merge main into amd-staging

Change-Id: I093b48120154cc4a706cb2ce7575ea40a41a7b02

Author: Jenkins

clang/docs/ReleaseNotes.rst

@@ -234,6 +234,11 @@ C++2c Feature Support
 
 Resolutions to C++ Defect Reports
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+- Implemented `CWG2137 <https://wg21.link/CWG2137>`_ which allows
+  list-initialization from objects of the same type.
+- Implemented `CWG2311 <https://wg21.link/CWG2311>`_: given a prvalue ``e`` of object type
+  ``T``, ``T{e}`` will try to resolve an initializer list constructor and will use it if successful (CWG2137).
+  Otherwise, if there is no initializer list constructor, the copy will be elided as if it was ``T(e)``.
 
 - Implemented `CWG2598 <https://wg21.link/CWG2598>`_ and `CWG2096 <https://wg21.link/CWG2096>`_,
   making unions (that have either no members or at least one literal member) literal types.

clang/include/clang/AST/Expr.h

@@ -1136,7 +1136,6 @@ class ConstantExpr final
     return ConstantExprBits.APValueKind != APValue::None;
   }
   APValue getAPValueResult() const;
-  APValue &getResultAsAPValue() const { return APValueResult(); }
   llvm::APSInt getResultAsAPSInt() const;
   // Iterators
   child_range children() { return child_range(&SubExpr, &SubExpr+1); }

clang/include/clang/Basic/LangOptions.def

@@ -367,16 +367,16 @@ BENIGN_ENUM_LANGOPT(TypeVisibilityMode, Visibility, 3, DefaultVisibility,
              "default visibility for types [-ftype-visibility]")
 LANGOPT(SetVisibilityForExternDecls, 1, 0,
         "apply global symbol visibility to external declarations without an explicit visibility")
-LANGOPT(VisibilityFromDLLStorageClass, 1, 0,
-        "set the visiblity of globals from their DLL storage class [-fvisibility-from-dllstorageclass]")
-ENUM_LANGOPT(DLLExportVisibility, Visibility, 3, DefaultVisibility,
-             "visibility for functions and variables with dllexport annotations [-fvisibility-from-dllstorageclass]")
-ENUM_LANGOPT(NoDLLStorageClassVisibility, Visibility, 3, HiddenVisibility,
-             "visibility for functions and variables without an explicit DLL storage class [-fvisibility-from-dllstorageclass]")
-ENUM_LANGOPT(ExternDeclDLLImportVisibility, Visibility, 3, DefaultVisibility,
-             "visibility for external declarations with dllimport annotations [-fvisibility-from-dllstorageclass]")
-ENUM_LANGOPT(ExternDeclNoDLLStorageClassVisibility, Visibility, 3, HiddenVisibility,
-             "visibility for external declarations without an explicit DLL storage class [-fvisibility-from-dllstorageclass]")
+BENIGN_LANGOPT(VisibilityFromDLLStorageClass, 1, 0,
+               "override the visibility of globals based on their final DLL storage class [-fvisibility-from-dllstorageclass]")
+BENIGN_ENUM_LANGOPT(DLLExportVisibility, VisibilityFromDLLStorageClassKinds, 3, VisibilityFromDLLStorageClassKinds::Default,
+             "how to adjust the visibility for functions and variables with dllexport annotations [-fvisibility-dllexport]")
+BENIGN_ENUM_LANGOPT(NoDLLStorageClassVisibility, VisibilityFromDLLStorageClassKinds, 3, VisibilityFromDLLStorageClassKinds::Hidden,
+             "how to adjust the visibility for functions and variables without an explicit DLL storage class [-fvisibility-nodllstorageclass]")
+BENIGN_ENUM_LANGOPT(ExternDeclDLLImportVisibility, VisibilityFromDLLStorageClassKinds, 3, VisibilityFromDLLStorageClassKinds::Default,
+             "how to adjust the visibility for external declarations with dllimport annotations [-fvisibility-externs-dllimport]")
+BENIGN_ENUM_LANGOPT(ExternDeclNoDLLStorageClassVisibility, VisibilityFromDLLStorageClassKinds, 3,  VisibilityFromDLLStorageClassKinds::Hidden,
+             "how to adjust the visibility for external declarations without an explicit DLL storage class [-fvisibility-externs-nodllstorageclass]")
 BENIGN_LANGOPT(SemanticInterposition        , 1, 0, "semantic interposition")
 BENIGN_LANGOPT(HalfNoSemanticInterposition, 1, 0,
                "Like -fno-semantic-interposition but don't use local aliases")

clang/include/clang/Basic/LangOptions.h

@@ -381,6 +381,17 @@ class LangOptions : public LangOptionsBase {
     All,
   };
 
