<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Dec 31, 2016 at 1:41 PM, Richard Smith 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:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: rsmith<br>
Date: Sat Dec 31 15:41:23 2016<br>
New Revision: 290792<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=290792&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project?rev=290792&view=rev</a><br>
Log:<br>
[c++17] Implement P0522R0 as written. This allows a template template argument<br>
to be specified for a template template parameter whenever the parameter is at<br>
least as specialized as the argument (when there's an obvious and correct<br>
mapping from uses of the parameter to uses of the argument). For example, a<br>
template with more parameters can be passed to a template template parameter<br>
with fewer, if those trailing parameters have default arguments.<br>
<br>
This is disabled by default, despite being a DR resolution, as it's fairly<br>
broken in its current state: there are no partial ordering rules to cope with<br>
template template parameters that have different parameter lists, meaning that<br>
code that attempts to decompose template-ids based on arity can hit unavoidable<br>
ambiguity issues.<br>
<br>
The diagnostics produced on a non-matching argument are also pretty bad right<br>
now, but I aim to improve them in a subsequent commit.<br>
<br>
Added:<br>
cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template_cxx1z.cpp<br>
Modified:<br>
cfe/trunk/include/clang/Basic/<wbr>LangOptions.def<br>
cfe/trunk/include/clang/<wbr>Driver/Options.td<br>
cfe/trunk/include/clang/Sema/<wbr>Sema.h<br>
cfe/trunk/lib/Driver/Tools.cpp<br>
cfe/trunk/lib/Frontend/<wbr>CompilerInvocation.cpp<br>
cfe/trunk/lib/Sema/<wbr>SemaTemplate.cpp<br>
cfe/trunk/lib/Sema/<wbr>SemaTemplateDeduction.cpp<br>
cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template.cpp<br>
cfe/trunk/www/cxx_status.html<br>
<br>
Modified: cfe/trunk/include/clang/Basic/<wbr>LangOptions.def<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/LangOptions.def?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/include/<wbr>clang/Basic/LangOptions.def?<wbr>rev=290792&r1=290791&r2=<wbr>290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/include/clang/Basic/<wbr>LangOptions.def (original)<br>
+++ cfe/trunk/include/clang/Basic/<wbr>LangOptions.def Sat Dec 31 15:41:23 2016<br>
@@ -134,6 +134,7 @@ LANGOPT(NoBuiltin , 1, 0, "disab<br>
LANGOPT(NoMathBuiltin , 1, 0, "disable math builtin functions")<br>
LANGOPT(GNUAsm , 1, 1, "GNU-style inline assembly")<br>
LANGOPT(CoroutinesTS , 1, 0, "C++ coroutines TS")<br>
+LANGOPT(<wbr>RelaxedTemplateTemplateArgs, 1, 0, "C++17 relaxed matching of tempalte template arguments")<br></blockquote><div><br></div><div>Typo: tempalte</div><div><br></div><div>-- Sean Silva</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
BENIGN_LANGOPT(<wbr>ThreadsafeStatics , 1, 1, "thread-safe static initializers")<br>
LANGOPT(POSIXThreads , 1, 0, "POSIX thread support")<br>
<br>
Modified: cfe/trunk/include/clang/<wbr>Driver/Options.td<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/include/<wbr>clang/Driver/Options.td?rev=<wbr>290792&r1=290791&r2=290792&<wbr>view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/include/clang/<wbr>Driver/Options.td (original)<br>
+++ cfe/trunk/include/clang/<wbr>Driver/Options.td Sat Dec 31 15:41:23 2016<br>
@@ -1088,6 +1088,11 @@ def fapplication_extension : Flag<["-"],<br>
