Attachment #175498 for bug #320170

Lines 1-5 Link Here

(-)compiler/org/eclipse/jdt/internal/compiler/flow/NullInfoRegistry.java (-2 / +15 lines)
1	/*******************************************************************************	1	/*******************************************************************************
2	* Copyright (c) 2006, 2009 IBM Corporation and others.	2	* Copyright (c) 2006, 2010 IBM Corporation and others.
3	* All rights reserved. This program and the accompanying materials	3	* All rights reserved. This program and the accompanying materials
4	* are made available under the terms of the Eclipse Public License v1.0	4	* are made available under the terms of the Eclipse Public License v1.0
5	* which accompanies this distribution, and is available at	5	* which accompanies this distribution, and is available at
Lines 7-12 Link Here
7	*	7	*
8	* Contributors:	8	* Contributors:
9	* IBM Corporation - initial API and implementation	9	* IBM Corporation - initial API and implementation
		10	* Stephan Herrmann <stephan@cs.tu-berlin.de> - [compiler] [null] Whitebox issues in null analysis, see https://bugs.eclipse.org/320170
10	*******************************************************************************/	11	*******************************************************************************/
11	package org.eclipse.jdt.internal.compiler.flow;	12	package org.eclipse.jdt.internal.compiler.flow;
12		13
Lines 319-325 Link Here
319	// prot. non null	320	// prot. non null
320	& ((a2 = this.nullBit2) \| (a4 = this.nullBit4));	321	& ((a2 = this.nullBit2) \| (a4 = this.nullBit4));
321	// null or unknown	322	// null or unknown
322	m2 = s1 & (s2 = this.nullBit2) & (s3 ^ s4)	323	m2 = s1 & (s2 = this.nullBit2) & (s3 ^ s4) // TODO(stephan): potential typo: should this be "s2 = source.nullBit2"???
323	// prot. null	324	// prot. null
324	& ((a3 = this.nullBit3) \| a4);	325	& ((a3 = this.nullBit3) \| a4);
325	// non null or unknown	326	// non null or unknown
Lines 336-341 Link Here
336	source.nullBit2 &= (nm1 = ~m1) & ((nm2 = ~m2) \| a4);	337	source.nullBit2 &= (nm1 = ~m1) & ((nm2 = ~m2) \| a4);
337	source.nullBit3 &= (nm1 \| a2) & nm2;	338	source.nullBit3 &= (nm1 \| a2) & nm2;
338	source.nullBit4 &= nm1 & nm2;	339	source.nullBit4 &= nm1 & nm2;
		340	// any variable that is (pot n, pot nn, pot un) at end of try (as captured by this NullInfoRegistry)
		341	// has the same uncertainty also for the mitigated case (function result)
		342	// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=320170 - [compiler] [null] Whitebox issues in null analysis
		343	// and org.eclipse.jdt.core.tests.compiler.regression.NullReferenceTest.test0536_try_finally()
		344	long x = ~this.nullBit1 & a2 & a3 & a4; // x is set for all variable ids that have state 0111 (pot n, pot nn, pot un)
		345	if (x != 0) {
		346	// restore state 0111 for all variable ids in x:
		347	source.nullBit1 &= ~x;
		348	source.nullBit2 \|= x;
		349	source.nullBit3 \|= x;
		350	source.nullBit4 \|= x;
		351	}
339	}	352	}
340	if (this.extra != null && source.extra != null) {	353	if (this.extra != null && source.extra != null) {
341	int length = this.extra[2].length, sourceLength = source.extra[0].length;	354	int length = this.extra[2].length, sourceLength = source.extra[0].length;

Lines 7-12 Link Here

(-)compiler/org/eclipse/jdt/internal/compiler/flow/UnconditionalFlowInfo.java (+2 lines)
7	*	7	*
8	* Contributors:	8	* Contributors:
9	* IBM Corporation - initial API and implementation	9	* IBM Corporation - initial API and implementation
		10	* Stephan Herrmann <stephan@cs.tu-berlin.de> - [compiler] [null] Whitebox issues in null analysis, see https://bugs.eclipse.org/320170
10	*******************************************************************************/	11	*******************************************************************************/
11	package org.eclipse.jdt.internal.compiler.flow;	12	package org.eclipse.jdt.internal.compiler.flow;
12		13
Lines 63-68 Link Here
63	0100 pot. null	64	0100 pot. null
64	0101 pot. n & pot. un	65	0101 pot. n & pot. un
65	0110 pot. n & pot. nn	66	0110 pot. n & pot. nn
		67	0111 pot. n & pot. nn & pot. un
66	1001 def. unknown	68	1001 def. unknown
67	1010 def. non null	69	1010 def. non null
68	1011 pot. nn & prot. nn	70	1011 pot. nn & prot. nn

