[cfe-commits] r112310 - /cfe/trunk/lib/Checker/UnreachableCodeChecker.cpp

[Tom Care]

Both, in a way.

The problem is that a checker might place a sink somewhere that breaks this assumption. This could be due to a valid bug being found by another checker (eg, null deref). However this can also happen when another checker creates a sink incorrectly.

If the sink is correct, then this assertion can trigger when there is a real bug. If the sink is incorrect, this assertion has the power to reveal it.

The usual case so far has been this assertion triggering on correct sinks that happen to break the property.

On Aug 27, 2010, at 4:02 PM, Ted Kremenek wrote:

> Bugs in other checkers or bugs found by other checkers?
> 
> On Aug 27, 2010, at 3:37 PM, Tom Care wrote:
> 
>> Author: tcare
>> Date: Fri Aug 27 17:37:31 2010
>> New Revision: 112310
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=112310&view=rev
>> Log:
>> Remove an assertion in UnreachableCodeChecker that can be triggered by bugs in other checkers.
>> 
>> Modified:
>>   cfe/trunk/lib/Checker/UnreachableCodeChecker.cpp
>> 
>> Modified: cfe/trunk/lib/Checker/UnreachableCodeChecker.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Checker/UnreachableCodeChecker.cpp?rev=112310&r1=112309&r2=112310&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/Checker/UnreachableCodeChecker.cpp (original)
>> +++ cfe/trunk/lib/Checker/UnreachableCodeChecker.cpp Fri Aug 27 17:37:31 2010
>> @@ -188,8 +188,11 @@
>> // There will never be more than one predecessor.
>> bool UnreachableCodeChecker::isInvalidPath(const CFGBlock *CB,
>>                                           const ParentMap &PM) {
>> -  // Assert this CFGBlock only has one or zero predecessors
>> -  assert(CB->pred_size() == 0 || CB->pred_size() == 1);
>> +  // We only expect a predecessor size of 0 or 1. If it is >1, then an external
>> +  // condition has broken our assumption (for example, a sink being placed by
>> +  // another check). In these cases, we choose not to report.
>> +  if (CB->pred_size() > 1)
>> +    return true;
>> 
>>  // If there are no predecessors, then this block is trivially unreachable
>>  if (CB->pred_size() == 0)
>> 
>> 
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>