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Expression.java
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Expression.java
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/*******************************************************************************
* Copyright (c) 2000, 2023 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
* Stephan Herrmann - Contributions for
* bug 292478 - Report potentially null across variable assignment
* bug 345305 - [compiler][null] Compiler misidentifies a case of "variable can only be null"
* bug 392862 - [1.8][compiler][null] Evaluate null annotations on array types
* bug 331649 - [compiler][null] consider null annotations for fields
* bug 383368 - [compiler][null] syntactic null analysis for field references
* bug 400761 - [compiler][null] null may be return as boolean without a diagnostic
* bug 402993 - [null] Follow up of bug 401088: Missing warning about redundant null check
* bug 403147 - [compiler][null] FUP of bug 400761: consolidate interaction between unboxing, NPE, and deferred checking
* Bug 392099 - [1.8][compiler][null] Apply null annotation on types for null analysis
* Bug 417295 - [1.8[[null] Massage type annotated null analysis to gel well with deep encoded type bindings.
* Bug 400874 - [1.8][compiler] Inference infrastructure should evolve to meet JLS8 18.x (Part G of JSR335 spec)
* Bug 426792 - [1.8][inference][impl] generify new type inference engine
* Bug 423505 - [1.8] Implement "18.5.4 More Specific Method Inference"
* Bug 427438 - [1.8][compiler] NPE at org.eclipse.jdt.internal.compiler.ast.ConditionalExpression.generateCode(ConditionalExpression.java:280)
* Bug 426996 - [1.8][inference] try to avoid method Expression.unresolve()?
* Bug 428274 - [1.8] [compiler] Cannot cast from Number to double
* Bug 428352 - [1.8][compiler] Resolution errors don't always surface
* Bug 452788 - [1.8][compiler] Type not correctly inferred in lambda expression
* Lars Vogel <Lars.Vogel@vogella.com> - Contributions for
* Bug 473178
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.codegen.BranchLabel;
import org.eclipse.jdt.internal.compiler.codegen.CodeStream;
import org.eclipse.jdt.internal.compiler.flow.FlowContext;
import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.impl.ReferenceContext;
import org.eclipse.jdt.internal.compiler.lookup.ArrayBinding;
import org.eclipse.jdt.internal.compiler.lookup.BaseTypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.Binding;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.ClassScope;
import org.eclipse.jdt.internal.compiler.lookup.FieldBinding;
import org.eclipse.jdt.internal.compiler.lookup.InferenceContext18;
import org.eclipse.jdt.internal.compiler.lookup.LocalVariableBinding;
import org.eclipse.jdt.internal.compiler.lookup.MethodBinding;
import org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding;
import org.eclipse.jdt.internal.compiler.lookup.Scope;
import org.eclipse.jdt.internal.compiler.lookup.TagBits;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeConstants;
import org.eclipse.jdt.internal.compiler.lookup.TypeIds;
import org.eclipse.jdt.internal.compiler.lookup.TypeVariableBinding;
import org.eclipse.jdt.internal.compiler.lookup.VariableBinding;
import org.eclipse.jdt.internal.compiler.lookup.WildcardBinding;
import org.eclipse.jdt.internal.compiler.problem.ShouldNotImplement;
import org.eclipse.jdt.internal.compiler.util.Messages;
public abstract class Expression extends Statement {
public Constant constant;
public int statementEnd = -1;
//Some expression may not be used - from a java semantic point
//of view only - as statements. Other may. In order to avoid the creation
//of wrappers around expression in order to tune them as expression
//Expression is a subclass of Statement. See the message isValidJavaStatement()
public int implicitConversion;
public TypeBinding resolvedType;
public static Expression [] NO_EXPRESSIONS = new Expression[0];
public static final boolean isConstantValueRepresentable(Constant constant, int constantTypeID, int targetTypeID) {
//true if there is no loss of precision while casting.
