Revert "[clang] Build UsingType for elaborated type specifiers."

hokein · tru · commit c39e95cf4562 · 2023-01-27T15:28:06.000+01:00
This reverts commit e70ca7b and the followup patch "[clang] Fix the location of UsingTypeLoc" (ebbeb16). The patch causes an incorrect lookup result: ``` namespace ns { struct Foo { };} using ns::Foo; void test() { struct Foo { } k; // the type of k refers to ns::Foo, rather than the local Foo! } ``` (cherry picked from commit e400c63)
diff --git a/clang-tools-extra/clangd/unittests/SelectionTests.cpp b/clang-tools-extra/clangd/unittests/SelectionTests.cpp
@@ -520,13 +520,6 @@ TEST(SelectionTest, CommonAncestor) {
       )cpp",
        "TypedefTypeLoc"},
 
-      {R"cpp(
-        namespace ns { class Foo {}; }
-        using ns::Foo;
-        class [[^Foo]] foo;
-      )cpp",
-       "UsingTypeLoc"},
-
       // lambda captured var-decl
       {R"cpp(
         void test(int bar) {
diff --git a/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp b/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
@@ -150,9 +150,6 @@ TEST(WalkAST, Using) {
     }
     using ns::$explicit^Y;)cpp",
            "^Y<int> x;");
-  testWalk(R"cpp(
-    namespace ns { class Foo {}; }
-  )cpp", "using ns::$explicit^Foo; class ^Foo foo;");
 }
 
 TEST(WalkAST, Namespaces) {
diff --git a/clang/include/clang/Sema/DeclSpec.h b/clang/include/clang/Sema/DeclSpec.h
@@ -506,16 +506,8 @@ class DeclSpec {
     assert(isTypeRep((TST) TypeSpecType) && "DeclSpec does not store a type");
     return TypeRep;
   }
-  // Returns the underlying decl, if any.
   Decl *getRepAsDecl() const {
-    auto *D = getRepAsFoundDecl();
-    if (const auto *Using = dyn_cast_or_null<UsingShadowDecl>(D))
-      return Using->getTargetDecl();
-    return D;
-  }
-  // Returns the originally found decl, if any.
-  Decl *getRepAsFoundDecl() const {
-    assert(isDeclRep((TST)TypeSpecType) && "DeclSpec does not store a decl");
+    assert(isDeclRep((TST) TypeSpecType) && "DeclSpec does not store a decl");
     return DeclRep;
   }
   Expr *getRepAsExpr() const {
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -3327,9 +3327,7 @@ class Sema final {
                       SourceLocation ScopedEnumKWLoc,
                       bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
                       bool IsTypeSpecifier, bool IsTemplateParamOrArg,
-                      OffsetOfKind OOK,
-                      UsingShadowDecl*& FoundUsingShadow,
-                      SkipBodyInfo *SkipBody = nullptr);
+                      OffsetOfKind OOK, SkipBodyInfo *SkipBody = nullptr);
 
   DeclResult ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
                                      unsigned TagSpec, SourceLocation TagLoc,
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
@@ -4965,7 +4965,6 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
   bool IsDependent = false;
   const char *PrevSpec = nullptr;
   unsigned DiagID;
-  UsingShadowDecl* FoundUsing = nullptr;
   Decl *TagDecl =
       Actions.ActOnTag(getCurScope(), DeclSpec::TST_enum, TUK, StartLoc, SS,
                     Name, NameLoc, attrs, AS, DS.getModulePrivateSpecLoc(),
@@ -4974,7 +4973,7 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
                     BaseType, DSC == DeclSpecContext::DSC_type_specifier,
                     DSC == DeclSpecContext::DSC_template_param ||
                         DSC == DeclSpecContext::DSC_template_type_arg,
-                    OffsetOfState, FoundUsing, &SkipBody).get();
+                    OffsetOfState, &SkipBody).get();
 
   if (SkipBody.ShouldSkip) {
     assert(TUK == Sema::TUK_Definition && "can only skip a definition");
@@ -4984,8 +4983,8 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
     T.skipToEnd();
 