+  enum class VisibilityFromDLLStorageClassKinds {
+    /// Keep the IR-gen assigned visibility.
+    Keep,
+    /// Override the IR-gen assigned visibility with default visibility.
+    Default,
+    /// Override the IR-gen assigned visibility with hidden visibility.
+    Hidden,
+    /// Override the IR-gen assigned visibility with protected visibility.
+    Protected,
+  };
+
   enum class StrictFlexArraysLevelKind {
     /// Any trailing array member is a FAM.
     Default = 0,

clang/include/clang/Driver/Options.td

@@ -3932,27 +3932,32 @@ def dA : Flag<["-"], "dA">, Alias<fverbose_asm>;
 defm visibility_from_dllstorageclass : BoolFOption<"visibility-from-dllstorageclass",
   LangOpts<"VisibilityFromDLLStorageClass">, DefaultFalse,
   PosFlag<SetTrue, [], [ClangOption, CC1Option],
-          "Set the visibility of symbols in the generated code from their DLL storage class">,
+          "Override the visibility of globals based on their final DLL storage class.">,
   NegFlag<SetFalse>>;
+class MarshallingInfoVisibilityFromDLLStorage<KeyPathAndMacro kpm, code default>
+  : MarshallingInfoEnum<kpm, default>,
+    Values<"keep,hidden,protected,default">,
+    NormalizedValuesScope<"LangOptions::VisibilityFromDLLStorageClassKinds">,
+    NormalizedValues<["Keep", "Hidden", "Protected", "Default"]> {}
 def fvisibility_dllexport_EQ : Joined<["-"], "fvisibility-dllexport=">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,
-  HelpText<"The visibility for dllexport definitions [-fvisibility-from-dllstorageclass]">,
-  MarshallingInfoVisibility<LangOpts<"DLLExportVisibility">, "DefaultVisibility">,
+  HelpText<"The visibility for dllexport definitions. If Keep is specified the visibility is not adjusted [-fvisibility-from-dllstorageclass]">,
+  MarshallingInfoVisibilityFromDLLStorage<LangOpts<"DLLExportVisibility">, "Default">,
   ShouldParseIf<fvisibility_from_dllstorageclass.KeyPath>;
 def fvisibility_nodllstorageclass_EQ : Joined<["-"], "fvisibility-nodllstorageclass=">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,
-  HelpText<"The visibility for definitions without an explicit DLL export class [-fvisibility-from-dllstorageclass]">,
-  MarshallingInfoVisibility<LangOpts<"NoDLLStorageClassVisibility">, "HiddenVisibility">,
+  HelpText<"The visibility for definitions without an explicit DLL storage class. If Keep is specified the visibility is not adjusted [-fvisibility-from-dllstorageclass]">,
+  MarshallingInfoVisibilityFromDLLStorage<LangOpts<"NoDLLStorageClassVisibility">, "Hidden">,
   ShouldParseIf<fvisibility_from_dllstorageclass.KeyPath>;
 def fvisibility_externs_dllimport_EQ : Joined<["-"], "fvisibility-externs-dllimport=">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,
-  HelpText<"The visibility for dllimport external declarations [-fvisibility-from-dllstorageclass]">,
-  MarshallingInfoVisibility<LangOpts<"ExternDeclDLLImportVisibility">, "DefaultVisibility">,
+  HelpText<"The visibility for dllimport external declarations. If Keep is specified the visibility is not adjusted [-fvisibility-from-dllstorageclass]">,
+  MarshallingInfoVisibilityFromDLLStorage<LangOpts<"ExternDeclDLLImportVisibility">, "Default">,
   ShouldParseIf<fvisibility_from_dllstorageclass.KeyPath>;
 def fvisibility_externs_nodllstorageclass_EQ : Joined<["-"], "fvisibility-externs-nodllstorageclass=">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,
-  HelpText<"The visibility for external declarations without an explicit DLL dllstorageclass [-fvisibility-from-dllstorageclass]">,
-  MarshallingInfoVisibility<LangOpts<"ExternDeclNoDLLStorageClassVisibility">, "HiddenVisibility">,
+  HelpText<"The visibility for external declarations without an explicit DLL storage class. If Keep is specified the visibility is not adjusted [-fvisibility-from-dllstorageclass]">,
+  MarshallingInfoVisibilityFromDLLStorage<LangOpts<"ExternDeclNoDLLStorageClassVisibility">, "Hidden">,
   ShouldParseIf<fvisibility_from_dllstorageclass.KeyPath>;
 def fvisibility_EQ : Joined<["-"], "fvisibility=">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,

