<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Hm, if I drop this into my clang sources (and update it to match changes in trunk), I don't see any issues with what you've written—building and running it on your sample input works fine. Are you sure you have it enabled? (I forgot to pass -analyzer-checker on my first test, so I have to ask.)</div><div><br></div><div>Jordan</div><br><div><div>On May 25, 2014, at 7:28 , Rafael Auler <<a href="mailto:rafaelauler@gmail.com">rafaelauler@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">Hi Jordan,<div><br></div><div>Sure, it is attached. Thanks for taking a look at this. </div><div><br></div><div>Cheers,</div><div>Rafael</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, May 25, 2014 at 4:13 AM, Jordan Rose <span dir="ltr"><<a href="mailto:jordan_rose@apple.com" target="_blank">jordan_rose@apple.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi, Rafael. From your description, this sounds like a bug in the analyzer—two program states with differing user data should not be folded. Can you attach your checker so I can take a look and see if there are any obvious mistakes? (on your part or ours).<br>
<br>
Thanks,<br>
Jordan<br>
<div><div class="h5"><br>
On May 24, 2014, at 22:01 , Rafael Auler <<a href="mailto:rafaelauler@gmail.com">rafaelauler@gmail.com</a>> wrote:<br>
<br>
> Hello,<br>
><br>
> I am trying to write a very simple checker for the clang static analyzer for the sake of writing a first exercise on this topic. Its goal is to simply alert whether a specific function has been called twice in a given path. Let's assume the name of this specific function that I am tracking is "doNotCallTwice()".<br>
><br>
> In order to record state information, I use the REGISTER_TRAIT_WITH_PROGRAMSTATE macro to register an unsigned together with the program state. This integer indicates whether the function "doNotCallTwice()" has been called in a path and, if it is equal to 1 in a node where I detect yet another call, I prepare to report a "double call" bug. I use "checkPostCall" for changing the state.<br>
><br>
> However, something strange happens. My extra integer registered in the program state is not sufficient to differentiate two ProgramStates with the same ProgramPoint: the engine fold the two nodes anyway, ignoring my new state information. On the other hand, the information *is* propagated. If I use other ways to avoid the nodes being folded, the checker works fine.<br>
><br>
> An example where it does not work:<br>
><br>
> void myfunc (int x, int y) {<br>
> if (x)<br>
> doNotCallTwice();<br>
> if (y)<br>
> doNotCallTwice();<br>
> doNotCallTwice();<br>
> }<br>
><br>
> Since programstates get folded in the ExplodedGraph, I never detect any path where two calls to doNotCallTwice() happen. However, change the code in the following way avoids the folding and make my checker work:<br>
><br>
> void myfunc (int x, int y) {<br>
> if (x)<br>
> doNotCallTwice();<br>
> if (y)<br>
> doNotCallTwice();<br>
> y = x; // Now x and y are not dead anymore and this won't be folded<br>
> doNotCallTwice();<br>
> }<br>
><br>
> I based my checker on SimpleStreamChecker.cpp. Am I doing something conceptually wrong?<br>
><br>
> Best regards,<br>
> Rafael<br>
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</blockquote></div><br></div>
<span><MyChecker.cpp></span><span><mytest.c></span></blockquote></div><br></body></html>