HelpText<"Restrict code to those available for App Extensions">;<br>
def fno_application_extension : Flag<["-"], "fno-application-extension">,<br>
Group<f_Group>;<br>
+def frelaxed_template_template_<wbr>args : Flag<["-"], "frelaxed-template-template-<wbr>args">,<br>
+ Flags<[CC1Option]>, HelpText<"Enable C++17 relaxed template template argument matching">,<br>
+ Group<f_Group>;<br>
+def fno_relaxed_template_template_<wbr>args : Flag<["-"], "fno-relaxed-template-<wbr>template-args">,<br>
+ Group<f_Group>;<br>
def fsized_deallocation : Flag<["-"], "fsized-deallocation">, Flags<[CC1Option]>,<br>
HelpText<"Enable C++14 sized global deallocation functions">, Group<f_Group>;<br>
def fno_sized_deallocation: Flag<["-"], "fno-sized-deallocation">, Group<f_Group>;<br>
<br>
Modified: cfe/trunk/include/clang/Sema/<wbr>Sema.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/include/<wbr>clang/Sema/Sema.h?rev=290792&<wbr>r1=290791&r2=290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/include/clang/Sema/<wbr>Sema.h (original)<br>
+++ cfe/trunk/include/clang/Sema/<wbr>Sema.h Sat Dec 31 15:41:23 2016<br>
@@ -6719,6 +6719,9 @@ public:<br>
bool isMoreSpecializedThanPrimary(<wbr>VarTemplatePartialSpecializati<wbr>onDecl *T,<br>
sema::TemplateDeductionInfo &Info);<br>
<br>
+ bool isTemplateTemplateParameterAtL<wbr>eastAsSpecializedAs(<br>
+ TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc);<br>
+<br>
void MarkUsedTemplateParameters(<wbr>const TemplateArgumentList &TemplateArgs,<br>
bool OnlyDeduced,<br>
unsigned Depth,<br>
<br>
Modified: cfe/trunk/lib/Driver/Tools.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/lib/Driver/<wbr>Tools.cpp?rev=290792&r1=<wbr>290791&r2=290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/lib/Driver/Tools.cpp (original)<br>
+++ cfe/trunk/lib/Driver/Tools.cpp Sat Dec 31 15:41:23 2016<br>
@@ -6020,6 +6020,13 @@ void Clang::ConstructJob(<wbr>Compilation &C,<br>
options::OPT_fno_assume_sane_<wbr>operator_new))<br>
CmdArgs.push_back("-fno-<wbr>assume-sane-operator-new");<br>
<br>
+ // -frelaxed-template-template-<wbr>args is off by default, as it is a severe<br>
+ // breaking change until a corresponding change to template partial ordering<br>
+ // is provided.<br>
+ if (Args.hasFlag(options::OPT_<wbr>frelaxed_template_template_<wbr>args,<br>
+ options::OPT_fno_relaxed_<wbr>template_template_args, false))<br>
+ CmdArgs.push_back("-frelaxed-<wbr>template-template-args");<br>
+<br>
// -fsized-deallocation is off by default, as it is an ABI-breaking change for<br>
// most platforms.<br>
if (Args.hasFlag(options::OPT_<wbr>fsized_deallocation,<br>
<br>
Modified: cfe/trunk/lib/Frontend/<wbr>CompilerInvocation.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/lib/<wbr>Frontend/CompilerInvocation.<wbr>cpp?rev=290792&r1=290791&r2=<wbr>290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/lib/Frontend/<wbr>CompilerInvocation.cpp (original)<br>
+++ cfe/trunk/lib/Frontend/<wbr>CompilerInvocation.cpp Sat Dec 31 15:41:23 2016<br>
@@ -1960,6 +1960,8 @@ static void ParseLangArgs(LangOptions &O<br>
if (!Opts.NoBuiltin)<br>
getAllNoBuiltinFuncValues(<wbr>Args, Opts.NoBuiltinFuncs);<br>
Opts.NoMathBuiltin = Args.hasArg(OPT_fno_math_<wbr>builtin);<br>
+ Opts.<wbr>RelaxedTemplateTemplateArgs =<br>
+ Args.hasArg(OPT_frelaxed_<wbr>template_template_args);<br>
Opts.SizedDeallocation = Args.hasArg(OPT_fsized_<wbr>deallocation);<br>
Opts.AlignedAllocation =<br>
