release/20.x: [clang] Forward TPL of NestedNameSpecifier #137806
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@llvm/pr-subscribers-clang Author: Jonas Hahnfeld (hahnjo) ChangesThis avoids type suffixes for integer constants when the type can be inferred from the template parameter, such as the Note: This issue does not exist anymore in Full diff: https://github.com/llvm/llvm-project/pull/137806.diff 2 Files Affected:
diff --git a/clang/lib/AST/NestedNameSpecifier.cpp b/clang/lib/AST/NestedNameSpecifier.cpp
index 76c77569da9fd..c043996f1ada3 100644
--- a/clang/lib/AST/NestedNameSpecifier.cpp
+++ b/clang/lib/AST/NestedNameSpecifier.cpp
@@ -283,13 +283,16 @@ void NestedNameSpecifier::print(raw_ostream &OS, const PrintingPolicy &Policy,
case TypeSpec: {
const auto *Record =
dyn_cast_or_null<ClassTemplateSpecializationDecl>(getAsRecordDecl());
- if (ResolveTemplateArguments && Record) {
+ const TemplateParameterList *TPL = nullptr;
+ if (Record) {
+ TPL = Record->getSpecializedTemplate()->getTemplateParameters();
+ if (ResolveTemplateArguments) {
// Print the type trait with resolved template parameters.
Record->printName(OS, Policy);
- printTemplateArgumentList(
- OS, Record->getTemplateArgs().asArray(), Policy,
- Record->getSpecializedTemplate()->getTemplateParameters());
+ printTemplateArgumentList(OS, Record->getTemplateArgs().asArray(),
+ Policy, TPL);
break;
+ }
}
const Type *T = getAsType();
@@ -313,8 +316,8 @@ void NestedNameSpecifier::print(raw_ostream &OS, const PrintingPolicy &Policy,
TemplateName::Qualified::None);
// Print the template argument list.
- printTemplateArgumentList(OS, SpecType->template_arguments(),
- InnerPolicy);
+ printTemplateArgumentList(OS, SpecType->template_arguments(), InnerPolicy,
+ TPL);
} else if (const auto *DepSpecType =
dyn_cast<DependentTemplateSpecializationType>(T)) {
// Print the template name without its corresponding
@@ -322,7 +325,7 @@ void NestedNameSpecifier::print(raw_ostream &OS, const PrintingPolicy &Policy,
OS << DepSpecType->getIdentifier()->getName();
// Print the template argument list.
printTemplateArgumentList(OS, DepSpecType->template_arguments(),
- InnerPolicy);
+ InnerPolicy, TPL);
} else {
// Print the type normally
QualType(T, 0).print(OS, InnerPolicy);
diff --git a/clang/unittests/Tooling/QualTypeNamesTest.cpp b/clang/unittests/Tooling/QualTypeNamesTest.cpp
index 5ded64d4fcc8c..49c40d633ad4b 100644
--- a/clang/unittests/Tooling/QualTypeNamesTest.cpp
+++ b/clang/unittests/Tooling/QualTypeNamesTest.cpp
@@ -265,6 +265,102 @@ TEST(QualTypeNameTest, InlineNamespace) {
TypeNameVisitor::Lang_CXX11);
}
+TEST(QualTypeNameTest, TemplatedClass) {
+ std::unique_ptr<ASTUnit> AST =
+ tooling::buildASTFromCode("template <unsigned U1> struct A {\n"
+ " template <unsigned U2> struct B {};\n"
+ "};\n"
+ "template struct A<1>;\n"
+ "template struct A<2u>;\n"
+ "template struct A<1>::B<3>;\n"
+ "template struct A<2u>::B<4u>;\n");
+
+ auto &Context = AST->getASTContext();
+ auto &Policy = Context.getPrintingPolicy();
+ auto getFullyQualifiedName = [&](QualType QT) {
+ return TypeName::getFullyQualifiedName(QT, Context, Policy);
+ };
+
+ auto *A = Context.getTranslationUnitDecl()
+ ->lookup(&Context.Idents.get("A"))
+ .find_first<ClassTemplateDecl>();
+ ASSERT_NE(A, nullptr);
+
+ // A has two explicit instantiations: A<1> and A<2u>
+ auto ASpec = A->spec_begin();
+ ASSERT_NE(ASpec, A->spec_end());
+ auto *A1 = *ASpec;
+ ASpec++;
+ ASSERT_NE(ASpec, A->spec_end());
+ auto *A2 = *ASpec;
+
+ // Their type names follow the records.
+ QualType A1RecordTy = Context.getRecordType(A1);
+ EXPECT_EQ(getFullyQualifiedName(A1RecordTy), "A<1>");
+ QualType A2RecordTy = Context.getRecordType(A2);
+ EXPECT_EQ(getFullyQualifiedName(A2RecordTy), "A<2U>");
+
+ // getTemplateSpecializationType() gives types that print the integral
+ // argument directly.
