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<p class="MsoNormal">Hello everyone,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am trying to address the following bug:<br>
<a href="https://bugs.llvm.org/show_bug.cgi?id=44418">https://bugs.llvm.org/show_bug.cgi?id=44418</a><o:p></o:p></p>
<p class="MsoNormal">Which asks for the implementation of the missing “-Wstack-usage=” which will report, on a per-function basis, if the stack usage exceeds the user input.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My first approach at implementing “-Wstack-usage” is the following:<o:p></o:p></p>
<p class="MsoNormal"><a href="https://reviews.llvm.org/D101965">https://reviews.llvm.org/D101965</a><o:p></o:p></p>
<p class="MsoNormal">This is virtually identical to the output of “-Wframe-larger-than” on clang. However when observing the behaviour of GCC I noticed that GCC outputs different values for “-Wstack-usage” and “-Wframe-larger-than”.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This led me to my second approach which changes the way clang reports “-Wframe-larger-than”. This can be found here:<br>
<a href="https://reviews.llvm.org/D101964">https://reviews.llvm.org/D101964</a><o:p></o:p></p>
<p class="MsoNormal">With this second approach, “-Wframe-larger-than” now reports the stack size minus any space allocated on the stack for the parameters of called functions. This more closely resembles GCC’s behaviour.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am unsure which implementation is preferred/correct and I am wondering if anyone can comment or provide some information on what a better approach would be, and what exactly the two flags should be reporting.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Ryan Santhirarajan<o:p></o:p></p>
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