[clang] fix error recovery for invalid nested name specifiers #156772
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@llvm/pr-subscribers-clang Author: Matheus Izvekov (mizvekov) ChangesThis fixes a regression which was introduced in #147835. Since this regression was never released, there are no release notes. Fixes #156458 Full diff: https://github.com/llvm/llvm-project/pull/156772.diff 5 Files Affected:
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index c3fb57774c8dc..f20c1e25a384d 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -5363,7 +5363,7 @@ class Sema final : public SemaBase {
SourceLocation UsingLoc,
SourceLocation EnumLoc, SourceRange TyLoc,
const IdentifierInfo &II, ParsedType Ty,
- CXXScopeSpec *SS = nullptr);
+ const CXXScopeSpec &SS);
Decl *ActOnAliasDeclaration(Scope *CurScope, AccessSpecifier AS,
MultiTemplateParamsArg TemplateParams,
SourceLocation UsingLoc, UnqualifiedId &Name,
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 8135f4f603907..19f94122f151e 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -672,7 +672,7 @@ Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration(
/*WantNontrivialTypeSourceInfo=*/true);
UED = Actions.ActOnUsingEnumDeclaration(
- getCurScope(), AS, UsingLoc, UELoc, IdentLoc, *IdentInfo, Type, &SS);
+ getCurScope(), AS, UsingLoc, UELoc, IdentLoc, *IdentInfo, Type, SS);
} else if (Tok.is(tok::annot_template_id)) {
TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
@@ -687,7 +687,7 @@ Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration(
UED = Actions.ActOnUsingEnumDeclaration(getCurScope(), AS, UsingLoc,
UELoc, Loc, *TemplateId->Name,
- Type.get(), &SS);
+ Type.get(), SS);
} else {
Diag(Tok.getLocation(), diag::err_using_enum_not_enum)
<< TemplateId->Name->getName()
diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index ef14dde5203a6..437c69aa1587d 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -398,6 +398,54 @@ class NestedNameSpecifierValidatorCCC final
}
+[[nodiscard]] static bool ExtendNestedNameSpecifier(Sema &S, CXXScopeSpec &SS,
+ const NamedDecl *ND,
+ SourceLocation NameLoc,
+ SourceLocation CCLoc) {
+ TypeLocBuilder TLB;
+ QualType T;
+ if (const auto *USD = dyn_cast<UsingShadowDecl>(ND)) {
+ T = S.Context.getUsingType(ElaboratedTypeKeyword::None, SS.getScopeRep(),
+ USD);
+ TLB.push<UsingTypeLoc>(T).set(/*ElaboratedKeywordLoc=*/SourceLocation(),
+ SS.getWithLocInContext(S.Context), NameLoc);
+ } else if (const auto *TD = dyn_cast<TypeDecl>(ND)) {
+ T = S.Context.getTypeDeclType(ElaboratedTypeKeyword::None, SS.getScopeRep(),
+ TD);
+ switch (T->getTypeClass()) {
+ case Type::Record:
+ case Type::InjectedClassName:
+ case Type::Enum: {
+ auto TTL = TLB.push<TagTypeLoc>(T);
+ TTL.setElaboratedKeywordLoc(SourceLocation());
+ TTL.setQualifierLoc(SS.getWithLocInContext(S.Context));
+ TTL.setNameLoc(NameLoc);
+ break;
+ }
+ case Type::Typedef:
+ TLB.push<TypedefTypeLoc>(T).set(/*ElaboratedKeywordLoc=*/SourceLocation(),
+ SS.getWithLocInContext(S.Context),
+ NameLoc);
+ break;
+ case Type::UnresolvedUsing:
+ TLB.push<UnresolvedUsingTypeLoc>(T).set(
+ /*ElaboratedKeywordLoc=*/SourceLocation(),
+ SS.getWithLocInContext(S.Context), NameLoc);
