lime created this revision.
lime added reviewers: aaron.ballman, erichkeane, cor3ntin, clang-language-wg.
lime added a project: clang.
Herald added a subscriber: yaxunl.
Herald added a project: All.
lime requested review of this revision.
Herald added a subscriber: cfe-commits.
D137531 <https://reviews.llvm.org/D137531> had once fixed the issue. However,
it caused a crash during compiling
llvm/unittests/IR/PatternMatch.cpp in stage-2. The reason is the predicator
`isDerivedFrom` does not consider independent types if the derived type is
dependent.
This patch improves D137531 <https://reviews.llvm.org/D137531> by adding an
option to make `isDerivedFrom` consider
independent types.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D142437
Files:
clang/docs/ReleaseNotes.rst
clang/include/clang/AST/DeclCXX.h
clang/lib/AST/CXXInheritance.cpp
clang/lib/Sema/SemaExpr.cpp
clang/test/SemaCXX/decltype.cpp
Index: clang/test/SemaCXX/decltype.cpp
===================================================================
--- clang/test/SemaCXX/decltype.cpp
+++ clang/test/SemaCXX/decltype.cpp
@@ -101,6 +101,44 @@
template<class T> void foo(decltype(T(LP1{ .p1 = g1, .p1.x[1] = 'x' }))) {}
}
+namespace GH58674 {
+ struct Foo {
+ float value_;
+ struct nested {
+ float value_;
+ };
+ };
+
+ template <typename T>
+ struct TemplateFoo {
+ float value_;
+ };
+
+ float bar;
+
+ template <typename T>
+ struct Animal{};
+
+ template <typename T>
+ class Cat : Animal<T> {
+ using okay = decltype(Foo::value_);
+ using also_okay = decltype(bar);
+ using okay2 = decltype(Foo::nested::value_);
+ using okay3 = decltype(TemplateFoo<T>::value_);
+ public:
+ void meow() {
+ using okay = decltype(Foo::value_);
+ using also_okay = decltype(bar);
+ using okay2 = decltype(Foo::nested::value_);
+ using okay3 = decltype(TemplateFoo<T>::value_);
+ }
+ };
+
+ void baz() {
+ Cat<void>{}.meow();
+ }
+}
+
template<typename>
class conditional {
};
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -2693,20 +2693,34 @@
// to get this right here so that we don't end up making a
// spuriously dependent expression if we're inside a dependent
// instance method.
+ //
+ // We also don't need to do this if R resolved to a member in another
+ // class, which can happen in an unevaluated operand:
+ //
+ // C++ [expr.prim.id]p3.3:
+ // If that id-expression denotes a non-static data member and it
+ // appears in an unevaluated operand.
if (!R.empty() && (*R.begin())->isCXXClassMember()) {
- bool MightBeImplicitMember;
- if (!IsAddressOfOperand)
- MightBeImplicitMember = true;
- else if (!SS.isEmpty())
- MightBeImplicitMember = false;
- else if (R.isOverloadedResult())
- MightBeImplicitMember = false;
- else if (R.isUnresolvableResult())
- MightBeImplicitMember = true;
- else
- MightBeImplicitMember = isa<FieldDecl>(R.getFoundDecl()) ||
- isa<IndirectFieldDecl>(R.getFoundDecl()) ||
- isa<MSPropertyDecl>(R.getFoundDecl());
+ bool MightBeImplicitMember = true, CheckField = true;
+ if (IsAddressOfOperand) {
+ MightBeImplicitMember = SS.isEmpty() && !R.isOverloadedResult();
+ CheckField = !R.isUnresolvableResult();
+ }
+ if (MightBeImplicitMember && CheckField) {
+ if (R.isSingleResult() &&
+ isa<FieldDecl, IndirectFieldDecl, MSPropertyDecl>(R.getFoundDecl())) {
+ auto Class = cast<CXXRecordDecl>((*R.begin())->getDeclContext());
+ for (auto Curr = S->getLookupEntity(); Curr && !Curr->isFileContext();
+ Curr = Curr->getParent()) {
+ if (auto ThisClass = dyn_cast_if_present<CXXRecordDecl>(Curr)) {
+ if ((MightBeImplicitMember = ThisClass->Equals(Class) ||
+ ThisClass->isDerivedFrom(Class, true)))
+ break;
+ }
+ }
+ } else if (IsAddressOfOperand)
+ MightBeImplicitMember = false;
+ }
if (MightBeImplicitMember)
return BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc,
Index: clang/lib/AST/CXXInheritance.cpp
===================================================================
--- clang/lib/AST/CXXInheritance.cpp
+++ clang/lib/AST/CXXInheritance.cpp
@@ -64,14 +64,16 @@
std::swap(DetectedVirtual, Other.DetectedVirtual);
}
-bool CXXRecordDecl::isDerivedFrom(const CXXRecordDecl *Base) const {
+bool CXXRecordDecl::isDerivedFrom(const CXXRecordDecl *Base,
+ bool LookupIndependent) const {
CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/false,
/*DetectVirtual=*/false);
- return isDerivedFrom(Base, Paths);
+ return isDerivedFrom(Base, Paths, LookupIndependent);
}
bool CXXRecordDecl::isDerivedFrom(const CXXRecordDecl *Base,
- CXXBasePaths &Paths) const {
+ CXXBasePaths &Paths,
+ bool LookupIndependent) const {
if (getCanonicalDecl() == Base->getCanonicalDecl())
return false;
@@ -80,9 +82,10 @@
const CXXRecordDecl *BaseDecl = Base->getCanonicalDecl();
return lookupInBases(
[BaseDecl](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
- return FindBaseClass(Specifier, Path, BaseDecl);
+ return Specifier->getType()->getAsRecordDecl() &&
+ FindBaseClass(Specifier, Path, BaseDecl);
},
- Paths);
+ Paths, LookupIndependent);
}
bool CXXRecordDecl::isVirtuallyDerivedFrom(const CXXRecordDecl *Base) const {
Index: clang/include/clang/AST/DeclCXX.h
===================================================================
--- clang/include/clang/AST/DeclCXX.h
+++ clang/include/clang/AST/DeclCXX.h
@@ -1547,7 +1547,8 @@
/// \param Base the base class we are searching for.
///
/// \returns true if this class is derived from Base, false otherwise.
- bool isDerivedFrom(const CXXRecordDecl *Base) const;
+ bool isDerivedFrom(const CXXRecordDecl *Base,
+ bool LookupIndependent = false) const;
/// Determine whether this class is derived from the type \p Base.
///
@@ -1565,7 +1566,8 @@
///
/// \todo add a separate parameter to configure IsDerivedFrom, rather than
/// tangling input and output in \p Paths
- bool isDerivedFrom(const CXXRecordDecl *Base, CXXBasePaths &Paths) const;
+ bool isDerivedFrom(const CXXRecordDecl *Base, CXXBasePaths &Paths,
+ bool LookupIndependent = false) const;
/// Determine whether this class is virtually derived from
/// the class \p Base.
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -356,6 +356,9 @@
`Issue 51227 <https://github.com/llvm/llvm-project/issues/51227>`_.
- Fix the bug of inserting the ``ZeroInitializationFixit`` before the template
argument list of ``VarTemplateSpecializationDecl``.
+- Fix an issue about ``decltype`` in the members of class templates derived from
+ templates with related parameters. This fixes
+ `Issue 58674 <https://github.com/llvm/llvm-project/issues/58674>`_
Improvements to Clang's diagnostics
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
