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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'>Hi Gael,<o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'><o:p> </o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'>Thanks a lot for your response, it was very helpful!<o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'>How did you manage to access the argument value at the IR stage?<o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'><o:p> </o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'>Thanks again,<o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;color:black'>Tehila.</span><span lang=HE dir=RTL style='font-size:13.5pt;font-family:"Arial","sans-serif";color:black'><o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><b><span style='font-size:13.5pt;color:black'><o:p> </o:p></span></b></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><b><span style='font-size:13.5pt;color:black'>Gaël Jobin via llvm-dev</span></b><span class=apple-converted-space><span style='font-size:13.5pt;color:black;background:white'> </span></span><a href="mailto:llvm-dev%40lists.llvm.org?Subject=Re%3A%20%5Bllvm-dev%5D%20Adding%20a%20function%20attribute%20with%20an%20argument&In-Reply-To=%3C1444291685.8458.15.camel%40switzerlandmail.ch%3E" title="[llvm-dev] Adding a function attribute with an argument"><span style='font-size:13.5pt'>llvm-dev at lists.llvm.org</span><span class=apple-converted-space><span style='font-size:13.5pt;color:blue;text-decoration:none'> </span></span></a><span style='font-size:13.5pt;color:black'><br><i>Thu Oct 8 01:08:05 PDT 2015</i></span><o:p></o:p></p><pre><span style='color:black'>>Hi Tehila,<o:p></o:p></span></pre><pre><span style='color:black'>>I recently added new function attributes to clang/llvm with arguments.<o:p></o:p></span></pre><pre><span style='color:black'>>What I did is the following:<o:p></o:p></span></pre><pre><span style='color:black'>>1. Add your attributes to tools/clang/include/clang/Basic/Attr.td<o:p></o:p></span></pre><pre><span style='color:black'>>def MYATTR : InheritableAttr {<o:p></o:p></span></pre><pre><span style='color:black'>> let Spellings = [GNU<"myattr">, CXX11<"gnu", "myattr">];<o:p></o:p></span></pre><pre><span style='color:black'>> let Args = [DefaultIntArgument<"myargument", 5>];<o:p></o:p></span></pre><pre><span style='color:black'>> let Subjects = SubjectList<[Function]>;<o:p></o:p></span></pre><pre><span style='color:black'>> let Documentation = [Undocumented];<o:p></o:p></span></pre><pre><span style='color:black'>>}<o:p></o:p></span></pre><pre><span style='color:black'>>2. Manage it in tools/clang/lib/CodeGen/CGCall.cpp...<o:p></o:p></span></pre><pre><span style='color:black'>>void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,<o:p></o:p></span></pre><pre><span style='color:black'>> const Decl *TargetDecl,<o:p></o:p></span></pre><pre><span style='color:black'>> AttributeListType &PAL,<o:p></o:p></span></pre><pre><span style='color:black'>> unsigned &CallingConv,<o:p></o:p></span></pre><pre><span style='color:black'>> bool AttrOnCallSite) {<o:p></o:p></span></pre><pre><span style='color:black'>>//other code...<o:p></o:p></span></pre><pre><span style='color:black'>>if (TargetDecl) {<o:p></o:p></span></pre><pre><span style='color:black'>>if (TargetDecl->hasAttr<MYEXAMPLEAttr>())<o:p></o:p></span></pre><pre><span style='color:black'>> {<o:p></o:p></span></pre><pre><span style='color:black'>> auto myexample = TargetDecl->getAttr<MYEXAMPLEAttr>();<o:p></o:p></span></pre><pre><span style='color:black'>> FuncAttrs.addAttribute("myexample");<o:p></o:p></span></pre><pre><span style='color:black'>> unsigned myargument = myexample->getMyargument();<o:p></o:p></span></pre><pre><span style='color:black'>><o:p> </o:p></span></pre><pre><span style='color:black'>><o:p> </o:p></span></pre><pre><span style='color:black'>> FuncAttrs.addAttribute("myargument",<o:p></o:p></span></pre><pre><span style='color:black'>>llvm::utostr(myargument));<o:p></o:p></span></pre><pre><span style='color:black'>> }<o:p></o:p></span></pre><pre><span style='color:black'>>//other code...<o:p></o:p></span></pre><pre><span style='color:black'>>}<o:p></o:p></span></pre><pre><span style='color:black'>>//other code...