Args.hasFlag(OPT_faligned_<wbr>allocation, OPT_fno_aligned_allocation,<br>
<br>
Modified: cfe/trunk/lib/Sema/<wbr>SemaTemplate.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/lib/Sema/<wbr>SemaTemplate.cpp?rev=290792&<wbr>r1=290791&r2=290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/lib/Sema/<wbr>SemaTemplate.cpp (original)<br>
+++ cfe/trunk/lib/Sema/<wbr>SemaTemplate.cpp Sat Dec 31 15:41:23 2016<br>
@@ -5585,6 +5585,10 @@ ExprResult Sema::CheckTemplateArgument(N<br>
return Arg;<br>
}<br>
<br>
+static void DiagnoseTemplateParameterListA<wbr>rityMismatch(<br>
+ Sema &S, TemplateParameterList *New, TemplateParameterList *Old,<br>
+ Sema::<wbr>TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc);<br>
+<br>
/// \brief Check a template argument against its corresponding<br>
/// template template parameter.<br>
///<br>
@@ -5601,6 +5605,9 @@ bool Sema::CheckTemplateArgument(<wbr>Templat<br>
return false;<br>
}<br>
<br>
+ if (Template->isInvalidDecl())<br>
+ return true;<br>
+<br>
// C++0x [temp.arg.template]p1:<br>
// A template-argument for a template template-parameter shall be<br>
// the name of a class template or an alias template, expressed as an<br>
@@ -5628,6 +5635,25 @@ bool Sema::CheckTemplateArgument(<wbr>Templat<br>
if (Param-><wbr>isExpandedParameterPack())<br>
Params = Param-><wbr>getExpansionTemplateParameters<wbr>(ArgumentPackIndex);<br>
<br>
+ // C++1z [temp.arg.template]p3: (DR 150)<br>
+ // A template-argument matches a template template-parameter P when P<br>
+ // is at least as specialized as the template-argument A.<br>
+ if (getLangOpts().<wbr>RelaxedTemplateTemplateArgs) {<br>
+ // Quick check for the common case:<br>
+ // If P contains a parameter pack, then A [...] matches P if each of A's<br>
+ // template parameters matches the corresponding template parameter in<br>
+ // the template-parameter-list of P.<br>
+ if (<wbr>TemplateParameterListsAreEqual<wbr>(<br>
+ Template-><wbr>getTemplateParameters(), Params, false,<br>
+ TPL_<wbr>TemplateTemplateArgumentMatch, Arg.getLocation()))<br>
+ return false;<br>
+<br>
+ if (<wbr>isTemplateTemplateParameterAtL<wbr>eastAsSpecializedAs(Params, Template,<br>
+ Arg.getLocation()))<br>
+ return false;<br>
+ // FIXME: Produce better diagnostics for deduction failures.<br>
+ }<br>
+<br>
return !<wbr>TemplateParameterListsAreEqual<wbr>(Template-><wbr>getTemplateParameters(),<br>
Params,<br>
true,<br>
@@ -5839,7 +5865,7 @@ static bool MatchTemplateParameterKind(S<br>
return false;<br>
}<br>
<br>
- // Check that both are parameter packs are neither are parameter packs.<br>
+ // Check that both are parameter packs or neither are parameter packs.<br>
// However, if we are matching a template template argument to a<br>
// template template parameter, the template template parameter can have<br>
// a parameter pack where the template template argument does not.<br>
<br>
Modified: cfe/trunk/lib/Sema/<wbr>SemaTemplateDeduction.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/lib/Sema/<wbr>SemaTemplateDeduction.cpp?rev=<wbr>290792&r1=290791&r2=290792&<wbr>view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/lib/Sema/<wbr>SemaTemplateDeduction.cpp (original)<br>
+++ cfe/trunk/lib/Sema/<wbr>SemaTemplateDeduction.cpp Sat Dec 31 15:41:23 2016<br>
@@ -1898,11 +1898,11 @@ DeduceTemplateArguments(Sema &S, Templat<br>
return NumberOfArgumentsMustMatch ? Sema::TDK_TooFewArguments<br>
: Sema::TDK_Success;<br>
<br>
- if (Args[ArgIdx].isPackExpansion(<wbr>)) {<br>
