<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>Le 4 juil. 2012 à 14:42, Abramo Bagnara a écrit :</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Il 04/07/2012 14:01, Jean-Daniel Dupas ha scritto:<br><blockquote type="cite"><br></blockquote><blockquote type="cite">Le 4 juil. 2012 à 12:42, Enea Zaffanella a écrit :<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><blockquote type="cite">We have noticed that, in the AST produced by clang, the expression <br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">argument of a CXXDeleteExpr node is implicitly converted to void*:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"># cat delete.cc<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">struct S {};<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">void free(S* ps) {<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"> delete ps;<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">}<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"># llvm/Debug+Asserts/bin/clang -cc1 -ast-dump delete.cc<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">[...]<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">void free(S *ps) (CompoundStmt 0x4822650 <delete.cc:3:18, line:5:1><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"> (CXXDeleteExpr 0x4822628 <line:4:3, col:10> 'void'<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"> (ImplicitCastExpr 0x4821df8 <col:10> 'void *' <BitCast><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"> (ImplicitCastExpr 0x4821de0 <col:10> 'struct S *' <LValueToRValue><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"> (DeclRefExpr 0x4821db8 <col:10> 'struct S *' lvalue ParmVar <br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">0x47eeb20 'ps' 'struct S *')))))<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">What are the reasons for introducing such an implicit cast?<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Enea.<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Just a though, but isn't it because the signature of delete is:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">operator delete(void *);<br></blockquote><br>I don't think so:<br><br>delete ptr;<br><br>is something very different from<br><br>operator delete(ptr);<br></div></blockquote><br></div><div><br></div><div>I'm not sure it is quite different.</div><div><br></div><div>This is the IR generated by clang++ for this code with c++filt <span style="font-family: Menlo; font-size: 11px; ">_ZdlPv = </span>operator delete(void*):</div><div><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; ">define void @_Z4freeP1S(%struct.S* %ps) nounwind uwtable ssp {</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; ">entry:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "> %isnull = icmp eq %struct.S* %ps, null</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "> br i1 %isnull, label %delete.end, label %delete.notnull</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; min-height: 13px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; ">delete.notnull: <span style="color: #008426">; preds = %entry</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "> %<span style="color: #2f2fcf">0</span> = getelementptr inbounds %struct.S* %ps, i64 <span style="color: #2f2fcf">0</span>, i32 <span style="color: #2f2fcf">0</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "> tail call void @_ZdlPv(i8* %<span style="color: #2f2fcf">0</span>) nounwind</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "> br label %delete.end</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; min-height: 13px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; ">delete.end: <span style="color: #008426">; preds = %delete.notnull, %entry</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "> ret void</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; ">}</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; min-height: 13px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; ">declare void @_ZdlPv(i8*) nounwind</div><div><br></div><div><br></div></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Menlo; font-size: 11px; "><br></div></div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; "><div>-- Jean-Daniel</div><div><br></div><div><br></div></span><br class="Apple-interchange-newline">
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