duke@1:                                  CRT_BLOCK,
duke@1:                                  startpcCrt,
duke@1:                                  code.curPc());
duke@1: 
duke@1:                 code.endScopes(0);
duke@1: 
duke@1:                 // If we exceeded limits, panic
duke@1:                 if (code.checkLimits(tree.pos(), log)) {
duke@1:                     nerrs++;
duke@1:                     return;
duke@1:                 }
duke@1: 
duke@1:                 // If we generated short code but got a long jump, do it again
duke@1:                 // with fatCode = true.
duke@1:                 if (!fatcode && code.fatcode) genMethod(tree, env, true);
duke@1: 
duke@1:                 // Clean up
duke@1:                 if(stackMap == StackMapFormat.JSR202) {
duke@1:                     code.lastFrame = null;
duke@1:                     code.frameBeforeLast = null;
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1: 
duke@1:         private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
duke@1:             MethodSymbol meth = tree.sym;
duke@1: 
duke@1:             // Create a new code structure.
duke@1:             meth.code = code = new Code(meth,
duke@1:                                         fatcode,
duke@1:                                         lineDebugInfo ? toplevel.lineMap : null,
duke@1:                                         varDebugInfo,
duke@1:                                         stackMap,
duke@1:                                         debugCode,
duke@1:                                         genCrt ? new CRTable(tree, env.toplevel.endPositions)
duke@1:                                                : null,
duke@1:                                         syms,
duke@1:                                         types,
duke@1:                                         pool);
duke@1:             items = new Items(pool, code, syms, types);
duke@1:             if (code.debugCode)
duke@1:                 System.err.println(meth + " for body " + tree);
duke@1: 
duke@1:             // If method is not static, create a new local variable address
duke@1:             // for `this'.
duke@1:             if ((tree.mods.flags & STATIC) == 0) {
duke@1:                 Type selfType = meth.owner.type;
duke@1:                 if (meth.isConstructor() && selfType != syms.objectType)
duke@1:                     selfType = UninitializedType.uninitializedThis(selfType);
duke@1:                 code.setDefined(
duke@1:                         code.newLocal(
duke@1:                             new VarSymbol(FINAL, names._this, selfType, meth.owner)));
duke@1:             }
duke@1: 
duke@1:             // Mark all parameters as defined from the beginning of
duke@1:             // the method.
duke@1:             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
duke@1:                 checkDimension(l.head.pos(), l.head.sym.type);
duke@1:                 code.setDefined(code.newLocal(l.head.sym));
duke@1:             }
duke@1: 
duke@1:             // Get ready to generate code for method body.
duke@1:             int startpcCrt = genCrt ? code.curPc() : 0;
duke@1:             code.entryPoint();
duke@1: 
duke@1:             // Suppress initial stackmap
duke@1:             code.pendingStackMap = false;
duke@1: 
duke@1:             return startpcCrt;
duke@1:         }
duke@1: 
duke@1:     public void visitVarDef(JCVariableDecl tree) {
duke@1:         VarSymbol v = tree.sym;
duke@1:         code.newLocal(v);
duke@1:         if (tree.init != null) {
duke@1:             checkStringConstant(tree.init.pos(), v.getConstValue());
duke@1:             if (v.getConstValue() == null || varDebugInfo) {
duke@1:                 genExpr(tree.init, v.erasure(types)).load();
duke@1:                 items.makeLocalItem(v).store();
duke@1:             }
duke@1:         }
duke@1:         checkDimension(tree.pos(), v.type);
duke@1:     }
duke@1: 
duke@1:     public void visitSkip(JCSkip tree) {
duke@1:     }
duke@1: 
duke@1:     public void visitBlock(JCBlock tree) {
duke@1:         int limit = code.nextreg;
duke@1:         Env<GenContext> localEnv = env.dup(tree, new GenContext());
duke@1:         genStats(tree.stats, localEnv);
duke@1:         // End the scope of all block-local variables in variable info.
duke@1:         if (env.tree.getTag() != JCTree.METHODDEF) {
duke@1:             code.statBegin(tree.endpos);
duke@1:             code.endScopes(limit);
duke@1:             code.pendingStatPos = Position.NOPOS;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     public void visitDoLoop(JCDoWhileLoop tree) {
duke@1:         genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
duke@1:     }
duke@1: 
duke@1:     public void visitWhileLoop(JCWhileLoop tree) {
duke@1:         genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
duke@1:     }
duke@1: 
duke@1:     public void visitForLoop(JCForLoop tree) {
duke@1:         int limit = code.nextreg;
duke@1:         genStats(tree.init, env);
duke@1:         genLoop(tree, tree.body, tree.cond, tree.step, true);
duke@1:         code.endScopes(limit);
duke@1:     }
duke@1:     //where
duke@1:         /** Generate code for a loop.
duke@1:          *  @param loop       The tree representing the loop.
duke@1:          *  @param body       The loop's body.
duke@1:          *  @param cond       The loop's controling condition.
duke@1:          *  @param step       "Step" statements to be inserted at end of
duke@1:          *                    each iteration.
duke@1:          *  @param testFirst  True if the loop test belongs before the body.
duke@1:          */
duke@1:         private void genLoop(JCStatement loop,
duke@1:                              JCStatement body,
duke@1:                              JCExpression cond,
duke@1:                              List<JCExpressionStatement> step,
duke@1:                              boolean testFirst) {
duke@1:             Env<GenContext> loopEnv = env.dup(loop, new GenContext());
duke@1:             int startpc = code.entryPoint();
duke@1:             if (testFirst) {
duke@1:                 CondItem c;
duke@1:                 if (cond != null) {
duke@1:                     code.statBegin(cond.pos);
duke@1:                     c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
duke@1:                 } else {
duke@1:                     c = items.makeCondItem(goto_);
duke@1:                 }
duke@1:                 Chain loopDone = c.jumpFalse();
duke@1:                 code.resolve(c.trueJumps);
duke@1:                 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
duke@1:                 code.resolve(loopEnv.info.cont);
duke@1:                 genStats(step, loopEnv);
duke@1:                 code.resolve(code.branch(goto_), startpc);
duke@1:                 code.resolve(loopDone);
duke@1:             } else {
duke@1:                 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
duke@1:                 code.resolve(loopEnv.info.cont);
duke@1:                 genStats(step, loopEnv);
duke@1:                 CondItem c;
duke@1:                 if (cond != null) {
duke@1:                     code.statBegin(cond.pos);
duke@1:                     c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
duke@1:                 } else {
duke@1:                     c = items.makeCondItem(goto_);
duke@1:                 }
duke@1:                 code.resolve(c.jumpTrue(), startpc);
duke@1:                 code.resolve(c.falseJumps);
duke@1:             }
duke@1:             code.resolve(loopEnv.info.exit);
duke@1:         }
duke@1: 
duke@1:     public void visitForeachLoop(JCEnhancedForLoop tree) {
duke@1:         throw new AssertionError(); // should have been removed by Lower.
duke@1:     }
duke@1: 
duke@1:     public void visitLabelled(JCLabeledStatement tree) {
duke@1:         Env<GenContext> localEnv = env.dup(tree, new GenContext());
duke@1:         genStat(tree.body, localEnv, CRT_STATEMENT);
duke@1:         code.resolve(localEnv.info.exit);
duke@1:     }
duke@1: 
duke@1:     public void visitSwitch(JCSwitch tree) {
duke@1:         int limit = code.nextreg;
jjg@816:         Assert.check(tree.selector.type.tag != CLASS);
duke@1:         int startpcCrt = genCrt ? code.curPc() : 0;
duke@1:         Item sel = genExpr(tree.selector, syms.intType);
duke@1:         List<JCCase> cases = tree.cases;
duke@1:         if (cases.isEmpty()) {
duke@1:             // We are seeing:  switch <sel> {}
duke@1:             sel.load().drop();
duke@1:             if (genCrt)
duke@1:                 code.crt.put(TreeInfo.skipParens(tree.selector),
duke@1:                              CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
duke@1:         } else {
duke@1:             // We are seeing a nonempty switch.