<o:p></o:p></span></pre><pre><span style='color:black'>>}<o:p></o:p></span></pre><pre><span style='color:black'>>3. ...and in tools/clang/lib/Sema/SemaDeclAttr.cpp<o:p></o:p></span></pre><pre><span style='color:black'>>static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,<o:p></o:p></span></pre><pre><span style='color:black'>> const AttributeList &Attr,<o:p></o:p></span></pre><pre><span style='color:black'>> bool IncludeCXX11Attributes) {<o:p></o:p></span></pre><pre><span style='color:black'>>//other code...<o:p></o:p></span></pre><pre><span style='color:black'>>switch (Attr.getKind()) {<o:p></o:p></span></pre><pre><span style='color:black'>>case AttributeList::AT_MYEXAMPLE:<o:p></o:p></span></pre><pre><span style='color:black'>> handleMYEXAMPLEAttr(S, D, Attr);<o:p></o:p></span></pre><pre><span style='color:black'>> break;<o:p></o:p></span></pre><pre><span style='color:black'>>//other code...<o:p></o:p></span></pre><pre><span style='color:black'>>}<o:p></o:p></span></pre><pre><span style='color:black'>><o:p> </o:p></span></pre><pre><span style='color:black'>><o:p> </o:p></span></pre><pre><span style='color:black'>>static void handleMYEXAMPLEAttr(Sema &S, Decl *D, const AttributeList<o:p></o:p></span></pre><pre><span style='color:black'>>&Attr) {<o:p></o:p></span></pre><pre><span style='color:black'>> uint32_t myargument = AVMAttr::DefaultMyargument;<o:p></o:p></span></pre><pre><span style='color:black'>><o:p> </o:p></span></pre><pre><span style='color:black'>> if (Attr.getNumArgs() && !checkUInt32Argument(S, Attr,<o:p></o:p></span></pre><pre><span style='color:black'>>Attr.getArgAsExpr(0), myargument))<o:p></o:p></span></pre><pre><span style='color:black'>> return;<o:p></o:p></span></pre><pre><span style='color:black'>><o:p> </o:p></span></pre><pre><span style='color:black'>> D->addAttr(::new (S.Context)<o:p></o:p></span></pre><pre><span style='color:black'>> AVMAttr(Attr.getRange(), S.Context, myargument,<o:p></o:p></span></pre><pre><span style='color:black'>> Attr.getAttributeSpellingListIndex()));<o:p></o:p></span></pre><pre><span style='color:black'>>}<o:p></o:p></span></pre><pre><span style='color:black'>>Then you should have access to it in LLVM IR.<o:p></o:p></span></pre><pre><span style='color:black'>>I may have forgotten some stuff but it should help you get started.<o:p></o:p></span></pre><pre><span style='color:black'>>Regards,<o:p></o:p></span></pre><pre><span style='color:black'>>Gael<o:p></o:p></span></pre><pre><span style='color:black'>>Le jeudi 08 octobre 2015 à 10:02 +0300, Tehila Mayzels via llvm-dev a<o:p></o:p></span></pre><pre><span style='color:black'>>écrit :<o:p></o:p></span></pre><pre><span style='color:black'>>><i> Hi,<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> I'm trying to add a function attribute to clang/llvm.<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> I need an attribute that will have an additional information of a<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> variable name.<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> e.g. I would like to add support for something like:<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> void foo() __attribute__ ((xyz(v)) {…}<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> such that on the IR stage I can realize that the function foo has the<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> attribute xyz and an argument v that marks variable v (which is a<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> variable inside foo) for my needs.<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> I was able to add a function attribute without an argument, but I<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> don't understand how to parse/save/analyze the argument.<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> I would appreciate any ideas/examples/references.<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> Thanks a lot,<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> Tehila.<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> _______________________________________________<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> LLVM Developers mailing list<o:p></o:p></i></span></pre><pre><span style='color:black'>>><i> <a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev">llvm-dev at lists.llvm.org</a><o:p></o:p></i></span></pre><pre><span style='color:black'>><i> <a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a></i><o:p></o:p></span></pre><p class=MsoNormal dir=RTL><span dir=LTR><o:p> </o:p></span></p></div></body></html>