+ break;
+ default:
+ assert(SS.isEmpty());
+ T = S.Context.getTypeDeclType(TD);
+ TLB.pushTypeSpec(T).setNameLoc(NameLoc);
+ break;
+ }
+ } else {
+ return false;
+ }
+ SS.clear();
+ SS.Make(S.Context, TLB.getTypeLocInContext(S.Context, T), CCLoc);
+ return true;
+}
+
bool Sema::BuildCXXNestedNameSpecifier(Scope *S, NestedNameSpecInfo &IdInfo,
bool EnteringContext, CXXScopeSpec &SS,
NamedDecl *ScopeLookupResult,
@@ -653,40 +701,9 @@ bool Sema::BuildCXXNestedNameSpecifier(Scope *S, NestedNameSpecInfo &IdInfo,
if (isa<EnumDecl>(TD))
Diag(IdInfo.IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec);
- QualType T;
- TypeLocBuilder TLB;
- if (const auto *USD = dyn_cast<UsingShadowDecl>(SD)) {
- T = Context.getUsingType(ElaboratedTypeKeyword::None, SS.getScopeRep(),
- USD);
- TLB.push<UsingTypeLoc>(T).set(/*ElaboratedKeywordLoc=*/SourceLocation(),
- SS.getWithLocInContext(Context),
- IdInfo.IdentifierLoc);
- } else if (const auto *Tag = dyn_cast<TagDecl>(TD)) {
- T = Context.getTagType(ElaboratedTypeKeyword::None, SS.getScopeRep(), Tag,
- /*OwnsTag=*/false);
- auto TTL = TLB.push<TagTypeLoc>(T);
- TTL.setElaboratedKeywordLoc(SourceLocation());
- TTL.setQualifierLoc(SS.getWithLocInContext(SemaRef.Context));
- TTL.setNameLoc(IdInfo.IdentifierLoc);
- } else if (auto *TN = dyn_cast<TypedefNameDecl>(TD)) {
- T = Context.getTypedefType(ElaboratedTypeKeyword::None, SS.getScopeRep(),
- TN);
- TLB.push<TypedefTypeLoc>(T).set(/*ElaboratedKeywordLoc=*/SourceLocation(),
- SS.getWithLocInContext(SemaRef.Context),
- IdInfo.IdentifierLoc);
- } else if (auto *UD = dyn_cast<UnresolvedUsingTypenameDecl>(TD)) {
- T = Context.getUnresolvedUsingType(ElaboratedTypeKeyword::None,
- SS.getScopeRep(), UD);
- TLB.push<UnresolvedUsingTypeLoc>(T).set(
- /*ElaboratedKeywordLoc=*/SourceLocation(),
- SS.getWithLocInContext(SemaRef.Context), IdInfo.IdentifierLoc);
- } else {
- assert(SS.isEmpty());
- T = Context.getTypeDeclType(TD);
- TLB.pushTypeSpec(T).setNameLoc(IdInfo.IdentifierLoc);
- }
- SS.clear();
- SS.Make(Context, TLB.getTypeLocInContext(Context, T), IdInfo.CCLoc);
+ [[maybe_unused]] bool IsType = ::ExtendNestedNameSpecifier(
+ *this, SS, SD, IdInfo.IdentifierLoc, IdInfo.CCLoc);
+ assert(IsType && "unhandled declaration kind");
return false;
}
@@ -762,21 +779,16 @@ bool Sema::BuildCXXNestedNameSpecifier(Scope *S, NestedNameSpecInfo &IdInfo,
}
if (!Found.empty()) {
- if (TypeDecl *TD = Found.getAsSingle<TypeDecl>()) {
- QualType T;
- if (auto *TN = dyn_cast<TypedefNameDecl>(TD)) {
- T = Context.getTypedefType(ElaboratedTypeKeyword::None,
- SS.getScopeRep(), TN);
- } else {
- // FIXME: Enumerate the possibilities here.
- assert(!isa<TagDecl>(TD));
- assert(SS.isEmpty());
- T = Context.getTypeDeclType(TD);
- }
-
+ const auto *ND = Found.getAsSingle<NamedDecl>();
+ if (::ExtendNestedNameSpecifier(*this, SS, ND, IdInfo.IdentifierLoc,
+ IdInfo.CCLoc)) {
+ const Type *T = SS.getScopeRep().getAsType();
Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace)
- << T << getLangOpts().CPlusPlus;
- } else if (Found.getAsSingle<TemplateDecl>()) {
+ << QualType(T, 0) << getLangOpts().CPlusPlus;
+ // Recover with this type if it would be a valid nested name specifier.
