1 /*******************************************************************************
2  * Copyright (c) 2000, 2013 IBM Corporation and others.
3  * All rights reserved. This program and the accompanying materials
4  * are made available under the terms of the Eclipse Public License v1.0
5  * which accompanies this distribution, and is available at
6  * http://www.eclipse.org/legal/epl-v10.html
7  *
8  * Contributors:
9  *     IBM Corporation - initial API and implementation
10  *     Stephan Herrmann - Contributions for
11  *								bug 349326 - [1.7] new warning for missing try-with-resources
12  *								bug 186342 - [compiler][null] Using annotations for null checking
13  *								bug 365519 - editorial cleanup after bug 186342 and bug 365387
14  *								bug 368546 - [compiler][resource] Avoid remaining false positives found when compiling the Eclipse SDK
15  *								bug 382353 - [1.8][compiler] Implementation property modifiers should be accepted on default methods.
16  *								bug 383368 - [compiler][null] syntactic null analysis for field references
17  *								Bug 392099 - [1.8][compiler][null] Apply null annotation on types for null analysis
18  *								Bug 392238 - [1.8][compiler][null] Detect semantically invalid null type annotations
19  *								Bug 416176 - [1.8][compiler][null] null type annotations cause grief on type variables
20  *     Jesper S Moller <jesper@selskabet.org> - Contributions for
21  *								bug 378674 - "The method can be declared as static" is wrong
22  *******************************************************************************/
23 package org.eclipse.jdt.internal.compiler.ast;
24 
25 import java.util.List;
26 
27 import org.eclipse.jdt.core.compiler.CharOperation;
28 import org.eclipse.jdt.internal.compiler.ASTVisitor;
29 import org.eclipse.jdt.internal.compiler.CompilationResult;
30 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
31 import org.eclipse.jdt.internal.compiler.flow.ExceptionHandlingFlowContext;
32 import org.eclipse.jdt.internal.compiler.flow.FlowContext;
33 import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
34 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
35 import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
36 import org.eclipse.jdt.internal.compiler.lookup.ClassScope;
37 import org.eclipse.jdt.internal.compiler.lookup.ExtraCompilerModifiers;
38 import org.eclipse.jdt.internal.compiler.lookup.LocalTypeBinding;
39 import org.eclipse.jdt.internal.compiler.lookup.MemberTypeBinding;
40 import org.eclipse.jdt.internal.compiler.lookup.TagBits;
41 import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
42 import org.eclipse.jdt.internal.compiler.lookup.TypeConstants;
43 import org.eclipse.jdt.internal.compiler.lookup.TypeVariableBinding;
44 import org.eclipse.jdt.internal.compiler.parser.Parser;
45 import org.eclipse.jdt.internal.compiler.problem.AbortMethod;
46 import org.eclipse.jdt.internal.compiler.problem.ProblemSeverities;
47 import org.eclipse.jdt.internal.compiler.ast.TypeReference.AnnotationCollector;
48 
49 public class MethodDeclaration extends AbstractMethodDeclaration {
50 
51 	public TypeReference returnType;
52 	public TypeParameter[] typeParameters;
53 
54 	/**
55 	 * MethodDeclaration constructor comment.
56 	 */
MethodDeclaration(CompilationResult compilationResult)57 	public MethodDeclaration(CompilationResult compilationResult) {
58 		super(compilationResult);
59 		this.bits |= ASTNode.CanBeStatic; // Start with this assumption, will course correct during resolve and analyseCode.