Lines 1-5 Link Here

(-)src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceImplTests.java (-2 / +3 lines)
1	/*******************************************************************************	1	/*******************************************************************************
2	* Copyright (c) 2005, 2009 IBM Corporation and others.	2	* Copyright (c) 2005, 2010 IBM Corporation and others.
3	* All rights reserved. This program and the accompanying materials	3	* All rights reserved. This program and the accompanying materials
4	* are made available under the terms of the Eclipse Public License v1.0	4	* are made available under the terms of the Eclipse Public License v1.0
5	* which accompanies this distribution, and is available at	5	* which accompanies this distribution, and is available at
Lines 7-12 Link Here
7	*	7	*
8	* Contributors:	8	* Contributors:
9	* IBM Corporation - initial API and implementation	9	* IBM Corporation - initial API and implementation
		10	* Stephan Herrmann <stephan@cs.tu-berlin.de> - [compiler] [null] Whitebox issues in null analysis, see https://bugs.eclipse.org/320170
10	*******************************************************************************/	11	*******************************************************************************/
11	package org.eclipse.jdt.core.tests.compiler.regression;	12	package org.eclipse.jdt.core.tests.compiler.regression;
12		13
Lines 96-102 Link Here
96	011001	97	011001
97	011010	98	011010
98	011011	99	011011
99	011100	100	011100 pot. n & pot. nn & pot. un
100	011101	101	011101
101	011110	102	011110
102	011111	103	011111




 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Stephan Herrmann <stephan@cs.tu-berlin.de> - [compiler] [null] Whitebox issues in null analysis,  see https://bugs.eclipse.org/320170   
 *******************************************************************************/
package org.eclipse.jdt.core.tests.compiler.regression;


			"");
}

// null analysis -- try/finally
// https://bugs.eclipse.org/bugs/show_bug.cgi?id=320170 -  [compiler] [null] Whitebox issues in null analysis
// trigger nullbits 0111 (pot n|nn|un), don't let "definitely unknown" override previous information
public void test0536_try_finally() {
	this.runNegativeTest(
		new String[] {
			"X.java",
			"public class X {\n" +
			" X bar () { return null; }\n" +
			" void foo() {\n" +
			"   X x = new X();\n" +
			"   try {\n" +
			"     x = null;\n" +
			"     x = new X();\n" +  // if this throws an exception finally finds x==null
			"     x = bar();\n" +
			"   } finally {\n" +
			"     x.toString();\n" + // complain
			"   }\n" +
			" }\n" +
			"}\n"},
		"----------\n" + 
		"1. ERROR in X.java (at line 10)\n" + 
		"	x.toString();\n" + 
		"	^\n" + 
		"Potential null pointer access: The variable x may be null at this location\n" + 
		"----------\n",
	    JavacTestOptions.Excuse.EclipseWarningConfiguredAsError);
}

// null analysis -- try/finally
// https://bugs.eclipse.org/bugs/show_bug.cgi?id=320170 -  [compiler] [null] Whitebox issues in null analysis
// trigger nullbits 0111 (pot n|nn|un), don't let "definitely unknown" override previous information
// multiple variables
public void test0537_try_finally() {
	this.runNegativeTest(
		new String[] {
			"X.java",
			"public class X {\n" +
			" X bar () { return null; }\n" +
			" void foo() {\n" +
			"   X x1 = new X();\n" +
			"   X x2 = new X();\n" +
			"   X x3 = new X();\n" +
			"   try {\n" +
			"     x1 = null;\n" +
			"     x2 = null;\n" +
			"     x1 = new X();\n" +  // if this throws an exception finally finds x1==null
			"     x2 = new X();\n" +  // if this throws an exception finally finds x2==null
			"     x3 = new X();\n" +  // if this throws an exception finally still finds x3!=null
			"     x1 = bar();\n" +
			"     x2 = bar();\n" +
			"   } finally {\n" +
			"     x1.toString();\n" + // complain
			"     x2.toString();\n" + // complain
			"     x3.toString();\n" + // don't complain
			"   }\n" +
			" }\n" +
			"}\n"},
		"----------\n" + 
		"1. ERROR in X.java (at line 16)\n" + 
		"	x1.toString();\n" + 
		"	^^\n" + 
		"Potential null pointer access: The variable x1 may be null at this location\n" + 
		"----------\n" + 
		"2. ERROR in X.java (at line 17)\n" + 
		"	x2.toString();\n" + 
		"	^^\n" + 
		"Potential null pointer access: The variable x2 may be null at this location\n" + 
		"----------\n",
	    JavacTestOptions.Excuse.EclipseWarningConfiguredAsError);
}

// null analysis -- try/catch
public void test0550_try_catch() {
	this.runConformTest(

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