// constantTypeID == constant.typeID
if (targetTypeID == constantTypeID)
return true;
switch (targetTypeID) {
case T_char :
switch (constantTypeID) {
case T_char :
return true;
case T_double :
return constant.doubleValue() == constant.charValue();
case T_float :
return constant.floatValue() == constant.charValue();
case T_int :
return constant.intValue() == constant.charValue();
case T_short :
return constant.shortValue() == constant.charValue();
case T_byte :
return constant.byteValue() == constant.charValue();
case T_long :
return constant.longValue() == constant.charValue();
default :
return false;//boolean
}
case T_float :
switch (constantTypeID) {
case T_char :
return constant.charValue() == constant.floatValue();
case T_double :
return constant.doubleValue() == constant.floatValue();
case T_float :
return true;
case T_int :
return constant.intValue() == constant.floatValue();
case T_short :
return constant.shortValue() == constant.floatValue();
case T_byte :
return constant.byteValue() == constant.floatValue();
case T_long :
return constant.longValue() == constant.floatValue();
default :
return false;//boolean
}
case T_double :
switch (constantTypeID) {
case T_char :
return constant.charValue() == constant.doubleValue();
case T_double :
return true;
case T_float :
return constant.floatValue() == constant.doubleValue();
case T_int :
return constant.intValue() == constant.doubleValue();
case T_short :
return constant.shortValue() == constant.doubleValue();
case T_byte :
return constant.byteValue() == constant.doubleValue();
case T_long :
return constant.longValue() == constant.doubleValue();
default :
return false; //boolean
}
case T_byte :
switch (constantTypeID) {
case T_char :
return constant.charValue() == constant.byteValue();
case T_double :
return constant.doubleValue() == constant.byteValue();
case T_float :
return constant.floatValue() == constant.byteValue();
case T_int :
return constant.intValue() == constant.byteValue();
case T_short :
return constant.shortValue() == constant.byteValue();
case T_byte :
return true;
case T_long :
return constant.longValue() == constant.byteValue();
default :
return false; //boolean
}
case T_short :
switch (constantTypeID) {
case T_char :
return constant.charValue() == constant.shortValue();
case T_double :
return constant.doubleValue() == constant.shortValue();
case T_float :
return constant.floatValue() == constant.shortValue();
case T_int :
return constant.intValue() == constant.shortValue();
case T_short :
return true;
case T_byte :
return constant.byteValue() == constant.shortValue();
case T_long :
return constant.longValue() == constant.shortValue();
default :
return false; //boolean
}
case T_int :
switch (constantTypeID) {
case T_char :
return constant.charValue() == constant.intValue();
case T_double :
return constant.doubleValue() == constant.intValue();
case T_float :
return constant.floatValue() == constant.intValue();
case T_int :
return true;
case T_short :
return constant.shortValue() == constant.intValue();
case T_byte :
return constant.byteValue() == constant.intValue();
case T_long :
return constant.longValue() == constant.intValue();
default :
return false; //boolean
}
case T_long :
switch (constantTypeID) {
case T_char :
return constant.charValue() == constant.longValue();
case T_double :
return constant.doubleValue() == constant.longValue();
case T_float :
return constant.floatValue() == constant.longValue();
case T_int :
return constant.intValue() == constant.longValue();
case T_short :
return constant.shortValue() == constant.longValue();
case T_byte :
return constant.byteValue() == constant.longValue();
case T_long :
return true;
default :
return false; //boolean
}
default :
return false; //boolean
}
}
public Expression() {
super();
}
@Override
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
return flowInfo;
}
/**
* More sophisticated for of the flow analysis used for analyzing expressions, and be able to optimize out
* portions of expressions where no actual value is required.
*
* @return The state of initialization after the analysis of the current expression
*/
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo, boolean valueRequired) {
return analyseCode(currentScope, flowContext, flowInfo);
}
/**
* Back-propagation of flow info: before analysing a branch where a given condition is known to hold true/false respectively,
* ask the condition to contribute its information to the given flowInfo.
* @param flowInfo the info to be used for analysing the branch
* @param result condition result that would cause entering the branch
*/
protected void updateFlowOnBooleanResult(FlowInfo flowInfo, boolean result) {
// nop
}
/**
* Returns false if cast is not legal.
*/
public final boolean checkCastTypesCompatibility(Scope scope, TypeBinding castType, TypeBinding expressionType, Expression expression, boolean useAutoBoxing) {
// see specifications 5.5
// handle errors and process constant when needed
// if either one of the type is null ==>
// some error has been already reported some where ==>
// we then do not report an obvious-cascade-error.
if (castType == null || expressionType == null) return true;
// identity conversion cannot be performed upfront, due to side-effects
// like constant propagation
boolean use15specifics = scope.compilerOptions().sourceLevel >= ClassFileConstants.JDK1_5;
boolean use17specifics = scope.compilerOptions().sourceLevel >= ClassFileConstants.JDK1_7;
useAutoBoxing &= use15specifics;
if (castType.isBaseType()) {
if (expressionType.isBaseType()) {
if (TypeBinding.equalsEquals(expressionType, castType)) {
if (expression != null) {
this.constant = expression.constant; //use the same constant
}
tagAsUnnecessaryCast(scope, castType);
return true;
}
boolean necessary = false;
if (expressionType.isCompatibleWith(castType)
|| (necessary = BaseTypeBinding.isNarrowing(castType.id, expressionType.id))) {
if (expression != null) {
expression.implicitConversion = (castType.id << 4) + expressionType.id;
if (expression.constant != Constant.NotAConstant) {
this.constant = expression.constant.castTo(expression.implicitConversion);
}
}
if (!necessary) tagAsUnnecessaryCast(scope, castType);
return true;
}
} else if (useAutoBoxing && use17specifics && castType.isPrimitiveType() && expressionType instanceof ReferenceBinding &&
!expressionType.isBoxedPrimitiveType() && checkCastTypesCompatibility(scope, scope.boxing(castType), expressionType, expression, useAutoBoxing)) {
// cast from any reference type (other than boxing types) to base type allowed from 1.7, see JLS $5.5
// by our own interpretation (in accordance with javac) we reject arays, though.