duke@1:             sel.load();
duke@1:             if (genCrt)
duke@1:                 code.crt.put(TreeInfo.skipParens(tree.selector),
duke@1:                              CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
duke@1:             Env<GenContext> switchEnv = env.dup(tree, new GenContext());
duke@1:             switchEnv.info.isSwitch = true;
duke@1: 
duke@1:             // Compute number of labels and minimum and maximum label values.
duke@1:             // For each case, store its label in an array.
duke@1:             int lo = Integer.MAX_VALUE;  // minimum label.
duke@1:             int hi = Integer.MIN_VALUE;  // maximum label.
duke@1:             int nlabels = 0;               // number of labels.
duke@1: 
duke@1:             int[] labels = new int[cases.length()];  // the label array.
duke@1:             int defaultIndex = -1;     // the index of the default clause.
duke@1: 
duke@1:             List<JCCase> l = cases;
duke@1:             for (int i = 0; i < labels.length; i++) {
duke@1:                 if (l.head.pat != null) {
duke@1:                     int val = ((Number)l.head.pat.type.constValue()).intValue();
duke@1:                     labels[i] = val;
duke@1:                     if (val < lo) lo = val;
duke@1:                     if (hi < val) hi = val;
duke@1:                     nlabels++;
duke@1:                 } else {
jjg@816:                     Assert.check(defaultIndex == -1);
duke@1:                     defaultIndex = i;
duke@1:                 }
duke@1:                 l = l.tail;
duke@1:             }
duke@1: 
duke@1:             // Determine whether to issue a tableswitch or a lookupswitch
duke@1:             // instruction.
duke@1:             long table_space_cost = 4 + ((long) hi - lo + 1); // words
duke@1:             long table_time_cost = 3; // comparisons
duke@1:             long lookup_space_cost = 3 + 2 * (long) nlabels;
duke@1:             long lookup_time_cost = nlabels;
duke@1:             int opcode =
duke@1:                 nlabels > 0 &&
duke@1:                 table_space_cost + 3 * table_time_cost <=
duke@1:                 lookup_space_cost + 3 * lookup_time_cost
duke@1:                 ?
duke@1:                 tableswitch : lookupswitch;
duke@1: 
duke@1:             int startpc = code.curPc();    // the position of the selector operation
duke@1:             code.emitop0(opcode);
duke@1:             code.align(4);
duke@1:             int tableBase = code.curPc();  // the start of the jump table
duke@1:             int[] offsets = null;          // a table of offsets for a lookupswitch
duke@1:             code.emit4(-1);                // leave space for default offset
duke@1:             if (opcode == tableswitch) {
duke@1:                 code.emit4(lo);            // minimum label
duke@1:                 code.emit4(hi);            // maximum label
duke@1:                 for (long i = lo; i <= hi; i++) {  // leave space for jump table
duke@1:                     code.emit4(-1);
duke@1:                 }
duke@1:             } else {
duke@1:                 code.emit4(nlabels);    // number of labels
duke@1:                 for (int i = 0; i < nlabels; i++) {
duke@1:                     code.emit4(-1); code.emit4(-1); // leave space for lookup table
duke@1:                 }
duke@1:                 offsets = new int[labels.length];
duke@1:             }
duke@1:             Code.State stateSwitch = code.state.dup();
duke@1:             code.markDead();
duke@1: 
duke@1:             // For each case do:
duke@1:             l = cases;
duke@1:             for (int i = 0; i < labels.length; i++) {
duke@1:                 JCCase c = l.head;
duke@1:                 l = l.tail;
duke@1: 
duke@1:                 int pc = code.entryPoint(stateSwitch);
duke@1:                 // Insert offset directly into code or else into the
duke@1:                 // offsets table.
duke@1:                 if (i != defaultIndex) {
duke@1:                     if (opcode == tableswitch) {
duke@1:                         code.put4(
duke@1:                             tableBase + 4 * (labels[i] - lo + 3),
duke@1:                             pc - startpc);
duke@1:                     } else {
duke@1:                         offsets[i] = pc - startpc;
duke@1:                     }
duke@1:                 } else {
duke@1:                     code.put4(tableBase, pc - startpc);
duke@1:                 }
duke@1: 
duke@1:                 // Generate code for the statements in this case.
duke@1:                 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
duke@1:             }
duke@1: 
duke@1:             // Resolve all breaks.
duke@1:             code.resolve(switchEnv.info.exit);
duke@1: 
duke@1:             // If we have not set the default offset, we do so now.
duke@1:             if (code.get4(tableBase) == -1) {
duke@1:                 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
duke@1:             }
duke@1: 
duke@1:             if (opcode == tableswitch) {
duke@1:                 // Let any unfilled slots point to the default case.
duke@1:                 int defaultOffset = code.get4(tableBase);
duke@1:                 for (long i = lo; i <= hi; i++) {
duke@1:                     int t = (int)(tableBase + 4 * (i - lo + 3));
duke@1:                     if (code.get4(t) == -1)
duke@1:                         code.put4(t, defaultOffset);
duke@1:                 }
duke@1:             } else {
duke@1:                 // Sort non-default offsets and copy into lookup table.
duke@1:                 if (defaultIndex >= 0)
duke@1:                     for (int i = defaultIndex; i < labels.length - 1; i++) {
duke@1:                         labels[i] = labels[i+1];
duke@1:                         offsets[i] = offsets[i+1];
duke@1:                     }
duke@1:                 if (nlabels > 0)
duke@1:                     qsort2(labels, offsets, 0, nlabels - 1);
duke@1:                 for (int i = 0; i < nlabels; i++) {
duke@1:                     int caseidx = tableBase + 8 * (i + 1);
duke@1:                     code.put4(caseidx, labels[i]);
duke@1:                     code.put4(caseidx + 4, offsets[i]);
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1:         code.endScopes(limit);
duke@1:     }
duke@1: //where
duke@1:         /** Sort (int) arrays of keys and values
duke@1:          */
duke@1:        static void qsort2(int[] keys, int[] values, int lo, int hi) {
duke@1:             int i = lo;
duke@1:             int j = hi;
duke@1:             int pivot = keys[(i+j)/2];
duke@1:             do {
duke@1:                 while (keys[i] < pivot) i++;
duke@1:                 while (pivot < keys[j]) j--;
duke@1:                 if (i <= j) {
duke@1:                     int temp1 = keys[i];
duke@1:                     keys[i] = keys[j];
duke@1:                     keys[j] = temp1;
duke@1:                     int temp2 = values[i];
duke@1:                     values[i] = values[j];
duke@1:                     values[j] = temp2;
duke@1:                     i++;
duke@1:                     j--;
duke@1:                 }
duke@1:             } while (i <= j);
duke@1:             if (lo < j) qsort2(keys, values, lo, j);
duke@1:             if (i < hi) qsort2(keys, values, i, hi);
duke@1:         }
duke@1: 
duke@1:     public void visitSynchronized(JCSynchronized tree) {
duke@1:         int limit = code.nextreg;
duke@1:         // Generate code to evaluate lock and save in temporary variable.
duke@1:         final LocalItem lockVar = makeTemp(syms.objectType);
duke@1:         genExpr(tree.lock, tree.lock.type).load().duplicate();
duke@1:         lockVar.store();
duke@1: 
duke@1:         // Generate code to enter monitor.
duke@1:         code.emitop0(monitorenter);
duke@1:         code.state.lock(lockVar.reg);
duke@1: 
duke@1:         // Generate code for a try statement with given body, no catch clauses
duke@1:         // in a new environment with the "exit-monitor" operation as finalizer.
