Merge branch 'main' into main

Author: wecing

clang/docs/LanguageExtensions.rst

@@ -1715,11 +1715,40 @@ Variadic Friends                              __cpp_variadic_friend            C
 Trivial Relocatability                        __cpp_trivial_relocatability     C++26         C++03
 --------------------------------------------- -------------------------------- ------------- -------------
 Designated initializers (N494)                                                 C99           C89
+``_Complex`` (N693)                                                            C99           C89, C++
+``_Bool`` (N815)                                                               C99           C89
+Variable-length arrays (N683)                                                  C99           C89, C++
+Flexible array members                                                         C99           C89, C++
+static and type quals in arrays                                                C99           C89
+``long long`` (N601)                                                           C99           C89
+Hexadecimal floating constants (N308)                                          C99           C89
+Compound literals (N716)                                                       C99           C89, C++
+``//`` comments (N644)                                                         C99           C89
+Mixed declarations and code (N740)                                             C99           C89
+Variadic macros (N707)                                                         C99           C89
+Empty macro arguments (N570)                                                   C99           C89
+Trailing comma in enum declaration                                             C99           C89
+Implicit ``return 0`` in ``main``                                              C99           C89
+``__func__`` (N611)                                                            C99           C89
+``_Generic`` (N1441)                                                           C11           C89, C++
+``_Static_assert`` (N1330)                                                     C11           C89, C++
+``_Atomic`` (N1485)                                                            C11           C89, C++
+``_Thread_local`` (N1364)                                                      C11           C89, C++
 Array & element qualification (N2607)                                          C23           C89
 Attributes (N2335)                                                             C23           C89
 ``#embed`` (N3017)                                                             C23           C89, C++
+Enum with fixed underlying type (N3030)                                        C23           C89
+``#warning`` (N2686)                                                           C23           C89
+``_BitInt`` (N3035)                                                            C23           C89, C++
+Binary literals (N2549)                                                        C23           C89
+Unnamed parameters in a function definition                                    C23           C89
+Free positioning of labels (N2508)                                             C23           C89
+``#elifdef`` (N2645)                                                           C23           C89
+``__has_include`` (N2799)                                                      C23           C89
 Octal literals prefixed with ``0o`` or ``0O``                                  C2y           C89, C++
 ``_Countof`` (N3369, N3469)                                                    C2y           C89
+``_Generic`` with a type operand (N3260)                                       C2y           C89, C++
+``++``/``--`` on ``_Complex`` value (N3259)                                    C2y           C89, C++
 ============================================= ================================ ============= =============
 
 Builtin type aliases

clang/docs/ReleaseNotes.rst

@@ -77,6 +77,9 @@ AST Dumping Potentially Breaking Changes
 
 Clang Frontend Potentially Breaking Changes
 -------------------------------------------
+- Members of anonymous unions/structs are now injected as ``IndirectFieldDecl``
+  into the enclosing record even if their names conflict with other names in the
+  scope. These ``IndirectFieldDecl`` are marked invalid.
 
 Clang Python Bindings Potentially Breaking Changes
 --------------------------------------------------
@@ -217,6 +220,8 @@ Bug Fixes to C++ Support
 - Fix the dynamic_cast to final class optimization to correctly handle
   casts that are guaranteed to fail (#GH137518).
 - Fix bug rejecting partial specialization of variable templates with auto NTTPs (#GH118190).
+- Fix a crash if errors "member of anonymous [...] redeclares" and
+  "intializing multiple members of union" coincide (#GH149985).
 - Fix a crash when using ``explicit(bool)`` in pre-C++11 language modes. (#GH152729)
 - Fix the parsing of variadic member functions when the ellipis immediately follows a default argument.(#GH153445)
 