return true;
} else if (useAutoBoxing
&& scope.environment().computeBoxingType(expressionType).isCompatibleWith(castType)) { // unboxing - only widening match is allowed
tagAsUnnecessaryCast(scope, castType);
return true;
}
return false;
} else if (useAutoBoxing
&& expressionType.isBaseType()
&& scope.environment().computeBoxingType(expressionType).isCompatibleWith(castType)) { // boxing - only widening match is allowed
tagAsUnnecessaryCast(scope, castType);
return true;
}
if (castType.isIntersectionType18()) {
ReferenceBinding [] intersectingTypes = castType.getIntersectingTypes();
for (ReferenceBinding intersectingType : intersectingTypes) {
if (!checkCastTypesCompatibility(scope, intersectingType, expressionType, expression, useAutoBoxing))
return false;
}
return true;
}
switch(expressionType.kind()) {
case Binding.BASE_TYPE :
//-----------cast to something which is NOT a base type--------------------------
if (expressionType == TypeBinding.NULL) {
tagAsUnnecessaryCast(scope, castType);
return true; //null is compatible with every thing
}
return false;
case Binding.ARRAY_TYPE :
if (TypeBinding.equalsEquals(castType, expressionType)) {
tagAsUnnecessaryCast(scope, castType);
return true; // identity conversion
}
switch (castType.kind()) {
case Binding.ARRAY_TYPE :
// ( ARRAY ) ARRAY
TypeBinding castElementType = ((ArrayBinding) castType).elementsType();
TypeBinding exprElementType = ((ArrayBinding) expressionType).elementsType();
if (exprElementType.isBaseType() || castElementType.isBaseType()) {
if (TypeBinding.equalsEquals(castElementType, exprElementType)) {
tagAsNeedCheckCast();
return true;
}
return false;
}
// recurse on array type elements
return checkCastTypesCompatibility(scope, castElementType, exprElementType, expression, useAutoBoxing);
case Binding.TYPE_PARAMETER :
// ( TYPE_PARAMETER ) ARRAY
TypeBinding match = expressionType.findSuperTypeOriginatingFrom(castType);
if (match == null) {
checkUnsafeCast(scope, castType, expressionType, null /*no match*/, true);
}
for (TypeBinding bound : ((TypeVariableBinding) castType).allUpperBounds()) {
if (!checkCastTypesCompatibility(scope, bound, expressionType, expression, useAutoBoxing))
return false;
}
return true;
default:
// ( CLASS/INTERFACE ) ARRAY
switch (castType.id) {
case T_JavaLangCloneable :
case T_JavaIoSerializable :
tagAsNeedCheckCast();
return true;
case T_JavaLangObject :
tagAsUnnecessaryCast(scope, castType);
return true;
default :
return false;
}
}
case Binding.TYPE_PARAMETER :
TypeBinding match = expressionType.findSuperTypeOriginatingFrom(castType);
if (match == null) {
// recursively on the type variable upper bounds
if (castType instanceof TypeVariableBinding) {
// prefer iterating over required types, not provides
for (TypeBinding bound : ((TypeVariableBinding)castType).allUpperBounds()) {
if (!checkCastTypesCompatibility(scope, bound, expressionType, expression, useAutoBoxing))
return false;
}
} else {
for (TypeBinding bound : ((TypeVariableBinding)expressionType).allUpperBounds()) {
if (!checkCastTypesCompatibility(scope, castType, bound, expression, useAutoBoxing))
return false;
}
}
}
// if no incompatibility found:
return checkUnsafeCast(scope, castType, expressionType, match, match == null);
case Binding.WILDCARD_TYPE :
case Binding.INTERSECTION_TYPE :
match = expressionType.findSuperTypeOriginatingFrom(castType);
if (match != null) {
return checkUnsafeCast(scope, castType, expressionType, match, false);
}
TypeBinding bound = ((WildcardBinding)expressionType).bound;
if (bound == null) bound = scope.getJavaLangObject();
// recursively on the type variable upper bound
return checkCastTypesCompatibility(scope, castType, bound, expression, useAutoBoxing);
case Binding.INTERSECTION_TYPE18:
ReferenceBinding [] intersectingTypes = expressionType.getIntersectingTypes();
for (ReferenceBinding intersectingType : intersectingTypes) {
if (checkCastTypesCompatibility(scope, castType, intersectingType, expression, useAutoBoxing))
return true;
}
return false;
default:
if (expressionType.isInterface()) {
switch (castType.kind()) {
case Binding.ARRAY_TYPE :
// ( ARRAY ) INTERFACE
switch (expressionType.id) {
case T_JavaLangCloneable :
case T_JavaIoSerializable :
tagAsNeedCheckCast();
return true;
default :
return false;
}
case Binding.TYPE_PARAMETER :
// ( INTERFACE ) TYPE_PARAMETER
match = expressionType.findSuperTypeOriginatingFrom(castType);
if (match == null) {
checkUnsafeCast(scope, castType, expressionType, null /*no match*/, true);
}
