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<p class="MsoNormal"><span style="color:black">`clang` is the driver not the compiler.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:black">Run this to get the compiler invocation: (“path/to/clang” “-cc1” ….), then debug that instead.<o:p></o:p></span></p>
<p class="MsoNormal">"clang -flto -fsanitize=cfi-icall indirect.c -o indirect -###"<span style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:black">-Yuanfang<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> llvm-dev <llvm-dev-bounces@lists.llvm.org> <b>On Behalf Of
</b>Shishir V Jessu via llvm-dev<br>
<b>Sent:</b> Monday, September 30, 2019 12:42 PM<br>
<b>To:</b> llvm-dev@lists.llvm.org<br>
<b>Subject:</b> [llvm-dev] Debugging LowerTypeTests in LLVM Using GDB<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Hi, <br>
<br>
I am looking into Control-Flow Integrity for indirect function calls, implemented with jump tables. I want to step through the code that produces these jump tables in GDB. I have built clang and opt from source with debugging symbols. I believe this code lives
in llvm/lib/Transforms/LowerTypeTests.cpp, but when I try to debug <i>opt</i> by running the command "run -lowertypetests cfi-icall.bc > /dev/null", I am never able to reach this file.
<br>
<br>
Also, I have tried to debug the command "clang -flto -fsanitize=cfi-icall indirect.c -o indirect" (where indirect.c is a C file containing an indirect call), and am able to see the CFI jump tables in the resulting assembly, but I cannot reach the code that
produces these jump tables in GDB. Am I targeting the wrong code for these changes, or is there something more I need in order to run through this code in GDB? Thanks for your help!<br>
<br>
Shishir Jessu<o:p></o:p></p>
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