duke@1:         final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
duke@1:         syncEnv.info.finalize = new GenFinalizer() {
duke@1:             void gen() {
duke@1:                 genLast();
jjg@816:                 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
duke@1:                 syncEnv.info.gaps.append(code.curPc());
duke@1:             }
duke@1:             void genLast() {
duke@1:                 if (code.isAlive()) {
duke@1:                     lockVar.load();
duke@1:                     code.emitop0(monitorexit);
duke@1:                     code.state.unlock(lockVar.reg);
duke@1:                 }
duke@1:             }
duke@1:         };
duke@1:         syncEnv.info.gaps = new ListBuffer<Integer>();
duke@1:         genTry(tree.body, List.<JCCatch>nil(), syncEnv);
duke@1:         code.endScopes(limit);
duke@1:     }
duke@1: 
duke@1:     public void visitTry(final JCTry tree) {
duke@1:         // Generate code for a try statement with given body and catch clauses,
duke@1:         // in a new environment which calls the finally block if there is one.
duke@1:         final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
duke@1:         final Env<GenContext> oldEnv = env;
duke@1:         if (!useJsrLocally) {
duke@1:             useJsrLocally =
duke@1:                 (stackMap == StackMapFormat.NONE) &&
duke@1:                 (jsrlimit <= 0 ||
duke@1:                 jsrlimit < 100 &&
duke@1:                 estimateCodeComplexity(tree.finalizer)>jsrlimit);
duke@1:         }
duke@1:         tryEnv.info.finalize = new GenFinalizer() {
duke@1:             void gen() {
duke@1:                 if (useJsrLocally) {
duke@1:                     if (tree.finalizer != null) {
duke@1:                         Code.State jsrState = code.state.dup();
jjg@507:                         jsrState.push(Code.jsrReturnValue);
duke@1:                         tryEnv.info.cont =
duke@1:                             new Chain(code.emitJump(jsr),
duke@1:                                       tryEnv.info.cont,
duke@1:                                       jsrState);
duke@1:                     }
jjg@816:                     Assert.check(tryEnv.info.gaps.length() % 2 == 0);
duke@1:                     tryEnv.info.gaps.append(code.curPc());
duke@1:                 } else {
jjg@816:                     Assert.check(tryEnv.info.gaps.length() % 2 == 0);
duke@1:                     tryEnv.info.gaps.append(code.curPc());
duke@1:                     genLast();
duke@1:                 }
duke@1:             }
duke@1:             void genLast() {
duke@1:                 if (tree.finalizer != null)
duke@1:                     genStat(tree.finalizer, oldEnv, CRT_BLOCK);
duke@1:             }
duke@1:             boolean hasFinalizer() {
duke@1:                 return tree.finalizer != null;
duke@1:             }
duke@1:         };
duke@1:         tryEnv.info.gaps = new ListBuffer<Integer>();
duke@1:         genTry(tree.body, tree.catchers, tryEnv);
duke@1:     }
duke@1:     //where
duke@1:         /** Generate code for a try or synchronized statement
duke@1:          *  @param body      The body of the try or synchronized statement.
duke@1:          *  @param catchers  The lis of catch clauses.
duke@1:          *  @param env       the environment current for the body.
duke@1:          */
duke@1:         void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
duke@1:             int limit = code.nextreg;
duke@1:             int startpc = code.curPc();
duke@1:             Code.State stateTry = code.state.dup();
duke@1:             genStat(body, env, CRT_BLOCK);
duke@1:             int endpc = code.curPc();
duke@1:             boolean hasFinalizer =
duke@1:                 env.info.finalize != null &&
duke@1:                 env.info.finalize.hasFinalizer();
duke@1:             List<Integer> gaps = env.info.gaps.toList();
duke@1:             code.statBegin(TreeInfo.endPos(body));
duke@1:             genFinalizer(env);
duke@1:             code.statBegin(TreeInfo.endPos(env.tree));
duke@1:             Chain exitChain = code.branch(goto_);
duke@1:             endFinalizerGap(env);
duke@1:             if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
duke@1:                 // start off with exception on stack
duke@1:                 code.entryPoint(stateTry, l.head.param.sym.type);
duke@1:                 genCatch(l.head, env, startpc, endpc, gaps);
duke@1:                 genFinalizer(env);
duke@1:                 if (hasFinalizer || l.tail.nonEmpty()) {
duke@1:                     code.statBegin(TreeInfo.endPos(env.tree));
jjg@507:                     exitChain = Code.mergeChains(exitChain,
duke@1:                                                  code.branch(goto_));
duke@1:                 }
duke@1:                 endFinalizerGap(env);
duke@1:             }
duke@1:             if (hasFinalizer) {
duke@1:                 // Create a new register segement to avoid allocating
duke@1:                 // the same variables in finalizers and other statements.
duke@1:                 code.newRegSegment();
duke@1: 
duke@1:                 // Add a catch-all clause.
duke@1: 
duke@1:                 // start off with exception on stack
duke@1:                 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
duke@1: 
duke@1:                 // Register all exception ranges for catch all clause.
duke@1:                 // The range of the catch all clause is from the beginning
duke@1:                 // of the try or synchronized block until the present
duke@1:                 // code pointer excluding all gaps in the current
duke@1:                 // environment's GenContext.
duke@1:                 int startseg = startpc;
duke@1:                 while (env.info.gaps.nonEmpty()) {
duke@1:                     int endseg = env.info.gaps.next().intValue();
duke@1:                     registerCatch(body.pos(), startseg, endseg,
duke@1:                                   catchallpc, 0);
duke@1:                     startseg = env.info.gaps.next().intValue();
duke@1:                 }
duke@1:                 code.statBegin(TreeInfo.finalizerPos(env.tree));
duke@1:                 code.markStatBegin();
duke@1: 
duke@1:                 Item excVar = makeTemp(syms.throwableType);
duke@1:                 excVar.store();
duke@1:                 genFinalizer(env);
duke@1:                 excVar.load();
duke@1:                 registerCatch(body.pos(), startseg,
duke@1:                               env.info.gaps.next().intValue(),
duke@1:                               catchallpc, 0);
duke@1:                 code.emitop0(athrow);
duke@1:                 code.markDead();
duke@1: 
duke@1:                 // If there are jsr's to this finalizer, ...
duke@1:                 if (env.info.cont != null) {
duke@1:                     // Resolve all jsr's.
duke@1:                     code.resolve(env.info.cont);
duke@1: 
duke@1:                     // Mark statement line number
duke@1:                     code.statBegin(TreeInfo.finalizerPos(env.tree));
duke@1:                     code.markStatBegin();
duke@1: 
duke@1:                     // Save return address.
duke@1:                     LocalItem retVar = makeTemp(syms.throwableType);
duke@1:                     retVar.store();
duke@1: 
duke@1:                     // Generate finalizer code.
duke@1:                     env.info.finalize.genLast();
duke@1: 
duke@1:                     // Return.
duke@1:                     code.emitop1w(ret, retVar.reg);
duke@1:                     code.markDead();
duke@1:                 }
duke@1:             }
duke@1: 
duke@1:             // Resolve all breaks.
duke@1:             code.resolve(exitChain);
duke@1: 
duke@1:             code.endScopes(limit);
duke@1:         }
duke@1: 
duke@1:         /** Generate code for a catch clause.
duke@1:          *  @param tree     The catch clause.
duke@1:          *  @param env      The environment current in the enclosing try.
duke@1:          *  @param startpc  Start pc of try-block.
duke@1:          *  @param endpc    End pc of try-block.
