[Soot-list] incoherent stack height

[Eric Bodden]

Hi Khilan.

Did you try using -validate?

This may be a bug in Jimple-to-Jasmin conversion. But it's hard to say
without having a complete .jimple file that exposes this error. It's
more likely that there's something wrong with your code generation.

Eric

--
Dr. Eric Bodden
Software Technology Group, Technische Universität Darmstadt, Germany
Tel: +49 6151 16-5478    Fax: +49 6151 16-5410
Mailing Address: S2|02 A209, Hochschulstraße 10, 64289 Darmstadt



On 11 July 2010 17:22, Khilan Gudka <khilan at doc.ic.ac.uk> wrote:
> Hi,
>
> I apologise for the previous email. The example was too complicated. I
> now have a much simpler example:
>
> Exception in thread "main" java.lang.RuntimeException:
> <test.StaticFieldLoad1: void main(java.lang.String[])>: incoherent
> stack height at block merge point Block 1:
> [preds: 0 2 ] [succs: 2 4 ]
> nop;
> push class "test/StaticFieldLoad1";
> store.r _p1;
> load.r _p1;
> ifnull nop;
> Block 2:
> [preds: 1 ] [succs: 3 1 ]
> load.r _p1;
> push 1;
> staticinvoke <MyClass: boolean m(java.lang.Object)>;
> ifeq nop;
>
> computed blockHeight == 1 recorded blockHeight = 0
>        at soot.baf.JasminClass.calculateStackHeight(JasminClass.java:1845)
>        at soot.baf.JasminClass.calculateStackHeight(JasminClass.java:1850)
>
> The corresponding jimple code is:
>
>     label0:
>        nop;
>        _p1 = class "test/StaticFieldLoad1";
>        if _p1 == null goto label1;
>
>        _locked1 = staticinvoke <MyClass: boolean m(java.lang.Object)>(_p1, 1);
>        if _locked1 == 0 goto label0;
>
>        nop;
>
>     label1:
>        nop;
>
> One thing that I'm not sure about is the instruction "ifeq nop;"
> Looking at the jimple, this corresponds to "if _locked1 == 0 goto
> label0;" However, in the bytecode there is no instruction that pushes
> 0 onto the stack for the comparison (the only predecessor for block 2
> is block 1 and block 1 doesn't have an instruction that pushes 0 onto
> the stack). Am I missing something here?
>
> Thanks,
> Khilan
>
> On 11 July 2010 15:27, Khilan Gudka <khilan at doc.ic.ac.uk> wrote:
>> Hi,
>>
>> I'm instrumenting code but jasmin is throwing the following exception
>> for one particular class:
>>
>>        Exception in thread "main" java.lang.RuntimeException:
>> <org.hsqldb.jdbc.jdbcConnection: java.util.Map getTypeMap()>:
>> incoherent stack height at block merge point Block 193:
>>        [preds: 192 196 ] [succs: 194 197 ]
>>                Block 196:
>>        [preds: 194 195 ] [succs: 193 ]
>>        inc.i $elem235 1;
>>        goto load.i $elem235;
>>
>>        computed blockHeight == 18 recorded blockHeight = 17
>>                at soot.baf.JasminClass.calculateStackHeight(JasminClass.java:1842)
>>                at soot.baf.JasminClass.calculateStackHeight(JasminClass.java:1847)
>>                ...
>>
>> The corresponding jimple code (i think) is:
>>
>>        $p213 = $c213.<java.util.HashMap:
>> java.util.HashMap$HashEntry[] buckets>;
>>        if $p213 == null goto label58;
>>
>>        $locked213 = staticinvoke <MyClass: boolean
>> m(java.lang.Object)>($p213, 1);
>>        if $locked213 == 0 goto label0;
>>
>>        $idx235 = 0;
>>
>>     label55:
>>        $len235 = lengthof $p213;
>>        if $idx235 >= $len235 goto label57;
>>
>>        $elem235 = $p213[$idx235];
>>        if $elem235 == null goto label56;
>>
>>        $locked235 = staticinvoke < MyClass: boolean
>> m(java.lang.Object)>($elem235, 1);
>>        if $locked235 == 0 goto label0;
>>
>>     label56:
>>        $idx235 = $idx235 + 1;
>>        goto label55;
>>
>>     label57:
>>        nop;
>>
>> However, I don't understand why $elem235 is being incremented and not
>> $idx235 (as is being done in the jimple?). All the $ variables are
>> local variables.
>>
>> Thanks,
>> Khilan
>>
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