[clang] [Clang] Preserve the fully-substituted flag in PackIndexingType (PR #107181)
Younan Zhang via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 3 21:57:01 PDT 2024
https://github.com/zyn0217 created https://github.com/llvm/llvm-project/pull/107181
We should avoid another round of transformation of the pattern if the pattern has already turned out to be an empty pack. As an outcome, the empty SubstTemplateTypeParmPackType won't occur, and we don't need to collect any unexpanded packs.
Fixes https://github.com/llvm/llvm-project/issues/105903
>From 40421929c74a1494ba358457a9e6579b48998112 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Wed, 4 Sep 2024 12:50:32 +0800
Subject: [PATCH] [Clang] Preserve the fully-substituted flag in
PackIndexingType
We should avoid another round of transformation of the pattern if
the pattern has already turned out to be an empty pack. As an
outcome, the empty SubstTemplateTypeParmPackType won't occur,
and we don't need to collect any unexpanded packs.
---
clang/docs/ReleaseNotes.rst | 1 +
clang/include/clang/AST/Type.h | 13 +++++++++----
clang/include/clang/AST/TypeProperties.td | 5 ++++-
clang/lib/AST/ASTContext.cpp | 10 +++++-----
clang/lib/AST/Type.cpp | 7 ++++---
clang/lib/Sema/TreeTransform.h | 4 ++--
clang/test/SemaCXX/cxx2c-pack-indexing.cpp | 12 ++++++++++++
7 files changed, 37 insertions(+), 15 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0eee71d00a2c5f..82d85cecd97cfe 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -342,6 +342,7 @@ Bug Fixes to C++ Support
specialization right before its declaration context. (#GH64082)
- Fixed a constraint comparison bug for friend declarations. (#GH78101)
- Fix handling of ``_`` as the name of a lambda's init capture variable. (#GH107024)
+- Fixed a bug in the substitution of empty pack indexing types. (#GH105903)
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 08f7638d7d8f96..62426b6e81292f 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -5828,12 +5828,15 @@ class PackIndexingType final
QualType Pattern;
Expr *IndexExpr;
- unsigned Size;
+ unsigned Size : 31;
+
+ LLVM_PREFERRED_TYPE(bool)
+ unsigned FullySubstituted : 1;
protected:
friend class ASTContext; // ASTContext creates these.
PackIndexingType(const ASTContext &Context, QualType Canonical,
- QualType Pattern, Expr *IndexExpr,
+ QualType Pattern, Expr *IndexExpr, bool FullySubstituted,
ArrayRef<QualType> Expansions = {});
public:
@@ -5857,6 +5860,8 @@ class PackIndexingType final
bool hasSelectedType() const { return getSelectedIndex() != std::nullopt; }
+ bool isFullySubstituted() const { return FullySubstituted; }
+
ArrayRef<QualType> getExpansions() const {
return {getExpansionsPtr(), Size};
}
@@ -5869,10 +5874,10 @@ class PackIndexingType final
if (hasSelectedType())
getSelectedType().Profile(ID);
else
- Profile(ID, Context, getPattern(), getIndexExpr());
+ Profile(ID, Context, getPattern(), getIndexExpr(), isFullySubstituted());
}
static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
- QualType Pattern, Expr *E);
+ QualType Pattern, Expr *E, bool FullySubstituted);
private:
const QualType *getExpansionsPtr() const {
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 3df19315fd573f..93a1054de9ced8 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -473,9 +473,12 @@ let Class = PackIndexingType in {
def : Property<"indexExpression", ExprRef> {
let Read = [{ node->getIndexExpr() }];
}
+ def : Property<"fullySubstituted", Bool> {
+ let Read = [{ node->isFullySubstituted() }];
+ }
def : Creator<[{
- return ctx.getPackIndexingType(pattern, indexExpression);
+ return ctx.getPackIndexingType(pattern, indexExpression, fullySubstituted);
}]>;
}