duke@1:          */
duke@1:         void genCatch(JCCatch tree,
duke@1:                       Env<GenContext> env,
duke@1:                       int startpc, int endpc,
duke@1:                       List<Integer> gaps) {
duke@1:             if (startpc != endpc) {
mcimadamore@550:                 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
darcy@969:                         ((JCTypeUnion)tree.param.vartype).alternatives :
mcimadamore@641:                         List.of(tree.param.vartype);
mcimadamore@641:                 while (gaps.nonEmpty()) {
mcimadamore@641:                     for (JCExpression subCatch : subClauses) {
mcimadamore@641:                         int catchType = makeRef(tree.pos(), subCatch.type);
mcimadamore@641:                         int end = gaps.head.intValue();
mcimadamore@550:                         registerCatch(tree.pos(),
mcimadamore@550:                                       startpc,  end, code.curPc(),
mcimadamore@550:                                       catchType);
mcimadamore@550:                     }
mcimadamore@641:                     gaps = gaps.tail;
mcimadamore@641:                     startpc = gaps.head.intValue();
mcimadamore@641:                     gaps = gaps.tail;
mcimadamore@641:                 }
mcimadamore@641:                 if (startpc < endpc) {
mcimadamore@641:                     for (JCExpression subCatch : subClauses) {
mcimadamore@641:                         int catchType = makeRef(tree.pos(), subCatch.type);
mcimadamore@550:                         registerCatch(tree.pos(),
mcimadamore@550:                                       startpc, endpc, code.curPc(),
mcimadamore@550:                                       catchType);
mcimadamore@641:                     }
duke@1:                 }
duke@1:                 VarSymbol exparam = tree.param.sym;
duke@1:                 code.statBegin(tree.pos);
duke@1:                 code.markStatBegin();
duke@1:                 int limit = code.nextreg;
duke@1:                 int exlocal = code.newLocal(exparam);
duke@1:                 items.makeLocalItem(exparam).store();
duke@1:                 code.statBegin(TreeInfo.firstStatPos(tree.body));
duke@1:                 genStat(tree.body, env, CRT_BLOCK);
duke@1:                 code.endScopes(limit);
duke@1:                 code.statBegin(TreeInfo.endPos(tree.body));
duke@1:             }
duke@1:         }
duke@1: 
duke@1:         /** Register a catch clause in the "Exceptions" code-attribute.
duke@1:          */
duke@1:         void registerCatch(DiagnosticPosition pos,
duke@1:                            int startpc, int endpc,
duke@1:                            int handler_pc, int catch_type) {
duke@1:             if (startpc != endpc) {
duke@1:                 char startpc1 = (char)startpc;
duke@1:                 char endpc1 = (char)endpc;
duke@1:                 char handler_pc1 = (char)handler_pc;
duke@1:                 if (startpc1 == startpc &&
duke@1:                     endpc1 == endpc &&
duke@1:                     handler_pc1 == handler_pc) {
duke@1:                     code.addCatch(startpc1, endpc1, handler_pc1,
duke@1:                                   (char)catch_type);
duke@1:                 } else {
duke@1:                     if (!useJsrLocally && !target.generateStackMapTable()) {
duke@1:                         useJsrLocally = true;
duke@1:                         throw new CodeSizeOverflow();
duke@1:                     } else {
duke@1:                         log.error(pos, "limit.code.too.large.for.try.stmt");
duke@1:                         nerrs++;
duke@1:                     }
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1: 
duke@1:     /** Very roughly estimate the number of instructions needed for
duke@1:      *  the given tree.
duke@1:      */
duke@1:     int estimateCodeComplexity(JCTree tree) {
duke@1:         if (tree == null) return 0;
duke@1:         class ComplexityScanner extends TreeScanner {
duke@1:             int complexity = 0;
duke@1:             public void scan(JCTree tree) {
duke@1:                 if (complexity > jsrlimit) return;
duke@1:                 super.scan(tree);
duke@1:             }
duke@1:             public void visitClassDef(JCClassDecl tree) {}
duke@1:             public void visitDoLoop(JCDoWhileLoop tree)
duke@1:                 { super.visitDoLoop(tree); complexity++; }
duke@1:             public void visitWhileLoop(JCWhileLoop tree)
duke@1:                 { super.visitWhileLoop(tree); complexity++; }
duke@1:             public void visitForLoop(JCForLoop tree)
duke@1:                 { super.visitForLoop(tree); complexity++; }
duke@1:             public void visitSwitch(JCSwitch tree)
duke@1:                 { super.visitSwitch(tree); complexity+=5; }
duke@1:             public void visitCase(JCCase tree)
duke@1:                 { super.visitCase(tree); complexity++; }
duke@1:             public void visitSynchronized(JCSynchronized tree)
duke@1:                 { super.visitSynchronized(tree); complexity+=6; }
duke@1:             public void visitTry(JCTry tree)
duke@1:                 { super.visitTry(tree);
duke@1:                   if (tree.finalizer != null) complexity+=6; }
duke@1:             public void visitCatch(JCCatch tree)
duke@1:                 { super.visitCatch(tree); complexity+=2; }
duke@1:             public void visitConditional(JCConditional tree)
duke@1:                 { super.visitConditional(tree); complexity+=2; }
duke@1:             public void visitIf(JCIf tree)
duke@1:                 { super.visitIf(tree); complexity+=2; }
duke@1:             // note: for break, continue, and return we don't take unwind() into account.
duke@1:             public void visitBreak(JCBreak tree)
duke@1:                 { super.visitBreak(tree); complexity+=1; }
duke@1:             public void visitContinue(JCContinue tree)
duke@1:                 { super.visitContinue(tree); complexity+=1; }
duke@1:             public void visitReturn(JCReturn tree)
duke@1:                 { super.visitReturn(tree); complexity+=1; }
duke@1:             public void visitThrow(JCThrow tree)
duke@1:                 { super.visitThrow(tree); complexity+=1; }
duke@1:             public void visitAssert(JCAssert tree)
duke@1:                 { super.visitAssert(tree); complexity+=5; }
duke@1:             public void visitApply(JCMethodInvocation tree)
duke@1:                 { super.visitApply(tree); complexity+=2; }
duke@1:             public void visitNewClass(JCNewClass tree)
duke@1:                 { scan(tree.encl); scan(tree.args); complexity+=2; }
duke@1:             public void visitNewArray(JCNewArray tree)
duke@1:                 { super.visitNewArray(tree); complexity+=5; }
duke@1:             public void visitAssign(JCAssign tree)
duke@1:                 { super.visitAssign(tree); complexity+=1; }
duke@1:             public void visitAssignop(JCAssignOp tree)
duke@1:                 { super.visitAssignop(tree); complexity+=2; }
duke@1:             public void visitUnary(JCUnary tree)
duke@1:                 { complexity+=1;
duke@1:                   if (tree.type.constValue() == null) super.visitUnary(tree); }
duke@1:             public void visitBinary(JCBinary tree)
duke@1:                 { complexity+=1;
duke@1:                   if (tree.type.constValue() == null) super.visitBinary(tree); }
duke@1:             public void visitTypeTest(JCInstanceOf tree)
duke@1:                 { super.visitTypeTest(tree); complexity+=1; }
duke@1:             public void visitIndexed(JCArrayAccess tree)
duke@1:                 { super.visitIndexed(tree); complexity+=1; }
duke@1:             public void visitSelect(JCFieldAccess tree)
duke@1:                 { super.visitSelect(tree);
duke@1:                   if (tree.sym.kind == VAR) complexity+=1; }
duke@1:             public void visitIdent(JCIdent tree) {
duke@1:                 if (tree.sym.kind == VAR) {
duke@1:                     complexity+=1;
duke@1:                     if (tree.type.constValue() == null &&
duke@1:                         tree.sym.owner.kind == TYP)
duke@1:                         complexity+=1;
duke@1:                 }
duke@1:             }
duke@1:             public void visitLiteral(JCLiteral tree)
duke@1:                 { complexity+=1; }
duke@1:             public void visitTree(JCTree tree) {}
duke@1:             public void visitWildcard(JCWildcard tree) {
duke@1:                 throw new AssertionError(this.getClass().getName());
duke@1:             }
duke@1:         }
duke@1:         ComplexityScanner scanner = new ComplexityScanner();
duke@1:         tree.accept(scanner);
duke@1:         return scanner.complexity;
duke@1:     }
duke@1: 
duke@1:     public void visitIf(JCIf tree) {
duke@1:         int limit = code.nextreg;
duke@1:         Chain thenExit = null;
duke@1:         CondItem c = genCond(TreeInfo.skipParens(tree.cond),
duke@1:                              CRT_FLOW_CONTROLLER);
duke@1:         Chain elseChain = c.jumpFalse();
duke@1:         if (!c.isFalse()) {
duke@1:             code.resolve(c.trueJumps);
duke@1:             genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
duke@1:             thenExit = code.branch(goto_);
duke@1:         }
duke@1:         if (elseChain != null) {
duke@1:             code.resolve(elseChain);
duke@1:             if (tree.elsepart != null)
duke@1:                 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
duke@1:         }
duke@1:         code.resolve(thenExit);
duke@1:         code.endScopes(limit);
duke@1:     }
duke@1: 
duke@1:     public void visitExec(JCExpressionStatement tree) {
duke@1:         // Optimize x++ to ++x and x-- to --x.
