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</o:shapelayout></xml><![endif]--></head><body lang="EN-US"><div>Hi Tehila,</div><div><br></div><div>I recently added new function attributes to clang/llvm with arguments.</div><div><br></div><div>What I did is the following:</div><div><br></div><div>1. Add your attributes to tools/clang/include/clang/Basic/Attr.td</div><div><br></div><div><font face="monospace">def MYATTR : InheritableAttr {</font></div><div><font face="monospace"> let Spellings = [GNU<"myattr">, CXX11<"gnu", "myattr">];</font></div><div><font face="monospace"> let Args = [DefaultIntArgument<"myargument", 5>];</font></div><div><font face="monospace"> let Subjects = SubjectList<[Function]>;</font></div><div><font face="monospace"> let Documentation = [Undocumented];</font></div><div><font face="monospace">}</font></div><div><br></div><div>2. Manage it in tools/clang/lib/CodeGen/CGCall.cpp...</div><div><br></div><div><font face="monospace">void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,</font></div><div><font face="monospace"> const Decl *TargetDecl,</font></div><div><font face="monospace"> AttributeListType &PAL,</font></div><div><font face="monospace"> unsigned &CallingConv,</font></div><div><font face="monospace"> bool AttrOnCallSite) {</font></div><div><font face="monospace">//other code...</font></div><div><font face="monospace">if (TargetDecl) {</font></div><div><font face="monospace">if (TargetDecl->hasAttr<MYEXAMPLEAttr>())</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>{</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>auto myexample = TargetDecl->getAttr<MYEXAMPLEAttr>();</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>FuncAttrs.addAttribute("myexample");</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>unsigned myargument = myexample->getMyargument();</font></div><div><font face="monospace"><br></font></div><div><font face="monospace"><br></font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>FuncAttrs.addAttribute("myargument", llvm::utostr(myargument));</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>}</font></div><div><font face="monospace">//other code...</font></div><div><font face="monospace">}</font></div><div><font face="monospace">//other code...</font></div><div><font face="monospace">}</font></div><div><br></div><div><br></div><div>3. ...and in tools/clang/lib/Sema/SemaDeclAttr.cpp</div><div><br></div><div><font face="monospace">static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,</font></div><div><font face="monospace"> const AttributeList &Attr,</font></div><div><font face="monospace"> bool IncludeCXX11Attributes) {</font></div><div><font face="monospace">//other code...</font></div><div><font face="monospace">switch (Attr.getKind()) {</font></div><div><font face="monospace">case AttributeList::AT_MYEXAMPLE:</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>handleMYEXAMPLEAttr(S, D, Attr);</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>break;</font></div><div><font face="monospace">//other code...</font></div><div><font face="monospace">}</font></div><div><font face="monospace"><br></font></div><div><font face="monospace"><br></font></div><div><font face="monospace">static void handleMYEXAMPLEAttr(Sema &S, Decl *D, const AttributeList &Attr) {</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>uint32_t myargument = AVMAttr::DefaultMyargument;</font></div><div><font face="monospace"><br></font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>if (Attr.getNumArgs() && !checkUInt32Argument(S, Attr, Attr.getArgAsExpr(0), myargument))</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>return;</font></div><div><font face="monospace"><br></font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span>D->addAttr(::new (S.Context)</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>AVMAttr(Attr.getRange(), S.Context, myargument,</font></div><div><font face="monospace"><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>Attr.getAttributeSpellingListIndex()));</font></div><div><font face="monospace">}</font></div><div><br></div><div>Then you should have access to it in LLVM IR.</div><div><br></div><div>I may have forgotten some stuff but it should help you get started.</div><div><br></div><div>Regards,</div><div>Gael</div><div><br></div><div>Le jeudi 08 octobre 2015 à 10:02 +0300, Tehila Mayzels via llvm-dev a écrit :</div><blockquote type="cite"><div class="WordSection1"><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">Hi,<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">I'm trying to add a function attribute to clang/llvm.<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">I need an attribute that will have an additional information of a variable name.<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">e.g. I would like to add support for something like:<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">void foo() __attribute__ ((xyz(v)) {…}<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">such that on the IR stage I can realize that the function foo has the attribute xyz and an argument v that marks variable v (which is a variable inside foo) for my needs.<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">I was able to add a function attribute without an argument, but I don't understand how to parse/save/analyze the argument.<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><span style="font-size:11.5pt;background:#FCFAF3">I would appreciate any ideas</span>/examples/references.<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">Thanks a lot,<o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed">Tehila. <o:p></o:p></p><p class="MsoNormal" style="text-align:left;direction:ltr;unicode-bidi:embed"><o:p> </o:p></p><p class="MsoNormal" dir="RTL"><span dir="LTR"><o:p> </o:p></span></p></div><pre>_______________________________________________
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