- // FIXME: We follow the logic of C++0x [temp.deduct.type]p22 here,<br>
- // but applied to pack expansions that are template arguments.<br>
+ // C++1z [temp.deduct.type]p9:<br>
+ // During partial ordering, if Ai was originally a pack expansion [and]<br>
+ // Pi is not a pack expansion, template argument deduction fails.<br>
+ if (Args[ArgIdx].isPackExpansion(<wbr>))<br>
return Sema::TDK_<wbr>MiscellaneousDeductionFailure;<br>
- }<br>
<br>
// Perform deduction for this Pi/Ai pair.<br>
if (Sema::TemplateDeductionResult Result<br>
@@ -1965,7 +1965,8 @@ DeduceTemplateArguments(Sema &S,<br>
TemplateDeductionInfo &Info,<br>
SmallVectorImpl<<wbr>DeducedTemplateArgument> &Deduced) {<br>
return DeduceTemplateArguments(S, TemplateParams, ParamList.asArray(),<br>
- ArgList.asArray(), Info, Deduced, false);<br>
+ ArgList.asArray(), Info, Deduced,<br>
+ /*NumberOfArgumentsMustMatch*/<wbr>false);<br>
}<br>
<br>
/// \brief Determine whether two template arguments are the same.<br>
@@ -4581,13 +4582,13 @@ UnresolvedSetIterator Sema::getMostSpeci<br>
/// Determine whether one partial specialization, P1, is at least as<br>
/// specialized than another, P2.<br>
///<br>
-/// \tparam PartialSpecializationDecl The kind of P2, which must be a<br>
-/// {Class,Var}Template{<wbr>PartialSpecialization,}Decl.<br>
+/// \tparam TemplateLikeDecl The kind of P2, which must be a<br>
+/// TemplateDecl or {Class,Var}<wbr>TemplatePartialSpecializationD<wbr>ecl.<br>
/// \param T1 The injected-class-name of P1 (faked for a variable template).<br>
/// \param T2 The injected-class-name of P2 (faked for a variable template).<br>
-template<typename PartialSpecializationDecl><br>
+template<typename TemplateLikeDecl><br>
static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2,<br>
- PartialSpecializationDecl *P2,<br>
+ TemplateLikeDecl *P2,<br>
TemplateDeductionInfo &Info) {<br>
// C++ [temp.class.order]p1:<br>
// For two class template partial specializations, the first is at least as<br>
@@ -4729,6 +4730,72 @@ bool Sema::<wbr>isMoreSpecializedThanPrimary(<br>
return true;<br>
}<br>
<br>
+bool Sema::<wbr>isTemplateTemplateParameterAtL<wbr>eastAsSpecializedAs(<br>
+ TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc) {<br>
+ // C++1z [temp.arg.template]p4: (DR 150)<br>
+ // A template template-parameter P is at least as specialized as a<br>
+ // template template-argument A if, given the following rewrite to two<br>
+ // function templates...<br>
+<br>
+ // Rather than synthesize function templates, we merely perform the<br>
+ // equivalent partial ordering by performing deduction directly on<br>
+ // the template parameter lists of the template template parameters.<br>
+ //<br>
+ // Given an invented class template X with the template parameter list of<br>
+ // A (including default arguments):<br>
+ TemplateName X = Context.<wbr>getCanonicalTemplateName(<wbr>TemplateName(AArg));<br>
+ TemplateParameterList *A = AArg->getTemplateParameters();<br>
+<br>
+ // - Each function template has a single function parameter whose type is<br>
+ // a specialization of X with template arguments corresponding to the<br>
+ // template parameters from the respective function template<br>
+ SmallVector<TemplateArgument, 8> AArgs;<br>
+ Context.<wbr>getInjectedTemplateArgs(A, AArgs);<br>
+<br>
+ // Check P's arguments against A's parameter list. This will fill in default<br>
+ // template arguments as needed. AArgs are already correct by construction.<br>
