[clang] Substitute alias templates from correct context #75069
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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. This is a recommit of 6b1aa31 with a slight modification in order to fix reported regression. Fixes llvm#41693
llvmbot
added
clang
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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/75069.diff 6 Files Affected:
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index b4b5352a306c1c..1d460ae8375e88 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -677,6 +677,9 @@ Bug Fixes in This Version
(`#62157 <https://github.com/llvm/llvm-project/issues/62157>`_) and
(`#64885 <https://github.com/llvm/llvm-project/issues/64885>`_) and
(`#65568 <https://github.com/llvm/llvm-project/issues/65568>`_)
+- 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/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index f45e0a7d3d52d4..d8f4b01ee455f1 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -8738,7 +8738,7 @@ class Sema final {
SourceLocation IILoc,
bool DeducedTSTContext = true);
-
+ bool RebuildingTypesInCurrentInstantiation = false;
TypeSourceInfo *RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
SourceLocation Loc,
DeclarationName Name);
diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index 44a40215b90dfb..b3b19b7ed7ffff 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -30,6 +30,20 @@ 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 +51,12 @@ static CXXRecordDecl *getCurrentInstantiationOf(QualType T,
return Record;
return nullptr;
- } else if (isa<InjectedClassNameType>(Ty))
- return cast<InjectedClassNameType>(Ty)->getDecl();
- else
- return nullptr;
+ }
+
+ if (auto *ICNT = dyn_cast<InjectedClassNameType>(Ty))
+ return ICNT->getDecl();
+
+ 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 f10abeaba0d451..810a93f37d74e0 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -39,6 +39,7 @@
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/SaveAndRestore.h"
#include <iterator>
#include <optional>
@@ -3990,9 +3991,16 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
if (Inst.isInvalid())
return QualType();
- CanonType = SubstType(Pattern->getUnderlyingType(),
- TemplateArgLists, AliasTemplate->getLocation(),
- AliasTemplate->getDeclName());
+ if (!RebuildingTypesInCurrentInstantiation) {
+ Sema::ContextRAII SavedContext(*this, Pattern->getDeclContext());
+ CanonType =
+ SubstType(Pattern->getUnderlyingType(), TemplateArgLists,
+ AliasTemplate->getLocation(), AliasTemplate->getDeclName());
+ } else {
+ 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
@@ -11392,6 +11400,8 @@ TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
if (!T || !T->getType()->isInstantiationDependentType())
return T;
+ llvm::SaveAndRestore DisableContextSwitchForTypeAliases(
+ RebuildingTypesInCurrentInstantiation, true);
CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
return Rebuilder.TransformType(T);
}
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 2d46502e1d9b35..2b33a4ef566dad 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 5189405e23db56..dca63e15f5bb8a 100644
--- a/clang/test/SemaCXX/alias-template.cpp
+++ b/clang/test/SemaCXX/alias-template.cpp
@@ -192,3 +192,68 @@ 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 {
+// No errors when a type alias defined in a class or a friend of a class
+// accesses private members of the same class.
+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>);
+}
+
+// Test case that regressed with the first iteration of the fix for GH41693.
+template <typename T> class SP {
+ T* data;
+};
+
+template <typename T> class A {
+ static SP<A> foo();
+};
+
+template<typename T> using TRet = SP<A<T>>;
+
+template<typename T> TRet<T> A<T>::foo() { return TRet<T>{};};
+
+}
|
|
Can you point out the diff from the previous patch? |
To fix the following case: I had to disable The concrete important diff is: |
erichkeane
reviewed
Dec 11, 2023
erichkeane
approved these changes
Dec 12, 2023
|
After this commit, I'm seeing another "out-of-line definition" error for class Foo {};
template <class X, class Y = void>
struct Stuff;
template <class Unused>
struct Stuff<Foo, Unused> {
Stuff& operator=(Stuff&& that);
};
template <class T>
using Alias = Stuff<Foo, T>;
template <class T>
Alias<T>& Alias<T>::operator=(Alias<T>&& that) {
return *this;
}Results in: <source>:15:21: error: out-of-line definition of 'operator=' does not match any declaration in 'Stuff<Foo, type-parameter-0-0>'
15 | Alias<T>& Alias<T>::operator=(Alias<T>&& that) {
| ^~~~~~~~Is that error expected? Live conformance view: https://godbolt.org/z/eanhMEevn I'm also seeing a separate |
|
@rupprecht , no, this is not expected. Please feel free to revert since it is night in my time zone. Otherwise I will revert tomorrow. |
MaskRay
added a commit
that referenced
this pull request
Dec 14, 2023
…)" This reverts commit dbf67ea. It caused spurious "out-of-line definition of 'operator=' does not match any declaration in" error. #75069 (comment)
|
Thanks to @MaskRay for handling the revert. A reduction for the second class Foo {};
template <class T>
struct Ptr {};
template <class X, class Y = void>
class Data;
template <class Unused>
struct Data<Foo, Unused> {
using Type = int;
void func();
};
template <class T>
using Alias = Data<Foo, T>;
template <class T>
void Alias<T>::func() {
auto x = Ptr<Alias<T>::Type>();
(void)x;
}Results in: <source>:20:16: error: template argument for template type parameter must be a type; did you forget 'typename'?
20 | auto x = Ptr<Alias<T>::Type>();
| ^
| typename Live link, until compiler explorer catches up to the revert: https://godbolt.org/z/zvT4jzqbv I'd be happy to just add |
qihangkong
pushed a commit
to rvgpu/rvgpu-llvm
that referenced
this pull request
Apr 23, 2024
…69)" This reverts commit dbf67ea. It caused spurious "out-of-line definition of 'operator=' does not match any declaration in" error. llvm/llvm-project#75069 (comment)
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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.
This is a recommit of 6b1aa31 with a slight modification in order to fix reported regression.
Fixes #41693