https://github.com/zyn0217 updated
https://github.com/llvm/llvm-project/pull/149782
>From 32be32e2ae072f920389c61e42b9e392a6b92798 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7...@gmail.com>
Date: Mon, 21 Jul 2025 17:17:48 +0800
Subject: [PATCH 1/2] [Clang] Fix a partial ordering bug involving CTAD
injected template arguments
---
clang/lib/Sema/SemaTemplateDeduction.cpp | 12 +++++++++---
clang/test/SemaTemplate/deduction-guide.cpp | 16 ++++++++++++++++
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp
b/clang/lib/Sema/SemaTemplateDeduction.cpp
index d09a72b71b805..f990e609d9823 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -5525,6 +5525,8 @@ static TemplateDeductionResult CheckDeductionConsistency(
// FIXME: A substitution can be incomplete on a non-structural part of the
// type. Use the canonical type for now, until the TemplateInstantiator can
// deal with that.
+ if (auto *Injected = P->getAs<InjectedClassNameType>())
+ P = Injected->getInjectedSpecializationType();
QualType InstP = S.SubstType(P.getCanonicalType(), MLTAL, FTD->getLocation(),
FTD->getDeclName(), &IsIncompleteSubstitution);
if (InstP.isNull() && !IsIncompleteSubstitution)
@@ -5539,9 +5541,13 @@ static TemplateDeductionResult CheckDeductionConsistency(
if (auto *PA = dyn_cast<PackExpansionType>(A);
PA && !isa<PackExpansionType>(InstP))
A = PA->getPattern();
- if (!S.Context.hasSameType(
- S.Context.getUnqualifiedArrayType(InstP.getNonReferenceType()),
- S.Context.getUnqualifiedArrayType(A.getNonReferenceType())))
+ auto T1 = S.Context.getUnqualifiedArrayType(InstP.getNonReferenceType());
+ auto T2 = S.Context.getUnqualifiedArrayType(A.getNonReferenceType());
+ if (auto *Injected = T1->getAs<InjectedClassNameType>())
+ T1 = Injected->getInjectedSpecializationType();
+ if (auto *Injected = T2->getAs<InjectedClassNameType>())
+ T2 = Injected->getInjectedSpecializationType();
+ if (!S.Context.hasSameType(T1, T2))
return TemplateDeductionResult::NonDeducedMismatch;
return TemplateDeductionResult::Success;
}
diff --git a/clang/test/SemaTemplate/deduction-guide.cpp
b/clang/test/SemaTemplate/deduction-guide.cpp
index 0953f647426fa..f6bc6ee3673c2 100644
--- a/clang/test/SemaTemplate/deduction-guide.cpp
+++ b/clang/test/SemaTemplate/deduction-guide.cpp
@@ -966,3 +966,19 @@ Expand<Type, Invocable<>> _{};
// CHECK-NEXT: | `-ParmVarDecl {{.+}} 'T...' pack
}
+
+namespace GH134613 {
+template <typename R> struct Foo {
+ using value_type = R;
+
+ Foo() = default;
+ Foo(Foo<Foo<R>> &&rhs) {}
+};
+
+void main() {
+ auto r1 = Foo(Foo<Foo<int>>{});
+
+ static_assert(__is_same(decltype(r1)::value_type, int));
+}
+
+}
>From 0fa71d3eb2f03e115da5ebd97bef52226affbd1b Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7...@gmail.com>
Date: Wed, 23 Jul 2025 18:47:58 +0800
Subject: [PATCH 2/2] Apply suggestions
---
clang/lib/Sema/SemaTemplateDeduction.cpp | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp
b/clang/lib/Sema/SemaTemplateDeduction.cpp
index f990e609d9823..ce78ecc2d4a2d 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -5525,8 +5525,15 @@ static TemplateDeductionResult CheckDeductionConsistency(
// FIXME: A substitution can be incomplete on a non-structural part of the
// type. Use the canonical type for now, until the TemplateInstantiator can
// deal with that.
- if (auto *Injected = P->getAs<InjectedClassNameType>())
- P = Injected->getInjectedSpecializationType();
+
+ // Workaround: Implicit deduction guides use InjectedClassNameTypes, whereas
+ // the explicit guides don't. The substitution doesn't transform these types,
+ // so let it transform their specializations instead.
+ bool IsDeductionGuide = isa<CXXDeductionGuideDecl>(FTD->getTemplatedDecl());
+ if (IsDeductionGuide) {
+ if (auto *Injected = P->getAs<InjectedClassNameType>())
+ P = Injected->getInjectedSpecializationType();
+ }
QualType InstP = S.SubstType(P.getCanonicalType(), MLTAL, FTD->getLocation(),
FTD->getDeclName(), &IsIncompleteSubstitution);
if (InstP.isNull() && !IsIncompleteSubstitution)
@@ -5543,10 +5550,12 @@ static TemplateDeductionResult
CheckDeductionConsistency(
A = PA->getPattern();
auto T1 = S.Context.getUnqualifiedArrayType(InstP.getNonReferenceType());
auto T2 = S.Context.getUnqualifiedArrayType(A.getNonReferenceType());
- if (auto *Injected = T1->getAs<InjectedClassNameType>())
- T1 = Injected->getInjectedSpecializationType();
- if (auto *Injected = T2->getAs<InjectedClassNameType>())
- T2 = Injected->getInjectedSpecializationType();
+ if (IsDeductionGuide) {
+ if (auto *Injected = T1->getAs<InjectedClassNameType>())
+ T1 = Injected->getInjectedSpecializationType();
+ if (auto *Injected = T2->getAs<InjectedClassNameType>())
+ T2 = Injected->getInjectedSpecializationType();
+ }
if (!S.Context.hasSameType(T1, T2))
return TemplateDeductionResult::NonDeducedMismatch;
return TemplateDeductionResult::Success;
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