60 	}
61 
analyseCode(ClassScope classScope, FlowContext flowContext, FlowInfo flowInfo)62 	public void analyseCode(ClassScope classScope, FlowContext flowContext, FlowInfo flowInfo) {
63 		// starting of the code analysis for methods
64 		if (this.ignoreFurtherInvestigation)
65 			return;
66 		try {
67 			if (this.binding == null)
68 				return;
69 
70 			if (!this.binding.isUsed() && !this.binding.isAbstract()) {
71 				if (this.binding.isPrivate()
72 					|| (((this.binding.modifiers & (ExtraCompilerModifiers.AccOverriding|ExtraCompilerModifiers.AccImplementing)) == 0)
73 						&& this.binding.isOrEnclosedByPrivateType())) {
74 					if (!classScope.referenceCompilationUnit().compilationResult.hasSyntaxError) {
75 						this.scope.problemReporter().unusedPrivateMethod(this);
76 					}
77 				}
78 			}
79 
80 			// skip enum implicit methods
81 			if (this.binding.declaringClass.isEnum() && (this.selector == TypeConstants.VALUES || this.selector == TypeConstants.VALUEOF))
82 				return;
83 
84 			// may be in a non necessary <clinit> for innerclass with static final constant fields
85 			if (this.binding.isAbstract() || this.binding.isNative())
86 				return;
87 
88 			// https://bugs.eclipse.org/bugs/show_bug.cgi?id=385780
89 			if (this.typeParameters != null &&
90 					!this.scope.referenceCompilationUnit().compilationResult.hasSyntaxError) {
91 				for (int i = 0, length = this.typeParameters.length; i < length; ++i) {
92 					TypeParameter typeParameter = this.typeParameters[i];
93 					if ((typeParameter.binding.modifiers  & ExtraCompilerModifiers.AccLocallyUsed) == 0) {
94 						this.scope.problemReporter().unusedTypeParameter(typeParameter);
95 					}
96 				}
97 			}
98 			ExceptionHandlingFlowContext methodContext =
99 				new ExceptionHandlingFlowContext(
100 					flowContext,
101 					this,
102 					this.binding.thrownExceptions,
103 					null,
104 					this.scope,
105 					FlowInfo.DEAD_END);
106 
107 			// nullity and mark as assigned
108 			if (classScope.compilerOptions().sourceLevel < ClassFileConstants.JDK1_8)
109 				analyseArguments(flowInfo, this.arguments, this.binding);
110 			else
111 				analyseArguments18(flowInfo, this.arguments, this.binding);
112 
113 			if (this.binding.declaringClass instanceof MemberTypeBinding && !this.binding.declaringClass.isStatic()) {
114 				// method of a non-static member type can't be static.
115 				this.bits &= ~ASTNode.CanBeStatic;
116 			}
117 			// propagate to statements
118 			if (this.statements != null) {
119 				boolean enableSyntacticNullAnalysisForFields = this.scope.compilerOptions().enableSyntacticNullAnalysisForFields;
120 				int complaintLevel = (flowInfo.reachMode() & FlowInfo.UNREACHABLE) == 0 ? Statement.NOT_COMPLAINED : Statement.COMPLAINED_FAKE_REACHABLE;
121 				for (int i = 0, count = this.statements.length; i < count; i++) {
122 					Statement stat = this.statements[i];
123 					if ((complaintLevel = stat.complainIfUnreachable(flowInfo, this.scope, complaintLevel, true)) < Statement.COMPLAINED_UNREACHABLE) {
124 						flowInfo = stat.analyseCode(this.scope, methodContext, flowInfo);
125 					}
126 					if (enableSyntacticNullAnalysisForFields) {
127 						methodContext.expireNullCheckedFieldInfo();
128 					}
129 				}
130 			} else {
131 				// method with empty body should not be flagged as static.