// recursively on the type variable upper bounds
for (TypeBinding upperBound : ((TypeVariableBinding)castType).allUpperBounds()) {
if (!checkCastTypesCompatibility(scope, upperBound, expressionType, expression, useAutoBoxing))
return false;
}
return true;
default :
if (castType.isInterface()) {
// ( INTERFACE ) INTERFACE
ReferenceBinding interfaceType = (ReferenceBinding) expressionType;
match = interfaceType.findSuperTypeOriginatingFrom(castType);
if (match != null) {
return checkUnsafeCast(scope, castType, interfaceType, match, false);
}
tagAsNeedCheckCast();
match = castType.findSuperTypeOriginatingFrom(interfaceType);
if (match != null) {
return checkUnsafeCast(scope, castType, interfaceType, match, true);
}
if (use15specifics) {
checkUnsafeCast(scope, castType, expressionType, null /*no match*/, true);
// ensure there is no collision between both interfaces: i.e. I1 extends List<String>, I2 extends List<Object>
if (scope.compilerOptions().complianceLevel < ClassFileConstants.JDK1_7) {
if (interfaceType.hasIncompatibleSuperType((ReferenceBinding) castType)) {
return false;
}
} else if (!castType.isRawType() && interfaceType.hasIncompatibleSuperType((ReferenceBinding) castType)) {
return false;
}
} else {
// pre1.5 semantics - no covariance allowed (even if 1.5 compliant, but 1.4 source)
// look at original methods rather than the parameterized variants at 1.4 to detect
// covariance. Otherwise when confronted with one raw type and one parameterized type,
// we could mistakenly detect covariance and scream foul. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=332744
MethodBinding[] castTypeMethods = getAllOriginalInheritedMethods((ReferenceBinding) castType);
MethodBinding[] expressionTypeMethods = getAllOriginalInheritedMethods((ReferenceBinding) expressionType);
int exprMethodsLength = expressionTypeMethods.length;
for (MethodBinding castTypeMethod : castTypeMethods) {
for (int j = 0; j < exprMethodsLength; j++) {
if ((TypeBinding.notEquals(castTypeMethod.returnType, expressionTypeMethods[j].returnType))
&& (CharOperation.equals(castTypeMethod.selector, expressionTypeMethods[j].selector))
&& castTypeMethod.areParametersEqual(expressionTypeMethods[j])) {
return false;
}
}
}
}
return true;
} else {
// ( CLASS ) INTERFACE
if (castType.id == TypeIds.T_JavaLangObject) { // no runtime error
tagAsUnnecessaryCast(scope, castType);
return true;
}
// can only be a downcast
tagAsNeedCheckCast();
match = castType.findSuperTypeOriginatingFrom(expressionType);
if (match != null) {
return checkUnsafeCast(scope, castType, expressionType, match, true);
}
if (((ReferenceBinding) castType).isFinal()) {
// no subclass for castType, thus compile-time check is invalid
return false;
}
if (use15specifics) {
checkUnsafeCast(scope, castType, expressionType, null /*no match*/, true);
// ensure there is no collision between both interfaces: i.e. I1 extends List<String>, I2 extends List<Object>
if (scope.compilerOptions().complianceLevel < ClassFileConstants.JDK1_7) {
if (((ReferenceBinding)castType).hasIncompatibleSuperType((ReferenceBinding) expressionType)) {
return false;
}
} else if (!castType.isRawType() && ((ReferenceBinding)castType).hasIncompatibleSuperType((ReferenceBinding) expressionType)) {
return false;
}
}
return true;
}
}
} else {
switch (castType.kind()) {
case Binding.ARRAY_TYPE :
// ( ARRAY ) CLASS
if (expressionType.id == TypeIds.T_JavaLangObject) { // potential runtime error
if (use15specifics) checkUnsafeCast(scope, castType, expressionType, expressionType, true);
tagAsNeedCheckCast();
return true;
}
return false;
case Binding.TYPE_PARAMETER :
// ( TYPE_PARAMETER ) CLASS
match = expressionType.findSuperTypeOriginatingFrom(castType);
if (match == null) {
checkUnsafeCast(scope, castType, expressionType, null, true);
}
// recursively on the type variable upper bounds
for (TypeBinding upperBound : ((TypeVariableBinding)castType).allUpperBounds()) {
if (!checkCastTypesCompatibility(scope, upperBound, expressionType, expression, useAutoBoxing))
return false;
}
return true;
default :
if (castType.isInterface()) {
// ( INTERFACE ) CLASS
ReferenceBinding refExprType = (ReferenceBinding) expressionType;
match = refExprType.findSuperTypeOriginatingFrom(castType);
if (match != null) {
return checkUnsafeCast(scope, castType, expressionType, match, false);
}
// unless final a subclass may implement the interface ==> no check at compile time
if (refExprType.isFinal()) {
return false;
}
tagAsNeedCheckCast();
