[clang] Substitute alias templates from correct context #74335
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Current context set to where alias was met, not where it is declared caused incorrect access check in case alias referenced private members of the parent class. Fixes llvm#41693
llvmbot
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@llvm/pr-subscribers-clang Author: Mariya Podchishchaeva (Fznamznon) ChangesCurrent context set to where alias was met, not where it is declared caused incorrect access check in case alias referenced private members of the parent class. Fixes #41693 Full diff: https://github.com/llvm/llvm-project/pull/74335.diff 5 Files Affected:
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 683d0026bb345..18a7afda3c8b0 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -653,6 +653,9 @@ Bug Fixes in This Version
Fixes (`#13826 <https://github.com/llvm/llvm-project/issues/13826>`_)
- Clang's ``-Wchar-subscripts`` no longer warns on chars whose values are known non-negative constants.
Fixes (`#18763 <https://github.com/llvm/llvm-project/issues/18763>`_)
+- Fixed false positive error emitted when templated alias inside a class
+ used private members of the same class.
+ Fixes (`#41693 <https://github.com/llvm/llvm-project/issues/41693>`_)
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index 44a40215b90df..56f83be78266f 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -30,6 +30,21 @@ static CXXRecordDecl *getCurrentInstantiationOf(QualType T,
return nullptr;
const Type *Ty = T->getCanonicalTypeInternal().getTypePtr();
+ if (isa<TemplateSpecializationType>(Ty)) {
+ if (auto *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
+ if (isa<ClassTemplatePartialSpecializationDecl>(Record) ||
+ Record->getDescribedClassTemplate()) {
+ const Type *ICNT = Record->getTypeForDecl();
+ QualType Injected =
+ cast<InjectedClassNameType>(ICNT)->getInjectedSpecializationType();
+
+ if (Ty == Injected->getCanonicalTypeInternal().getTypePtr()) {
+ return Record;
+ }
+ }
+ }
+ }
+
if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl());
if (!Record->isDependentContext() ||
@@ -37,10 +52,12 @@ static CXXRecordDecl *getCurrentInstantiationOf(QualType T,
return Record;
return nullptr;
- } else if (isa<InjectedClassNameType>(Ty))
+ }
+
+ if (isa<InjectedClassNameType>(Ty))
return cast<InjectedClassNameType>(Ty)->getDecl();
- else
- return nullptr;
+
+ return nullptr;
}
/// Compute the DeclContext that is associated with the given type.
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 09bbf14d39af5..23a175da6bc4d 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -3990,9 +3990,14 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
if (Inst.isInvalid())
return QualType();
- CanonType = SubstType(Pattern->getUnderlyingType(),
- TemplateArgLists, AliasTemplate->getLocation(),
- AliasTemplate->getDeclName());
+ bool ForLambdaCallOperator = false;
+ if (const auto *Rec = dyn_cast<CXXRecordDecl>(Pattern->getDeclContext()))
+ ForLambdaCallOperator = Rec->isLambda();
+ Sema::ContextRAII SavedContext(*this, Pattern->getDeclContext(),
+ !ForLambdaCallOperator);
+ CanonType =
+ SubstType(Pattern->getUnderlyingType(), TemplateArgLists,
+ AliasTemplate->getLocation(), AliasTemplate->getDeclName());
if (CanonType.isNull()) {
// If this was enable_if and we failed to find the nested type
// within enable_if in a SFINAE context, dig out the specific
diff --git a/clang/test/CXX/temp/temp.decls/temp.alias/p3.cpp b/clang/test/CXX/temp/temp.decls/temp.alias/p3.cpp
index 2d46502e1d9b3..2b33a4ef566da 100644
--- a/clang/test/CXX/temp/temp.decls/temp.alias/p3.cpp
+++ b/clang/test/CXX/temp/temp.decls/temp.alias/p3.cpp
@@ -2,11 +2,12 @@
// The example given in the standard (this is rejected for other reasons anyway).
template<class T> struct A;
-template<class T> using B = typename A<T>::U; // expected-error {{no type named 'U' in 'A<T>'}}
+template<class T> using B = typename A<T>::U; // expected-error {{no type named 'U' in 'A<short>'}}
+ // expected-note@-1 {{in instantiation of template class 'A<short>' requested here}}
template<class T> struct A {
typedef B<T> U; // expected-note {{in instantiation of template type alias 'B' requested here}}
};
-B<short> b;
+B<short> b; // expected-note {{in instantiation of template type alias 'B' requested here}}
template<typename T> using U = int;
diff --git a/clang/test/SemaCXX/alias-template.cpp b/clang/test/SemaCXX/alias-template.cpp
index 5189405e23db5..cd415c6cd4e9b 100644
--- a/clang/test/SemaCXX/alias-template.cpp
+++ b/clang/test/SemaCXX/alias-template.cpp
@@ -192,3 +192,53 @@ int g = sfinae_me<int>(); // expected-error{{no matching function for call to 's
namespace NullExceptionDecl {
template<int... I> auto get = []() { try { } catch(...) {}; return I; }; // expected-error{{initializer contains unexpanded parameter pack 'I'}}
}
+
+namespace GH41693 {
+struct S {
+private:
+ template <typename> static constexpr void Impl() {}
+
+public:
+ template <typename X> using U = decltype(Impl<X>());
+};
+
+using X = S::U<void>;
+struct Y {
+private:
+ static constexpr int x=0;
+
+ template <typename>
+ static constexpr int y=0;
+
+ template <typename>
+ static constexpr int foo();
+
+public:
+ template <typename U>
+ using bar1 = decltype(foo<U>());
+ using bar2 = decltype(x);
+ template <typename U>
+ using bar3 = decltype(y<U>);
+};
+
+
+using type1 = Y::bar1<float>;
+using type2 = Y::bar2;
+using type3 = Y::bar3<float>;
+
+struct theFriend{
+ template<class T>
+ using theAlias = decltype(&T::i);
+};
+
+class theC{
+ int i;
+ public:
+ friend struct theFriend;
+};
+
+int foo(){
+ (void)sizeof(theFriend::theAlias<theC>);
+}
+
+}
|
erichkeane
approved these changes
Dec 4, 2023
erichkeane
approved these changes
Dec 4, 2023
|
This started to give errors to code previously considere valid with "out-of-line definition of X differs from that in". |
Please provide one as soon as you can! In the meantime, we should probably revert @Fznamznon |
Ok, I'll prepare revert. |
Fznamznon
added a commit
that referenced
this pull request
Dec 6, 2023
…)" It was reported in the PR that commit caused clang giving errors for code previously considered valid. This reverts commit 6b1aa31.
|
Ok, revert is done. |
|
here is a sample for OSS ducc https://gitlab.mpcdf.mpg.de/mtr/ducc.git (lines might be off) sorry I don't have a smaller repro. It seems that "using" in the class body somehow messes things up. |
|
Thanks, I reproduced the problem with |
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Current context set to where alias was met, not where it is declared caused incorrect access check in case alias referenced private members of the parent class.
Fixes #41693