clang/lib/CodeGen/CodeGenModule.cpp

@@ -726,43 +726,70 @@ void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
   }
 }
 
+static std::optional<llvm::GlobalValue::VisibilityTypes>
+getLLVMVisibility(clang::LangOptions::VisibilityFromDLLStorageClassKinds K) {
+  // Map to LLVM visibility.
+  switch (K) {
+  case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Keep:
+    return std::nullopt;
+  case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Default:
+    return llvm::GlobalValue::DefaultVisibility;
+  case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Hidden:
+    return llvm::GlobalValue::HiddenVisibility;
+  case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Protected:
+    return llvm::GlobalValue::ProtectedVisibility;
+  }
+  llvm_unreachable("unknown option value!");
+}
+
+void setLLVMVisibility(llvm::GlobalValue &GV,
+                       std::optional<llvm::GlobalValue::VisibilityTypes> V) {
+  if (!V)
+    return;
+
+  // Reset DSO locality before setting the visibility. This removes
+  // any effects that visibility options and annotations may have
+  // had on the DSO locality. Setting the visibility will implicitly set
+  // appropriate globals to DSO Local; however, this will be pessimistic
+  // w.r.t. to the normal compiler IRGen.
+  GV.setDSOLocal(false);
+  GV.setVisibility(*V);
+}
+
 static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
                                              llvm::Module &M) {
   if (!LO.VisibilityFromDLLStorageClass)
     return;
 
-  llvm::GlobalValue::VisibilityTypes DLLExportVisibility =
-      CodeGenModule::GetLLVMVisibility(LO.getDLLExportVisibility());
-  llvm::GlobalValue::VisibilityTypes NoDLLStorageClassVisibility =
-      CodeGenModule::GetLLVMVisibility(LO.getNoDLLStorageClassVisibility());
-  llvm::GlobalValue::VisibilityTypes ExternDeclDLLImportVisibility =
-      CodeGenModule::GetLLVMVisibility(LO.getExternDeclDLLImportVisibility());
-  llvm::GlobalValue::VisibilityTypes ExternDeclNoDLLStorageClassVisibility =
-      CodeGenModule::GetLLVMVisibility(
-          LO.getExternDeclNoDLLStorageClassVisibility());
+  std::optional<llvm::GlobalValue::VisibilityTypes> DLLExportVisibility =
+      getLLVMVisibility(LO.getDLLExportVisibility());
+
+  std::optional<llvm::GlobalValue::VisibilityTypes>
+      NoDLLStorageClassVisibility =
+          getLLVMVisibility(LO.getNoDLLStorageClassVisibility());
+
+  std::optional<llvm::GlobalValue::VisibilityTypes>
+      ExternDeclDLLImportVisibility =
+          getLLVMVisibility(LO.getExternDeclDLLImportVisibility());
+
+  std::optional<llvm::GlobalValue::VisibilityTypes>
+      ExternDeclNoDLLStorageClassVisibility =
+          getLLVMVisibility(LO.getExternDeclNoDLLStorageClassVisibility());
 
   for (llvm::GlobalValue &GV : M.global_values()) {
     if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
       continue;
 
