Agree, any suggestions on where / how to add the tests? I don't find any existing regression tests that cover attributes print.<br><br>Michael<br><br><div class="gmail_quote">On Wed, Jan 16, 2013 at 6:56 PM, Richard Smith <span dir="ltr"><<a href="mailto:richard@metafoo.co.uk" target="_blank">richard@metafoo.co.uk</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">On Wed, Jan 16, 2013 at 6:35 PM, Michael Han <<a href="mailto:fragmentshaders@gmail.com">fragmentshaders@gmail.com</a>> wrote:<br>
> Attached patch should fix all issues pointed out in last review. Thanks!<br>
<br>
</div>Great, thanks. This looks basically fine, but it will need tests<br>
before it can be checked in. (Also, there are a couple of stray blank<br>
lines added to lib/Sema/CMakeLists.txt.)<br>
<div class="HOEnZb"><div class="h5"><br>
> On Wed, Jan 16, 2013 at 4:01 PM, Richard Smith <<a href="mailto:richard@metafoo.co.uk">richard@metafoo.co.uk</a>><br>
> wrote:<br>
>><br>
>> On Wed, Jan 16, 2013 at 3:27 PM, Michael Han <<a href="mailto:fragmentshaders@gmail.com">fragmentshaders@gmail.com</a>><br>
>> wrote:<br>
>> > Thanks! I have some inline comments below.<br>
>> ><br>
>> ><br>
>> > On Wed, Jan 16, 2013 at 2:27 PM, Richard Smith <<a href="mailto:richard@metafoo.co.uk">richard@metafoo.co.uk</a>><br>
>> > wrote:<br>
>> >><br>
>> >> Index: utils/TableGen/ClangAttrEmitter.cpp<br>
>> >> ===================================================================<br>
>> >> --- utils/TableGen/ClangAttrEmitter.cpp (revision 172543)<br>
>> >> +++ utils/TableGen/ClangAttrEmitter.cpp (working copy)<br>
>> >> @@ -735,6 +735,82 @@<br>
>> >> [...]<br>
>> >> + OS <<<br>
>> >> + " case(" << I << ") : {\n"<br>
>> >> + " OS << \"" + Prefix.str() + Spelling.str();<br>
>> >> +<br>
>> >> + if (Args.size()) OS << "(";<br>
>> >><br>
>> >> Please only generate parens if there are arguments. This has a<br>
>> >> semantic impact; for instance, [[noreturn()]] is ill-formed in C++11.<br>
>> ><br>
>> ><br>
>> > This code will not emit the parens if there is no arguments as<br>
>> > Args.size()<br>
>> > will be zero thus OS << "(" will not be executed. Is there an issue<br>
>> > here?<br>
>><br>
>> Just a lack of caffeine on my part! :)<br>
><br>
><br>
> OK :)<br>
><br>
>><br>
>><br>
>> >> @@ -1044,6 +1105,63 @@<br>
>> >> [...]<br>
>> >> + // We only care about attributes that participate sema checking,<br>
>> >> so<br>
>> >> + // skip those attributes that are not able to make their way to<br>
>> >> Sema.<br>
>> >><br>
>> >> ... participate *in* Sema checking<br>
>> >><br>
>> >> + if (!R.getValueAsBit("SemaHandler"))<br>
>> >> + continue;<br>
>> >><br>
>> >> Is this check necessary?<br>
>> ><br>
>> ><br>
>> > I think it is necessary. Attributes with sema handler set to 0 never<br>
>> > made to<br>
>> > Sema, and as a result no Attr will be constructed for these attributes.<br>
>><br>
>> OK, so we skip the !ASTNode items because there is no Attr subclass on<br>
>> which to store the spelling index, and we skip the !SemaHandler items<br>
>> because the parser itself ignores them, so they can't have a spelling.<br>
>> Makes sense, thanks.<br>
>><br>
>> Presumably that means the check for ASTNode isn't essential? In fact,<br>
>> we might want to be able to ask an AttributeList for, say, AT_Mode for<br>
>> its spelling, so perhaps we should drop the ASTNode check?<br>
><br>
><br>
> Agree. The ASTNode check is removed.<br>
><br>
>><br>
>><br>
>> >> + // Each distinct spelling yield an attribute kind.<br>
>> >> + if (R.getValueAsBit("DistinctSpellings")) {<br>
>> >> + for (unsigned I = 0; I < Spellings.size(); ++ I) {<br>
>> >> + OS <<<br>
>> >> + " case AT_" << Spellings[I]->getValueAsString("Name") << ":<br>
>> >> {\n"<br>
>> >> + " Index = " << I << ";\n"<br>
>> >> + " break;\n"<br>
>> >> + "}\n";<br>
>> >><br>
>> >> I think all DistinctSpellings spellings should have spelling index 0.<br>
>> >><br>
>> ><br>