132 				this.bits &= ~ASTNode.CanBeStatic;
133 			}
134 			// check for missing returning path
135 			TypeBinding returnTypeBinding = this.binding.returnType;
136 			if ((returnTypeBinding == TypeBinding.VOID) || isAbstract()) {
137 				if ((flowInfo.tagBits & FlowInfo.UNREACHABLE_OR_DEAD) == 0) {
138 					this.bits |= ASTNode.NeedFreeReturn;
139 				}
140 			} else {
141 				if (flowInfo != FlowInfo.DEAD_END) {
142 					this.scope.problemReporter().shouldReturn(returnTypeBinding, this);
143 				}
144 			}
145 			// check unreachable catch blocks
146 			methodContext.complainIfUnusedExceptionHandlers(this);
147 			// check unused parameters
148 			this.scope.checkUnusedParameters(this.binding);
149 			// check if the method could have been static
150 			if (!this.binding.isStatic() && (this.bits & ASTNode.CanBeStatic) != 0 && !this.isDefaultMethod()) {
151 				if(!this.binding.isOverriding() && !this.binding.isImplementing()) {
152 					if (this.binding.isPrivate() || this.binding.isFinal() || this.binding.declaringClass.isFinal()) {
153 						this.scope.problemReporter().methodCanBeDeclaredStatic(this);
154 					} else {
155 						this.scope.problemReporter().methodCanBePotentiallyDeclaredStatic(this);
156 					}
157 				}
158 
159 			}
160 			this.scope.checkUnclosedCloseables(flowInfo, null, null/*don't report against a specific location*/, null);
161 		} catch (AbortMethod e) {
162 			this.ignoreFurtherInvestigation = true;
163 		}
164 	}
165 
getAllAnnotationContexts(int targetType, List allAnnotationContexts)166 	public void getAllAnnotationContexts(int targetType, List allAnnotationContexts) {
167 		AnnotationCollector collector = new AnnotationCollector(this.returnType, targetType, allAnnotationContexts);
168 		for (int i = 0, max = this.annotations.length; i < max; i++) {
169 			Annotation annotation = this.annotations[i];
170 			annotation.traverse(collector, (BlockScope) null);
171 		}
172 	}
173 
isDefaultMethod()174 	public boolean isDefaultMethod() {
175 		return (this.modifiers & ExtraCompilerModifiers.AccDefaultMethod) != 0;
176 	}
177 
isMethod()178 	public boolean isMethod() {
179 		return true;
180 	}
181 
parseStatements(Parser parser, CompilationUnitDeclaration unit)182 	public void parseStatements(Parser parser, CompilationUnitDeclaration unit) {
183 		//fill up the method body with statement
184 		parser.parse(this, unit);
185 	}
186 
printReturnType(int indent, StringBuffer output)187 	public StringBuffer printReturnType(int indent, StringBuffer output) {
188 		if (this.returnType == null) return output;
189 		return this.returnType.printExpression(0, output).append(' ');
190 	}
191 
resolveStatements()192 	public void resolveStatements() {
193 		// ========= abort on fatal error =============
194 		if (this.returnType != null && this.binding != null) {
195 			this.bits |= (this.returnType.bits & ASTNode.HasTypeAnnotations);
196 			this.returnType.resolvedType = this.binding.returnType;
197 			// record the return type binding
198 		}
199 		// check if method with constructor name
200 		if (CharOperation.equals(this.scope.enclosingSourceType().sourceName, this.selector)) {
201 			this.scope.problemReporter().methodWithConstructorName(this);
202 		}
203 		// to check whether the method returns a type parameter not declared by it.
