<div dir="auto"><div class="gmail_extra" dir="auto"><div class="gmail_quote">On 7 Apr 2017 11:49 am, "David Majnemer via cfe-commits" <<a href="mailto:cfe-commits@lists.llvm.org">cfe-commits@lists.llvm.org</a>> wrote:<br type="attribution"><blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote"><div class="quoted-text">On Fri, Apr 7, 2017 at 8:30 AM, Aaron Ballman via cfe-commits <span dir="ltr"><<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><span class="m_1340148197748705084gmail-">On Fri, Apr 7, 2017 at 11:13 AM, Saleem Abdulrasool via cfe-commits<br>
<<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>> wrote:<br>
> Author: compnerd<br>
> Date: Fri Apr 7 10:13:47 2017<br>
> New Revision: 299774<br>
><br>
> URL: <a href="http://llvm.org/viewvc/llvm-project?rev=299774&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-pr<wbr>oject?rev=299774&view=rev</a><br>
> Log:<br>
> Sema: prevent __declspec(naked) use on x64<br>
><br>
> MSDN (<a href="https://msdn.microsoft.com/en-us/library/h5w10wxs.aspx" rel="noreferrer" target="_blank">https://msdn.microsoft.com/en<wbr>-us/library/h5w10wxs.aspx</a>) indicates<br>
> that `__declspec(naked)` is only permitted on x86 and ARM targets.<br>
> Testing with cl does confirm this behaviour. Provide a warning for use<br>
> of `__declspec(naked)` on x64.<br>
<br>
</span>Your patch is not providing a warning, it's providing an error, which<br>
seems inappropriate (to me). Why is this attribute not silently<br>
ignored there instead?<br></blockquote><div><br></div></div><div>FWIW, MSVC diagnoses this with an error: <a href="https://godbolt.org/g/T5sQr5" target="_blank">https://godbolt.org/g/<wbr>T5sQr5</a></div></div></div></div></blockquote></div></div><div dir="auto"><br></div><div dir="auto">Is there a reason we can't support this? Was our existing support broken in some way? We generally allow our features to be combined in arbitrary ways unless there's a reason not to.</div><div dir="auto"><br></div><div class="gmail_extra" dir="auto"><div class="gmail_quote"><blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div class="elided-text"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
(Btw, I did not see a review thread for this, did I miss one?) More<br>
comments below.<br>
<div><div class="m_1340148197748705084gmail-h5"><br>
><br>
> Added:<br>
> cfe/trunk/test/Sema/declspec-<wbr>naked.c<br>
> Modified:<br>
> cfe/trunk/include/clang/<wbr>Basic/DiagnosticSemaKinds.td<br>
> cfe/trunk/lib/Sema/SemaDeclAt<wbr>tr.cpp<br>
> cfe/trunk/test/Sema/ms-<wbr>inline-asm.c<br>
><br>
> Modified: cfe/trunk/include/clang/Basic/<wbr>DiagnosticSemaKinds.td<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=299774&r1=299773&r2=299774&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-pr<wbr>oject/cfe/trunk/include/clang/<wbr>Basic/DiagnosticSemaKinds.td?<wbr>rev=299774&r1=299773&r2=<wbr>299774&view=diff</a><br>
> ==============================<wbr>==============================<wbr>==================<br>
> --- cfe/trunk/include/clang/Basic/<wbr>DiagnosticSemaKinds.td (original)<br>
> +++ cfe/trunk/include/clang/Basic/<wbr>DiagnosticSemaKinds.td Fri Apr 7 10:13:47 2017<br>
> @@ -3231,7 +3231,8 @@ def err_attribute_regparm_invalid_<wbr>number<br>
> "'regparm' parameter must be between 0 and %0 inclusive">;<br>
> def err_attribute_not_supported_in<wbr>_lang : Error<<br>
> "%0 attribute is not supported in %select{C|C++|Objective-C}1">;<br>
> -<br>
> +def err_attribute_not_supported_on<wbr>_arch<br>
> + : Error<"%0 attribute is not supported on '%1'">;<br>
><br>
> // Clang-Specific Attributes<br>
> def warn_attribute_iboutlet : Warning<<br>
><br>
