[clang] [Clang][Sema] Use the correct lookup context when building overloaded 'operator->' in the current instantiation (PR #104458)
Krystian Stasiowski via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 3 09:18:49 PDT 2024
https://github.com/sdkrystian updated https://github.com/llvm/llvm-project/pull/104458
>From a719de89be6af3607f67baddd8868f8e0fc7882f Mon Sep 17 00:00:00 2001
From: Krystian Stasiowski <sdkrystian at gmail.com>
Date: Thu, 15 Aug 2024 11:27:34 -0400
Subject: [PATCH 1/3] [Clang][Sema] Use the correct lookup context when
building overloaded 'operator->' in the current instantiation
---
clang/include/clang/Sema/Sema.h | 3 +--
clang/lib/Sema/SemaExprCXX.cpp | 25 ++++++++-----------
clang/lib/Sema/SemaOverload.cpp | 14 +++++++----
clang/lib/Sema/TreeTransform.h | 4 +--
.../temp.res/temp.dep/temp.dep.type/p4.cpp | 24 ++++++++++--------
5 files changed, 35 insertions(+), 35 deletions(-)
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 0358259945c796..023b99db41db42 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -10639,8 +10639,7 @@ class Sema final : public SemaBase {
/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
/// (if one exists), where @c Base is an expression of class type and
/// @c Member is the name of the member we're trying to find.
- ExprResult BuildOverloadedArrowExpr(Scope *S, Expr *Base,
- SourceLocation OpLoc,
+ ExprResult BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc,
bool *NoArrowOperatorFound = nullptr);
ExprResult BuildCXXMemberCallExpr(Expr *Exp, NamedDecl *FoundDecl,
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index b7531581d37ff0..45c0d0e22d9605 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -7955,18 +7955,6 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
QualType BaseType = Base->getType();
MayBePseudoDestructor = false;
- if (BaseType->isDependentType()) {
- // If we have a pointer to a dependent type and are using the -> operator,
- // the object type is the type that the pointer points to. We might still
- // have enough information about that type to do something useful.
- if (OpKind == tok::arrow)
- if (const PointerType *Ptr = BaseType->getAs<PointerType>())
- BaseType = Ptr->getPointeeType();
-
- ObjectType = ParsedType::make(BaseType);
- MayBePseudoDestructor = true;
- return Base;
- }
// C++ [over.match.oper]p8:
// [...] When operator->returns, the operator-> is applied to the value
@@ -7981,7 +7969,7 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
SmallVector<FunctionDecl*, 8> OperatorArrows;
CTypes.insert(Context.getCanonicalType(BaseType));
- while (BaseType->isRecordType()) {
+ while (BaseType->getAsRecordDecl()) {
if (OperatorArrows.size() >= getLangOpts().ArrowDepth) {
Diag(OpLoc, diag::err_operator_arrow_depth_exceeded)
<< StartingType << getLangOpts().ArrowDepth << Base->getSourceRange();
@@ -7992,7 +7980,7 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
}
Result = BuildOverloadedArrowExpr(
- S, Base, OpLoc,
+ Base, OpLoc,
// When in a template specialization and on the first loop iteration,
// potentially give the default diagnostic (with the fixit in a
// separate note) instead of having the error reported back to here
@@ -8018,7 +8006,14 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
}
}
return ExprError();
+ } else if (Result.isUnset()) {
+ // BuildOverloadedArrowExpr returns an empty expression to indicate
+ // that we need to build a dependent overloaded arrow expression.
+ assert(BaseType->isDependentType());
+ BaseType = Context.DependentTy;
+ break;
}
+
Base = Result.get();
if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base))
OperatorArrows.push_back(OpCall->getDirectCallee());
@@ -8056,7 +8051,7 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
// it's legal for the type to be incomplete if this is a pseudo-destructor
// call. We'll do more incomplete-type checks later in the lookup process,
// so just skip this check for ObjC types.
- if (!BaseType->isRecordType()) {
+ if (!BaseType->getAsRecordDecl()) {
ObjectType = ParsedType::make(BaseType);
MayBePseudoDestructor = true;
return Base;
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 95551173df91a5..6170ae579fd2a0 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -15876,10 +15876,9 @@ Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
return CheckForImmediateInvocation(MaybeBindToTemporary(TheCall), Method);
}
-ExprResult
-Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
- bool *NoArrowOperatorFound) {
- assert(Base->getType()->isRecordType() &&
+ExprResult Sema::BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc,
+ bool *NoArrowOperatorFound) {
+ assert(Base->getType()->getAsRecordDecl() &&
"left-hand side must have class type");
if (checkPlaceholderForOverload(*this, Base))
@@ -15902,7 +15901,12 @@ Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
return ExprError();
LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
- LookupQualifiedName(R, Base->getType()->castAs<RecordType>()->getDecl());
+ LookupParsedName(R, /*S=*/nullptr, /*SS=*/nullptr, Base->getType());
+
+ if (R.wasNotFoundInCurrentInstantiation() ||
+ (Base->isTypeDependent() && !R.empty()))
+ return ExprEmpty();
+
R.suppressAccessDiagnostics();
for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 66e3f27fed9de0..85b0dafb2edac5 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -16565,10 +16565,10 @@ ExprResult TreeTransform<Derived>::RebuildCXXOperatorCallExpr(
} else if (Op == OO_Arrow) {
// It is possible that the type refers to a RecoveryExpr created earlier
// in the tree transformation.