match = castType.findSuperTypeOriginatingFrom(expressionType);
if (match != null) {
return checkUnsafeCast(scope, castType, expressionType, match, true);
}
if (use15specifics) {
checkUnsafeCast(scope, castType, expressionType, null /*no match*/, true);
// ensure there is no collision between both interfaces: i.e. I1 extends List<String>, I2 extends List<Object>
if (scope.compilerOptions().complianceLevel < ClassFileConstants.JDK1_7) {
if (refExprType.hasIncompatibleSuperType((ReferenceBinding) castType)) {
return false;
}
} else if (!castType.isRawType() && refExprType.hasIncompatibleSuperType((ReferenceBinding) castType)) {
return false;
}
}
return true;
} else {
// ( CLASS ) CLASS
match = expressionType.findSuperTypeOriginatingFrom(castType);
if (match != null) {
if (expression != null && castType.id == TypeIds.T_JavaLangString) this.constant = expression.constant; // (String) cst is still a constant
return checkUnsafeCast(scope, castType, expressionType, match, false);
}
match = castType.findSuperTypeOriginatingFrom(expressionType);
if (match != null) {
tagAsNeedCheckCast();
return checkUnsafeCast(scope, castType, expressionType, match, true);
}
return false;
}
}
}
}
}
/**
* Check this expression against potential NPEs, which may occur:
* <ul>
* <li>if the expression is the receiver in a field access, qualified allocation, array reference or message send
* incl. implicit message sends like it happens for the collection in a foreach statement.</li>
* <li>if the expression is subject to unboxing</li>
* <li>if the expression is the exception in a throw statement</li>
* </ul>
* If a risk of NPE is detected report it to the context.
* If the expression denotes a local variable, mark it as checked, which affects the flow info.
* @param scope the scope of the analysis
* @param flowContext the current flow context
* @param flowInfo the upstream flow info; caveat: may get modified
* @param ttlForFieldCheck if this is a reference to a field we will mark that field as nonnull for the specified timeToLive
* @return could this expression be checked by the current implementation?
*/
public boolean checkNPE(BlockScope scope, FlowContext flowContext, FlowInfo flowInfo, int ttlForFieldCheck) {
boolean isNullable = false;
if (this.resolvedType != null) {
// 1. priority: @NonNull
if ((this.resolvedType.tagBits & TagBits.AnnotationNonNull) != 0) {
return true; // no danger
} else if ((this.resolvedType.tagBits & TagBits.AnnotationNullable) != 0) {
isNullable = true;
}
}
LocalVariableBinding local = localVariableBinding();
if (local != null &&
(local.type.tagBits & TagBits.IsBaseType) == 0) {
// 2. priority: local with flow analysis (via the FlowContext)
if ((this.bits & ASTNode.IsNonNull) == 0) {
flowContext.recordUsingNullReference(scope, local, this,
FlowContext.MAY_NULL, flowInfo);
// account for possible NPE:
if (!flowInfo.isDefinitelyNonNull(local)) {
flowContext.recordAbruptExit();
}
}
flowInfo.markAsComparedEqualToNonNull(local);
// from thereon it is set
flowContext.markFinallyNullStatus(local, FlowInfo.NON_NULL);
return true;
} else if (isNullable) {
// 3. priority: @Nullable without a local
scope.problemReporter().dereferencingNullableExpression(this);
return true;
}
return false; // not checked
}
public boolean checkNPE(BlockScope scope, FlowContext flowContext, FlowInfo flowInfo) {
return checkNPE(scope, flowContext, flowInfo, 0); // default: don't mark field references as checked for null
}
/** If this expression requires unboxing check if that operation can throw NPE. */
protected void checkNPEbyUnboxing(BlockScope scope, FlowContext flowContext, FlowInfo flowInfo) {
int status;
if ((this.implicitConversion & UNBOXING) != 0
&& (this.bits & ASTNode.IsNonNull) == 0
&& (status = nullStatus(flowInfo, flowContext)) != FlowInfo.NON_NULL)
{
flowContext.recordUnboxing(scope, this, status, flowInfo);
}
}
public boolean checkUnsafeCast(Scope scope, TypeBinding castType, TypeBinding expressionType, TypeBinding match, boolean isNarrowing) {
if (TypeBinding.equalsEquals(match, castType)) {
if (!isNarrowing) tagAsUnnecessaryCast(scope, castType);
return true;
}
if (match != null && (!castType.isReifiable() || !expressionType.isReifiable())) {
if(isNarrowing
? match.isProvablyDistinct(expressionType)
: castType.isProvablyDistinct(match)) {
return false;
}
}
if (!isNarrowing) tagAsUnnecessaryCast(scope, castType);
return true;
}
/**
* Base types need that the widening is explicitly done by the compiler using some bytecode like i2f.