> Modified: cfe/trunk/lib/Sema/SemaDeclAtt<wbr>r.cpp<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=299774&r1=299773&r2=299774&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-pr<wbr>oject/cfe/trunk/lib/Sema/SemaD<wbr>eclAttr.cpp?rev=299774&r1=<wbr>299773&r2=299774&view=diff</a><br>
> ==============================<wbr>==============================<wbr>==================<br>
> --- cfe/trunk/lib/Sema/SemaDeclAtt<wbr>r.cpp (original)<br>
> +++ cfe/trunk/lib/Sema/SemaDeclAtt<wbr>r.cpp Fri Apr 7 10:13:47 2017<br>
> @@ -1923,6 +1923,17 @@ static void handleNakedAttr(Sema &S, Dec<br>
> Attr.getName()))<br>
> return;<br>
><br>
> + if (Attr.isDeclspecAttribute()) {<br>
> + const auto &Triple = S.getASTContext().getTargetInf<wbr>o().getTriple();<br>
<br>
</div></div>No need to have the Triple variable (which is a rather poor name given<br>
that it's also the type name).<br>
<span class="m_1340148197748705084gmail-">> + const auto &Arch = Triple.getArch();<br>
<br>
</span>Do not use auto for either of these.<br>
<br>
~Aaron<br>
<div class="m_1340148197748705084gmail-HOEnZb"><div class="m_1340148197748705084gmail-h5"><br>
> + if (Arch != llvm::Triple::x86 &&<br>
> + (Arch != llvm::Triple::arm && Arch != llvm::Triple::thumb)) {<br>
> + S.Diag(Attr.getLoc(), diag::err_attribute_not_suppor<wbr>ted_on_arch)<br>
> + << Attr.getName() << Triple.getArchName();<br>
> + return;<br>
> + }<br>
> + }<br>
> +<br>
> D->addAttr(::new (S.Context) NakedAttr(Attr.getRange(), S.Context,<br>
> Attr.getAttributeSpellingList<wbr>Index()));<br>
> }<br>
><br>
> Added: cfe/trunk/test/Sema/declspec-n<wbr>aked.c<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/declspec-naked.c?rev=299774&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-pr<wbr>oject/cfe/trunk/test/Sema/decl<wbr>spec-naked.c?rev=299774&view=<wbr>auto</a><br>
> ==============================<wbr>==============================<wbr>==================<br>
> --- cfe/trunk/test/Sema/declspec-n<wbr>aked.c (added)<br>
> +++ cfe/trunk/test/Sema/declspec-n<wbr>aked.c Fri Apr 7 10:13:47 2017<br>
> @@ -0,0 +1,11 @@<br>
> +// RUN: %clang_cc1 -triple i686-unknown-windows-msvc -fsyntax-only -fdeclspec -verify %s<br>
> +// RUN: %clang_cc1 -triple thumbv7-unknown-windows-msvc -fsyntax-only -fdeclspec -verify %s<br>
> +// RUN: %clang_cc1 -triple x86_64-unknown-windows-msvc -fsyntax-only -fdeclspec -verify %s<br>
> +#if defined(_M_IX86) || defined(_M_ARM)<br>
> +// CHECK: expected-no-diagnostics<br>
> +#endif<br>
> +<br>
> +void __declspec(naked) f(void) {}<br>
> +#if !defined(_M_IX86) && !defined(_M_ARM)<br>
> +// expected-error@-2{{'naked' attribute is not supported on 'x86_64'}}<br>
> +#endif<br>
><br>
> Modified: cfe/trunk/test/Sema/ms-inline-<wbr>asm.c<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/ms-inline-asm.c?rev=299774&r1=299773&r2=299774&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-pr<wbr>oject/cfe/trunk/test/Sema/ms-<wbr>inline-asm.c?rev=299774&r1=299<wbr>773&r2=299774&view=diff</a><br>
> ==============================<wbr>==============================<wbr>==================<br>
> --- cfe/trunk/test/Sema/ms-inline-<wbr>asm.c (original)<br>
> +++ cfe/trunk/test/Sema/ms-inline-<wbr>asm.c Fri Apr 7 10:13:47 2017<br>
> @@ -1,5 +1,5 @@<br>
> // REQUIRES: x86-registered-target<br>
> -// RUN: %clang_cc1 %s -triple x86_64-apple-darwin10 -fms-extensions -fasm-blocks -Wno-microsoft -Wunused-label -verify -fsyntax-only<br>
> +// RUN: %clang_cc1 %s -triple i386-apple-darwin10 -fms-extensions -fasm-blocks -Wno-microsoft -Wunused-label -verify -fsyntax-only<br>
><br>
> void t1(void) {<br>
> __asm __asm // expected-error {{__asm used with no assembly instructions}}<br>
><br>
><br>
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