duke@1:         JCExpression e = tree.expr;
duke@1:         switch (e.getTag()) {
duke@1:             case JCTree.POSTINC:
duke@1:                 ((JCUnary) e).setTag(JCTree.PREINC);
duke@1:                 break;
duke@1:             case JCTree.POSTDEC:
duke@1:                 ((JCUnary) e).setTag(JCTree.PREDEC);
duke@1:                 break;
duke@1:         }
duke@1:         genExpr(tree.expr, tree.expr.type).drop();
duke@1:     }
duke@1: 
duke@1:     public void visitBreak(JCBreak tree) {
duke@1:         Env<GenContext> targetEnv = unwind(tree.target, env);
jjg@816:         Assert.check(code.state.stacksize == 0);
duke@1:         targetEnv.info.addExit(code.branch(goto_));
duke@1:         endFinalizerGaps(env, targetEnv);
duke@1:     }
duke@1: 
duke@1:     public void visitContinue(JCContinue tree) {
duke@1:         Env<GenContext> targetEnv = unwind(tree.target, env);
jjg@816:         Assert.check(code.state.stacksize == 0);
duke@1:         targetEnv.info.addCont(code.branch(goto_));
duke@1:         endFinalizerGaps(env, targetEnv);
duke@1:     }
duke@1: 
duke@1:     public void visitReturn(JCReturn tree) {
duke@1:         int limit = code.nextreg;
duke@1:         final Env<GenContext> targetEnv;
duke@1:         if (tree.expr != null) {
duke@1:             Item r = genExpr(tree.expr, pt).load();
duke@1:             if (hasFinally(env.enclMethod, env)) {
duke@1:                 r = makeTemp(pt);
duke@1:                 r.store();
duke@1:             }
duke@1:             targetEnv = unwind(env.enclMethod, env);
duke@1:             r.load();
duke@1:             code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
duke@1:         } else {
duke@1:             targetEnv = unwind(env.enclMethod, env);
duke@1:             code.emitop0(return_);
duke@1:         }
duke@1:         endFinalizerGaps(env, targetEnv);
duke@1:         code.endScopes(limit);
duke@1:     }
duke@1: 
duke@1:     public void visitThrow(JCThrow tree) {
duke@1:         genExpr(tree.expr, tree.expr.type).load();
duke@1:         code.emitop0(athrow);
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * Visitor methods for expressions
duke@1:  *************************************************************************/
duke@1: 
duke@1:     public void visitApply(JCMethodInvocation tree) {
duke@1:         // Generate code for method.
duke@1:         Item m = genExpr(tree.meth, methodType);
duke@1:         // Generate code for all arguments, where the expected types are
duke@1:         // the parameters of the method's external type (that is, any implicit
duke@1:         // outer instance of a super(...) call appears as first parameter).
duke@1:         genArgs(tree.args,
duke@1:                 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
duke@1:         result = m.invoke();
duke@1:     }
duke@1: 
duke@1:     public void visitConditional(JCConditional tree) {
duke@1:         Chain thenExit = null;
duke@1:         CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
duke@1:         Chain elseChain = c.jumpFalse();
duke@1:         if (!c.isFalse()) {
duke@1:             code.resolve(c.trueJumps);
duke@1:             int startpc = genCrt ? code.curPc() : 0;
duke@1:             genExpr(tree.truepart, pt).load();
duke@1:             code.state.forceStackTop(tree.type);
duke@1:             if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
duke@1:                                      startpc, code.curPc());
duke@1:             thenExit = code.branch(goto_);
duke@1:         }
duke@1:         if (elseChain != null) {
duke@1:             code.resolve(elseChain);
duke@1:             int startpc = genCrt ? code.curPc() : 0;
duke@1:             genExpr(tree.falsepart, pt).load();
duke@1:             code.state.forceStackTop(tree.type);
duke@1:             if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
duke@1:                                      startpc, code.curPc());
duke@1:         }
duke@1:         code.resolve(thenExit);
duke@1:         result = items.makeStackItem(pt);
duke@1:     }
duke@1: 
duke@1:     public void visitNewClass(JCNewClass tree) {
duke@1:         // Enclosing instances or anonymous classes should have been eliminated
duke@1:         // by now.
jjg@816:         Assert.check(tree.encl == null && tree.def == null);
duke@1: 
duke@1:         code.emitop2(new_, makeRef(tree.pos(), tree.type));
duke@1:         code.emitop0(dup);
duke@1: 
duke@1:         // Generate code for all arguments, where the expected types are
duke@1:         // the parameters of the constructor's external type (that is,
duke@1:         // any implicit outer instance appears as first parameter).
duke@1:         genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
duke@1: 
duke@1:         items.makeMemberItem(tree.constructor, true).invoke();
duke@1:         result = items.makeStackItem(tree.type);
duke@1:     }
duke@1: 
duke@1:     public void visitNewArray(JCNewArray tree) {
jjg@308: 
duke@1:         if (tree.elems != null) {
duke@1:             Type elemtype = types.elemtype(tree.type);
duke@1:             loadIntConst(tree.elems.length());
duke@1:             Item arr = makeNewArray(tree.pos(), tree.type, 1);
duke@1:             int i = 0;
duke@1:             for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
duke@1:                 arr.duplicate();
duke@1:                 loadIntConst(i);
duke@1:                 i++;
duke@1:                 genExpr(l.head, elemtype).load();
duke@1:                 items.makeIndexedItem(elemtype).store();
duke@1:             }
duke@1:             result = arr;
duke@1:         } else {
duke@1:             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
duke@1:                 genExpr(l.head, syms.intType).load();
duke@1:             }
duke@1:             result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
duke@1:         }
duke@1:     }
duke@1: //where
duke@1:         /** Generate code to create an array with given element type and number
duke@1:          *  of dimensions.
