Fixed Bug 406859 - [1.8][compiler] Bad hint that method could be

declared static

3 files changed, 138 insertions, 4 deletions

diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NegativeLambdaExpressionsTest.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NegativeLambdaExpressionsTest.java
index d00f07a158..0b00f6203e 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NegativeLambdaExpressionsTest.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NegativeLambdaExpressionsTest.java
@@ -6534,6 +6534,134 @@ public void test406773() {
 			compilerOptions /* custom options */
 		);
 }
+//https://bugs.eclipse.org/bugs/show_bug.cgi?id=406859,  [1.8][compiler] Bad hint that method could be declared static
+public void test406859a() {
+		Map compilerOptions = getCompilerOptions();
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBeStatic, CompilerOptions.ERROR);
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBePotentiallyStatic, CompilerOptions.ERROR);
+		this.runNegativeTest(
+			new String[] {
+					"X.java",
+					"interface I {\n" +
+					"	int foo(int i);\n" +
+					"}\n" +
+					"public class X {\n" +
+					"	public static void main(String[] args) {\n" +
+					"		X x = new X();\n" +
+					"		I i = x::foo;\n" +
+					"		i.foo(3);\n" +
+					"	}\n" +
+					"	int foo(int x) {\n" +
+					"		return x;\n" +
+					"	}   \n" +
+					"}\n"
+			},
+			"",
+			null /* no extra class libraries */,
+			true /* flush output directory */,
+			compilerOptions /* custom options */
+		);
+}
+//https://bugs.eclipse.org/bugs/show_bug.cgi?id=406859,  [1.8][compiler] Bad hint that method could be declared static
+public void test406859b() {
+		Map compilerOptions = getCompilerOptions();
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBeStatic, CompilerOptions.ERROR);
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBePotentiallyStatic, CompilerOptions.ERROR);
+		this.runNegativeTest(
+			new String[] {
+					"X.java",
+					"interface I {\n" +
+					"	void doit (Y y);\n" +
+					"}\n" +
+					"\n" +
+					"class Y {\n" +
+					"	void foo() {\n" +
+					"		return;\n" +
+					"	}\n" +
+					"}\n" +
+					"\n" +
+					"public class X {\n" +
+					"	public static void main(String[] args) {\n" +
+					"		I i = Y::foo; \n" +
+					"		Y y = new Y();\n" +
+					"		i.doit(y);\n" +
+					"	}\n" +
+					"}\n"
+			},
+			"",
+			null /* no extra class libraries */,
+			true /* flush output directory */,
+			compilerOptions /* custom options */
+		);
+}
+//https://bugs.eclipse.org/bugs/show_bug.cgi?id=406859,  [1.8][compiler] Bad hint that method could be declared static
+public void test406859c() {
+		Map compilerOptions = getCompilerOptions();
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBeStatic, CompilerOptions.ERROR);
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBePotentiallyStatic, CompilerOptions.ERROR);
+		this.runNegativeTest(
+			new String[] {
+					"X.java",
+					"interface I {\n" +
+					"	void doit ();\n" +
+					"}\n" +
+					"\n" +
+					"class Y {\n" +
+					"	void foo() {  \n" +
+					"		return;\n" +
+					"	}\n" +
+					"}\n" +
+					"\n" +
+					"public class X {\n" +
+					"	public static void main(String[] args) {\n" +
+					"		I i = new Y()::foo;\n" +
+					"		i.doit();\n" +
+					"	}\n" +
+					"}\n"
+			},
+			"",
+			null /* no extra class libraries */,
+			true /* flush output directory */,
+			compilerOptions /* custom options */
+		);
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=406859,  [1.8][compiler] Bad hint that method could be declared static
+// A case where we can't help but report the wrong hint due to separate compilation.
+public void test406859d() {
+	Map compilerOptions = getCompilerOptions();
+	compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBeStatic, CompilerOptions.ERROR);
+	compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBePotentiallyStatic, CompilerOptions.WARNING);
+	this.runNegativeTest(
+		new String[] {
+				"Y.java",
+				"public class Y {\n" +
+				"	void foo() {\n" +
+				"		return;\n" +
+				"	}\n" +
+				"}",
+				"X.java",
+				"interface I {\n" +
+				"	void doit ();\n" +
+				"}\n" +
+				"\n" +
+				"public class X {\n" +
+				"	public static void main(String[] args) {\n" +
+				"		I i = new Y()::foo;\n" +
+				"		i.doit();\n" +
+				"	}\n" +
+				"}\n"
+		},
+		"----------\n" +
+		"1. WARNING in Y.java (at line 2)\n" +
+		"	void foo() {\n" +
+		"	     ^^^^^\n" +
+		"The method foo() from the type Y can potentially be declared as static\n" +
+		"----------\n",
+		null /* no extra class libraries */,
+		true /* flush output directory */,
+		compilerOptions /* custom options */
+	);
+}
 public static Class testClass() {
 	return NegativeLambdaExpressionsTest.class;
 }
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/ReferenceExpression.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/ReferenceExpression.java
index 4a4a314a2c..a9134aa1c8 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/ReferenceExpression.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/ReferenceExpression.java
@@ -399,9 +399,15 @@ public class ReferenceExpression extends FunctionalExpression implements Invocat
         if (this.binding.isAbstract() && this.lhs.isSuper())
         	scope.problemReporter().cannotDireclyInvokeAbstractMethod(this, this.binding);
         
-        if (this.binding.isStatic() && this.binding.declaringClass != this.receiverType)
-			scope.problemReporter().indirectAccessToStaticMethod(this, this.binding);
-    
+        if (this.binding.isStatic()) {
+        	if (this.binding.declaringClass != this.receiverType)
+        		scope.problemReporter().indirectAccessToStaticMethod(this, this.binding);
+        } else {
+        	AbstractMethodDeclaration srcMethod = this.binding.sourceMethod();
+        	if (srcMethod != null && srcMethod.isMethod())
+        		srcMethod.bits &= ~ASTNode.CanBeStatic;
+        }
+        
     	if (isMethodUseDeprecated(this.binding, scope, true))
     		scope.problemReporter().deprecatedMethod(this.binding, this);
 
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/MethodBinding.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/MethodBinding.java
index a3acc6961d..025b07804d 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/MethodBinding.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/MethodBinding.java
@@ -1129,7 +1129,7 @@ public AbstractMethodDeclaration sourceMethod() {
 		return null;
 	}
 
-	AbstractMethodDeclaration[] methods = sourceType.scope.referenceContext.methods;
+	AbstractMethodDeclaration[] methods = sourceType.scope != null ? sourceType.scope.referenceContext.methods : null;
 	if (methods != null) {
 		for (int i = methods.length; --i >= 0;)
 			if (this == methods[i].binding)