+ // We can't just use CheckTemplateIdType because that will expand alias<br>
+ // templates.<br>
+ SmallVector<TemplateArgument, 4> PArgs;<br>
+ {<br>
+ SFINAETrap Trap(*this);<br>
+<br>
+ Context.<wbr>getInjectedTemplateArgs(P, PArgs);<br>
+ TemplateArgumentListInfo PArgList(P->getLAngleLoc(), P->getRAngleLoc());<br>
+ for (unsigned I = 0, N = P->size(); I != N; ++I) {<br>
+ // Unwrap packs that getInjectedTemplateArgs wrapped around pack<br>
+ // expansions, to form an "as written" argument list.<br>
+ TemplateArgument Arg = PArgs[I];<br>
+ if (Arg.getKind() == TemplateArgument::Pack) {<br>
+ assert(Arg.pack_size() == 1 && Arg.pack_begin()-><wbr>isPackExpansion());<br>
+ Arg = *Arg.pack_begin();<br>
+ }<br>
+ PArgList.addArgument(<wbr>getTrivialTemplateArgumentLoc(<br>
+ Arg, QualType(), P->getParam(I)->getLocation())<wbr>);<br>
+ }<br>
+ PArgs.clear();<br>
+<br>
+ // C++1z [temp.arg.template]p3:<br>
+ // If the rewrite produces an invalid type, then P is not at least as<br>
+ // specialized as A.<br>
+ if (CheckTemplateArgumentList(<wbr>AArg, Loc, PArgList, false, PArgs) ||<br>
+ Trap.hasErrorOccurred())<br>
+ return false;<br>
+ }<br>
+<br>
+ QualType AType = Context.<wbr>getTemplateSpecializationType(<wbr>X, AArgs);<br>
+ QualType PType = Context.<wbr>getTemplateSpecializationType(<wbr>X, PArgs);<br>
+<br>
+ SmallVector<<wbr>DeducedTemplateArgument, 4> Deduced;<br>
+ Deduced.resize(A->size());<br>
+<br>
+ // ... the function template corresponding to P is at least as specialized<br>
+ // as the function template corresponding to A according to the partial<br>
+ // ordering rules for function templates.<br>
+ TemplateDeductionInfo Info(Loc, A->getDepth());<br>
+ return isAtLeastAsSpecializedAs(*<wbr>this, PType, AType, AArg, Info);<br>
+}<br>
+<br>
static void<br>
MarkUsedTemplateParameters(<wbr>ASTContext &Ctx,<br>
const TemplateArgument &TemplateArg,<br>
<br>
Modified: cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTemplate/temp_arg_template.cpp?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/test/<wbr>SemaTemplate/temp_arg_<wbr>template.cpp?rev=290792&r1=<wbr>290791&r2=290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template.cpp (original)<br>
+++ cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template.cpp Sat Dec 31 15:41:23 2016<br>
@@ -6,11 +6,12 @@ template<template<typename T> class X> s<br>
<br>
template<template<typename T, int I> class X> struct B; // expected-note{{previous template template parameter is here}}<br>
<br>
-template<template<int I> class X> struct C; // expected-note{{previous non-type template parameter with type 'int' is here}}<br>
+template<template<int I> class X> struct C; // expected-note 2{{previous non-type template parameter with type 'int' is here}}<br>
<br>
template<class> struct X; // expected-note{{too few template parameters in template template argument}}<br>
template<int N> struct Y; // expected-note{{template parameter has a different kind in template argument}}<br>
template<long N> struct Ylong; // expected-note{{template non-type parameter has a different type 'long' in template argument}}<br>
+template<const int &N> struct Yref; // expected-note{{template non-type parameter has a different type 'const int &' in template argument}}<br>
<br>
namespace N {<br>
template<class> struct Z;<br>
@@ -27,6 +28,7 @@ A<TooMany> *a5; // expected-error{{templ<br>
B<X> *a6; // expected-error{{template template argument has different template parameters than its corresponding template template parameter}}<br>
