mjc

org.multijava.mjc
Class JThisExpression

java.lang.Object
  extended byorg.multijava.util.Utils
      extended byorg.multijava.util.compiler.Phylum
          extended byorg.multijava.mjc.JPhylum
              extended byorg.multijava.mjc.JExpression
                  extended byorg.multijava.mjc.JThisExpression
All Implemented Interfaces:
Cloneable, Constants, Constants, PhylumType

public class JThisExpression
extends JExpression

A 'this' expression


Field Summary
private  boolean generated
          Indicates whether this this expression was generated by the compiler.
private  JExpression prefix
           
private  CClass self
           
private  CClassType selfType
           
 
Fields inherited from class org.multijava.mjc.JExpression
EMPTY
 
Fields inherited from class org.multijava.util.compiler.Phylum
 
Fields inherited from class org.multijava.util.Utils
DBG_LEVEL_HIGH, DBG_LEVEL_LOW, DBG_LEVEL_NO
 
Fields inherited from interface org.multijava.mjc.Constants
ACC_MODIFIER_FLAGS_MASK, ACC_NON_NULL, ACC_NON_NULL_BY_DEFAULT, ACC_NULLABLE, ACC_NULLABLE_BY_DEFAULT, ACC_PURE, ACCESS_FLAG_ARRAY, ACCESS_FLAG_NAMES, AMID_JAVA_MATH, AMID_MAX, AMID_SAFE_MATH, CMP_VERSION, IMPLICITLY_NON_NULL, JAV_ASSERTION_ERROR, JAV_CLASS, JAV_CLASSLOADER, JAV_CLASSNOTFOUND_EXCEPTION, JAV_CLONE, JAV_CLONEABLE, JAV_CONSTRUCTOR, JAV_ERROR, JAV_EXCEPTION, JAV_INIT, JAV_LENGTH, JAV_NAME_SEPARATOR, JAV_NOCLASSDEFFOUND_ERROR, JAV_OBJECT, JAV_OUTER_THIS, JAV_RMJ_RUNTIME_EXCEPTION, JAV_RUNTIME, JAV_RUNTIME_EXCEPTION, JAV_SERIALIZABLE, JAV_STATIC_INIT, JAV_STRING, JAV_STRINGBUFFER, JAV_SUPER, JAV_THIS, JAV_THROWABLE, MJ_ANCHOR, NULLITY_MODS, OPE_BAND, OPE_BNOT, OPE_BOR, OPE_BSR, OPE_BXOR, OPE_EQ, OPE_GE, OPE_GT, OPE_LAND, OPE_LE, OPE_LNOT, OPE_LOR, OPE_LT, OPE_MINUS, OPE_NE, OPE_PERCENT, OPE_PLUS, OPE_POSTDEC, OPE_POSTINC, OPE_PREDEC, OPE_PREINC, OPE_SIMPLE, OPE_SL, OPE_SLASH, OPE_SR, OPE_STAR, TID_ARRAY, TID_BOOLEAN, TID_BYTE, TID_CHAR, TID_CLASS, TID_DOUBLE, TID_FLOAT, TID_INT, TID_LONG, TID_MAX, TID_SHORT, TID_VOID, UNIV_ARRAY_TMP, UNIV_TMP
 