204 		boolean returnsUndeclTypeVar = false;
205 		if (this.returnType != null && this.returnType.resolvedType instanceof TypeVariableBinding) {
206 			returnsUndeclTypeVar = true;
207 		}
208 		if (this.typeParameters != null) {
209 			for (int i = 0, length = this.typeParameters.length; i < length; i++) {
210 				TypeParameter typeParameter = this.typeParameters[i];
211 				this.bits |= (typeParameter.bits & ASTNode.HasTypeAnnotations);
212 				// typeParameter is already resolved from Scope#connectTypeVariables()
213 				if (returnsUndeclTypeVar && TypeBinding.equalsEquals(this.typeParameters[i].binding, this.returnType.resolvedType)) {
214 					returnsUndeclTypeVar = false;
215 				}
216 			}
217 		}
218 
219 		// check @Override annotation
220 		final CompilerOptions compilerOptions = this.scope.compilerOptions();
221 		checkOverride: {
222 			if (this.binding == null) break checkOverride;
223 			long complianceLevel = compilerOptions.complianceLevel;
224 			if (complianceLevel < ClassFileConstants.JDK1_5) break checkOverride;
225 			int bindingModifiers = this.binding.modifiers;
226 			boolean hasOverrideAnnotation = (this.binding.tagBits & TagBits.AnnotationOverride) != 0;
227 			boolean hasUnresolvedArguments = (this.binding.tagBits & TagBits.HasUnresolvedArguments) != 0;
228 			if (hasOverrideAnnotation  && !hasUnresolvedArguments) {
229 				// no static method is considered overriding
230 				if ((bindingModifiers & (ClassFileConstants.AccStatic|ExtraCompilerModifiers.AccOverriding)) == ExtraCompilerModifiers.AccOverriding)
231 					break checkOverride;
232 				//	in 1.5, strictly for overriding superclass method
233 				//	in 1.6 and above, also tolerate implementing interface method
234 				if (complianceLevel >= ClassFileConstants.JDK1_6
235 						&& ((bindingModifiers & (ClassFileConstants.AccStatic|ExtraCompilerModifiers.AccImplementing)) == ExtraCompilerModifiers.AccImplementing))
236 					break checkOverride;
237 				// claims to override, and doesn't actually do so
238 				this.scope.problemReporter().methodMustOverride(this, complianceLevel);
239 			} else {
240 				//In case of  a concrete class method, we have to check if it overrides(in 1.5 and above) OR implements a method(1.6 and above).
241 				//Also check if the method has a signature that is override-equivalent to that of any public method declared in Object.
242 				if (!this.binding.declaringClass.isInterface()){
243 						if((bindingModifiers & (ClassFileConstants.AccStatic|ExtraCompilerModifiers.AccOverriding)) == ExtraCompilerModifiers.AccOverriding) {
244 							this.scope.problemReporter().missingOverrideAnnotation(this);
245 						} else {
246 							if(complianceLevel >= ClassFileConstants.JDK1_6
247 								&& compilerOptions.reportMissingOverrideAnnotationForInterfaceMethodImplementation
248 								&& this.binding.isImplementing()) {
249 									// actually overrides, but did not claim to do so
250 									this.scope.problemReporter().missingOverrideAnnotationForInterfaceMethodImplementation(this);
251 							}
252 
253 						}
254 				}
255 				else {	//For 1.6 and above only
256 					//In case of a interface class method, we have to check if it overrides a method (isImplementing returns true in case it overrides)
257 					//Also check if the method has a signature that is override-equivalent to that of any public method declared in Object.
258 					if(complianceLevel >= ClassFileConstants.JDK1_6
259 							&& compilerOptions.reportMissingOverrideAnnotationForInterfaceMethodImplementation
260 							&& (((bindingModifiers & (ClassFileConstants.AccStatic|ExtraCompilerModifiers.AccOverriding)) == ExtraCompilerModifiers.AccOverriding) || this.binding.isImplementing())){
261 						// actually overrides, but did not claim to do so
262 						this.scope.problemReporter().missingOverrideAnnotationForInterfaceMethodImplementation(this);
263 					}
264 				}
265 			}
266 		}
267 
268 		switch (TypeDeclaration.kind(this.scope.referenceType().modifiers)) {
269 			case TypeDeclaration.ENUM_DECL :
