X-Git-Url: http://git.phpeclipse.com

diff --git a/net.sourceforge.phpeclipse/src/net/sourceforge/phpeclipse/internal/compiler/ast/Expression.java b/net.sourceforge.phpeclipse/src/net/sourceforge/phpeclipse/internal/compiler/ast/Expression.java
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+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials 
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package net.sourceforge.phpeclipse.internal.compiler.ast;
+
+import net.sourceforge.phpdt.internal.compiler.codegen.Label;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
+import net.sourceforge.phpdt.internal.compiler.impl.Constant;
+import net.sourceforge.phpdt.internal.compiler.lookup.BaseTypeBinding;
+import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
+import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
+import net.sourceforge.phpdt.internal.compiler.problem.ShouldNotImplement;
+import net.sourceforge.phpdt.internal.compiler.util.Util;
+
+public abstract class Expression extends Statement {
+	
+	//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 Constant constant;
+
+	public Expression() {
+		super();
+	}
+
+	public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
+
+		return flowInfo;
+	}
+
+	public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo, boolean valueRequired) {
+
+		return analyseCode(currentScope, flowContext, flowInfo);
+	}
+
+	/**
+	 * Constant usable for bytecode pattern optimizations, but cannot be inlined
+	 * since it is not strictly equivalent to the definition of constant expressions.
+	 * In particular, some side-effects may be required to occur (only the end value
+	 * is known).
+	 * Constant is known to be of boolean type
+	 */ 
+	public Constant optimizedBooleanConstant() {
+
+		return this.constant;
+	}
+
+	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
+		} 
+	}
+
+	/**
+	 * 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 
+	 */
+//	public void generateCode(BlockScope currentScope, CodeStream codeStream) {
+//
+//		if ((bits & IsReachableMASK) == 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 (constant != NotAConstant) {
+//			// generate a constant expression
+//			int pc = codeStream.position;
+//			codeStream.generateConstant(constant, implicitConversion);
+//			codeStream.recordPositionsFrom(pc, this.sourceStart);
+//		} else {
+//			// actual non-constant code generation
+//			throw new ShouldNotImplement(Util.bind("ast.missingCode")); //$NON-NLS-1$
+//		}
+//	}
+
+	/**
+	 * Default generation of a boolean value
+	 */
+//	public void generateOptimizedBoolean(
+//		BlockScope currentScope,
+//		CodeStream codeStream,
+//		Label trueLabel,
+//		Label 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
+//
+//		if ((constant != Constant.NotAConstant) && (constant.typeID() == T_boolean)) {
+//			int pc = codeStream.position;
+//			if (constant.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;
+//		}
+//		generateCode(currentScope, codeStream, valueRequired);
+//		// 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
+//				}
+//			}
+//		}
+//		// reposition the endPC
+//		codeStream.updateLastRecordedEndPC(position);
+//	}
+//
+//	/* 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 generateOptimizedStringBuffer(
+//		BlockScope blockScope,
+//		org.eclipse.jdt.internal.compiler.codegen.CodeStream codeStream,
+//		int typeID) {
+//
+//		generateCode(blockScope, codeStream, true);
+//		codeStream.invokeStringBufferAppendForType(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 generateOptimizedStringBufferCreation(
+//		BlockScope blockScope,
+//		CodeStream codeStream,
+//		int typeID) {
+//
+//		// Optimization only for integers and strings
+//		if (typeID == T_Object) {
+//			// 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 append(String).
+//			codeStream.newStringBuffer();
+//			codeStream.dup();
+//			codeStream.invokeStringBufferDefaultConstructor();
+//			generateCode(blockScope, codeStream, true);
+//			codeStream.invokeStringBufferAppendForType(T_Object);
+//			return;
+//		}
+//		codeStream.newStringBuffer();
+//		codeStream.dup();
+//		if (typeID == T_String || typeID == T_null) {
+//			if (constant != NotAConstant) {
+//				codeStream.ldc(constant.stringValue());
+//			} else {
+//				generateCode(blockScope, codeStream, true);
+//				codeStream.invokeStringValueOf(T_Object);
+//			}
+//		} else {
+//			generateCode(blockScope, codeStream, true);
+//			codeStream.invokeStringValueOf(typeID);
+//		}
+//		codeStream.invokeStringBufferStringConstructor();
+//	}
+
+	// Base types need that the widening is explicitly done by the compiler using some bytecode like i2f
+	public void implicitWidening(
+		TypeBinding runtimeTimeType,
+		TypeBinding compileTimeType) {
+
+		if (runtimeTimeType == null || compileTimeType == null)
+			return;
+
+//		if (compileTimeType.id == T_null) {
+//			// this case is possible only for constant null
+//			// The type of runtime is a reference type
+//			// The code gen use the constant id thus any value
+//			// for the runtime id (akak the <<4) could be used.