>> > There are many parsed attribute kinds for an attribute with<br>
>> > DistinctSpellings set to 1, but it is still a single parsed attribute<br>
>> > (and I<br>
>> > think in fact we only have one attribute with DistinctSpellings set to 1<br>
>> > in<br>
>> > clang : the OwnershipAttr) and share a single spelling list that contain<br>
>> > multiple spellings, with each spelling maps to a source form, so we need<br>
>> > different indexes here.<br>
>><br>
>> They get different AT_ values but the same Attr subclass? OK, then<br>
>> this is fine. Thanks!<br>
>><br>
>> >> + OS << " if (Name == \""<br>
>> >> + << Spellings[I]->getValueAsString("Name") << "\" && "<br>
>> >> + << "AttrSyntax == \"" <<<br>
>> >> Spellings[I]->getValueAsString("Variety")<br>
>> >> + << "\" && Scope == \"" << Namespace << "\")\n"<br>
>> >> + << " return " << I << ";\n";<br>
>> >><br>
>> >> Please convert the Variety into the syntax enumeration, rather than<br>
>> >> converting the syntax value into a string, and compare this first.<br>
>> >> It'd be great to use a StringSwitch here, too (or even something<br>
>> >> faster, since we know that one of the syntaxes must match).<br>
>> >><br>
>> ><br>
>> > Thanks, I'll use the enumeration for now and think about produce faster<br>
>> > code<br>
>> > here.<br>
><br>
><br>
> The updated patch uses StringSwitch for this.<br>
><br>
>><br>
>> ><br>
>> >><br>
>> >> Index: lib/Sema/AttributeList.cpp<br>
>> >> ===================================================================<br>
>> >> --- lib/Sema/AttributeList.cpp (revision 172543)<br>
>> >> +++ lib/Sema/AttributeList.cpp (working copy)<br>
>> >> @@ -125,3 +125,39 @@<br>
>> >><br>
>> >> return ::getAttrKind(Buf);<br>
>> >> }<br>
>> >> +<br>
>> >> +unsigned AttributeList::getAttributeSpellListIndex() const {<br>
>> >><br>
>> >> getAttributeSpellingListIndex?<br>
>> >><br>
>> >> + switch (SyntaxUsed) {<br>
>> >> + default : {<br>
>> >> + llvm_unreachable("Unknown attribute syntax!");<br>
>> >> + break;<br>
>> >> + }<br>
>> >> + case (AS_GNU) : {<br>
>> >> + AttrSyntax = "GNU";<br>
>> >> + break;<br>
>> >> + }<br>
>> >><br>
>> >> This should be formatted as:<br>
>> ><br>
>> ><br>
>> > Thanks for pointing this out! I'll kill the curly braces in tablegen<br>
>> > emitted<br>
>> > code too :)<br>
>> ><br>
>> >><br>
>> >> switch (SyntaxUsed) {<br>
>> >> default:<br>
>> >> llvm_unreachable("Unknown attribute syntax!");<br>
>> >><br>
>> >> case AS_GNU:<br>
>> >> AttrSyntax = "GNU";<br>
>> >> break;<br>
>> >><br>
>> >> ... but, as noted above, don't do this conversion.<br>
>> >><br>
>> ><br>
>> > Thanks!<br>
>> > Michael<br>
>> ><br>
>> >><br>
>> >> On Wed, Jan 16, 2013 at 1:55 PM, Michael Han<br>
>> >> <<a href="mailto:fragmentshaders@gmail.com">fragmentshaders@gmail.com</a>><br>
>> >> wrote:<br>
>> >> > Cool thanks. Please take a look at attached patch, a brief<br>
>> >> > description :<br>
>> >> > - Introduce a new bit field in Attr to store the index into the<br>
>> >> > spelling<br>
>> >> > list of each attribute in Attr.td.<br>
>> >> > - Introduce a new method to AttributeList to generate the index based<br>
>> >> > on<br>
>> >> > attribute syntax, name, and scope.<br>
>> >> > Implementation of this method is generated through table-gen.<br>
>> >> > - Teach table-gen to print an attribute based on this index.<br>
>> >> ><br>
>> >> > Michael<br>
>> >> ><br>
>> >> ><br>
>> >> > On Mon, Jan 14, 2013 at 6:55 PM, Richard Smith<br>
>> >> > <<a href="mailto:richard@metafoo.co.uk">richard@metafoo.co.uk</a>><br>
>> >> > wrote:<br>
>> >> >><br>
>> >> >> On Mon, Jan 14, 2013 at 11:40 AM, Michael Han<br>
>> >> >> <<a href="mailto:fragmentshaders@gmail.com">fragmentshaders@gmail.com</a>><br>
>> >> >> wrote:<br>
>> >> >>><br>
>> >> >>> Hi Richard,<br>
>> >> >>><br>
>> >> >>> I think that is a great idea but I am not sure what value to pass<br>
>> >> >>> to<br>
>> >> >>> Attr<br>
>> >> >>> when it's constructed in SemaDeclAttr.cpp. I was hoping to reuse<br>
