r310972 - Do not look through pack expansions when looking for unexpanded parameter packs.
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Tue Aug 15 15:58:45 PDT 2017
Author: rsmith
Date: Tue Aug 15 15:58:45 2017
New Revision: 310972
URL: http://llvm.org/viewvc/llvm-project?rev=310972&view=rev
Log:
Do not look through pack expansions when looking for unexpanded parameter packs.
Fixes a selection of rejects-valids when pack-expanding a lambda that itself
contains a pack expansion.
Modified:
cfe/trunk/include/clang/AST/RecursiveASTVisitor.h
cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp
cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/p4.cpp
cfe/trunk/utils/TableGen/ClangAttrEmitter.cpp
Modified: cfe/trunk/include/clang/AST/RecursiveASTVisitor.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/RecursiveASTVisitor.h?rev=310972&r1=310971&r2=310972&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/RecursiveASTVisitor.h (original)
+++ cfe/trunk/include/clang/AST/RecursiveASTVisitor.h Tue Aug 15 15:58:45 2017
@@ -267,6 +267,12 @@ public:
bool TraverseTemplateArguments(const TemplateArgument *Args,
unsigned NumArgs);
+ /// \brief Recursively visit a base specifier. This can be overridden by a
+ /// subclass.
+ ///
+ /// \returns false if the visitation was terminated early, true otherwise.
+ bool TraverseCXXBaseSpecifier(const CXXBaseSpecifier &Base);
+
/// \brief Recursively visit a constructor initializer. This
/// automatically dispatches to another visitor for the initializer
/// expression, but not for the name of the initializer, so may
@@ -1769,12 +1775,19 @@ bool RecursiveASTVisitor<Derived>::Trave
}
template <typename Derived>
+bool RecursiveASTVisitor<Derived>::TraverseCXXBaseSpecifier(
+ const CXXBaseSpecifier &Base) {
+ TRY_TO(TraverseTypeLoc(Base.getTypeSourceInfo()->getTypeLoc()));
+ return true;
+}
+
+template <typename Derived>
bool RecursiveASTVisitor<Derived>::TraverseCXXRecordHelper(CXXRecordDecl *D) {
if (!TraverseRecordHelper(D))
return false;
if (D->isCompleteDefinition()) {
for (const auto &I : D->bases()) {
- TRY_TO(TraverseTypeLoc(I.getTypeSourceInfo()->getTypeLoc()));
+ TRY_TO(TraverseCXXBaseSpecifier(I));
}
// We don't traverse the friends or the conversions, as they are
// already in decls_begin()/decls_end().
Modified: cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp?rev=310972&r1=310971&r2=310972&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplateVariadic.cpp Tue Aug 15 15:58:45 2017
@@ -161,7 +161,7 @@ namespace {
return true;
}
- /// \brief Suppress traversel into types with location information
+ /// \brief Suppress traversal into types with location information
/// that do not contain unexpanded parameter packs.
bool TraverseTypeLoc(TypeLoc TL) {
if ((!TL.getType().isNull() &&
@@ -172,19 +172,48 @@ namespace {
return true;
}
- /// \brief Suppress traversal of non-parameter declarations, since
- /// they cannot contain unexpanded parameter packs.
+ /// \brief Suppress traversal of parameter packs.
bool TraverseDecl(Decl *D) {
- auto *PVD = dyn_cast_or_null<ParmVarDecl>(D);
// A function parameter pack is a pack expansion, so cannot contain
- // an unexpanded parameter pack.
- if (PVD && PVD->isParameterPack())
+ // an unexpanded parameter pack. Likewise for a template parameter
+ // pack that contains any references to other packs.
+ if (D->isParameterPack())
return true;
- if (PVD || InLambda)
- return inherited::TraverseDecl(D);
+ return inherited::TraverseDecl(D);
+ }
- return true;
+ /// \brief Suppress traversal of pack-expanded attributes.
+ bool TraverseAttr(Attr *A) {
+ if (A->isPackExpansion())
+ return true;
+
+ return inherited::TraverseAttr(A);
+ }
+
+ /// \brief Suppress traversal of pack expansion expressions and types.
+ ///@{
+ bool TraversePackExpansionType(PackExpansionType *T) { return true; }
+ bool TraversePackExpansionTypeLoc(PackExpansionTypeLoc TL) { return true; }
+ bool TraversePackExpansionExpr(PackExpansionExpr *E) { return true; }
+ bool TraverseCXXFoldExpr(CXXFoldExpr *E) { return true; }
+
+ ///@}
+
+ /// \brief Suppress traversal of using-declaration pack expansion.
+ bool TraverseUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
+ if (D->isPackExpansion())
+ return true;
+
+ return inherited::TraverseUnresolvedUsingValueDecl(D);
+ }
+
+ /// \brief Suppress traversal of using-declaration pack expansion.
+ bool TraverseUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
+ if (D->isPackExpansion())
+ return true;
+
+ return inherited::TraverseUnresolvedUsingTypenameDecl(D);
}
/// \brief Suppress traversal of template argument pack expansions.