-    // Reset DSO locality before setting the visibility. This removes
-    // any effects that visibility options and annotations may have
-    // had on the DSO locality. Setting the visibility will implicitly set
-    // appropriate globals to DSO Local; however, this will be pessimistic
-    // w.r.t. to the normal compiler IRGen.
-    GV.setDSOLocal(false);
-
-    if (GV.isDeclarationForLinker()) {
-      GV.setVisibility(GV.getDLLStorageClass() ==
-                               llvm::GlobalValue::DLLImportStorageClass
-                           ? ExternDeclDLLImportVisibility
-                           : ExternDeclNoDLLStorageClassVisibility);
-    } else {
-      GV.setVisibility(GV.getDLLStorageClass() ==
-                               llvm::GlobalValue::DLLExportStorageClass
-                           ? DLLExportVisibility
-                           : NoDLLStorageClassVisibility);
-    }
+    if (GV.isDeclarationForLinker())
+      setLLVMVisibility(GV, GV.getDLLStorageClass() ==
+                                    llvm::GlobalValue::DLLImportStorageClass
+                                ? ExternDeclDLLImportVisibility
+                                : ExternDeclNoDLLStorageClassVisibility);
+    else
+      setLLVMVisibility(GV, GV.getDLLStorageClass() ==
+                                    llvm::GlobalValue::DLLExportStorageClass
+                                ? DLLExportVisibility
+                                : NoDLLStorageClassVisibility);
 
     GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
   }

clang/lib/Sema/SemaInit.cpp

@@ -4200,7 +4200,7 @@ static OverloadingResult ResolveConstructorOverload(
 /// \param IsListInit     Is this list-initialization?
 /// \param IsInitListCopy Is this non-list-initialization resulting from a
 ///                       list-initialization from {x} where x is the same
-///                       type as the entity?
+///                       aggregate type as the entity?
 static void TryConstructorInitialization(Sema &S,
                                          const InitializedEntity &Entity,
                                          const InitializationKind &Kind,
@@ -4230,6 +4230,14 @@ static void TryConstructorInitialization(Sema &S,
         Entity.getKind() !=
             InitializedEntity::EK_LambdaToBlockConversionBlockElement);
 
+  bool CopyElisionPossible = false;
+  auto ElideConstructor = [&] {
+    // Convert qualifications if necessary.
+    Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
+    if (ILE)
+      Sequence.RewrapReferenceInitList(DestType, ILE);
+  };
+
   // C++17 [dcl.init]p17:
   //     - If the initializer expression is a prvalue and the cv-unqualified
   //       version of the source type is the same class as the class of the
@@ -4242,11 +4250,17 @@ static void TryConstructorInitialization(Sema &S,
   if (S.getLangOpts().CPlusPlus17 && !RequireActualConstructor &&
       UnwrappedArgs.size() == 1 && UnwrappedArgs[0]->isPRValue() &&
       S.Context.hasSameUnqualifiedType(UnwrappedArgs[0]->getType(), DestType)) {
-    // Convert qualifications if necessary.
-    Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
-    if (ILE)
-      Sequence.RewrapReferenceInitList(DestType, ILE);
-    return;
+    if (ILE && !DestType->isAggregateType()) {
+      // CWG2311: T{ prvalue_of_type_T } is not eligible for copy elision
+      // Make this an elision if this won't call an initializer-list
+      // constructor. (Always on an aggregate type or check constructors first.)
+      assert(!IsInitListCopy &&
+             "IsInitListCopy only possible with aggregate types");
+      CopyElisionPossible = true;
+    } else {
+      ElideConstructor();
+      return;
+    }
   }
 
   const RecordType *DestRecordType = DestType->getAs<RecordType>();
@@ -4291,6 +4305,12 @@ static void TryConstructorInitialization(Sema &S,
           S, Kind.getLocation(), Args, CandidateSet, DestType, Ctors, Best,
           CopyInitialization, AllowExplicit,
           /*OnlyListConstructors=*/true, IsListInit, RequireActualConstructor);
+
+    if (CopyElisionPossible && Result == OR_No_Viable_Function) {
+      // No initializer list candidate
+      ElideConstructor();
+      return;
+    }
   }
 
   // C++11 [over.match.list]p1:
@@ -4572,9 +4592,9 @@ static void TryListInitialization(Sema &S,
     return;
   }
 