- if (First->getType()->isDependentType())
+ if (First->containsErrors())
return ExprError();
// -> is never a builtin operation.
- return SemaRef.BuildOverloadedArrowExpr(nullptr, First, OpLoc);
+ return SemaRef.BuildOverloadedArrowExpr(First, OpLoc);
} else if (Second == nullptr || isPostIncDec) {
if (!First->getType()->isOverloadableType() ||
(Op == OO_Amp && getSema().isQualifiedMemberAccess(First))) {
diff --git a/clang/test/CXX/temp/temp.res/temp.dep/temp.dep.type/p4.cpp b/clang/test/CXX/temp/temp.res/temp.dep/temp.dep.type/p4.cpp
index f32f49ef4539a5..89c22a0bc137d9 100644
--- a/clang/test/CXX/temp/temp.res/temp.dep/temp.dep.type/p4.cpp
+++ b/clang/test/CXX/temp/temp.res/temp.dep/temp.dep.type/p4.cpp
@@ -484,16 +484,19 @@ namespace N4 {
template<typename T>
struct A {
void not_instantiated(A a, A<T> b, T c) {
- a->x;
- b->x;
+ a->x; // expected-error {{member reference type 'A<T>' is not a pointer; did you mean to use '.'?}}
+ b->x; // expected-error {{member reference type 'A<T>' is not a pointer; did you mean to use '.'?}}
c->x;
}
void instantiated(A a, A<T> b, T c) {
- a->x; // expected-error {{member reference type 'A<int>' is not a pointer; did you mean to use '.'?}}
- // expected-error at -1 {{no member named 'x' in 'N4::A<int>'}}
- b->x; // expected-error {{member reference type 'A<int>' is not a pointer; did you mean to use '.'?}}
- // expected-error at -1 {{no member named 'x' in 'N4::A<int>'}}
+ // FIXME: We should only emit a single diagnostic suggesting to use '.'!
+ a->x; // expected-error {{member reference type 'A<T>' is not a pointer; did you mean to use '.'?}}
+ // expected-error at -1 {{member reference type 'A<int>' is not a pointer; did you mean to use '.'?}}
+ // expected-error at -2 {{no member named 'x' in 'N4::A<int>'}}
+ b->x; // expected-error {{member reference type 'A<T>' is not a pointer; did you mean to use '.'?}}
+ // expected-error at -1 {{member reference type 'A<int>' is not a pointer; did you mean to use '.'?}}
+ // expected-error at -2 {{no member named 'x' in 'N4::A<int>'}}
c->x; // expected-error {{member reference type 'int' is not a pointer}}
}
};
@@ -540,11 +543,10 @@ namespace N4 {
a->T::f();
a->T::g();
- // FIXME: 'U' should be a dependent name, and its lookup context should be 'a.operator->()'!
- a->U::x; // expected-error {{use of undeclared identifier 'U'}}
- a->U::y; // expected-error {{use of undeclared identifier 'U'}}
- a->U::f(); // expected-error {{use of undeclared identifier 'U'}}
- a->U::g(); // expected-error {{use of undeclared identifier 'U'}}
+ a->U::x;
+ a->U::y;
+ a->U::f();
+ a->U::g();
}
void instantiated(D a) {
>From 8e39f017e3c8d0cad53fb98504b2328c01ce3764 Mon Sep 17 00:00:00 2001
From: Krystian Stasiowski <sdkrystian at gmail.com>
Date: Thu, 15 Aug 2024 13:24:27 -0400
Subject: [PATCH 2/3] [FOLD] fix destructor lookup when the object expression
is dependent
---
clang/lib/Sema/SemaExprCXX.cpp | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 45c0d0e22d9605..10aa043c7b910b 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -8069,6 +8069,10 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
return CreateRecoveryExpr(Base->getBeginLoc(), Base->getEndLoc(), {Base});
}
+ // We can't implicitly declare the destructor for a templated class.
