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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">With my copy of Clang, the two parameters have entirely different types.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">DWARF is describing the mapping of source to object. The two parameters have different types. They have separate locations. When you're stopped at a place where
the parameters are in-scope, the location tells you where to find them. There's no ABI knowledge inherent in any of this.<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""> David Blaikie [mailto:dblaikie@gmail.com]
<br>
<b>Sent:</b> Tuesday, August 18, 2015 10:36 AM<br>
<b>To:</b> Robinson, Paul<br>
<b>Cc:</b> reviews+D7895+public+7827be49c0b04087@reviews.llvm.org; Romanova, Katya; Eric Christopher; Frédéric Riss; Duncan P. N. Exon Smith; llvm-commits<br>
<b>Subject:</b> Re: [PATCH] D7895: Anonymous namespaces are missing import DW_TAG_imported_module.<o:p></o:p></span></p>
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<p class="MsoNormal">On Tue, Aug 18, 2015 at 10:28 AM, Robinson, Paul <<a href="mailto:Paul_Robinson@playstation.sony.com" target="_blank">Paul_Robinson@playstation.sony.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">Sorry I wasn't clear - I was referring to the ABI lowering of C++ by value parameters. <br>
<br>
struct foo { foo(const foo&); int i; };<br>
struct bar { int i; };<br>
void func(foo, bar) { }<br>
<br>
foo and bar are passed quite differently in the ABI<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">And the formal parameters are described quite differently in the DWARF,
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<p class="MsoNormal"><br>
What differences are you referring to? They're described quite the same. The only difference in the two parameters is their DW_AT_location, and you can't rely on that for the calling convention - it just describes where to find the variable once you're past
the prologue. In LLVM, that's often /just/ the alloca we copy the value into, not the register the parameter was passed in.<br>
<br>
<br>
<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">meaning the debugger doesn't need special knowledge of the ABI to interpret the DWARF correctly.
I still don't see how this is relevant to the discussion at hand.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">--paulr</span><o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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