-  // C++11 [dcl.init.list]p3, per DR1467:
-  // - If T is a class type and the initializer list has a single element of
-  //   type cv U, where U is T or a class derived from T, the object is
+  // C++11 [dcl.init.list]p3, per DR1467 and DR2137:
+  // - If T is an aggregate class and the initializer list has a single element
+  //   of type cv U, where U is T or a class derived from T, the object is
   //   initialized from that element (by copy-initialization for
   //   copy-list-initialization, or by direct-initialization for
   //   direct-list-initialization).
@@ -4585,7 +4605,7 @@ static void TryListInitialization(Sema &S,
   // - Otherwise, if T is an aggregate, [...] (continue below).
   if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1 &&
       !IsDesignatedInit) {
-    if (DestType->isRecordType()) {
+    if (DestType->isRecordType() && DestType->isAggregateType()) {
       QualType InitType = InitList->getInit(0)->getType();
       if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
           S.IsDerivedFrom(InitList->getBeginLoc(), InitType, DestType)) {

clang/lib/Sema/SemaOverload.cpp

@@ -1568,19 +1568,37 @@ TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
     //   called for those cases.
     if (CXXConstructorDecl *Constructor
           = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
-      QualType FromCanon
-        = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
+      QualType FromType;
+      SourceLocation FromLoc;
+      // C++11 [over.ics.list]p6, per DR2137:
+      // C++17 [over.ics.list]p6:
+      //   If C is not an initializer-list constructor and the initializer list
+      //   has a single element of type cv U, where U is X or a class derived
+      //   from X, the implicit conversion sequence has Exact Match rank if U is
+      //   X, or Conversion rank if U is derived from X.
+      if (const auto *InitList = dyn_cast<InitListExpr>(From);
+          InitList && InitList->getNumInits() == 1 &&
+          !S.isInitListConstructor(Constructor)) {
+        const Expr *SingleInit = InitList->getInit(0);
+        FromType = SingleInit->getType();
+        FromLoc = SingleInit->getBeginLoc();
+      } else {
+        FromType = From->getType();
+        FromLoc = From->getBeginLoc();
+      }
+      QualType FromCanon =
+          S.Context.getCanonicalType(FromType.getUnqualifiedType());
       QualType ToCanon
         = S.Context.getCanonicalType(ToType).getUnqualifiedType();
       if (Constructor->isCopyConstructor() &&
           (FromCanon == ToCanon ||
-           S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
+           S.IsDerivedFrom(FromLoc, FromCanon, ToCanon))) {
         // Turn this into a "standard" conversion sequence, so that it
         // gets ranked with standard conversion sequences.
         DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
         ICS.setStandard();
         ICS.Standard.setAsIdentityConversion();
-        ICS.Standard.setFromType(From->getType());
+        ICS.Standard.setFromType(FromType);
         ICS.Standard.setAllToTypes(ToType);
         ICS.Standard.CopyConstructor = Constructor;
         ICS.Standard.FoundCopyConstructor = Found;
@@ -5306,18 +5324,18 @@ TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
       IsDesignatedInit)
     return Result;
 
-  // Per DR1467:
-  //   If the parameter type is a class X and the initializer list has a single
-  //   element of type cv U, where U is X or a class derived from X, the
-  //   implicit conversion sequence is the one required to convert the element
-  //   to the parameter type.
+  // Per DR1467 and DR2137:
+  //   If the parameter type is an aggregate class X and the initializer list
+  //   has a single element of type cv U, where U is X or a class derived from
+  //   X, the implicit conversion sequence is the one required to convert the
+  //   element to the parameter type.
   //
   //   Otherwise, if the parameter type is a character array [... ]
   //   and the initializer list has a single element that is an
   //   appropriately-typed string literal (8.5.2 [dcl.init.string]), the
   //   implicit conversion sequence is the identity conversion.
   if (From->getNumInits() == 1 && !IsDesignatedInit) {
-    if (ToType->isRecordType()) {
+    if (ToType->isRecordType() && ToType->isAggregateType()) {
       QualType InitType = From->getInit(0)->getType();
       if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
           S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))