+ if (BaseType->isDependentType())
+ MayBePseudoDestructor = true;
+
// C++ [basic.lookup.classref]p2:
// If the id-expression in a class member access (5.2.5) is an
// unqualified-id, and the type of the object expression is of a class
>From 4cdb2b4329352a66713a8e4200b7e1ac38e742fa Mon Sep 17 00:00:00 2001
From: Krystian Stasiowski <sdkrystian at gmail.com>
Date: Tue, 3 Sep 2024 12:17:39 -0400
Subject: [PATCH 3/3] [FOLD] use IsDependent output parameter
---
clang/include/clang/Sema/Sema.h | 3 ++-
clang/lib/Sema/SemaExprCXX.cpp | 19 ++++++++++++-------
clang/lib/Sema/SemaOverload.cpp | 16 +++++++++++++---
clang/lib/Sema/TreeTransform.h | 6 +++++-
4 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 023b99db41db42..a6d6d9d02fc326 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -10640,7 +10640,8 @@ class Sema final : public SemaBase {
/// (if one exists), where @c Base is an expression of class type and
/// @c Member is the name of the member we're trying to find.
ExprResult BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc,
- bool *NoArrowOperatorFound = nullptr);
+ bool *NoArrowOperatorFound,
+ bool &IsDependent);
ExprResult BuildCXXMemberCallExpr(Expr *Exp, NamedDecl *FoundDecl,
CXXConversionDecl *Method,
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 10aa043c7b910b..2a630d2ed2d853 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -7979,6 +7979,7 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
return ExprError();
}
+ bool IsDependent;
Result = BuildOverloadedArrowExpr(
Base, OpLoc,
// When in a template specialization and on the first loop iteration,
@@ -7987,7 +7988,17 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
// and giving a diagnostic with a fixit attached to the error itself.
(FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization())
? nullptr
- : &NoArrowOperatorFound);
+ : &NoArrowOperatorFound,
+ IsDependent);
+
+ if (IsDependent) {
+ // BuildOverloadedArrowExpr sets IsDependent to indicate that we need
+ // to build a dependent overloaded arrow expression.
+ assert(BaseType->isDependentType());
+ BaseType = Context.DependentTy;
+ break;
+ }
+
if (Result.isInvalid()) {
if (NoArrowOperatorFound) {
if (FirstIteration) {
@@ -8006,12 +8017,6 @@ ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
}
}
return ExprError();
- } else if (Result.isUnset()) {
- // BuildOverloadedArrowExpr returns an empty expression to indicate
- // that we need to build a dependent overloaded arrow expression.
- assert(BaseType->isDependentType());
- BaseType = Context.DependentTy;
- break;
}
Base = Result.get();
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 6170ae579fd2a0..5d7a5239d06dce 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -15877,10 +15877,13 @@ Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
}
ExprResult Sema::BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc,
- bool *NoArrowOperatorFound) {
+ bool *NoArrowOperatorFound,
+ bool &IsDependent) {
assert(Base->getType()->getAsRecordDecl() &&
"left-hand side must have class type");
+ IsDependent = false;
+
if (checkPlaceholderForOverload(*this, Base))
return ExprError();
@@ -15903,9 +15906,16 @@ ExprResult Sema::BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc,
LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
LookupParsedName(R, /*S=*/nullptr, /*SS=*/nullptr, Base->getType());
+ // If the expression is dependent and we either:
+ // - Found a member of the current instantiation named 'operator->', or
+ // - Found nothing, and the lookup context has no dependent base classes
+ //
+ // Then we should build a dependent class member access expression.
if (R.wasNotFoundInCurrentInstantiation() ||
- (Base->isTypeDependent() && !R.empty()))
- return ExprEmpty();
+ (Base->isTypeDependent() && !R.empty())) {
+ IsDependent = true;
+ return Base;
+ }
R.suppressAccessDiagnostics();
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 85b0dafb2edac5..af793beb4b7cc8 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -16567,8 +16567,12 @@ ExprResult TreeTransform<Derived>::RebuildCXXOperatorCallExpr(
// in the tree transformation.
if (First->containsErrors())
return ExprError();
+ bool IsDependent;
// -> is never a builtin operation.
- return SemaRef.BuildOverloadedArrowExpr(First, OpLoc);
+ ExprResult Result = SemaRef.BuildOverloadedArrowExpr(
+ First, OpLoc, /*NoArrowOperatorFound=*/nullptr, IsDependent);
+ assert(!IsDependent);
+ return Result;
} else if (Second == nullptr || isPostIncDec) {
if (!First->getType()->isOverloadableType() ||
(Op == OO_Amp && getSema().isQualifiedMemberAccess(First))) {
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