* Also check unsafe type operations.
*/
public void computeConversion(Scope scope, TypeBinding runtimeType, TypeBinding compileTimeType) {
if (runtimeType == null || compileTimeType == null)
return;
if (this.implicitConversion != 0) return; // already set independently
// it is possible for a Byte to be unboxed to a byte & then converted to an int
// but it is not possible for a byte to become Byte & then assigned to an Integer,
// or to become an int before boxed into an Integer
if (runtimeType != TypeBinding.NULL && runtimeType.isBaseType()) {
if (!compileTimeType.isBaseType()) {
TypeBinding unboxedType = scope.environment().computeBoxingType(compileTimeType);
this.implicitConversion = TypeIds.UNBOXING;
scope.problemReporter().autoboxing(this, compileTimeType, runtimeType);
compileTimeType = unboxedType;
}
} else if (compileTimeType != TypeBinding.NULL && compileTimeType.isBaseType()) {
TypeBinding boxedType = scope.environment().computeBoxingType(runtimeType);
if (TypeBinding.equalsEquals(boxedType, runtimeType)) // Object o = 12;
boxedType = compileTimeType;
if (boxedType.id > TypeIds.T_JavaLangBoolean) { // (Comparable & Serializable) 0
boxedType = compileTimeType;
}
this.implicitConversion = TypeIds.BOXING | (boxedType.id << 4) + compileTimeType.id;
scope.problemReporter().autoboxing(this, compileTimeType, scope.environment().computeBoxingType(boxedType));
return;
} else if (this.constant != Constant.NotAConstant && this.constant.typeID() != TypeIds.T_JavaLangString) {
this.implicitConversion = TypeIds.BOXING;
return;
}
int compileTimeTypeID, runtimeTypeID;
if ((compileTimeTypeID = compileTimeType.id) >= TypeIds.T_LastWellKnownTypeId) { // e.g. ? extends String ==> String (103227); >= TypeIds.T_LastWellKnownTypeId implies TypeIds.NoId
compileTimeTypeID = compileTimeType.erasure().id == TypeIds.T_JavaLangString ? TypeIds.T_JavaLangString : TypeIds.T_JavaLangObject;
} else if (runtimeType.isPrimitiveType() && compileTimeType instanceof ReferenceBinding && !compileTimeType.isBoxedPrimitiveType()) {
compileTimeTypeID = TypeIds.T_JavaLangObject; // treatment is the same as for jlO.
}
switch (runtimeTypeID = runtimeType.id) {
case T_byte :
case T_short :
case T_char :
if (compileTimeTypeID == TypeIds.T_JavaLangObject) {
this.implicitConversion |= (runtimeTypeID << 4) + compileTimeTypeID;
} else {
this.implicitConversion |= (TypeIds.T_int << 4) + compileTimeTypeID;
}
break;
case T_JavaLangString :
case T_float :
case T_boolean :
case T_double :
case T_int : //implicitConversion may result in i2i which will result in NO code gen
case T_long :
this.implicitConversion |= (runtimeTypeID << 4) + compileTimeTypeID;
break;
default : // regular object ref
// if (compileTimeType.isRawType() && runtimeTimeType.isBoundParameterizedType()) {
// scope.problemReporter().unsafeRawExpression(this, compileTimeType, runtimeTimeType);
// }
}
}
public static int computeNullStatus(int status, int combinedStatus) {
if ((combinedStatus & (FlowInfo.NULL|FlowInfo.POTENTIALLY_NULL)) != 0)
status |= FlowInfo.POTENTIALLY_NULL;
if ((combinedStatus & (FlowInfo.NON_NULL|FlowInfo.POTENTIALLY_NON_NULL)) != 0)
status |= FlowInfo.POTENTIALLY_NON_NULL;
if ((combinedStatus & (FlowInfo.UNKNOWN|FlowInfo.POTENTIALLY_UNKNOWN)) != 0)
status |= FlowInfo.POTENTIALLY_UNKNOWN;
return status;
}
/**
* Expression statements are plain expressions, however they generate like
* normal expressions with no value required.