clang/lib/Sema/SemaDecl.cpp

@@ -5503,48 +5503,54 @@ InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
     if ((isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) &&
         cast<NamedDecl>(D)->getDeclName()) {
       ValueDecl *VD = cast<ValueDecl>(D);
-      if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, VD->getDeclName(),
-                                       VD->getLocation(), AnonRecord->isUnion(),
-                                       SC)) {
-        // C++ [class.union]p2:
-        //   The names of the members of an anonymous union shall be
-        //   distinct from the names of any other entity in the
-        //   scope in which the anonymous union is declared.
+      // C++ [class.union]p2:
+      //   The names of the members of an anonymous union shall be
+      //   distinct from the names of any other entity in the
+      //   scope in which the anonymous union is declared.
+
+      bool FieldInvalid = CheckAnonMemberRedeclaration(
+          SemaRef, S, Owner, VD->getDeclName(), VD->getLocation(),
+          AnonRecord->isUnion(), SC);
+      if (FieldInvalid)
         Invalid = true;
-      } else {
-        // C++ [class.union]p2:
-        //   For the purpose of name lookup, after the anonymous union
-        //   definition, the members of the anonymous union are
-        //   considered to have been defined in the scope in which the
-        //   anonymous union is declared.
-        unsigned OldChainingSize = Chaining.size();
-        if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
-          Chaining.append(IF->chain_begin(), IF->chain_end());
-        else
-          Chaining.push_back(VD);
 
-        assert(Chaining.size() >= 2);
-        NamedDecl **NamedChain =
-          new (SemaRef.Context)NamedDecl*[Chaining.size()];
-        for (unsigned i = 0; i < Chaining.size(); i++)
-          NamedChain[i] = Chaining[i];
+      // Inject the IndirectFieldDecl even if invalid, because later
+      // diagnostics may depend on it being present, see findDefaultInitializer.
+
+      // C++ [class.union]p2:
+      //   For the purpose of name lookup, after the anonymous union
+      //   definition, the members of the anonymous union are
+      //   considered to have been defined in the scope in which the
+      //   anonymous union is declared.
+      unsigned OldChainingSize = Chaining.size();
+      if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
+        Chaining.append(IF->chain_begin(), IF->chain_end());
+      else
+        Chaining.push_back(VD);
 
-        IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
-            SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
-            VD->getType(), {NamedChain, Chaining.size()});
+      assert(Chaining.size() >= 2);
+      NamedDecl **NamedChain =
+          new (SemaRef.Context) NamedDecl *[Chaining.size()];
+      for (unsigned i = 0; i < Chaining.size(); i++)
+        NamedChain[i] = Chaining[i];
 
-        for (const auto *Attr : VD->attrs())
-          IndirectField->addAttr(Attr->clone(SemaRef.Context));
+      IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
+          SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
+          VD->getType(), {NamedChain, Chaining.size()});
 
-        IndirectField->setAccess(AS);
-        IndirectField->setImplicit();
-        SemaRef.PushOnScopeChains(IndirectField, S);
+      for (const auto *Attr : VD->attrs())
+        IndirectField->addAttr(Attr->clone(SemaRef.Context));
 
-        // That includes picking up the appropriate access specifier.
-        if (AS != AS_none) IndirectField->setAccess(AS);
+      IndirectField->setAccess(AS);
+      IndirectField->setImplicit();
+      IndirectField->setInvalidDecl(FieldInvalid);
+      SemaRef.PushOnScopeChains(IndirectField, S);
 
-        Chaining.resize(OldChainingSize);
-      }
+      // That includes picking up the appropriate access specifier.
+      if (AS != AS_none)
+        IndirectField->setAccess(AS);
+
+      Chaining.resize(OldChainingSize);
     }
   }
 

clang/lib/Sema/SemaDeclCXX.cpp

@@ -7012,9 +7012,12 @@ void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
     for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
          ++I) {
       NamedDecl *D = (*I)->getUnderlyingDecl();
+      // Invalid IndirectFieldDecls have already been diagnosed with
+      // err_anonymous_record_member_redecl in
+      // SemaDecl.cpp:CheckAnonMemberRedeclaration.
       if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
            Record->hasUserDeclaredConstructor()) ||
-          isa<IndirectFieldDecl>(D)) {
+          (isa<IndirectFieldDecl>(D) && !D->isInvalidDecl())) {
         Diag((*I)->getLocation(), diag::err_member_name_of_class)
           << D->getDeclName();
         break;

clang/lib/Sema/SemaOpenACC.cpp

@@ -2604,31 +2604,120 @@ SemaOpenACC::CreateInitRecipe(OpenACCClauseKind CK, const Expr *VarExpr) {
   QualType VarTy =
       VarExpr->getType().getNonReferenceType().getUnqualifiedType();
 