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index c61234aa4d1af1..b03f286f9ece4b 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -6192,7 +6192,7 @@ QualType ASTContext::getPackIndexingType(QualType Pattern, Expr *IndexExpr,
Canonical = getCanonicalType(Expansions[Index]);
} else {
llvm::FoldingSetNodeID ID;
- PackIndexingType::Profile(ID, *this, Pattern, IndexExpr);
+ PackIndexingType::Profile(ID, *this, Pattern, IndexExpr, FullySubstituted);
void *InsertPos = nullptr;
PackIndexingType *Canon =
DependentPackIndexingTypes.FindNodeOrInsertPos(ID, InsertPos);
@@ -6200,8 +6200,8 @@ QualType ASTContext::getPackIndexingType(QualType Pattern, Expr *IndexExpr,
void *Mem = Allocate(
PackIndexingType::totalSizeToAlloc<QualType>(Expansions.size()),
TypeAlignment);
- Canon = new (Mem)
- PackIndexingType(*this, QualType(), Pattern, IndexExpr, Expansions);
+ Canon = new (Mem) PackIndexingType(*this, QualType(), Pattern, IndexExpr,
+ FullySubstituted, Expansions);
DependentPackIndexingTypes.InsertNode(Canon, InsertPos);
}
Canonical = QualType(Canon, 0);
@@ -6210,8 +6210,8 @@ QualType ASTContext::getPackIndexingType(QualType Pattern, Expr *IndexExpr,
void *Mem =
Allocate(PackIndexingType::totalSizeToAlloc<QualType>(Expansions.size()),
TypeAlignment);
- auto *T = new (Mem)
- PackIndexingType(*this, Canonical, Pattern, IndexExpr, Expansions);
+ auto *T = new (Mem) PackIndexingType(*this, Canonical, Pattern, IndexExpr,
+ FullySubstituted, Expansions);
Types.push_back(T);
return QualType(T, 0);
}
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index e89ce2e4b38445..670476f69c35dd 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3992,12 +3992,12 @@ void DependentDecltypeType::Profile(llvm::FoldingSetNodeID &ID,
PackIndexingType::PackIndexingType(const ASTContext &Context,
QualType Canonical, QualType Pattern,
- Expr *IndexExpr,
+ Expr *IndexExpr, bool FullySubstituted,
ArrayRef<QualType> Expansions)
: Type(PackIndexing, Canonical,
computeDependence(Pattern, IndexExpr, Expansions)),
Context(Context), Pattern(Pattern), IndexExpr(IndexExpr),
- Size(Expansions.size()) {
+ Size(Expansions.size()), FullySubstituted(FullySubstituted) {
std::uninitialized_copy(Expansions.begin(), Expansions.end(),
getTrailingObjects<QualType>());
@@ -4042,9 +4042,10 @@ PackIndexingType::computeDependence(QualType Pattern, Expr *IndexExpr,
void PackIndexingType::Profile(llvm::FoldingSetNodeID &ID,
const ASTContext &Context, QualType Pattern,
- Expr *E) {
+ Expr *E, bool FullySubstituted) {
Pattern.Profile(ID);
E->Profile(ID, Context, true);
+ ID.AddBoolean(FullySubstituted);
}
UnaryTransformType::UnaryTransformType(QualType BaseType,
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 66e3f27fed9de0..813bd23124c3ff 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -6687,10 +6687,10 @@ TreeTransform<Derived>::TransformPackIndexingType(TypeLocBuilder &TLB,
bool NotYetExpanded = Types.empty();
bool FullySubstituted = true;
- if (Types.empty())
+ if (Types.empty() && !PIT->isFullySubstituted())
Types = llvm::ArrayRef<QualType>(&Pattern, 1);
- for (const QualType &T : Types) {
+ for (QualType T : Types) {
if (!T->containsUnexpandedParameterPack()) {
QualType Transformed = getDerived().TransformType(T);
if (Transformed.isNull())
diff --git a/clang/test/SemaCXX/cxx2c-pack-indexing.cpp b/clang/test/SemaCXX/cxx2c-pack-indexing.cpp
index 7d7e808746217f..962dbb8137f289 100644
--- a/clang/test/SemaCXX/cxx2c-pack-indexing.cpp
+++ b/clang/test/SemaCXX/cxx2c-pack-indexing.cpp
@@ -258,4 +258,16 @@ void f() {
vars<0>::x<0>();
}
+} // namespace GH105900
+
+namespace GH105903 {
+
+template <typename... opts> struct temp {
+ template <unsigned s> static auto x() -> opts... [s] {} // expected-note {{invalid index 0 for pack 'opts' of size 0}}
+};
+
+void f() {
+ temp<>::x<0>(); // expected-error {{no matching}}
}
+
+} // namespace GH105903
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