*
* @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
* @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
*/
@Override
public void generateCode(BlockScope currentScope, CodeStream codeStream) {
if ((this.bits & ASTNode.IsReachable) == 0) {
return;
}
generateCode(currentScope, codeStream, false);
}
/**
* Every expression is responsible for generating its implicit conversion when necessary.
*
* @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
* @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
* @param valueRequired boolean
*/
public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
if (this.constant != Constant.NotAConstant) {
// generate a constant expression
int pc = codeStream.position;
codeStream.generateConstant(this.constant, this.implicitConversion);
codeStream.recordPositionsFrom(pc, this.sourceStart);
} else {
// actual non-constant code generation
throw new ShouldNotImplement(Messages.ast_missingCode);
}
}
/**
* Default generation of a boolean value
*/
public void generateOptimizedBoolean(BlockScope currentScope, CodeStream codeStream, BranchLabel trueLabel, BranchLabel falseLabel, boolean valueRequired) {
// a label valued to nil means: by default we fall through the case...
// both nil means we leave the value on the stack
Constant cst = optimizedBooleanConstant();
generateCode(currentScope, codeStream, valueRequired && cst == Constant.NotAConstant);
if ((cst != Constant.NotAConstant) && (cst.typeID() == TypeIds.T_boolean)) {
int pc = codeStream.position;
if (cst.booleanValue() == true) {
// constant == true
if (valueRequired) {
if (falseLabel == null) {
// implicit falling through the FALSE case
if (trueLabel != null) {
codeStream.goto_(trueLabel);
}
}
}
} else {
if (valueRequired) {
if (falseLabel != null) {
// implicit falling through the TRUE case
if (trueLabel == null) {
codeStream.goto_(falseLabel);
}
}
}
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
return;
}
// branching
int position = codeStream.position;
if (valueRequired) {
if (falseLabel == null) {
if (trueLabel != null) {
// Implicit falling through the FALSE case
codeStream.ifne(trueLabel);
}
} else {
if (trueLabel == null) {
// Implicit falling through the TRUE case
codeStream.ifeq(falseLabel);
} else {
// No implicit fall through TRUE/FALSE --> should never occur
}
}
}
codeStream.recordPositionsFrom(position, this.sourceEnd);
}
/* Optimized (java) code generation for string concatenations that involve StringBuffer
* creation: going through this path means that there is no need for a new StringBuffer
* creation, further operands should rather be only appended to the current one.
* By default: no optimization.
*/
public void generateOptimizedStringConcatenation(BlockScope blockScope, CodeStream codeStream, int typeID) {
if (typeID == TypeIds.T_JavaLangString && this.constant != Constant.NotAConstant && this.constant.stringValue().length() == 0) {
return; // optimize str + ""
}
generateCode(blockScope, codeStream, true);
codeStream.invokeStringConcatenationAppendForType(typeID);
}
/* Optimized (java) code generation for string concatenations that involve StringBuffer
* creation: going through this path means that there is no need for a new StringBuffer
* creation, further operands should rather be only appended to the current one.
*/
public void generateOptimizedStringConcatenationCreation(BlockScope blockScope, CodeStream codeStream, int typeID) {
codeStream.newStringContatenation();
codeStream.dup();
switch (typeID) {
case T_JavaLangObject :
case T_undefined :
// in the case the runtime value of valueOf(Object) returns null, we have to use append(Object) instead of directly valueOf(Object)
// append(Object) returns append(valueOf(Object)), which means that the null case is handled by the next case.