+ return !T->getAsCanonical<TagType>();
+ }
+ if (isa<TemplateDecl>(ND)) {
ParsedType SuggestedType;
DiagnoseUnknownTypeName(IdInfo.Identifier, IdInfo.IdentifierLoc, S, &SS,
SuggestedType);
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 4b0dead182543..63ce87b9b0607 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -12628,16 +12628,17 @@ Decl *Sema::ActOnUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
SourceLocation UsingLoc,
SourceLocation EnumLoc, SourceRange TyLoc,
const IdentifierInfo &II, ParsedType Ty,
- CXXScopeSpec *SS) {
- assert(SS && !SS->isInvalid() && "ScopeSpec is invalid");
+ const CXXScopeSpec &SS) {
TypeSourceInfo *TSI = nullptr;
SourceLocation IdentLoc = TyLoc.getBegin();
QualType EnumTy = GetTypeFromParser(Ty, &TSI);
if (EnumTy.isNull()) {
- Diag(IdentLoc, isDependentScopeSpecifier(*SS)
+ Diag(IdentLoc, isDependentScopeSpecifier(SS)
? diag::err_using_enum_is_dependent
: diag::err_unknown_typename)
- << II.getName() << SourceRange(SS->getBeginLoc(), TyLoc.getEnd());
+ << II.getName()
+ << SourceRange(SS.isValid() ? SS.getBeginLoc() : IdentLoc,
+ TyLoc.getEnd());
return nullptr;
}
diff --git a/clang/test/SemaCXX/GH156458.cpp b/clang/test/SemaCXX/GH156458.cpp
new file mode 100644
index 0000000000000..1e054a0958a83
--- /dev/null
+++ b/clang/test/SemaCXX/GH156458.cpp
@@ -0,0 +1,12 @@
+//RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %s
+
+// Force a fatal error
+#include <unknownheader> // expected-error {{file not found}}
+
+namespace N {}
+
+enum class E {};
+using enum N::E::V;
+
+using T = int;
+using enum N::T::v;
|
ckoparkar
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Sep 4, 2025
* main: (1483 commits) [clang] fix error recovery for invalid nested name specifiers (llvm#156772) Revert "[lldb] Add count for errors of DWO files in statistics and combine DWO file count functions" (llvm#156777) AMDGPU: Add agpr variants of multi-data DS instructions (llvm#156420) [libc][NFC] disable localtime on aarch64/baremetal (llvm#156776) [win/asan] Improve SharedReAlloc with HEAP_REALLOC_IN_PLACE_ONLY. (llvm#132558) [LLDB] Make internal shell the default for running LLDB lit tests. (llvm#156729) [lldb][debugserver] Max response size for qSpeedTest (llvm#156099) [AMDGPU] Define 1024 VGPRs on gfx1250 (llvm#156765) [flang] Check for BIND(C) name conflicts with alternate entries (llvm#156563) [RISCV] Add exhausted_gprs_fprs test to calling-conv-half.ll. NFC (llvm#156586) [NFC] Remove trailing whitespaces from `clang/include/clang/Basic/AttrDocs.td` [lldb] Mark scripted frames as synthetic instead of artificial (llvm#153117) [docs] Refine some of the wording in the quality developer policy (llvm#156555) [MLIR] Apply clang-tidy fixes for readability-identifier-naming in TransformOps.cpp (NFC) [MLIR] Add LDBG() tracing to VectorTransferOpTransforms.cpp (NFC) [NFC] Apply clang-format to PPCInstrFutureMMA.td (llvm#156749) [libc] implement template functions for localtime (llvm#110363) [llvm-objcopy][COFF] Update .symidx values after stripping (llvm#153322) Add documentation on debugging LLVM. [lldb] Add count for errors of DWO files in statistics and combine DWO file count functions (llvm#155023) ...
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This fixes a regression which was introduced in #147835.
Since this regression was never released, there are no release notes.
Fixes #156458