duke@1:          */
duke@1:         Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
duke@1:             Type elemtype = types.elemtype(type);
jjg@782:             if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
duke@1:                 log.error(pos, "limit.dimensions");
duke@1:                 nerrs++;
duke@1:             }
duke@1:             int elemcode = Code.arraycode(elemtype);
duke@1:             if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
duke@1:                 code.emitAnewarray(makeRef(pos, elemtype), type);
duke@1:             } else if (elemcode == 1) {
duke@1:                 code.emitMultianewarray(ndims, makeRef(pos, type), type);
duke@1:             } else {
duke@1:                 code.emitNewarray(elemcode, type);
duke@1:             }
duke@1:             return items.makeStackItem(type);
duke@1:         }
duke@1: 
duke@1:     public void visitParens(JCParens tree) {
duke@1:         result = genExpr(tree.expr, tree.expr.type);
duke@1:     }
duke@1: 
duke@1:     public void visitAssign(JCAssign tree) {
duke@1:         Item l = genExpr(tree.lhs, tree.lhs.type);
duke@1:         genExpr(tree.rhs, tree.lhs.type).load();
duke@1:         result = items.makeAssignItem(l);
duke@1:     }
duke@1: 
duke@1:     public void visitAssignop(JCAssignOp tree) {
duke@1:         OperatorSymbol operator = (OperatorSymbol) tree.operator;
duke@1:         Item l;
duke@1:         if (operator.opcode == string_add) {
duke@1:             // Generate code to make a string buffer
duke@1:             makeStringBuffer(tree.pos());
duke@1: 
duke@1:             // Generate code for first string, possibly save one
duke@1:             // copy under buffer
duke@1:             l = genExpr(tree.lhs, tree.lhs.type);
duke@1:             if (l.width() > 0) {
duke@1:                 code.emitop0(dup_x1 + 3 * (l.width() - 1));
duke@1:             }
duke@1: 
duke@1:             // Load first string and append to buffer.
duke@1:             l.load();
duke@1:             appendString(tree.lhs);
duke@1: 
duke@1:             // Append all other strings to buffer.
duke@1:             appendStrings(tree.rhs);
duke@1: 
duke@1:             // Convert buffer to string.
duke@1:             bufferToString(tree.pos());
duke@1:         } else {
duke@1:             // Generate code for first expression
duke@1:             l = genExpr(tree.lhs, tree.lhs.type);
duke@1: 
duke@1:             // If we have an increment of -32768 to +32767 of a local
duke@1:             // int variable we can use an incr instruction instead of
duke@1:             // proceeding further.
duke@1:             if ((tree.getTag() == JCTree.PLUS_ASG || tree.getTag() == JCTree.MINUS_ASG) &&
duke@1:                 l instanceof LocalItem &&
duke@1:                 tree.lhs.type.tag <= INT &&
duke@1:                 tree.rhs.type.tag <= INT &&
duke@1:                 tree.rhs.type.constValue() != null) {
duke@1:                 int ival = ((Number) tree.rhs.type.constValue()).intValue();
duke@1:                 if (tree.getTag() == JCTree.MINUS_ASG) ival = -ival;
duke@1:                 ((LocalItem)l).incr(ival);
duke@1:                 result = l;
duke@1:                 return;
duke@1:             }
duke@1:             // Otherwise, duplicate expression, load one copy
duke@1:             // and complete binary operation.
duke@1:             l.duplicate();
duke@1:             l.coerce(operator.type.getParameterTypes().head).load();
duke@1:             completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
duke@1:         }
duke@1:         result = items.makeAssignItem(l);
duke@1:     }
duke@1: 
duke@1:     public void visitUnary(JCUnary tree) {
duke@1:         OperatorSymbol operator = (OperatorSymbol)tree.operator;
duke@1:         if (tree.getTag() == JCTree.NOT) {
duke@1:             CondItem od = genCond(tree.arg, false);
duke@1:             result = od.negate();
duke@1:         } else {
duke@1:             Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
duke@1:             switch (tree.getTag()) {
duke@1:             case JCTree.POS:
duke@1:                 result = od.load();
duke@1:                 break;
duke@1:             case JCTree.NEG:
duke@1:                 result = od.load();
duke@1:                 code.emitop0(operator.opcode);
duke@1:                 break;
duke@1:             case JCTree.COMPL:
duke@1:                 result = od.load();
duke@1:                 emitMinusOne(od.typecode);
duke@1:                 code.emitop0(operator.opcode);
duke@1:                 break;
duke@1:             case JCTree.PREINC: case JCTree.PREDEC:
duke@1:                 od.duplicate();
duke@1:                 if (od instanceof LocalItem &&
duke@1:                     (operator.opcode == iadd || operator.opcode == isub)) {
duke@1:                     ((LocalItem)od).incr(tree.getTag() == JCTree.PREINC ? 1 : -1);
duke@1:                     result = od;
duke@1:                 } else {
duke@1:                     od.load();
duke@1:                     code.emitop0(one(od.typecode));
duke@1:                     code.emitop0(operator.opcode);
duke@1:                     // Perform narrowing primitive conversion if byte,
duke@1:                     // char, or short.  Fix for 4304655.
duke@1:                     if (od.typecode != INTcode &&
duke@1:                         Code.truncate(od.typecode) == INTcode)
duke@1:                       code.emitop0(int2byte + od.typecode - BYTEcode);
duke@1:                     result = items.makeAssignItem(od);
duke@1:                 }
duke@1:                 break;
duke@1:             case JCTree.POSTINC: case JCTree.POSTDEC:
duke@1:                 od.duplicate();
duke@1:                 if (od instanceof LocalItem &&
duke@1:                     (operator.opcode == iadd || operator.opcode == isub)) {
duke@1:                     Item res = od.load();
duke@1:                     ((LocalItem)od).incr(tree.getTag() == JCTree.POSTINC ? 1 : -1);
duke@1:                     result = res;
duke@1:                 } else {
duke@1:                     Item res = od.load();
duke@1:                     od.stash(od.typecode);
duke@1:                     code.emitop0(one(od.typecode));
duke@1:                     code.emitop0(operator.opcode);
duke@1:                     // Perform narrowing primitive conversion if byte,
duke@1:                     // char, or short.  Fix for 4304655.
duke@1:                     if (od.typecode != INTcode &&
duke@1:                         Code.truncate(od.typecode) == INTcode)
duke@1:                       code.emitop0(int2byte + od.typecode - BYTEcode);
duke@1:                     od.store();
duke@1:                     result = res;
duke@1:                 }
duke@1:                 break;
duke@1:             case JCTree.NULLCHK:
duke@1:                 result = od.load();
duke@1:                 code.emitop0(dup);
duke@1:                 genNullCheck(tree.pos());
duke@1:                 break;
duke@1:             default:
jjg@816:                 Assert.error();
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Generate a null check from the object value at stack top. */
duke@1:     private void genNullCheck(DiagnosticPosition pos) {
duke@1:         callMethod(pos, syms.objectType, names.getClass,
duke@1:                    List.<Type>nil(), false);
duke@1:         code.emitop0(pop);
duke@1:     }
duke@1: 
duke@1:     public void visitBinary(JCBinary tree) {
duke@1:         OperatorSymbol operator = (OperatorSymbol)tree.operator;
duke@1:         if (operator.opcode == string_add) {
duke@1:             // Create a string buffer.
duke@1:             makeStringBuffer(tree.pos());
duke@1:             // Append all strings to buffer.
duke@1:             appendStrings(tree);
duke@1:             // Convert buffer to string.
duke@1:             bufferToString(tree.pos());
duke@1:             result = items.makeStackItem(syms.stringType);
duke@1:         } else if (tree.getTag() == JCTree.AND) {
duke@1:             CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
duke@1:             if (!lcond.isFalse()) {
duke@1:                 Chain falseJumps = lcond.jumpFalse();
duke@1:                 code.resolve(lcond.trueJumps);
duke@1:                 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
duke@1:                 result = items.