codeStream.invokeStringConcatenationDefaultConstructor();
generateCode(blockScope, codeStream, true);
codeStream.invokeStringConcatenationAppendForType(TypeIds.T_JavaLangObject);
return;
case T_JavaLangString :
case T_null :
if (this.constant != Constant.NotAConstant) {
String stringValue = this.constant.stringValue();
if (stringValue.length() == 0) { // optimize ""+<str>
codeStream.invokeStringConcatenationDefaultConstructor();
return;
}
codeStream.ldc(stringValue);
} else {
// null case is not a constant
generateCode(blockScope, codeStream, true);
codeStream.invokeStringValueOf(TypeIds.T_JavaLangObject);
}
break;
default :
generateCode(blockScope, codeStream, true);
codeStream.invokeStringValueOf(typeID);
}
codeStream.invokeStringConcatenationStringConstructor();
}
private void addArgumentToRecipe(BlockScope blockScope, CodeStream codeStream, StringBuilder recipe, TypeBinding argType, List<TypeBinding> args) {
recipe.append(STRING_CONCAT_MARKER_1);
args.add(argType);
if (args.size() > 190) {
// StringConcatFactory#makeConcatWithConstants() can take only 200 arguments
// Commit whatever we have accumulated so far
// Get the result pushed to the stack and to be used as an operand
// for the subsequent concat operation
codeStream.invokeDynamicForStringConcat(recipe, args);
// Clear the arguments for the next batch
args.clear();
recipe.delete(0, recipe.length());
recipe.append(TypeConstants.STRING_CONCAT_MARKER_1);
args.add(blockScope.getJavaLangString());
// We popped 190 and adding 1 for the invokeDynamic
codeStream.stackDepth -= 189;
}
}
public void buildStringForConcatation(BlockScope blockScope, CodeStream codeStream, int typeID, StringBuilder recipe, List<TypeBinding> argTypes) {
if (this.constant == Constant.NotAConstant) {
switch (typeID) {
case T_JavaLangString :
case TypeIds.T_int :
case TypeIds.T_byte :
case TypeIds.T_short :
case TypeIds.T_long :
case TypeIds.T_float :
case TypeIds.T_double :
case TypeIds.T_char :
case TypeIds.T_boolean :
generateCode(blockScope, codeStream, true);
addArgumentToRecipe(blockScope, codeStream, recipe, this.resolvedType, argTypes);
break;
default :
if (this.resolvedType.id == TypeIds.T_null) {
codeStream.aconst_null();
} else {
generateCode(blockScope, codeStream, true);
codeStream.invokeStringValueOf(typeID);
}
addArgumentToRecipe(blockScope, codeStream, recipe, blockScope.getJavaLangString(), argTypes);
break;
}
} else {
// StringLiteral and CharLiteral may contain special characters
if (this.constant.stringValue().indexOf('\u0001') != -1 || this.constant.stringValue().indexOf('\u0002') != -1) {
codeStream.ldc(this.constant.stringValue());
addArgumentToRecipe(blockScope, codeStream, recipe, blockScope.getJavaLangString(), argTypes);
} else {
recipe.append(this.constant.stringValue());
}
}
}
private MethodBinding[] getAllOriginalInheritedMethods(ReferenceBinding binding) {
ArrayList<MethodBinding> collector = new ArrayList<>();
getAllInheritedMethods0(binding, collector);
for (int i = 0, len = collector.size(); i < len; i++) {
collector.set(i, collector.get(i).original());
}
return collector.toArray(new MethodBinding[collector.size()]);
}
private void getAllInheritedMethods0(ReferenceBinding binding, ArrayList<MethodBinding> collector) {
if (!binding.isInterface()) return;
MethodBinding[] methodBindings = binding.methods();
for (MethodBinding methodBinding : methodBindings) {
collector.add(methodBinding);
}
ReferenceBinding[] superInterfaces = binding.superInterfaces();
for (ReferenceBinding superInterface : superInterfaces) {
getAllInheritedMethods0(superInterface, collector);
}
}
public static Binding getDirectBinding(Expression someExpression) {
if ((someExpression.bits & ASTNode.IgnoreNoEffectAssignCheck) != 0) {
return null;
}
if (someExpression instanceof SingleNameReference) {
return ((SingleNameReference)someExpression).binding;
} else if (someExpression instanceof FieldReference) {
FieldReference fieldRef = (FieldReference)someExpression;
if (fieldRef.receiver.isThis() && !(fieldRef.receiver instanceof QualifiedThisReference)) {
return fieldRef.binding;
}
} else if (someExpression instanceof Assignment) {
Expression lhs = ((Assignment)someExpression).lhs;
if ((lhs.bits & ASTNode.IsStrictlyAssigned) != 0) {
// i = i = ...; // eq to int i = ...;
return getDirectBinding (((Assignment)someExpression).lhs);
} else if (someExpression instanceof PrefixExpression) {
// i = i++; // eq to ++i;
return getDirectBinding (((Assignment)someExpression).lhs);
}
} else if (someExpression instanceof QualifiedNameReference) {
QualifiedNameReference qualifiedNameReference = (QualifiedNameReference) someExpression;
if (qualifiedNameReference.indexOfFirstFieldBinding != 1
&& qualifiedNameReference.otherBindings == null) {
// case where a static field is retrieved using ClassName.fieldname
return qualifiedNameReference.binding;
}
} else if (someExpression.isThis()) { // https://bugs.eclipse.org/bugs/show_bug.cgi?id=276741
return someExpression.resolvedType;
}
// } else if (someExpression instanceof PostfixExpression) { // recurse for postfix: i++ --> i
// // note: "b = b++" is equivalent to doing nothing, not to "b++"
// return getDirectBinding(((PostfixExpression) someExpression).lhs);
return null;
}
public boolean isCompactableOperation() {