@@ -203,6 +232,22 @@ namespace {
return inherited::TraverseTemplateArgumentLoc(ArgLoc);
}
+ /// \brief Suppress traversal of base specifier pack expansions.
+ bool TraverseCXXBaseSpecifier(const CXXBaseSpecifier &Base) {
+ if (Base.isPackExpansion())
+ return true;
+
+ return inherited::TraverseCXXBaseSpecifier(Base);
+ }
+
+ /// \brief Suppress traversal of mem-initializer pack expansions.
+ bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
+ if (Init->isPackExpansion())
+ return true;
+
+ return inherited::TraverseConstructorInitializer(Init);
+ }
+
/// \brief Note whether we're traversing a lambda containing an unexpanded
/// parameter pack. In this case, the unexpanded pack can occur anywhere,
/// including all the places where we normally wouldn't look. Within a
@@ -233,6 +278,7 @@ namespace {
Expr *Init) {
if (C->isPackExpansion())
return true;
+
return inherited::TraverseLambdaCapture(Lambda, C, Init);
}
};
@@ -266,25 +312,25 @@ Sema::DiagnoseUnexpandedParameterPacks(S
// parameter pack, and we are done.
// FIXME: Store 'Unexpanded' on the lambda so we don't need to recompute it
// later.
- SmallVector<UnexpandedParameterPack, 4> GenericLambdaParamReferences;
+ SmallVector<UnexpandedParameterPack, 4> LambdaParamPackReferences;
for (unsigned N = FunctionScopes.size(); N; --N) {
if (sema::LambdaScopeInfo *LSI =
dyn_cast<sema::LambdaScopeInfo>(FunctionScopes[N-1])) {
- if (LSI->isGenericLambda()) {
+ if (N == FunctionScopes.size()) {
for (auto &Param : Unexpanded) {
auto *PD = dyn_cast_or_null<ParmVarDecl>(
Param.first.dyn_cast<NamedDecl *>());
if (PD && PD->getDeclContext() == LSI->CallOperator)
- GenericLambdaParamReferences.push_back(Param);
+ LambdaParamPackReferences.push_back(Param);
}
}
- // If we have references to a parameter of a generic lambda, only
- // diagnose those ones. We don't know whether any other unexpanded
- // parameters referenced herein are actually unexpanded; they might
- // be expanded at an outer level.
- if (!GenericLambdaParamReferences.empty()) {
- Unexpanded = GenericLambdaParamReferences;
+ // If we have references to a parameter pack of the innermost enclosing
+ // lambda, only diagnose those ones. We don't know whether any other
+ // unexpanded parameters referenced herein are actually unexpanded;
+ // they might be expanded at an outer level.
+ if (!LambdaParamPackReferences.empty()) {
+ Unexpanded = LambdaParamPackReferences;
break;
}
Modified: cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/p4.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/p4.cpp?rev=310972&r1=310971&r2=310972&view=diff
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/p4.cpp (original)
+++ cfe/trunk/test/CXX/temp/temp.decls/temp.variadic/p4.cpp Tue Aug 15 15:58:45 2017
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 -std=c++11 -fsyntax-only -fexceptions -fcxx-exceptions -verify %s
+// RUN: %clang_cc1 -std=c++2a -fsyntax-only -fexceptions -fcxx-exceptions -verify %s
template<typename... Types> struct tuple;
template<int I> struct int_c;
@@ -174,6 +175,7 @@ int check_temp_arg_1[is_same<tuple_of_in
tuple<int_c<1>, int_c<2>, int_c<3>, int_c<4>,
int_c<5>>>::value? 1 : -1];
+#if __cplusplus < 201703L
// In a dynamic-exception-specification (15.4); the pattern is a type-id.
template<typename ...Types>
struct f_with_except {
@@ -191,3 +193,99 @@ struct check_f_with_except_2 : f_with_ex
struct check_f_with_except_3 : f_with_except<int, float> {
virtual void f() throw(int, float, double); // expected-error{{exception specification of overriding function is more lax than base version}}
};
+#endif
+
+namespace PackExpansionWithinLambda {
+ void swallow(...);
+ template<typename ...T, typename ...U> void f(U ...u) {
+ swallow([=] {
+ // C++17 [temp.variadic]p4:
+ // Pack expansions can occur in the following contexts:
+
+ // - in a function parameter pack
+ void g(T...);
+
+#if __cplusplus >= 201703L
+ struct A : T... {
+ // - in a using-declaration
+ using T::x...;
+ using typename T::U...;
+ };
+#endif
+
+ // - in a template parameter pack that is a pack expansion
+ // FIXME: We do not support any way to reach this case yet.
+
+ // - in an initializer-list
+ int arr[] = {T().x...};
+
+ // - in a base-specifier-list
+ struct B : T... {
+ // - in a mem-initializer-list
+ B() : T{0}... {}
+ };
+
+ // - in a template-argument-list
+ f<T...>();
+
+ // - in an attribute-list
+ // FIXME: We do not support any such attributes yet.
