1) Moved net.sourceforge.phpeclipse.ui\src\net\sourceforge\phpdt back to net.sourcefo...
[phpeclipse.git] / net.sourceforge.phpeclipse / src / net / sourceforge / phpdt / internal / compiler / ast / Expression.java
index 76fc023..0b6c568 100644 (file)
+/*******************************************************************************
+ * 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.phpdt.internal.compiler.ast;
 
-/**
- * An expression.
- * @author Matthieu Casanova
- */
-public class Expression extends AstNode {
-
-  public String toString(int tab) {
-    String s = tabString(tab);
-    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();
-  }
+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;
+
+public 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
+        *            net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
+        * @param codeStream
+        *            net.sourceforge.phpdt.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
+        *            net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
+        * @param codeStream
+        *            net.sourceforge.phpdt.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(ProjectPrefUtil.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,
+       // net.sourceforge.phpdt.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 StringBuffer print(int indent, StringBuffer output) {
+               printIndent(indent, output);
+               return printExpression(indent, output);
+       }
+
+       public StringBuffer printExpression(int indent, StringBuffer output) {
+               output.append(super.toString(0));
+               return output;
+       }
+
+       public StringBuffer printStatement(int indent, StringBuffer output) {
+               return print(indent, output).append(";"); //$NON-NLS-1$
+       }
+
+       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;
+       }
 }