     if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc,
-                           NameLoc.isValid() ? NameLoc : StartLoc, PrevSpec,
-                           DiagID, FoundUsing ? FoundUsing : TagDecl, Owned,
+                           NameLoc.isValid() ? NameLoc : StartLoc,
+                           PrevSpec, DiagID, TagDecl, Owned,
                            Actions.getASTContext().getPrintingPolicy()))
       Diag(StartLoc, DiagID) << PrevSpec;
     return;
@@ -5039,8 +5038,8 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
   }
 
   if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc,
-                         NameLoc.isValid() ? NameLoc : StartLoc, PrevSpec,
-                         DiagID, FoundUsing ? FoundUsing : TagDecl, Owned,
+                         NameLoc.isValid() ? NameLoc : StartLoc,
+                         PrevSpec, DiagID, TagDecl, Owned,
                          Actions.getASTContext().getPrintingPolicy()))
     Diag(StartLoc, DiagID) << PrevSpec;
 }
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -1934,7 +1934,6 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
   // Create the tag portion of the class or class template.
   DeclResult TagOrTempResult = true; // invalid
   TypeResult TypeResult = true;      // invalid
-  UsingShadowDecl *FoundUsing = nullptr;
 
   bool Owned = false;
   Sema::SkipBodyInfo SkipBody;
@@ -2075,7 +2074,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
         DSC == DeclSpecContext::DSC_type_specifier,
         DSC == DeclSpecContext::DSC_template_param ||
             DSC == DeclSpecContext::DSC_template_type_arg,
-        OffsetOfState, FoundUsing, &SkipBody);
+        OffsetOfState, &SkipBody);
 
     // If ActOnTag said the type was dependent, try again with the
     // less common call.
@@ -2134,7 +2133,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
   } else if (!TagOrTempResult.isInvalid()) {
     Result = DS.SetTypeSpecType(
         TagType, StartLoc, NameLoc.isValid() ? NameLoc : StartLoc, PrevSpec,
-        DiagID, FoundUsing ? FoundUsing : TagOrTempResult.get(), Owned, Policy);
+        DiagID, TagOrTempResult.get(), Owned, Policy);
   } else {
     DS.SetTypeSpecError();
     return;
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
@@ -16616,8 +16616,7 @@ Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
                bool &IsDependent, SourceLocation ScopedEnumKWLoc,
                bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
                bool IsTypeSpecifier, bool IsTemplateParamOrArg,
-               OffsetOfKind OOK, UsingShadowDecl *&FoundUsingShadow,
-               SkipBodyInfo *SkipBody) {
+               OffsetOfKind OOK, SkipBodyInfo *SkipBody) {
   // If this is not a definition, it must have a name.
   IdentifierInfo *OrigName = Name;
   assert((Name != nullptr || TUK == TUK_Definition) &&
@@ -17052,7 +17051,6 @@ Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
     // redefinition if either context is within the other.
     if (auto *Shadow = dyn_cast<UsingShadowDecl>(DirectPrevDecl)) {
       auto *OldTag = dyn_cast<TagDecl>(PrevDecl);
-      FoundUsingShadow = Shadow;
       if (SS.isEmpty() && TUK != TUK_Reference && TUK != TUK_Friend &&
           isDeclInScope(Shadow, SearchDC, S, isMemberSpecialization) &&
           !(OldTag && isAcceptableTagRedeclContext(
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -16977,7 +16977,6 @@ DeclResult Sema::ActOnTemplatedFriendTag(
     if (SS.isEmpty()) {
       bool Owned = false;
       bool IsDependent = false;
-      UsingShadowDecl* FoundUsing = nullptr;
       return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc, Attr,
                       AS_public,
                       /*ModulePrivateLoc=*/SourceLocation(),
@@ -16986,7 +16985,7 @@ DeclResult Sema::ActOnTemplatedFriendTag(
                       /*ScopedEnumUsesClassTag=*/false,
                       /*UnderlyingType=*/TypeResult(),
                       /*IsTypeSpecifier=*/false,
-                      /*IsTemplateParamOrArg=*/false, /*OOK=*/OOK_Outside, FoundUsing);
+                      /*IsTemplateParamOrArg=*/false, /*OOK=*/OOK_Outside);
     }
 
     NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
@@ -10181,14 +10181,11 @@ Sema::ActOnExplicitInstantiation(Scope *S, SourceLocation ExternLoc,
 
   bool Owned = false;
   bool IsDependent = false;
-  UsingShadowDecl* FoundUsing = nullptr;
-  Decl *TagD =
-      ActOnTag(S, TagSpec, Sema::TUK_Reference, KWLoc, SS, Name, NameLoc, Attr,
-               AS_none, /*ModulePrivateLoc=*/SourceLocation(),
+  Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference, KWLoc, SS, Name,
+               NameLoc, Attr, AS_none, /*ModulePrivateLoc=*/SourceLocation(),
                MultiTemplateParamsArg(), Owned, IsDependent, SourceLocation(),
                false, TypeResult(), /*IsTypeSpecifier*/ false,
-               /*IsTemplateParamOrArg*/ false, /*OOK=*/OOK_Outside, FoundUsing)
-          .get();
+               /*IsTemplateParamOrArg*/ false, /*OOK=*/OOK_Outside).get();
   assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
 
   if (!TagD)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
@@ -1588,9 +1588,6 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
 
     // TypeQuals handled by caller.
     Result = Context.getTypeDeclType(D);
-    if (const auto *Using =
-            dyn_cast_or_null<UsingShadowDecl>(DS.getRepAsFoundDecl()))
-      Result = Context.getUsingType(Using, Result);
 
     // In both C and C++, make an ElaboratedType.
     ElaboratedTypeKeyword Keyword
@@ -6256,9 +6253,6 @@ namespace {
     void VisitTagTypeLoc(TagTypeLoc TL) {
       TL.setNameLoc(DS.getTypeSpecTypeNameLoc());
     }
-    void VisitUsingTypeLoc(UsingTypeLoc TL) {
-      TL.setNameLoc(DS.getTypeSpecTypeNameLoc());
-    }
     void VisitAtomicTypeLoc(AtomicTypeLoc TL) {
       // An AtomicTypeLoc can come from either an _Atomic(...) type specifier
       // or an _Atomic qualifier.
diff --git a/clang/test/CXX/drs/dr2xx.cpp b/clang/test/CXX/drs/dr2xx.cpp
@@ -992,7 +992,7 @@ namespace dr284 { // dr284: no
   }
   struct B::V {}; // expected-error {{no struct named 'V'}}
   struct B::W {};
-  struct B::X {}; // expected-error {{forward declaration of struct cannot have}}
+  struct B::X {}; // FIXME: ill-formed
   enum B::Y e; // ok per dr417
   class B::Z z; // ok per dr417
 
@@ -1009,7 +1009,7 @@ namespace dr284 { // dr284: no
   };
   struct D::V {}; // expected-error {{no struct named 'V'}}
   struct D::W {};
-  struct D::X {}; // expected-error {{forward declaration of struct cannot have}}
+  struct D::X {}; // FIXME: ill-formed
   enum D::Y e2; // ok per dr417
   class D::Z z2; // ok per dr417
 }
diff --git a/clang/test/CXX/drs/dr4xx.cpp b/clang/test/CXX/drs/dr4xx.cpp
@@ -301,8 +301,9 @@ namespace dr417 { // dr417: no
     struct F;
     struct H;
   }
+  // FIXME: This is ill-formed.
   using N::D;
-  struct dr417::D {}; // expected-error {{forward declaration of struct cannot}} expected-warning {{extra qualification}}
+  struct dr417::D {}; // expected-warning {{extra qualification}}
   using namespace N;
   struct dr417::E {}; // expected-warning {{extra qualification}} expected-error {{no struct named 'E'}}
   struct N::F {};

Original file line number	Diff line number	Diff line change
`@@ -150,9 +150,6 @@ TEST(WalkAST, Using) {`
`150`	`150`	`}`
`151`	`151`	`using ns::$explicit^Y;)cpp",`
`152`	`152`	`"^Y<int> x;");`
`153`		`- testWalk(R"cpp(`
`154`		`- namespace ns { class Foo {}; }`
`155`		`- )cpp", "using ns::$explicit^Foo; class ^Foo foo;");`
`156`	`153`	`}`
`157`	`154`
`158`	`155`	`TEST(WalkAST, Namespaces) {`