+
+ // - in an alignment-specifier
+ alignas(T...) int y;
+
+ // - in a capture-list
+ [](T ...t) { [t...]{}(); } (T()...);
+
+ // - in a sizeof... expression
+ const int k1 = sizeof...(T);
+
+#if __cplusplus >= 201703L
+ // - in a fold-expression
+ const int k2 = ((sizeof(T)/sizeof(T)) + ...);
+
+ static_assert(k1 == k2);
+#endif
+
+ // Trigger clang to look in here for unexpanded packs.
+ U u;
+ } ...);
+ }
+
+ template<typename ...T> void nested() {
+ swallow([=] {
+ [](T ...t) { [t]{}(); } (T()...); // expected-error {{unexpanded parameter pack 't'}}
+ }...); // expected-error {{does not contain any unexpanded}}
+ }
+
+ template <typename ...T> void g() {
+ // Check that we do detect the above cases when the pack is not expanded.
+ swallow([=] { void h(T); }); // expected-error {{unexpanded parameter pack 'T'}}
+ swallow([=] { struct A : T {}; }); // expected-error {{unexpanded parameter pack 'T'}}
+#if __cplusplus >= 201703L
+ swallow([=] { struct A : T... { using T::x; }; }); // expected-error {{unexpanded parameter pack 'T'}}
+ swallow([=] { struct A : T... { using typename T::U; }; }); // expected-error {{unexpanded parameter pack 'T'}}
+#endif
+
+ swallow([=] { int arr[] = {T().x}; }); // expected-error {{unexpanded parameter pack 'T'}}
+ swallow([=] { struct B : T... { B() : T{0} {} }; }); // expected-error {{unexpanded parameter pack 'T'}}
+ swallow([=] { f<T>(); }); // expected-error {{unexpanded parameter pack 'T'}}
+ swallow([=] { alignas(T) int y; }); // expected-error {{unexpanded parameter pack 'T'}}
+ swallow([=] { [](T ...t) {
+ [t]{}(); // expected-error {{unexpanded parameter pack 't'}}
+ } (T()...); });
+ }
+
+ struct T { int x; using U = int; };
+ void g() { f<T>(1, 2, 3); }
+
+ template<typename ...T, typename ...U> void pack_in_lambda(U ...u) { // expected-note {{here}}
+ // FIXME: Move this test into 'f' above once we support this syntax.
+ []<T *...v, template<T *> typename ...U>(U<v> ...uv) {}; // expected-error {{expected body of lambda}} expected-error {{does not refer to a value}}
+ }
+
+ template<typename ...T> void pack_expand_attr() {
+ // FIXME: Move this test into 'f' above once we support this.
+ [[gnu::aligned(alignof(T))...]] int x; // expected-error {{cannot be used as an attribute pack}} expected-error {{unexpanded}}
+ }
+}
Modified: cfe/trunk/utils/TableGen/ClangAttrEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/utils/TableGen/ClangAttrEmitter.cpp?rev=310972&r1=310971&r2=310972&view=diff
==============================================================================
--- cfe/trunk/utils/TableGen/ClangAttrEmitter.cpp (original)
+++ cfe/trunk/utils/TableGen/ClangAttrEmitter.cpp Tue Aug 15 15:58:45 2017
@@ -490,6 +490,17 @@ namespace {
OS << "}\n";
}
+ void writeASTVisitorTraversal(raw_ostream &OS) const override {
+ StringRef Name = getUpperName();
+ OS << " if (A->is" << Name << "Expr()) {\n"
+ << " if (!getDerived().TraverseStmt(A->get" << Name << "Expr()))\n"
+ << " return false;\n"
+ << " } else if (auto *TSI = A->get" << Name << "Type()) {\n"
+ << " if (!getDerived().TraverseTypeLoc(TSI->getTypeLoc()))\n"
+ << " return false;\n"
+ << " }\n";
+ }
+
void writeCloneArgs(raw_ostream &OS) const override {
OS << "is" << getLowerName() << "Expr, is" << getLowerName()
<< "Expr ? static_cast<void*>(" << getLowerName()
@@ -630,6 +641,10 @@ namespace {
<< "A->" << getLowerName() << "_size()";
}
+ void writeASTVisitorTraversal(raw_ostream &OS) const override {
+ // FIXME: Traverse the elements.
+ }
+
void writeCtorBody(raw_ostream &OS) const override {
OS << " std::copy(" << getUpperName() << ", " << getUpperName()
<< " + " << ArgSizeName << ", " << ArgName << ");\n";
@@ -1153,6 +1168,12 @@ namespace {
OS << " }";
}
+ void writeASTVisitorTraversal(raw_ostream &OS) const override {
+ OS << " if (auto *TSI = A->get" << getUpperName() << "Loc())\n";
+ OS << " if (!getDerived().TraverseTypeLoc(TSI->getTypeLoc()))\n";
+ OS << " return false;\n";
+ }
+
void writeTemplateInstantiationArgs(raw_ostream &OS) const override {
OS << "A->get" << getUpperName() << "Loc()";
}
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