[cfe-commits] r123279 - in /cfe/trunk: lib/Sema/SemaTemplateDeduction.cpp lib/Sema/TreeTransform.h test/CXX/temp/temp.decls/temp.variadic/partial-ordering.cpp test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.type/p22.cpp
Douglas Gregor
dgregor at apple.com
Tue Jan 11 14:21:25 PST 2011
Author: dgregor
Date: Tue Jan 11 16:21:24 2011
New Revision: 123279
URL: http://llvm.org/viewvc/llvm-project?rev=123279&view=rev
Log:
Implement partial ordering of class template partial specializations
and function templates that contain variadic templates. This involves
three small-ish changes:
(1) When transforming a pack expansion, if the transformed argument
still contains unexpanded parameter packs, build a pack
expansion. This can happen during the substitution that occurs into
class template partial specialiation template arguments during
partial ordering.
(2) When performing template argument deduction where the argument
is a pack expansion, match against the pattern of that pack
expansion.
(3) When performing template argument deduction against a non-pack
parameter, or a non-expansion template argument, deduction fails if
the argument itself is a pack expansion (C++0x
[temp.deduct.type]p22).
Added:
cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/partial-ordering.cpp
cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp
cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.type/p22.cpp
Modified:
cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp
cfe/trunk/lib/Sema/TreeTransform.h
Modified: cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp?rev=123279&r1=123278&r2=123279&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplateDeduction.cpp Tue Jan 11 16:21:24 2011
@@ -80,7 +80,7 @@
DeduceTemplateArguments(Sema &S,
TemplateParameterList *TemplateParams,
const TemplateArgument &Param,
- const TemplateArgument &Arg,
+ TemplateArgument Arg,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced);
@@ -677,6 +677,13 @@
if (ArgIdx >= NumArgs)
return Sema::TDK_NonDeducedMismatch;
+ if (isa<PackExpansionType>(Args[ArgIdx])) {
+ // C++0x [temp.deduct.type]p22:
+ // If the original function parameter associated with A is a function
+ // parameter pack and the function parameter associated with P is not
+ // a function parameter pack, then template argument deduction fails.
+ return Sema::TDK_NonDeducedMismatch;
+ }
if (Sema::TemplateDeductionResult Result
= DeduceTemplateArguments(S, TemplateParams,
@@ -814,6 +821,12 @@
QualType Param = S.Context.getCanonicalType(ParamIn);
QualType Arg = S.Context.getCanonicalType(ArgIn);
+ // If the argument type is a pack expansion, look at its pattern.
+ // This isn't explicitly called out
+ if (const PackExpansionType *ArgExpansion
+ = dyn_cast<PackExpansionType>(Arg))
+ Arg = ArgExpansion->getPattern();
+
if (PartialOrdering) {
// C++0x [temp.deduct.partial]p5:
// Before the partial ordering is done, certain transformations are
@@ -1273,9 +1286,15 @@
DeduceTemplateArguments(Sema &S,
TemplateParameterList *TemplateParams,
const TemplateArgument &Param,
- const TemplateArgument &Arg,
+ TemplateArgument Arg,
TemplateDeductionInfo &Info,
llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
+ // If the template argument is a pack expansion, perform template argument
+ // deduction against the pattern of that expansion. This only occurs during
+ // partial ordering.
+ if (Arg.isPackExpansion())
+ Arg = Arg.getPackExpansionPattern();
+
switch (Param.getKind()) {
case TemplateArgument::Null:
assert(false && "Null template argument in parameter list");
@@ -1448,11 +1467,17 @@
return NumberOfArgumentsMustMatch? Sema::TDK_NonDeducedMismatch
: Sema::TDK_Success;
+ if (Args[ArgIdx].isPackExpansion()) {
+ // FIXME: We follow the logic of C++0x [temp.deduct.type]p22 here,
+ // but applied to pack expansions that are template arguments.
+ return Sema::TDK_NonDeducedMismatch;
+ }
+
// Perform deduction for this Pi/Ai pair.
if (Sema::TemplateDeductionResult Result
- = DeduceTemplateArguments(S, TemplateParams,
- Params[ParamIdx], Args[ArgIdx],
- Info, Deduced))
+ = DeduceTemplateArguments(S, TemplateParams,
+ Params[ParamIdx], Args[ArgIdx],
+ Info, Deduced))
return Result;
// Move to the next argument.
@@ -1792,7 +1817,7 @@
return Sema::TDK_SubstitutionFailure;
}
}
-
+
// Form the template argument list from the deduced template arguments.