Fields inherited from interface org.multijava.util.classfile.Constants
ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VOLATILE, ATT_ANCHOR, ATT_BRIDGE, ATT_CODE, ATT_CONSTANTVALUE, ATT_DEPRECATED, ATT_DISPATCHER, ATT_EXCEPTIONS, ATT_GENERIC, ATT_GENERIC_FUNCTIONS, ATT_INNERCLASSES, ATT_LINENUMBERTABLE, ATT_LOCALVARIABLETABLE, ATT_MM_BODY, ATT_REDIRECTOR, ATT_RMJ_GLUE, ATT_RMJ_SIGNATURE, ATT_RUNTIME_VISIBLE_ANNOTATIONS, ATT_RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS, ATT_SIGNATURE, ATT_SOURCEFILE, ATT_SYNTHETIC, ATT_UNIVERSE_FIELD, ATT_UNIVERSE_METHOD, ATT_UNIVERSE_VERSION, CST_CLASS, CST_DOUBLE, CST_FIELD, CST_FLOAT, CST_INTEGER, CST_INTERFACEMETHOD, CST_LONG, CST_METHOD, CST_NAMEANDTYPE, CST_STRING, CST_UTF8, ENV_DEBUG_MODE, ENV_USE_CACHE, JAVA_MAGIC, JAVA_MAJOR, JAVA_MINOR, MAX_CODE_PER_METHOD, opc_aaload, opc_aastore, opc_aconst_null, opc_aload, opc_aload_0, opc_aload_1, opc_aload_2, opc_aload_3, opc_anewarray, opc_areturn, opc_arraylength, opc_astore, opc_astore_0, opc_astore_1, opc_astore_2, opc_astore_3, opc_athrow, opc_baload, opc_bastore, opc_bipush, opc_caload, opc_castore, opc_checkcast, opc_d2f, opc_d2i, opc_d2l, opc_dadd, opc_daload, opc_dastore, opc_dcmpg, opc_dcmpl, opc_dconst_0, opc_dconst_1, opc_ddiv, opc_dload, opc_dload_0, opc_dload_1, opc_dload_2, opc_dload_3, opc_dmul, opc_dneg, opc_drem, opc_dreturn, opc_dstore, opc_dstore_0, opc_dstore_1, opc_dstore_2, opc_dstore_3, opc_dsub, opc_dup, opc_dup2, opc_dup2_x1, opc_dup2_x2, opc_dup_x1, opc_dup_x2, opc_f2d, opc_f2i, opc_f2l, opc_fadd, opc_faload, opc_fastore, opc_fcmpg, opc_fcmpl, opc_fconst_0, opc_fconst_1, opc_fconst_2, opc_fdiv, opc_fload, opc_fload_0, opc_fload_1, opc_fload_2, opc_fload_3, opc_fmul, opc_fneg, opc_frem, opc_freturn, opc_fstore, opc_fstore_0, opc_fstore_1, opc_fstore_2, opc_fstore_3, opc_fsub, opc_getfield, opc_getstatic, opc_goto, opc_goto_w, opc_i2b, opc_i2c, opc_i2d, opc_i2f, opc_i2l, opc_i2s, opc_iadd, opc_iaload, opc_iand, opc_iastore, opc_iconst_0, opc_iconst_1, opc_iconst_2, opc_iconst_3, opc_iconst_4, opc_iconst_5, opc_iconst_m1, opc_idiv, opc_if_acmpeq, opc_if_acmpne, opc_if_icmpeq, opc_if_icmpge, opc_if_icmpgt, opc_if_icmple, opc_if_icmplt, opc_if_icmpne, opc_ifeq, opc_ifge, opc_ifgt, opc_ifle, opc_iflt, opc_ifne, opc_ifnonnull, opc_ifnull, opc_iinc, opc_iload, opc_iload_0, opc_iload_1, opc_iload_2, opc_iload_3, opc_imul, opc_ineg, opc_instanceof, opc_invokeinterface, opc_invokespecial, opc_invokestatic, opc_invokevirtual, opc_ior, opc_irem, opc_ireturn, opc_ishl, opc_ishr, opc_istore, opc_istore_0, opc_istore_1, opc_istore_2, opc_istore_3, opc_isub, opc_iushr, opc_ixor, opc_jsr, opc_jsr_w, opc_l2d, opc_l2f, opc_l2i, opc_ladd, opc_laload, opc_land, opc_lastore, opc_lcmp, opc_lconst_0, opc_lconst_1, opc_ldc, opc_ldc2_w, opc_ldc_w, opc_ldiv, opc_lload, opc_lload_0, opc_lload_1, opc_lload_2, opc_lload_3, opc_lmul, opc_lneg, opc_lookupswitch, opc_lor, opc_lrem, opc_lreturn, opc_lshl, opc_lshr, opc_lstore, opc_lstore_0, opc_lstore_1, opc_lstore_2, opc_lstore_3, opc_lsub, opc_lushr, opc_lxor, opc_monitorenter, opc_monitorexit, opc_multianewarray, opc_new, opc_newarray, opc_nop, opc_pop, opc_pop2, opc_putfield, opc_putstatic, opc_ret, opc_return, opc_saload, opc_sastore, opc_sipush, opc_swap, opc_tableswitch, opc_wide, opc_xxxunusedxxx, POO_ASCII_CONSTANT, POO_CLASS_CONSTANT, POO_DOUBLE_CONSTANT, POO_FLOAT_CONSTANT, POO_INTEGER_CONSTANT, POO_LONG_CONSTANT, POO_NAT_CONSTANT, POO_REF_CONSTANT, POO_STRING_CONSTANT, TYP_ADDRESS, TYP_DOUBLE, TYP_FLOAT, TYP_INT, TYP_LONG, TYP_REFERENCE, TYP_VOID
 
Constructor Summary
JThisExpression(TokenReference where)
          Construct an unqualified "this" expression node in the parsing tree.
JThisExpression(TokenReference where, CClass self)
          Construct a qualified "this" expression node in the parsing tree, where the actual CClass singleton of the qualifier is known.
JThisExpression(TokenReference where, JExpression prefix)
          Construct a qualified "this" expression node in the parsing tree, where only the qualifying expression is known, not its type.
 
