<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><base href="x-msg://230/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>This is correct, as detailed in our recent talk about the static analyzer (available at <a href="http://llvm.org/devmtg/2012-11/">http://llvm.org/devmtg/2012-11/</a>). However, my point is that it was correct behavior. There is not a reasonable way for the analyzer to continue simulating a program after the user has divided by zero. You have to fix the divide-by-zero error and run the analyzer again.</div><div><br></div><div>Jordan</div><div><br></div><div><br></div><br><div><div>On Dec 12, 2012, at 20:05 , Sujit Kamthe <<a href="mailto:Sujit.Kamthe@kpitcummins.com">Sujit.Kamthe@kpitcummins.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div lang="EN-US" link="blue" vlink="purple" style="font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div class="WordSection1" style="page: WordSection1; "><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(15, 36, 62); ">Hi Jordan,<o:p></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(15, 36, 62); ">Thanks for your reply.<o:p></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(15, 36, 62); ">I think this is achieved using C.generateSink() method where C is CheckerContext, which stops further exploration of the AST path.<o:p></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(15, 36, 62); ">In one of the checkers which is a Pre-stmt<BinaryOperator> checker, I have used C.addTransition(); which should not stop the further analysis, but in my case it stops the further analysis of the AST nodes in same file and only reports the first violation.<o:p></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(15, 36, 62); "> </span></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 8pt; font-family: 'Courier New'; color: rgb(31, 73, 125); ">Regards,</span><span style="font-size: 11pt; font-family: 'Courier New'; color: rgb(31, 73, 125); "><o:p></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><b><span style="font-size: 10pt; font-family: 'Courier New'; color: rgb(84, 141, 212); ">Sujit Kamthe</span></b><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; "> </span></div></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(15, 36, 62); "> </span></div><div><div style="border-style: solid none none; border-top-width: 1pt; border-top-color: rgb(181, 196, 223); padding: 3pt 0in 0in; "><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><b><span style="font-size: 10pt; font-family: Tahoma, sans-serif; ">From:</span></b><span style="font-size: 10pt; font-family: Tahoma, sans-serif; "><span class="Apple-converted-space"> </span>Jordan Rose [mailto:jordan_rose@<a href="http://apple.com">apple.com</a>]<span class="Apple-converted-space"> </span><br><b>Sent:</b><span class="Apple-converted-space"> </span>Tuesday, December 11, 2012 10:44 PM<br><b>To:</b><span class="Apple-converted-space"> </span>Sujit Kamthe<br><b>Cc:</b><span class="Apple-converted-space"> </span>Clang Developers<br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [cfe-dev] Divide by zero reporting<o:p></o:p></span></div></div></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Hi, Sujit. The checkers in the analyzer can choose to treat errors as fatal or non-fatal. In the case of divide-by-zero errors, we treat them as fatal, because (a) they will in fact trap in most runtimes, and (b) it's hard to continue evaluating if the division is used in a larger expression:<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">int a = 23 / 0;<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">int b = 34 / a; // ??<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Note that the analyzer only stops analyzing a particular<span class="Apple-converted-space"> </span><i>path</i> when it sees a fatal error, not the entire file. Both divide-by-zero violations should be reported in compute(), as well as the one in again(), even if both functions are in the same file.<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">int compute(int a) {<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span class="apple-tab-span"> <span class="Apple-converted-space"> </span></span>if (coin()) {<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span class="apple-tab-span"> <span class="Apple-converted-space"> </span></span>a = a / 0;<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span class="apple-tab-span"> <span class="Apple-converted-space"> </span></span>} else {<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span class="apple-tab-span"> <span class="Apple-converted-space"> </span></span>a = a / 0;<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span class="apple-tab-span"> <span class="Apple-converted-space"> </span></span>}<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">}<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">int again() {<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span class="apple-tab-span"> <span class="Apple-converted-space"> </span></span>return 24 / 0;<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">}<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Best,<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Jordan<o:p></o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div><div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">On Dec 11, 2012, at 1:36 , Sujit Kamthe <<a href="mailto:Sujit.Kamthe@kpitcummins.com" style="color: purple; text-decoration: underline; ">Sujit.Kamthe@kpitcummins.com</a>> wrote:<o:p></o:p></div></div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><br><br><o:p></o:p></div><div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); ">Hi,</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); ">While running clang tool on a code it was found that if there are multiple divide by zero violations(more than 1) in same file then only the first one is reported and rest of them are not reported.</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); ">Even it was found that when a Prestmt<BinaryOperator> check detects/emits a bugreport, it skips the subsequent binary operator nodes from the same file.</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); "> </span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); ">Example Code:</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); "> </span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); ">int a=23/0; //Detected and reported</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); ">int b=34/0; //Not detected</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: 'Trebuchet MS', sans-serif; color: rgb(23, 54, 93); "> </span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 8pt; font-family: 'Courier New'; color: rgb(31, 73, 125); ">Regards,</span><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><b><span style="font-size: 10pt; font-family: 'Courier New'; color: rgb(84, 141, 212); ">Sujit Kamthe</span></b><span style="font-size: 11pt; font-family: Calibri, sans-serif; "><o:p></o:p></span></div></div><div><div style="margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; "> <o:p></o:p></span></div></div><div style="margin: 0in 0in 0.0001pt; 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