+  IdentifierInfo *VarName = [&]() {
+    switch (CK) {
+    case OpenACCClauseKind::Private:
+      return &getASTContext().Idents.get("openacc.private.init");
+    case OpenACCClauseKind::FirstPrivate:
+      return &getASTContext().Idents.get("openacc.firstprivate.init");
+    case OpenACCClauseKind::Reduction:
+      return &getASTContext().Idents.get("openacc.reduction.init");
+    default:
+      llvm_unreachable("Unknown clause kind?");
+    }
+  }();
+
   VarDecl *Recipe = VarDecl::Create(
       getASTContext(), SemaRef.getCurContext(), VarExpr->getBeginLoc(),
-      VarExpr->getBeginLoc(),
-      &getASTContext().Idents.get("openacc.private.init"), VarTy,
+      VarExpr->getBeginLoc(), VarName, VarTy,
       getASTContext().getTrivialTypeSourceInfo(VarTy), SC_Auto);
 
   ExprResult Init;
   VarDecl *Temporary = nullptr;
-
-  if (CK == OpenACCClauseKind::Private) {
+  {
     // Trap errors so we don't get weird ones here. If we can't init, we'll just
     // swallow the errors.
     Sema::TentativeAnalysisScope Trap{SemaRef};
     InitializedEntity Entity = InitializedEntity::InitializeVariable(Recipe);
-    InitializationKind Kind =
-        InitializationKind::CreateDefault(Recipe->getLocation());
 
