<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
p.gmail-m3997524881775611987msolistparagraph, li.gmail-m3997524881775611987msolistparagraph, div.gmail-m3997524881775611987msolistparagraph
{mso-style-name:gmail-m_3997524881775611987msolistparagraph;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 2.0cm 70.85pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:239095895;
mso-list-template-ids:-566081794;}
@list l1
{mso-list-id:564027733;
mso-list-template-ids:-1927775990;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<div>
<div>
<div>
<p class="MsoNormal">On Mon, Jan 14, 2019 at 3:21 AM Gaier, Bjoern via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="DE">Hello LLVM-World,</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="DE"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">currently I play around with a „llvm::Module” and an external function defined there “puts”. Normally this function gets resolved in the JIT-Process but I wonder about two things:<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<ol start="1" type="1">
<li class="gmail-m3997524881775611987msolistparagraph" style="mso-list:l0 level1 lfo1">
Can I resolve the function already in this step? I used “replaceAllUsesWith” and passed a “llvm::ConstantInt” to the function. But this didn’t worked.<o:p></o:p></li></ol>
</div>
</div>
</blockquote>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">I'm not sure if I followed correctly, but you can't replace a function declaration with a constant int. The value for the function will be used (mostly) as an argument to the call instruction, which won't really be able to operate on an
int. It isn't clear to me what you're trying to do exactly, replace the call to puts with an indirect call to the pointer value that correspond to puts in your current process? You would need to at least cast this pointer value to the right type, and use an
indirect call.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="color:#4472C4">Hey Mehdi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#4472C4"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:#4472C4">I simply try overloading “puts” with a custom address before I start the JIT process. I want to replace the call to “puts” with my own address. For a test purpose I tried this now:<br>
</span><span style="font-size:9.5pt;font-family:Consolas;color:black"> mainModue->getFunction(</span><span style="font-size:9.5pt;font-family:Consolas;color:#A31515">"puts"</span><span style="font-size:9.5pt;font-family:Consolas;color:black">)->replaceAllUsesWith(<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::</span><span style="font-size:9.5pt;font-family:Consolas;color:#2B91AF">ConstantExpr</span><span style="font-size:9.5pt;font-family:Consolas;color:black">::getPointerCast(<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::</span><span style="font-size:9.5pt;font-family:Consolas;color:#2B91AF">ConstantInt</span><span style="font-size:9.5pt;font-family:Consolas;color:black">::get(llvm::</span><span style="font-size:9.5pt;font-family:Consolas;color:#2B91AF">IntegerType</span><span style="font-size:9.5pt;font-family:Consolas;color:black">::get(context,
64), 0xF),<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black"> mainModue->getFunction(</span><span style="font-size:9.5pt;font-family:Consolas;color:#A31515">"puts"</span><span style="font-size:9.5pt;font-family:Consolas;color:black">)->getType()<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black"> )<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.5pt;font-family:Consolas;color:black"> );</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#4472C4">This code will crash the application though. I know that 0xF is not a correct address and that there can be stuff optimized, but currently I just want to ‘see’ that “puts” was overloaded with 0xF.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#4472C4"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#4472C4">Kind greetings<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#4472C4">Björn<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Best,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">-- <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">Mehdi<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"> <o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
<div>
<div>
<ol start="1" type="1">
<li class="gmail-m3997524881775611987msolistparagraph" style="mso-list:l1 level1 lfo2">
<o:p> </o:p></li><li class="gmail-m3997524881775611987msolistparagraph" style="mso-list:l1 level1 lfo2">
What might happen if I have two modules and use “replaceAllUsesWith” on a function of Module A, passing a function of Module B.<o:p></o:p></li></ol>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Thank you for the help in advance!<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Kind greetings<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Björn<o:p></o:p></p>
</div>
<p class="MsoNormal">Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Takeshi Fukushima. Junichi Tajika
<o:p></o:p></p>
</div>
<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>
</blockquote>
</div>
</div>
</div>
Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Takeshi Fukushima. Junichi Tajika
</body>
</html>