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I guess the compiler can generate a warning for this but an error is a bit too much for the class below: package util; import java.util.Random; public class EclipseBug { public void showBug() throws MyException { System.out.println("test"); } protected void throwsMethod() throws MyException { if(new Random().nextInt() == 500) { throw new MyException(); } } class MyException extends Exception { } } class sub extends EclipseBug { public void showBug() throws MyException { if(false) { try { try { throwsMethod(); } finally { System.out.println("finally"); } } catch(MyException ex) { // THIS IS LINE 44 THE COMPILE COMPLAINS ex.printStackTrace(); } } super.showBug(); } } Result of compilation: 1. ERROR in D:\Dev\2003.2\corejrisk\src\util\EclipseBug.java (at line 44) { ex.printStackTrace(); } ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Unreachable catch block ---------- 1 problem (1 error) Compilation goes fine if this same code is in the base class or of the Exception is not a subclass of Exception.
Indeed, we should not complain.
test case reduced a little bit: public class Sample { public void method() { if (false) { try { try { throw new InterruptedException(); } finally { System.out.println(); } } catch(InterruptedException e) { } } } }
Created attachment 5575 [details] regression test
regression test added
Created attachment 5576 [details] regression test update added a test for if (true) {} else { ...code... } situation
proposed patch: Index: IfStatement.java =================================================================== RCS file: /home/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compi ler/ast/IfStatement.java,v retrieving revision 1.35 diff -u -r1.35 IfStatement.java --- IfStatement.java 26 Jun 2003 15:59:51 -0000 1.35 +++ IfStatement.java 29 Jul 2003 07:51:19 -0000 @@ -83,7 +83,7 @@ // Save info for code gen thenInitStateIndex = currentScope.methodScope ().recordInitializationStates(thenFlowInfo); - if (!thenStatement.complainIfUnreachable(thenFlowInfo, currentScope, false)) { + if (!isConditionOptimizedFalse && ! thenStatement.complainIfUnreachable(thenFlowInfo, currentScope, false)) { thenFlowInfo = thenStatement.analyseCode(currentScope, flowContext, thenFlowInfo); } @@ -100,7 +100,7 @@ // Save info for code gen elseInitStateIndex = currentScope.methodScope ().recordInitializationStates(elseFlowInfo); - if (!elseStatement.complainIfUnreachable(elseFlowInfo, currentScope, false)) { + if (!isConditionOptimizedTrue && ! elseStatement.complainIfUnreachable(elseFlowInfo, currentScope, false)) { elseFlowInfo = elseStatement.analyseCode(currentScope, flowContext, elseFlowInfo); }
This fix would not work as it would entirely skip the flow analysis inside offending fake reachable portions of the ASTs. The real fix is quite more complex and lives elsewhere. Unreachable code should still be processed during the analysis, slightly differently. e.g. if (false) { return; return; // should still complain about being unreachable } The real fix is actually in checks for unreachable flow infos, which should be replaced from "...info.isReachable()" into "...info == FlowInfo.DEAD_END". Down the road we should get rid of DEAD_ENDs since these are loosing track of the initialization information from thereon.
Fixed, regression tests added.
Backported to 2.1 stream for further integration. Regression test added.
Released for 2.1.2 (backported better version, see bug 42692).
Regression tests are InitializationTest#test161/test162. These were not backported to 2.1.2 stream. Added now.
2.1.2 stream was missing portion of the fix on TryStatement. Backport complete now.
Verified with build 2.1.2 RC2
Verified as well.