C<Y> *a7;<br>
C<Ylong> *a8; // expected-error{{template template argument has different template parameters than its corresponding template template parameter}}<br>
+C<Yref> *a9; // expected-error{{template template argument has different template parameters than its corresponding template template parameter}}<br>
<br>
template<typename T> void f(int);<br>
<br>
<br>
Added: cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template_cxx1z.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTemplate/temp_arg_template_cxx1z.cpp?rev=290792&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/test/<wbr>SemaTemplate/temp_arg_<wbr>template_cxx1z.cpp?rev=290792&<wbr>view=auto</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template_cxx1z.cpp (added)<br>
+++ cfe/trunk/test/SemaTemplate/<wbr>temp_arg_template_cxx1z.cpp Sat Dec 31 15:41:23 2016<br>
@@ -0,0 +1,102 @@<br>
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -frelaxed-template-template-<wbr>args %s<br>
+<br>
+// expected-note@temp_arg_<wbr>template_cxx1z.cpp:* 1+{{}}<br>
+<br>
+template<template<int> typename> struct Ti;<br>
+template<template<int...> typename> struct TPi;<br>
+template<template<int, int...> typename> struct TiPi;<br>
+template<template<int..., int...> typename> struct TPiPi; // FIXME: Why is this not ill-formed?<br>
+<br>
+template<typename T, template<T> typename> struct tT0;<br>
+template<template<typename T, T> typename> struct Tt0;<br>
+<br>
+template<template<typename> typename> struct Tt;<br>
+template<template<typename, typename...> typename> struct TtPt;<br>
+<br>
+template<int> struct i;<br>
+template<int, int = 0> struct iDi;<br>
+template<int, int> struct ii;<br>
+template<int...> struct Pi;<br>
+template<int, int, int...> struct iiPi;<br>
+<br>
+template<int, typename = int> struct iDt;<br>
+template<int, typename> struct it;<br>
+<br>
+template<typename T, T v> struct t0;<br>
+<br>
+template<typename...> struct Pt;<br>
+<br>
+namespace IntParam {<br>
+ using ok = Pt<Ti<i>,<br>
+ Ti<iDi>,<br>
+ Ti<Pi>,<br>
+ Ti<iDt>>;<br>
+ using err1 = Ti<ii>; // expected-error {{different template parameters}}<br>
+ using err2 = Ti<iiPi>; // expected-error {{different template parameters}}<br>
+ using err3 = Ti<t0>; // expected-error {{different template parameters}}<br>
+ using err4 = Ti<it>; // expected-error {{different template parameters}}<br>
+}<br>
+<br>
+// These are accepted by the backwards-compatibility "parameter pack in<br>
+// parameter matches any number of parameters in arguments" rule.<br>
+namespace IntPackParam {<br>
+ using ok = TPi<Pi>;<br>
+ using ok_compat = Pt<TPi<i>, TPi<iDi>, TPi<ii>, TPi<iiPi>>;<br>
+ using err1 = TPi<t0>; // expected-error {{different template parameters}}<br>
+ using err2 = TPi<iDt>; // expected-error {{different template parameters}}<br>
+ using err3 = TPi<it>; // expected-error {{different template parameters}}<br>
+}<br>
+<br>
+namespace IntAndPackParam {<br>
+ using ok = TiPi<Pi>;<br>
+ using ok_compat = Pt<TiPi<ii>, TiPi<iDi>, TiPi<iiPi>>;<br>
+ using err = TiPi<iDi>;<br>
+}<br>
+<br>
+namespace DependentType {<br>
+ using ok = Pt<tT0<int, i>, tT0<int, iDi>>;<br>
+ using err1 = tT0<int, ii>; // expected-error {{different template parameters}}<br>
+ using err2 = tT0<short, i>; // FIXME: should this be OK?<br>
+ using err2a = tT0<long long, i>; // FIXME: should this be OK (if long long is larger than int)?<br>