+//			// T_Object is used as some general T_reference
+//			implicitConversion = (T_Object << 4) + T_null;
+//			return;
+//		}
+
+		switch (runtimeTimeType.id) {
+			case T_byte :
+			case T_short :
+			case T_char :
+				implicitConversion = (T_int << 4) + compileTimeType.id;
+				break;
+			case T_String :
+			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 :
+				implicitConversion = (runtimeTimeType.id << 4) + compileTimeType.id;
+				break;
+			default : //nothing on regular object ref
+		}
+	}
+
+	public boolean isCompactableOperation() {
+
+		return false;
+	}
+
+	//Return true if the conversion is done AUTOMATICALLY by the vm
+	//while the javaVM is an int based-machine, thus for example pushing
+	//a byte onto the stack , will automatically creates a int on the stack
+	//(this request some work d be done by the VM on signed numbers)
+	public boolean isConstantValueOfTypeAssignableToType(
+		TypeBinding constantType,
+		TypeBinding targetType) {
+
+		if (constant == Constant.NotAConstant)
+			return false;
+		if (constantType == targetType)
+			return true;
+		if (constantType.isBaseType() && targetType.isBaseType()) {
+			//No free assignment conversion from anything but to integral ones.
+			if ((constantType == IntBinding
+				|| BaseTypeBinding.isWidening(T_int, constantType.id))
+				&& (BaseTypeBinding.isNarrowing(targetType.id, T_int))) {
+				//use current explicit conversion in order to get some new value to compare with current one
+				return isConstantValueRepresentable(constant, constantType.id, targetType.id);
+			}
+		}
+		return false;
+	}
+
+	public boolean isTypeReference() {
+		return false;
+	}
+
+	public void resolve(BlockScope scope) {
+		// drops the returning expression's type whatever the type is.
+
+		this.resolveType(scope);
+		return;
+	}
+
+	public TypeBinding resolveType(BlockScope scope) {
+		// by default... subclasses should implement a better TC if required.
+
+		return null;
+	}
+
+	public TypeBinding resolveTypeExpecting(
+		BlockScope scope,
+		TypeBinding expectedType) {
+
+		TypeBinding expressionType = this.resolveType(scope);
+		if (expressionType == null) return null;
+		if (expressionType == expectedType) return expressionType;
+		
+		if (!expressionType.isCompatibleWith(expectedType)) {
+			scope.problemReporter().typeMismatchError(expressionType, expectedType, this);
+			return null;
+		}
+		return expressionType;
+	}
+
+	public String toString(int tab) {
+
+		//Subclass re-define toStringExpression
+		String s = tabString(tab);
+		if (constant != null)
+			//before TC has runned
+			if (constant != NotAConstant)
+				//after the TC has runned
+				s += " /*cst:" + constant.toString() + "*/ "; //$NON-NLS-1$ //$NON-NLS-2$
+		return s + toStringExpression(tab);
+	}
+
+	//Subclass re-define toStringExpression
+	//This method is abstract and should never be called
+	//but we provide some code that is running.....just in case
+	//of developpement time (while every  thing is not built)
+	public String toStringExpression() {
+
+		return super.toString(0);
+	}
+
+	public String toStringExpression(int tab) {
+		// default is regular toString expression (qualified allocation expressions redifine this method)
+		return this.toStringExpression();
+	}
+
+	public Expression toTypeReference() {
+		//by default undefined
+
+		//this method is meanly used by the parser in order to transform
+		//an expression that is used as a type reference in a cast ....
+		//--appreciate the fact that castExpression and ExpressionWithParenthesis
+		//--starts with the same pattern.....
+
+		return this;
+	}
+}