TemplateArgumentList *DeducedArgumentList
= TemplateArgumentList::CreateCopy(S.Context, Builder.data(),
Modified: cfe/trunk/lib/Sema/TreeTransform.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=123279&r1=123278&r2=123279&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/TreeTransform.h (original)
+++ cfe/trunk/lib/Sema/TreeTransform.h Tue Jan 11 16:21:24 2011
@@ -2327,6 +2327,12 @@
if (Out.isInvalid())
return true;
+ if (Out.get()->containsUnexpandedParameterPack()) {
+ Out = RebuildPackExpansion(Out.get(), Expansion->getEllipsisLoc());
+ if (Out.isInvalid())
+ return true;
+ }
+
if (ArgChanged)
*ArgChanged = true;
Outputs.push_back(Out.get());
@@ -2847,6 +2853,12 @@
if (getDerived().TransformTemplateArgument(Pattern, Out))
return true;
+ if (Out.getArgument().containsUnexpandedParameterPack()) {
+ Out = getDerived().RebuildPackExpansion(Out, Ellipsis);
+ if (Out.getArgument().isNull())
+ return true;
+ }
+
Outputs.addArgument(Out);
}
Added: cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/partial-ordering.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/partial-ordering.cpp?rev=123279&view=auto
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/partial-ordering.cpp (added)
+++ cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/partial-ordering.cpp Tue Jan 11 16:21:24 2011
@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s
+
+// Various tests related to partial ordering of variadic templates.
+template<typename ...Types> struct tuple;
+
+template<typename Tuple>
+struct X1 {
+ static const unsigned value = 0;
+};
+
+template<typename Head, typename ...Tail>
+struct X1<tuple<Head, Tail...> > {
+ static const unsigned value = 1;
+};
+
+template<typename Head, typename ...Tail>
+struct X1<tuple<Head, Tail&...> > {
+ static const unsigned value = 2;
+};
+
+template<typename Head, typename ...Tail>
+struct X1<tuple<Head&, Tail&...> > {
+ static const unsigned value = 3;
+};
+
+int check0[X1<tuple<>>::value == 0? 1 : -1];
+int check1[X1<tuple<int>>::value == 2? 1 : -1];
+int check2[X1<tuple<int, int>>::value == 1? 1 : -1];
+int check3[X1<tuple<int, int&>>::value == 2? 1 : -1];
+int check4[X1<tuple<int&, int&>>::value == 3? 1 : -1];
Added: cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp?rev=123279&view=auto
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp (added)
+++ cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp Tue Jan 11 16:21:24 2011
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s
+
+// Note: Partial ordering of function templates containing template
+// parameter packs is independent of the number of deduced arguments
+// for those template parameter packs.
+template<class ...> struct Tuple { };
+template<class ... Types> int &g(Tuple<Types ...>); // #1
+template<class T1, class ... Types> float &g(Tuple<T1, Types ...>); // #2
+template<class T1, class ... Types> double &g(Tuple<T1, Types& ...>); // #3
+
+void test_g() {
+ int &ir1 = g(Tuple<>());
+ float &fr1 = g(Tuple<int, float>());
+ double &dr1 = g(Tuple<int, float&>());
+ double &dr2 = g(Tuple<int>());
+}
+
+template<class ... Types> int &h(int (*)(Types ...)); // #1
+template<class T1, class ... Types> float &h(int (*)(T1, Types ...)); // #2
+template<class T1, class ... Types> double &h(int (*)(T1, Types& ...)); // #3
+
+void test_h() {
+ int &ir1 = h((int(*)())0);
+ float &fr1 = h((int(*)(int, float))0);
+ double &dr1 = h((int(*)(int, float&))0);
+ double &dr2 = h((int(*)(int))0);
+}
Added: cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.type/p22.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.type/p22.cpp?rev=123279&view=auto
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.type/p22.cpp (added)
+++ cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.type/p22.cpp Tue Jan 11 16:21:24 2011
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s
+
+// If the original function parameter associated with A is a function
+// parameter pack and the function parameter associated with P is not
+// a function parameter pack, then template argument deduction fails.
+template<class ... Args> int& f(Args ... args);
+template<class T1, class ... Args> float& f(T1 a1, Args ... args);
+template<class T1, class T2> double& f(T1 a1, T2 a2);
+
+void test_f() {
+ int &ir1 = f();
+ float &fr1 = f(1, 2, 3);
+ double &dr1 = f(1, 2);
+}
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