https://github.com/jcsxky updated
https://github.com/llvm/llvm-project/pull/90376
>From c5c67ed879fc58e5371de6fc8296b7b6f653a072 Mon Sep 17 00:00:00 2001
From: huqizhi
Date: Sun, 28 Apr 2024 14:24:30 +0800
Subject: [PATCH] [Clang][Sema] Fix a bug on template partial specialization
with issue on deduction of nontype tempalte parameter
---
clang/docs/ReleaseNotes.rst | 2 ++
clang/include/clang/Sema/Sema.h | 10 ++
clang/lib/Sema/SemaTemplate.cpp | 19 +++
clang/lib/Sema/SemaTemplateDeduction.cpp | 10 ++
clang/test/SemaCXX/PR68885.cpp | 21 +
5 files changed, 50 insertions(+), 12 deletions(-)
create mode 100644 clang/test/SemaCXX/PR68885.cpp
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 98c80b6017f604..1abc00a25f1f42 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -612,6 +612,8 @@ Bug Fixes to C++ Support
- Fix CTAD for ``std::initializer_list``. This allows
``std::initializer_list{1, 2, 3}`` to be deduced as
``std::initializer_list`` as intended.
- Fix a bug on template partial specialization whose template parameter is
`decltype(auto)`.
+- Fix a bug on template partial specialization with issue on deduction of
nontype template parameter
+ whose type is `decltype(auto)`. Fixes (#GH68885).
Bug Fixes to AST Handling
^
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 1ca523ec88c2f9..809b9c4498f697 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -9249,7 +9249,8 @@ class Sema final : public SemaBase {
void NoteTemplateParameterLocation(const NamedDecl );
ExprResult BuildExpressionFromDeclTemplateArgument(
- const TemplateArgument , QualType ParamType, SourceLocation Loc);
+ const TemplateArgument , QualType ParamType, SourceLocation Loc,
+ NamedDecl *TemplateParam = nullptr);
ExprResult
BuildExpressionFromNonTypeTemplateArgument(const TemplateArgument ,
SourceLocation Loc);
@@ -9572,9 +9573,10 @@ class Sema final : public SemaBase {
bool isSameOrCompatibleFunctionType(QualType Param, QualType Arg);
- TemplateArgumentLoc getTrivialTemplateArgumentLoc(const TemplateArgument
,
-QualType NTTPType,
-SourceLocation Loc);
+ TemplateArgumentLoc
+ getTrivialTemplateArgumentLoc(const TemplateArgument , QualType NTTPType,
+SourceLocation Loc,
+NamedDecl *TemplateParam = nullptr);
/// Get a template argument mapping the given template parameter to itself,
/// e.g. for X in \c template, this would return an expression
template
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index ed5507c0ec0100..3c2a5a4ac47e69 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -8438,10 +8438,9 @@ void Sema::NoteTemplateParameterLocation(const NamedDecl
) {
/// declaration and the type of its corresponding non-type template
/// parameter, produce an expression that properly refers to that
/// declaration.
-ExprResult
-Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument ,
- QualType ParamType,
- SourceLocation Loc) {
+ExprResult Sema::BuildExpressionFromDeclTemplateArgument(
+const TemplateArgument , QualType ParamType, SourceLocation Loc,
+NamedDecl *TemplateParam) {
// C++ [temp.param]p8:
//
// A non-type template-parameter of type "array of T" or
@@ -8508,6 +8507,18 @@ Sema::BuildExpressionFromDeclTemplateArgument(const
TemplateArgument ,
} else {
assert(ParamType->isReferenceType() &&
"unexpected type for decl template argument");
+if (NonTypeTemplateParmDecl *NTTP =
+dyn_cast_if_present(TemplateParam)) {
+ QualType TemplateParamType = NTTP->getType();
+ const AutoType *AT = TemplateParamType->getAs();
+ if (AT && AT->isDecltypeAuto()) {
+RefExpr = new (getASTContext()) SubstNonTypeTemplateParmExpr(
+ParamType->getPointeeType(), RefExpr.get()->getValueKind(),
+RefExpr.get()->getExprLoc(), RefExpr.get(), VD, NTTP->getIndex(),
+/*PackIndex=*/std::nullopt,
+/*RefParam=*/true);
+ }
+}
}
// At this point we should have the right value category.
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp
b/clang/lib/Sema/SemaTemplateDeduction.cpp
index c3815bca038554..e93f7bd842e444 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -2639,7 +2639,8 @@ static bool isSameTemplateArg(ASTContext ,
/// argument.
TemplateArgumentLoc