duke@1:                     makeCondItem(rcond.opcode,
duke@1:                                  rcond.trueJumps,
jjg@507:                                  Code.mergeChains(falseJumps,
duke@1:                                                   rcond.falseJumps));
duke@1:             } else {
duke@1:                 result = lcond;
duke@1:             }
duke@1:         } else if (tree.getTag() == JCTree.OR) {
duke@1:             CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
duke@1:             if (!lcond.isTrue()) {
duke@1:                 Chain trueJumps = lcond.jumpTrue();
duke@1:                 code.resolve(lcond.falseJumps);
duke@1:                 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
duke@1:                 result = items.
duke@1:                     makeCondItem(rcond.opcode,
jjg@507:                                  Code.mergeChains(trueJumps, rcond.trueJumps),
duke@1:                                  rcond.falseJumps);
duke@1:             } else {
duke@1:                 result = lcond;
duke@1:             }
duke@1:         } else {
duke@1:             Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
duke@1:             od.load();
duke@1:             result = completeBinop(tree.lhs, tree.rhs, operator);
duke@1:         }
duke@1:     }
duke@1: //where
duke@1:         /** Make a new string buffer.
duke@1:          */
duke@1:         void makeStringBuffer(DiagnosticPosition pos) {
duke@1:             code.emitop2(new_, makeRef(pos, stringBufferType));
duke@1:             code.emitop0(dup);
duke@1:             callMethod(
duke@1:                 pos, stringBufferType, names.init, List.<Type>nil(), false);
duke@1:         }
duke@1: 
duke@1:         /** Append value (on tos) to string buffer (on tos - 1).
duke@1:          */
duke@1:         void appendString(JCTree tree) {
duke@1:             Type t = tree.type.baseType();
duke@1:             if (t.tag > lastBaseTag && t.tsym != syms.stringType.tsym) {
duke@1:                 t = syms.objectType;
duke@1:             }
duke@1:             items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
duke@1:         }
duke@1:         Symbol getStringBufferAppend(JCTree tree, Type t) {
jjg@816:             Assert.checkNull(t.constValue());
duke@1:             Symbol method = stringBufferAppend.get(t);
duke@1:             if (method == null) {
duke@1:                 method = rs.resolveInternalMethod(tree.pos(),
duke@1:                                                   attrEnv,
duke@1:                                                   stringBufferType,
duke@1:                                                   names.append,
duke@1:                                                   List.of(t),
duke@1:                                                   null);
duke@1:                 stringBufferAppend.put(t, method);
duke@1:             }
duke@1:             return method;
duke@1:         }
duke@1: 
duke@1:         /** Add all strings in tree to string buffer.
duke@1:          */
duke@1:         void appendStrings(JCTree tree) {
duke@1:             tree = TreeInfo.skipParens(tree);
duke@1:             if (tree.getTag() == JCTree.PLUS && tree.type.constValue() == null) {
duke@1:                 JCBinary op = (JCBinary) tree;
duke@1:                 if (op.operator.kind == MTH &&
duke@1:                     ((OperatorSymbol) op.operator).opcode == string_add) {
duke@1:                     appendStrings(op.lhs);
duke@1:                     appendStrings(op.rhs);
duke@1:                     return;
duke@1:                 }
duke@1:             }
duke@1:             genExpr(tree, tree.type).load();
duke@1:             appendString(tree);
duke@1:         }
duke@1: 
duke@1:         /** Convert string buffer on tos to string.
duke@1:          */
duke@1:         void bufferToString(DiagnosticPosition pos) {
duke@1:             callMethod(
duke@1:                 pos,
duke@1:                 stringBufferType,
duke@1:                 names.toString,
duke@1:                 List.<Type>nil(),
duke@1:                 false);
duke@1:         }
duke@1: 
duke@1:         /** Complete generating code for operation, with left operand
duke@1:          *  already on stack.
duke@1:          *  @param lhs       The tree representing the left operand.
duke@1:          *  @param rhs       The tree representing the right operand.
duke@1:          *  @param operator  The operator symbol.
duke@1:          */
duke@1:         Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
duke@1:             MethodType optype = (MethodType)operator.type;
duke@1:             int opcode = operator.opcode;
duke@1:             if (opcode >= if_icmpeq && opcode <= if_icmple &&
duke@1:                 rhs.type.constValue() instanceof Number &&
duke@1:                 ((Number) rhs.type.constValue()).intValue() == 0) {
duke@1:                 opcode = opcode + (ifeq - if_icmpeq);
duke@1:             } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
duke@1:                        TreeInfo.isNull(rhs)) {
duke@1:                 opcode = opcode + (if_acmp_null - if_acmpeq);
duke@1:             } else {
duke@1:                 // The expected type of the right operand is
duke@1:                 // the second parameter type of the operator, except for
duke@1:                 // shifts with long shiftcount, where we convert the opcode
duke@1:                 // to a short shift and the expected type to int.
duke@1:                 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
duke@1:                 if (opcode >= ishll && opcode <= lushrl) {
duke@1:                     opcode = opcode + (ishl - ishll);
duke@1:                     rtype = syms.intType;
duke@1:                 }
duke@1:                 // Generate code for right operand and load.
duke@1:                 genExpr(rhs, rtype).load();
duke@1:                 // If there are two consecutive opcode instructions,
duke@1:                 // emit the first now.
duke@1:                 if (opcode >= (1 << preShift)) {
duke@1:                     code.emitop0(opcode >> preShift);
duke@1:                     opcode = opcode & 0xFF;
duke@1:                 }
duke@1:             }
duke@1:             if (opcode >= ifeq && opcode <= if_acmpne ||
duke@1:                 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
duke@1:                 return items.makeCondItem(opcode);
duke@1:             } else {
duke@1:                 code.emitop0(opcode);
duke@1:                 return items.makeStackItem(optype.restype);
duke@1:             }
duke@1:         }
duke@1: 
duke@1:     public void visitTypeCast(JCTypeCast tree) {
duke@1:         result = genExpr(tree.expr, tree.clazz.type).load();
duke@1:         // Additional code is only needed if we cast to a reference type
duke@1:         // which is not statically a supertype of the expression's type.
duke@1:         // For basic types, the coerce(...) in genExpr(...) will do
duke@1:         // the conversion.
duke@1:         if (tree.clazz.type.tag > lastBaseTag &&
duke@1:             types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
duke@1:             code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     public void visitWildcard(JCWildcard tree) {
duke@1:         throw new AssertionError(this.getClass().getName());
duke@1:     }
duke@1: 
duke@1:     public void visitTypeTest(JCInstanceOf tree) {
duke@1:         genExpr(tree.expr, tree.expr.type).load();
duke@1:         code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
duke@1:         result = items.makeStackItem(syms.booleanType);
duke@1:     }
duke@1: 
duke@1:     public void visitIndexed(JCArrayAccess tree) {
duke@1:         genExpr(tree.indexed, tree.indexed.type).load();
duke@1:         genExpr(tree.index, syms.intType).load();
duke@1:         result = items.makeIndexedItem(tree.type);
duke@1:     }
duke@1: 
duke@1:     public void visitIdent(JCIdent tree) {
duke@1:         Symbol sym = tree.sym;
duke@1:         if (tree.name == names._this || tree.name == names._super) {
duke@1:             Item res = tree.name == names._this
duke@1:                 ? items.makeThisItem()
duke@1:                 : items.makeSuperItem();
duke@1:             if (sym.kind == MTH) {
duke@1:                 // Generate code to address the constructor.