270 				if (this.selector == TypeConstants.VALUES) break;
271 				if (this.selector == TypeConstants.VALUEOF) break;
272 				//$FALL-THROUGH$
273 			case TypeDeclaration.CLASS_DECL :
274 				// if a method has an semicolon body and is not declared as abstract==>error
275 				// native methods may have a semicolon body
276 				if ((this.modifiers & ExtraCompilerModifiers.AccSemicolonBody) != 0) {
277 					if ((this.modifiers & ClassFileConstants.AccNative) == 0)
278 						if ((this.modifiers & ClassFileConstants.AccAbstract) == 0)
279 							this.scope.problemReporter().methodNeedBody(this);
280 				} else {
281 					// the method HAS a body --> abstract native modifiers are forbidden
282 					if (((this.modifiers & ClassFileConstants.AccNative) != 0) || ((this.modifiers & ClassFileConstants.AccAbstract) != 0))
283 						this.scope.problemReporter().methodNeedingNoBody(this);
284 					else if (this.binding == null || this.binding.isStatic() || (this.binding.declaringClass instanceof LocalTypeBinding) || returnsUndeclTypeVar) {
285 						// Cannot be static for one of the reasons stated above
286 						this.bits &= ~ASTNode.CanBeStatic;
287 					}
288 				}
289 				break;
290 			case TypeDeclaration.INTERFACE_DECL :
291 				if (compilerOptions.sourceLevel >= ClassFileConstants.JDK1_8
292 						&& (this.modifiers & (ExtraCompilerModifiers.AccSemicolonBody | ClassFileConstants.AccAbstract)) == ExtraCompilerModifiers.AccSemicolonBody) {
293 					if ((this.modifiers & (ClassFileConstants.AccStatic | ExtraCompilerModifiers.AccDefaultMethod)) != 0) {
294 							this.scope.problemReporter().methodNeedBody(this);
295 					}
296 				}
297 				break;
298 		}
299 		super.resolveStatements();
300 
301 		// TagBits.OverridingMethodWithSupercall is set during the resolveStatements() call
302 		if (compilerOptions.getSeverity(CompilerOptions.OverridingMethodWithoutSuperInvocation) != ProblemSeverities.Ignore) {
303 			if (this.binding != null) {
304         		int bindingModifiers = this.binding.modifiers;
305         		if ((bindingModifiers & (ExtraCompilerModifiers.AccOverriding|ExtraCompilerModifiers.AccImplementing)) == ExtraCompilerModifiers.AccOverriding
306         				&& (this.bits & ASTNode.OverridingMethodWithSupercall) == 0) {
307         			this.scope.problemReporter().overridesMethodWithoutSuperInvocation(this.binding);
308         		}
309 			}
310 		}
311 	}
312 
traverse( ASTVisitor visitor, ClassScope classScope)313 	public void traverse(
314 		ASTVisitor visitor,
315 		ClassScope classScope) {
316 
317 		if (visitor.visit(this, classScope)) {
318 			if (this.javadoc != null) {
319 				this.javadoc.traverse(visitor, this.scope);
320 			}
321 			if (this.annotations != null) {
322 				int annotationsLength = this.annotations.length;
323 				for (int i = 0; i < annotationsLength; i++)
324 					this.annotations[i].traverse(visitor, this.scope);
325 			}
326 			if (this.typeParameters != null) {
327 				int typeParametersLength = this.typeParameters.length;
328 				for (int i = 0; i < typeParametersLength; i++) {
329 					this.typeParameters[i].traverse(visitor, this.scope);
330 				}
331 			}
332 			if (this.returnType != null)
333 				this.returnType.traverse(visitor, this.scope);
334 			if (this.arguments != null) {
335 				int argumentLength = this.arguments.length;
336 				for (int i = 0; i < argumentLength; i++)
337 					this.arguments[i].traverse(visitor, this.scope);
338 			}
339 			if (this.thrownExceptions != null) {
340 				int thrownExceptionsLength = this.thrownExceptions.length;
341 				for (int i = 0; i < thrownExceptionsLength; i++)
342 					this.thrownExceptions[i].traverse(visitor, this.scope);
343 			}
344 			if (this.statements != null) {
345 				int statementsLength = this.statements.length;
346 				for (int i = 0; i < statementsLength; i++)
347 					this.statements[i].traverse(visitor, this.scope);
348 			}
349 		}
350 		visitor.endVisit(this, classScope);
351 	}
typeParameters()352 	public TypeParameter[] typeParameters() {
353 	    return this.typeParameters;
354 	}
355 }
356