+ using err2b = tT0<void*, i>; // expected-error {{different template parameters}}<br>
+ using err3 = tT0<short, t0>; // expected-error {{different template parameters}}<br>
+<br>
+ using ok2 = Tt0<t0>;<br>
+ using err4 = Tt0<it>; // expected-error {{different template parameters}}<br>
+}<br>
+<br>
+namespace Auto {<br>
+ template<template<int> typename T> struct TInt {};<br>
+ template<template<int*> typename T> struct TIntPtr {};<br>
+ template<template<auto> typename T> struct TAuto {};<br>
+ template<template<auto*> typename T> struct TAutoPtr {};<br>
+ template<auto> struct Auto;<br>
+ template<auto*> struct AutoPtr;<br>
+ template<int> struct Int;<br>
+ template<int*> struct IntPtr;<br>
+<br>
+ TInt<Auto> ia;<br>
+ TInt<AutoPtr> iap; // FIXME: ill-formed<br>
+ TInt<Int> ii;<br>
+ TInt<IntPtr> iip; // expected-error {{different template parameters}}<br>
+<br>
+ TIntPtr<Auto> ipa;<br>
+ TIntPtr<AutoPtr> ipap;<br>
+ TIntPtr<Int> ipi; // expected-error {{different template parameters}}<br>
+ TIntPtr<IntPtr> ipip;<br>
+<br>
+ TAuto<Auto> aa;<br>
+ TAuto<AutoPtr> aap; // FIXME: ill-formed<br>
+ TAuto<Int> ai; // FIXME: ill-formed<br>
+ TAuto<IntPtr> aip; // FIXME: ill-formed<br>
+<br>
+ TAutoPtr<Auto> apa;<br>
+ TAutoPtr<AutoPtr> apap;<br>
+ TAutoPtr<Int> api; // FIXME: ill-formed<br>
+ TAutoPtr<IntPtr> apip; // FIXME: ill-formed<br>
+<br>
+ int n;<br>
+ template<auto A, decltype(A) B = &n> struct SubstFailure;<br>
+ TInt<SubstFailure> isf; // expected-error {{different template parameters}}<br>
+ TIntPtr<SubstFailure> ipsf; // expected-error {{different template parameters}}<br>
+}<br>
<br>
Modified: cfe/trunk/www/cxx_status.html<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_status.html?rev=290792&r1=290791&r2=290792&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/cfe/trunk/www/cxx_<wbr>status.html?rev=290792&r1=<wbr>290791&r2=290792&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- cfe/trunk/www/cxx_status.html (original)<br>
+++ cfe/trunk/www/cxx_status.html Sat Dec 31 15:41:23 2016<br>
@@ -733,7 +733,7 @@ as the draft C++1z standard evolves.<br>
<tr><br>
<td>Matching template template parameters to compatible arguments</td><br>
<td><a href="<a href="http://wg21.link/p0522r0" rel="noreferrer" target="_blank">http://wg21.link/p0522r0</a><wbr>">P0522R0</a></td><br>
- <td class="none" align="center">No <a href="#p0522">(12)</a></td><br>
+ <td class="partial" align="center">Partial <a href="#p0522">(12)</a></td><br>
</tr><br>
<tr><br>
<td>Removing deprecated dynamic exception specifications</td><br>
@@ -763,8 +763,12 @@ left to right in the callee. As a result<br>
functions using expression syntax are no longer guaranteed to be destroyed in<br>
reverse construction order in that ABI.<br>
</span><br><br>
-<span id="p0522">(12): This is the resolution to a Defect Report, so will be<br>
-applied to all language versions.<br>
+<span id="p0522">(12): Despite being the the resolution to a Defect Report, this<br>
+feature is disabled by default in all language versions, and can be enabled<br>
+explicitly with the flag <tt>-frelaxed-template-<wbr>template-args</tt>. The change<br>
+to the standard lacks a corresponding change for template partial ordering,<br>
+resulting in ambiguity errors for reasonable and previously-valid code. This<br>
+issue is expected to be rectified soon.<br>
</span><br>
</p><br>
</details><br>
<br>
<br>
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</blockquote></div><br></div></div>