-    InitializationSequence InitSeq(SemaRef.SemaRef, Entity, Kind, {});
-    Init = InitSeq.Perform(SemaRef.SemaRef, Entity, Kind, {});
-  } else if (CK == OpenACCClauseKind::FirstPrivate) {
-    // TODO: OpenACC: Implement this to do a 'copy' operation.
-  } else if (CK == OpenACCClauseKind::Reduction) {
-    // TODO: OpenACC: Implement this for whatever reduction needs.
-  } else {
-    llvm_unreachable("Unknown clause kind in CreateInitRecipe");
+    if (CK == OpenACCClauseKind::Private) {
+      InitializationKind Kind =
+          InitializationKind::CreateDefault(Recipe->getLocation());
+
+      InitializationSequence InitSeq(SemaRef.SemaRef, Entity, Kind, {});
+      Init = InitSeq.Perform(SemaRef.SemaRef, Entity, Kind, {});
+
+    } else if (CK == OpenACCClauseKind::FirstPrivate) {
+      // Create a VarDecl to be the 'copied-from' for the copy section of the
+      // recipe. This allows us to make the association so that we can use the
+      // standard 'generation' ability of the init.
+      Temporary = VarDecl::Create(
+          getASTContext(), SemaRef.getCurContext(), VarExpr->getBeginLoc(),
+          VarExpr->getBeginLoc(), &getASTContext().Idents.get("openacc.temp"),
+          VarTy, getASTContext().getTrivialTypeSourceInfo(VarTy), SC_Auto);
+      auto *TemporaryDRE = DeclRefExpr::Create(
+          getASTContext(), NestedNameSpecifierLoc{}, SourceLocation{},
+          Temporary,
+          /*ReferstoEnclosingVariableOrCapture=*/false,
+          DeclarationNameInfo{DeclarationName{Temporary->getDeclName()},
+                              VarExpr->getBeginLoc()},
+          VarTy, clang::VK_LValue, Temporary, nullptr, NOUR_None);
+
+      Expr *InitExpr = nullptr;
+
+      if (const auto *ArrTy = getASTContext().getAsConstantArrayType(VarTy)) {
+        // Arrays need to have each individual element initialized as there
+        // isn't a normal 'equals' feature in C/C++. This section sets these up
+        // as an init list after 'initializing' each individual element.
+        llvm::SmallVector<Expr *> Args;
+
+        // Decay to pointer for the array subscript expression.
+        auto *CastToPtr = ImplicitCastExpr::Create(
+            getASTContext(),
+            getASTContext().getPointerType(ArrTy->getElementType()),
+            CK_ArrayToPointerDecay, TemporaryDRE, /*BasePath=*/nullptr,
+            clang::VK_LValue, FPOptionsOverride{});
+
+        for (std::size_t I = 0; I < ArrTy->getLimitedSize(); ++I) {
+          // Each element needs to be some sort of copy initialization from an
+          // array-index of the original temporary (referenced via a
+          // DeclRefExpr).
+
+          auto *Idx = IntegerLiteral::Create(
+              getASTContext(), llvm::APInt(sizeof(std::size_t) * 8, I),
+              getASTContext().getSizeType(), VarExpr->getBeginLoc());
+
+          Expr *Subscript = new (getASTContext()) ArraySubscriptExpr(
+              CastToPtr, Idx, ArrTy->getElementType(), clang::VK_LValue,
+              OK_Ordinary, VarExpr->getBeginLoc());
+
+          // Generate a simple copy from the result of the subscript. This will
+          // do a bitwise copy or a copy-constructor, as necessary.
+          InitializedEntity CopyEntity =
+              InitializedEntity::InitializeElement(getASTContext(), I, Entity);
+          InitializationKind CopyKind =
+              InitializationKind::CreateCopy(VarExpr->getBeginLoc(), {});
+          InitializationSequence CopySeq(SemaRef.SemaRef, CopyEntity, CopyKind,
+                                         Subscript,
+                                         /*TopLevelOfInitList=*/true);
+
+          ExprResult ElemRes =
+              CopySeq.Perform(SemaRef.SemaRef, CopyEntity, CopyKind, Subscript);
+          Args.push_back(ElemRes.get());
+        }
+
+        InitExpr = new (getASTContext())
+            InitListExpr(getASTContext(), VarExpr->getBeginLoc(), Args,
+                         VarExpr->getEndLoc());
+        InitExpr->setType(VarTy);
+
+      } else {
+        // If this isn't an array, we can just do normal copy init from a simple
+        // variable reference, so set that up.
+        InitExpr = TemporaryDRE;
+      }
+
+      InitializationKind Kind = InitializationKind::CreateForInit(
+          Recipe->getLocation(), /*DirectInit=*/true, InitExpr);
+      InitializationSequence InitSeq(SemaRef.SemaRef, Entity, Kind, InitExpr,
+                                     /*TopLevelOfInitList=*/false,
+                                     /*TreatUnavailableAsInvalid=*/false);
+      Init = InitSeq.Perform(SemaRef.SemaRef, Entity, Kind, InitExpr, &VarTy);
+    } else if (CK == OpenACCClauseKind::Reduction) {
+      // TODO: OpenACC: Implement this for whatever reduction needs.
+    } else {
+      llvm_unreachable("Unknown clause kind in CreateInitRecipe");
+    }
   }
 
   if (Init.get()) {

clang/test/CXX/class/class.union/class.union.anon/p4.cpp

@@ -8,3 +8,28 @@ union U {
     int y = 1; // expected-error {{initializing multiple members of union}}
   };
 };
+
+namespace GH149985 {
+  union X {
+    enum {
+      csize = 42,
+      cs = sizeof(int) // expected-note {{previous declaration is here}}
+    };
+    struct {
+      int data; // expected-note {{previous declaration is here}}
+      union X *cs[csize] = {}; // expected-error {{member of anonymous struct redeclares}} expected-note {{previous initialization is here}}
+    };
+    struct {
+      int data; // expected-error {{member of anonymous struct redeclares}}
+      union X *ds[2] = {}; // expected-error {{initializing multiple members of union}}
+    };
+  };
+
+  union U {
+    int x; // expected-note {{previous declaration is here}}
+    union {
+      int x = {}; // expected-error {{member of anonymous union redeclares}} expected-note {{previous initialization is here}}
+    };
+    int y = {}; // expected-error {{initializing multiple members of union}}
+  };
+}