Method Summary
 void accept(MjcVisitor p)
          Accepts the specified visitor
 boolean equals(Object o)
           
 void genCode(CodeSequence code)
          Generates a sequence of bytecodes
 CType getType()
          Compute the type of this expression (called after parsing)
 int hashCode()
          Throws a runtime exception because hashCode isn't properly implemented yet.
 boolean isLValue(CExpressionContextType context)
           
private  JExpression makeThisVariableReference(CContextType context)
          Generates a synthetic variable reference to a local variable that will resolve to "this" at run time.
 JExpression prefix()
           
 String toString()
           
 JExpression typecheck(CExpressionContextType context)
          Typechecks the expression and mutates the context to record information gathered during typechecking.
 
Methods inherited from class org.multijava.mjc.JExpression
buildUniverseDynChecks, clone, convertType, dumpArray, fail, genBranch, genUniverseDynCheckCode, getApparentType, getBooleanLiteral, getFANonNulls, getFANulls, getLiteral, getNumberLiteral, getOrdinalLiteral, getRealLiteral, getStringLiteral, isAssignableTo, isBooleanLiteral, isConstant, isDeclaredNonNull, isLiteral, isMaybeInitializable, isNonNull, isOrdinalLiteral, isRealLiteral, isStatementExpression, isStringLiteral, typecheck, unParenthesize
 
Methods inherited from class org.multijava.mjc.JPhylum
check, check, check, check, fail, fail, warn, warn, warn, warn
 
Methods inherited from class org.multijava.util.compiler.Phylum
getTokenReference, setTokenReference
 
Methods inherited from class org.multijava.util.Utils
assertTrue, assertTrue, combineArrays, escapeString, escapeString, fail, fail, getFilePath, hasFlag, hasOtherFlags, parsePathParts, relativePathTo, splitQualifiedName, splitQualifiedName, stripJavaModifiers, stripNonJavaModifiers, stripPrivateModifier, unescapeString, vectorToArray, vectorToIntArray
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

self

private CClass self

selfType

private CClassType selfType

prefix

private JExpression prefix

generated

private boolean generated
Indicates whether this this expression was generated by the compiler.

Constructor Detail

JThisExpression

public JThisExpression(TokenReference where)
Construct an unqualified "this" expression node in the parsing tree.

Parameters:
where - the line of this node in the source code

JThisExpression

public JThisExpression(TokenReference where,
                       CClass self)
Construct a qualified "this" expression node in the parsing tree, where the actual CClass singleton of the qualifier is known. This is an abuse for referencing inherited fields or methods without qualifiers. The compiler actually cooks "this" expressions for such references, passing (in self) the declaring class of the inherited field or method. When typechecking this "this" we need to consider this abuse. Briefly, this is abusive because within a class B that extends A the expression A.this is illegal in regular Java.

Parameters:
where - the line of this node in the source code
self - the class onto which this suffix is applied

JThisExpression

public JThisExpression(TokenReference where,
                       JExpression prefix)
Construct a qualified "this" expression node in the parsing tree, where only the qualifying expression is known, not its type. Note that to be semantically correct prefix must be a JNameExpression where the qualified name denoted by prefix is a type name [JLS2 6.5.1].

Parameters:
where - the line of this node in the source code
prefix - the left expression like T in T.this
Method Detail

prefix

public JExpression prefix()

getType

public CType getType()
Compute the type of this expression (called after parsing)

Returns:
the type of this expression

isLValue

public boolean isLValue(CExpressionContextType context)
Returns:
is this expression a lvalue ?

typecheck

public JExpression typecheck(CExpressionContextType context)
                      throws PositionedError
Typechecks the expression and mutates the context to record information gathered during typechecking.

Parameters:
context - the context in which this expression appears
Returns:
a desugared java expression (see JExpression.typecheck())
Throws:
PositionedError - if the check fails

makeThisVariableReference

private JExpression makeThisVariableReference(CContextType context)
Generates a synthetic variable reference to a local variable that will resolve to "this" at run time. This synthetic reference is used for "this" expressions that appear in methods of external gfs.

Parameters:
context - the context in which the declaration appears, used to get correct variable slot number for code generation
Returns:
a synthetic variable reference expression

equals

public boolean equals(Object o)
Overrides:
equals in class Object

hashCode

public int hashCode()
Throws a runtime exception because hashCode isn't properly implemented yet.

Overrides:
hashCode in class Object

toString

public String toString()
Overrides:
toString in class Object

accept

public void accept(MjcVisitor p)
Accepts the specified visitor

Parameters:
p - the visitor

genCode

public void genCode(CodeSequence code)
Generates a sequence of bytecodes

Parameters:
code - the code list

mjc

mjc is Copyright (C) 2000-2004 by Iowa State University and is distributed under the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. mjc is based in part on the Kopi project Copyright (C) 1990-99 DMS Decision Management Systems Ges.m.b.H.