>> >> >>> the<br>
>> >> >>> syntax<br>
>> >> >>> enumerator value as the spelling list index but it does not work<br>
>> >> >>> for<br>
>> >> >>> all<br>
>> >> >>> cases (e.g. alignment attribute in GNU syntax has two spellings.).<br>
>> >> >>><br>
>> >> >>> Alternatively, at the time we construct an Attr, there is enough<br>
>> >> >>> information (both the syntax and the actual spelling) we can use to<br>
>> >> >>> print<br>
>> >> >>> the attribute in full fidelity. We can pass the spelling string to<br>
>> >> >>> the<br>
>> >> >>> Attr,<br>
>> >> >>> besides the syntax used as this patch did, so the printer will know<br>
>> >> >>> which<br>
>> >> >>> syntax and spelling to select. It would be more elegant to encode<br>
>> >> >>> both<br>
>> >> >>> information as a single index into the spelling list but I haven't<br>
>> >> >>> figured<br>
>> >> >>> out how to do that. Any suggestions on this?<br>
>> >> >><br>
>> >> >><br>
>> >> >> You would need to teach TableGen to emit a function which maps the<br>
>> >> >> attribute syntax, scope, and name to a spelling index (and to use<br>
>> >> >> the<br>
>> >> >> spelling index when printing the attribute). You can then use that<br>
>> >> >> to<br>
>> >> >> add a<br>
>> >> >> method to AttributeList to get the spelling index for an attribute.<br>
>> >> >><br>
>> >> >>><br>
>> >> >>> Cheers<br>
>> >> >>> Michael<br>
>> >> >>><br>
>> >> >>><br>
>> >> >>> On Fri, Jan 11, 2013 at 5:14 PM, Richard Smith<br>
>> >> >>> <<a href="mailto:richard@metafoo.co.uk">richard@metafoo.co.uk</a>><br>
>> >> >>> wrote:<br>
>> >> >>>><br>
>> >> >>>> Hi,<br>
>> >> >>>><br>
>> >> >>>> On Fri, Jan 11, 2013 at 3:53 PM, Michael Han<br>
>> >> >>>> <<a href="mailto:fragmentshaders@gmail.com">fragmentshaders@gmail.com</a>><br>
>> >> >>>> wrote:<br>
>> >> >>>>><br>
>> >> >>>>> Hi,<br>
>> >> >>>>><br>
>> >> >>>>> Attached patch is to fix PR14922. Currently when print an<br>
>> >> >>>>> attribute<br>
>> >> >>>>> the<br>
>> >> >>>>> GNU syntax will always be used, even if the attribute has no GNU<br>
>> >> >>>>> syntax.The<br>
>> >> >>>>> fix is to pass the syntax flag when constructing the Attr node<br>
>> >> >>>>> and<br>
>> >> >>>>> take that<br>
>> >> >>>>> into consideration when printing the attribute. The name of<br>
>> >> >>>>> actual<br>
>> >> >>>>> attribute<br>
>> >> >>>>> gets printed is read from table gen definition file so there is<br>
>> >> >>>>> still some<br>
>> >> >>>>> limitations, for example, when an attribute has multiple<br>
>> >> >>>>> spellings,<br>
>> >> >>>>> the<br>
>> >> >>>>> first spelling is used; and the namespace of the attribute (in<br>
>> >> >>>>> case<br>
>> >> >>>>> it's a<br>
>> >> >>>>> C++11 attribute) is not printed. I test the patch locally in my<br>
>> >> >>>>> project<br>
>> >> >>>>> which has access to Clang AST but I am not sure how to write a<br>
>> >> >>>>> stand<br>
>> >> >>>>> alone<br>
>> >> >>>>> test to test the attribute pretty print. After this patch gets<br>
>> >> >>>>> in<br>
>> >> >>>>> I'll send<br>
>> >> >>>>> another patch which updates the SemaDeclAttr to pass the actual<br>
>> >> >>>>> syntax flag<br>
>> >> >>>>> from AttributeList to Attr.<br>
>> >> >>>><br>
>> >> >>>><br>
>> >> >>>> I don't think this is the best approach: it still always uses the<br>
>> >> >>>> first<br>
>> >> >>>> spelling, so it still won't produce the right string for<br>
>> >> >>>> __attribute__((aligned(...))) versus __declspec(alignment(...))<br>
>> >> >>>> versus<br>
>> >> >>>> [[gnu::aligned(...)]] versus alignas(...).<br>
>> >> >>>><br>
>> >> >>>> Since we already have a list of possible spellings for an<br>
>> >> >>>> attribute<br>
>> >> >>>> in<br>
>> >> >>>> the attribute definition (which incorporates the syntax used), how<br>
>> >> >>>> about<br>
>> >> >>>> just storing an index into that list on the Attr?<br>
>> >> >>><br>
>> >> >>><br>
>> >> >><br>
>> >> ><br>
>> ><br>
>> ><br>
><br>
><br>
</div></div></blockquote></div><br>