duke@1:                 res.load();
duke@1:                 res = items.makeMemberItem(sym, true);
duke@1:             }
duke@1:             result = res;
duke@1:         } else if (sym.kind == VAR && sym.owner.kind == MTH) {
duke@1:             result = items.makeLocalItem((VarSymbol)sym);
duke@1:         } else if ((sym.flags() & STATIC) != 0) {
duke@1:             if (!isAccessSuper(env.enclMethod))
duke@1:                 sym = binaryQualifier(sym, env.enclClass.type);
duke@1:             result = items.makeStaticItem(sym);
duke@1:         } else {
duke@1:             items.makeThisItem().load();
duke@1:             sym = binaryQualifier(sym, env.enclClass.type);
duke@1:             result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     public void visitSelect(JCFieldAccess tree) {
duke@1:         Symbol sym = tree.sym;
duke@1: 
duke@1:         if (tree.name == names._class) {
jjg@816:             Assert.check(target.hasClassLiterals());
duke@1:             code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
duke@1:             result = items.makeStackItem(pt);
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         Symbol ssym = TreeInfo.symbol(tree.selected);
duke@1: 
duke@1:         // Are we selecting via super?
duke@1:         boolean selectSuper =
duke@1:             ssym != null && (ssym.kind == TYP || ssym.name == names._super);
duke@1: 
duke@1:         // Are we accessing a member of the superclass in an access method
duke@1:         // resulting from a qualified super?
duke@1:         boolean accessSuper = isAccessSuper(env.enclMethod);
duke@1: 
duke@1:         Item base = (selectSuper)
duke@1:             ? items.makeSuperItem()
duke@1:             : genExpr(tree.selected, tree.selected.type);
duke@1: 
duke@1:         if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
duke@1:             // We are seeing a variable that is constant but its selecting
duke@1:             // expression is not.
duke@1:             if ((sym.flags() & STATIC) != 0) {
duke@1:                 if (!selectSuper && (ssym == null || ssym.kind != TYP))
duke@1:                     base = base.load();
duke@1:                 base.drop();
duke@1:             } else {
duke@1:                 base.load();
duke@1:                 genNullCheck(tree.selected.pos());
duke@1:             }
duke@1:             result = items.
duke@1:                 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
duke@1:         } else {
duke@1:             if (!accessSuper)
duke@1:                 sym = binaryQualifier(sym, tree.selected.type);
duke@1:             if ((sym.flags() & STATIC) != 0) {
duke@1:                 if (!selectSuper && (ssym == null || ssym.kind != TYP))
duke@1:                     base = base.load();
duke@1:                 base.drop();
duke@1:                 result = items.makeStaticItem(sym);
duke@1:             } else {
duke@1:                 base.load();
duke@1:                 if (sym == syms.lengthVar) {
duke@1:                     code.emitop0(arraylength);
duke@1:                     result = items.makeStackItem(syms.intType);
duke@1:                 } else {
duke@1:                     result = items.
duke@1:                         makeMemberItem(sym,
duke@1:                                        (sym.flags() & PRIVATE) != 0 ||
duke@1:                                        selectSuper || accessSuper);
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     public void visitLiteral(JCLiteral tree) {
duke@1:         if (tree.type.tag == TypeTags.BOT) {
duke@1:             code.emitop0(aconst_null);
duke@1:             if (types.dimensions(pt) > 1) {
duke@1:                 code.emitop2(checkcast, makeRef(tree.pos(), pt));
duke@1:                 result = items.makeStackItem(pt);
duke@1:             } else {
duke@1:                 result = items.makeStackItem(tree.type);
duke@1:             }
duke@1:         }
duke@1:         else
duke@1:             result = items.makeImmediateItem(tree.type, tree.value);
duke@1:     }
duke@1: 
duke@1:     public void visitLetExpr(LetExpr tree) {
duke@1:         int limit = code.nextreg;
duke@1:         genStats(tree.defs, env);
duke@1:         result = genExpr(tree.expr, tree.expr.type).load();
duke@1:         code.endScopes(limit);
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * main method
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** Generate code for a class definition.
duke@1:      *  @param env   The attribution environment that belongs to the
duke@1:      *               outermost class containing this class definition.
duke@1:      *               We need this for resolving some additional symbols.
duke@1:      *  @param cdef  The tree representing the class definition.
duke@1:      *  @return      True if code is generated with no errors.
duke@1:      */
duke@1:     public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
duke@1:         try {
duke@1:             attrEnv = env;
duke@1:             ClassSymbol c = cdef.sym;
duke@1:             this.toplevel = env.toplevel;
duke@1:             this.endPositions = toplevel.endPositions;
duke@1:             // If this is a class definition requiring Miranda methods,
duke@1:             // add them.
duke@1:             if (generateIproxies &&
duke@1:                 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
duke@1:                 && !allowGenerics // no Miranda methods available with generics
duke@1:                 )
duke@1:                 implementInterfaceMethods(c);
duke@1:             cdef.defs = normalizeDefs(cdef.defs, c);
duke@1:             c.pool = pool;
duke@1:             pool.reset();
duke@1:             Env<GenContext> localEnv =
duke@1:                 new Env<GenContext>(cdef, new GenContext());
duke@1:             localEnv.toplevel = env.toplevel;
duke@1:             localEnv.enclClass = cdef;
duke@1:             for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
duke@1:                 genDef(l.head, localEnv);
duke@1:             }
duke@1:             if (pool.numEntries() > Pool.MAX_ENTRIES) {
duke@1:                 log.error(cdef.pos(), "limit.pool");
duke@1:                 nerrs++;
duke@1:             }
duke@1:             if (nerrs != 0) {
duke@1:                 // if errors, discard code
duke@1:                 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
duke@1:                     if (l.head.getTag() == JCTree.METHODDEF)
duke@1:                         ((JCMethodDecl) l.head).sym.code = null;
duke@1:                 }
duke@1:             }
duke@1:             cdef.defs = List.nil(); // discard trees
duke@1:             return nerrs == 0;
duke@1:         } finally {
duke@1:             // note: this method does NOT support recursion.
duke@1:             attrEnv = null;
duke@1:             this.env = null;
duke@1:             toplevel = null;
duke@1:             endPositions = null;
duke@1:             nerrs = 0;
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * Auxiliary classes
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** An abstract class for finalizer generation.
duke@1:      */
duke@1:     abstract class GenFinalizer {
duke@1:         /** Generate code to clean up when unwinding. */
duke@1:         abstract void gen();
duke@1: 
duke@1:         /** Generate code to clean up at last. */
duke@1:         abstract void genLast();
duke@1: 
duke@1:         /** Does this finalizer have some nontrivial cleanup to perform? */
duke@1:         boolean hasFinalizer() { return true; }
duke@1:     }
duke@1: 
duke@1:     /** code generation contexts,
duke@1:      *  to be used as type parameter for environments.
duke@1:      */
duke@1:     static class GenContext {
duke@1: 
duke@1:         /** A chain for all unresolved jumps that exit the current environment.
duke@1:          */
duke@1:         Chain exit = null;
duke@1: 
duke@1:         /** A chain for all unresolved jumps that continue in the
duke@1:          *  current environment.
duke@1:          */
duke@1:         Chain cont = null;
duke@1: 
duke@1:         /** A closure that generates the finalizer of the current environment.
duke@1:          *  Only set for Synchronized and Try contexts.
duke@1:          */
duke@1:         GenFinalizer finalize = null;
duke@1: 
duke@1:         /** Is this a switch statement?  If so, allocate registers
duke@1:          * even when the variable declaration is unreachable.
duke@1:          */
duke@1:         boolean isSwitch = false;
duke@1: 
duke@1:         /** A list buffer containing all gaps in the finalizer range,
duke@1:          *  where a catch all exception should not apply.
duke@1:          */
duke@1:         ListBuffer<Integer> gaps = null;
duke@1: 
duke@1:         /** Add given chain to exit chain.
duke@1:          */
duke@1:         void addExit(Chain c)  {
duke@1:             exit = Code.mergeChains(c, exit);
duke@1:         }
duke@1: 
duke@1:         /** Add given chain to cont chain.
duke@1:          */
duke@1:         void addCont(Chain c) {
duke@1:             cont = Code.mergeChains(c, cont);
duke@1:         }
duke@1:     }
duke@1: }