+ TemplateArgument Args1[] = {
+ {Context, llvm::APSInt::getUnsigned(1u), Context.UnsignedIntTy}};
+ QualType A1TemplateSpecTy =
+ Context.getTemplateSpecializationType(TemplateName(A), Args1, A1RecordTy);
+ EXPECT_EQ(A1TemplateSpecTy.getAsString(), "A<1>");
+
+ TemplateArgument Args2[] = {
+ {Context, llvm::APSInt::getUnsigned(2u), Context.UnsignedIntTy}};
+ QualType A2TemplateSpecTy =
+ Context.getTemplateSpecializationType(TemplateName(A), Args2, A2RecordTy);
+ EXPECT_EQ(A2TemplateSpecTy.getAsString(), "A<2>");
+
+ // Find A<1>::B and its specialization B<3>.
+ auto *A1B =
+ A1->lookup(&Context.Idents.get("B")).find_first<ClassTemplateDecl>();
+ ASSERT_NE(A1B, nullptr);
+ auto A1BSpec = A1B->spec_begin();
+ ASSERT_NE(A1BSpec, A1B->spec_end());
+ auto *A1B3 = *A1BSpec;
+ QualType A1B3RecordTy = Context.getRecordType(A1B3);
+ EXPECT_EQ(getFullyQualifiedName(A1B3RecordTy), "A<1>::B<3>");
+
+ // Construct A<1>::B<3> and check name.
+ TemplateArgument Args3[] = {
+ {Context, llvm::APSInt::getUnsigned(3u), Context.UnsignedIntTy}};
+ QualType A1B3TemplateSpecTy = Context.getTemplateSpecializationType(
+ TemplateName(A1B), Args3, A1B3RecordTy);
+ EXPECT_EQ(A1B3TemplateSpecTy.getAsString(), "B<3>");
+
+ NestedNameSpecifier *A1Nested = NestedNameSpecifier::Create(
+ Context, nullptr, false, A1TemplateSpecTy.getTypePtr());
+ QualType A1B3ElaboratedTy = Context.getElaboratedType(
+ ElaboratedTypeKeyword::None, A1Nested, A1B3TemplateSpecTy);
+ EXPECT_EQ(A1B3ElaboratedTy.getAsString(), "A<1>::B<3>");
+
+ // Find A<2u>::B and its specialization B<4u>.
+ auto *A2B =
+ A2->lookup(&Context.Idents.get("B")).find_first<ClassTemplateDecl>();
+ ASSERT_NE(A2B, nullptr);
+ auto A2BSpec = A2B->spec_begin();
+ ASSERT_NE(A2BSpec, A2B->spec_end());
+ auto *A2B4 = *A2BSpec;
+ QualType A2B4RecordTy = Context.getRecordType(A2B4);
+ EXPECT_EQ(getFullyQualifiedName(A2B4RecordTy), "A<2U>::B<4U>");
+
+ // Construct A<2>::B<4> and check name.
+ TemplateArgument Args4[] = {
+ {Context, llvm::APSInt::getUnsigned(4u), Context.UnsignedIntTy}};
+ QualType A2B4TemplateSpecTy = Context.getTemplateSpecializationType(
+ TemplateName(A2B), Args4, A2B4RecordTy);
+ EXPECT_EQ(A2B4TemplateSpecTy.getAsString(), "B<4>");
+
+ NestedNameSpecifier *A2Nested = NestedNameSpecifier::Create(
+ Context, nullptr, false, A2TemplateSpecTy.getTypePtr());
+ QualType A2B4ElaboratedTy = Context.getElaboratedType(
+ ElaboratedTypeKeyword::None, A2Nested, A2B4TemplateSpecTy);
+ EXPECT_EQ(A2B4ElaboratedTy.getAsString(), "A<2>::B<4>");
+}
+
TEST(QualTypeNameTest, AnonStrucs) {
TypeNameVisitor AnonStrucs;
AnonStrucs.ExpectedQualTypeNames["a"] = "short";
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This is great, @hahnjo. We need this to unbreak llvm20 for downstream clients. LGTM!
Is there a bug report for this, I would like to understand how this is breaking someone? IF there is not one, can we please file one. Without understanding the problem better, I don't see why we would want to backport this. |
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Hi @shafik, the issue is an inconsistency in the treatment of template specialization types depending on whether they are the prefix or the "final" type. To stay with the example of the test, the result without this patch is There is no issue for this because the problem is not present anymore in |
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@shafik do the explanations make sense? |
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In principle this also should fix the regression in the type correction but I failed to trigger that logic there. We really need this for enabling downstream clients that use the api for consistent type printing. |
This avoids type suffixes for integer constants when the type can be inferred from the template parameter, such as the unsigned parameter of A<1> and A<2> in the added test.
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@hahnjo (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR. |
This avoids type suffixes for integer constants when the type can be inferred from the template parameter, such as the
unsignedparameter ofA<1>andA<2>in the added test.Note: This issue does not exist anymore in
main, see #137804. However, I don't think dc17429 should be backported torelease/20.x, so I'm proposing a targeted fix.