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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I think a key point to understand is the MCStreamer interface, which has two implementations: one for object-file generation, and one for .s file generation.
CodeGen/AsmPrinter can attach to either of these implementations. MCAsmParser will generally attach to the object-file version of MCStreamer.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">--paulr<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> llvm-dev [mailto:llvm-dev-bounces@lists.llvm.org]
<b>On Behalf Of </b>Craig Topper via llvm-dev<br>
<b>Sent:</b> Thursday, May 10, 2018 4:47 PM<br>
<b>To:</b> soham1@bu.edu<br>
<b>Cc:</b> llvm-dev<br>
<b>Subject:</b> Re: [llvm-dev] Assembly file compilation flow<o:p></o:p></span></p>
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<p class="MsoNormal">Passing an assembly file to clang does not go through any CodeGen phases. It operates entirely in the MC layer. No MachineFunctions will be created. It just runs it through the MCAsmParser. Most of the setup for this is in clang's tools/driver/cc1as_main.cpp
in the function ExecuteAssembler<o:p></o:p></p>
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<p class="MsoNormal">~Craig<o:p></o:p></p>
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<p class="MsoNormal">On Thu, May 10, 2018 at 1:32 PM Soham Sinha via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Hello,<o:p></o:p></p>
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<p class="MsoNormal"><a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html" target="_blank">LLVM MC blog post</a> explains fairly well how the backend MC project is working. However, it's not clear to me how LLVM converts an assembly file (.s)
to an object file. The driver --verbose option is not giving me much information as well. I want to know the flow. Like, What CodeGen phases does this file pass through? Is it converted to MachineFunction ever? Where does it hook into the backend infrastructure?
Any documentation could also be helpful.<o:p></o:p></p>
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<p class="MsoNormal">Regards,<o:p></o:p></p>
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<p class="MsoNormal">Soham Sinha<o:p></o:p></p>
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<p class="MsoNormal">PhD Student, Department of Computer Science<o:p></o:p></p>
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<p class="MsoNormal">Boston University<o:p></o:p></p>
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<p class="MsoNormal">_______________________________________________<br>
LLVM Developers mailing list<br>
<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a><o:p></o:p></p>
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