[stable/21.x] Cherry-pick changes from previous stable branch

clang/include/clang/CodeGen/CodeGenABITypes.h

@@ -120,6 +120,20 @@ llvm::Type *convertTypeForMemory(CodeGenModule &CGM, QualType T);
 unsigned getLLVMFieldNumber(CodeGenModule &CGM,
                             const RecordDecl *RD, const FieldDecl *FD);
 
+/// Return a declaration discriminator for the given global decl.
+uint16_t getPointerAuthDeclDiscriminator(CodeGenModule &CGM, GlobalDecl GD);
+
+/// Return a type discriminator for the given function type.
+uint16_t getPointerAuthTypeDiscriminator(CodeGenModule &CGM,
+                                         QualType FunctionType);
+
+/// Return a signed constant pointer.
+llvm::Constant *getConstantSignedPointer(CodeGenModule &CGM,
+                                         llvm::Constant *pointer,
+                                         unsigned key,
+                                         llvm::Constant *storageAddress,
+                                         llvm::ConstantInt *otherDiscriminator);
+
 /// Given the language and code-generation options that Clang was configured
 /// with, set the default LLVM IR attributes for a function definition.
 /// The attributes set here are mostly global target-configuration and

clang/lib/CodeGen/CGPointerAuth.cpp

@@ -53,6 +53,16 @@ llvm::ConstantInt *CodeGenModule::getPointerAuthOtherDiscriminator(
   llvm_unreachable("bad discrimination kind");
 }
 
+uint16_t CodeGen::getPointerAuthTypeDiscriminator(CodeGenModule &CGM,
+                                                  QualType FunctionType) {
+  return CGM.getContext().getPointerAuthTypeDiscriminator(FunctionType);
+}
+
+uint16_t CodeGen::getPointerAuthDeclDiscriminator(CodeGenModule &CGM,
+                                                  GlobalDecl Declaration) {
+  return CGM.getPointerAuthDeclDiscriminator(Declaration);
+}
+
 /// Return the "other" decl-specific discriminator for the given decl.
 uint16_t
 CodeGenModule::getPointerAuthDeclDiscriminator(GlobalDecl Declaration) {
@@ -588,6 +598,15 @@ llvm::Constant *CodeGenModule::getConstantSignedPointer(
                                   OtherDiscriminator);
 }
 
+llvm::Constant *
+CodeGen::getConstantSignedPointer(CodeGenModule &CGM,
+                                  llvm::Constant *pointer, unsigned key,
+                                  llvm::Constant *storageAddress,
+                                  llvm::ConstantInt *otherDiscriminator) {
+  return CGM.getConstantSignedPointer(pointer, key, storageAddress,
+                                      otherDiscriminator);
+}
+
 void CodeGenModule::destroyConstantSignedPointerCaches() {
   destroyCache<ByConstantCacheTy>(ConstantSignedPointersByConstant);
   destroyCache<ByDeclCacheTy>(ConstantSignedPointersByDecl);

clang/lib/Frontend/CompilerInstance.cpp

@@ -1655,16 +1655,18 @@ static bool compileModuleAndReadASTImpl(CompilerInstance &ImportingInstance,
                                         SourceLocation ModuleNameLoc,
                                         Module *Module,
                                         StringRef ModuleFileName) {
-  auto Instance = ImportingInstance.cloneForModuleCompile(ModuleNameLoc, Module,
-                                                          ModuleFileName);
-
-  if (!ImportingInstance.compileModule(ModuleNameLoc,
-                                       Module->getTopLevelModuleName(),
-                                       ModuleFileName, *Instance)) {
-    ImportingInstance.getDiagnostics().Report(ModuleNameLoc,
-                                              diag::err_module_not_built)
-        << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
-    return false;
+  {
+    auto Instance = ImportingInstance.cloneForModuleCompile(ModuleNameLoc, Module,
+                                                            ModuleFileName);
+
+    if (!ImportingInstance.compileModule(ModuleNameLoc,
+                                         Module->getTopLevelModuleName(),
+                                         ModuleFileName, *Instance)) {
+      ImportingInstance.getDiagnostics().Report(ModuleNameLoc,
+                                                diag::err_module_not_built)
+          << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
+      return false;
+    }
   }
 
   return readASTAfterCompileModule(ImportingInstance, ImportLoc, ModuleNameLoc,

clang/lib/Parse/Parser.cpp

@@ -629,6 +629,11 @@ bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result,
                                Sema::ModuleImportState &ImportState) {
   DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(*this);
 
+  // Skip over the EOF token, flagging end of previous input for incremental
+  // processing
+  if (PP.isIncrementalProcessingEnabled() && Tok.is(tok::eof))
+    ConsumeToken();
+
   Result = nullptr;
   switch (Tok.getKind()) {
   case tok::annot_pragma_unused:
@@ -722,7 +727,8 @@ bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result,
 
     // Late template parsing can begin.
     Actions.SetLateTemplateParser(LateTemplateParserCallback, nullptr, this);
-    Actions.ActOnEndOfTranslationUnit();
+    if (!PP.isIncrementalProcessingEnabled())
+      Actions.ActOnEndOfTranslationUnit();
     //else don't tell Sema that we ended parsing: more input might come.
     return true;
 

clang/lib/Sema/SemaSwift.cpp

@@ -72,15 +72,6 @@ static bool isValidSwiftErrorResultType(QualType Ty) {
   return isValidSwiftContextType(Ty);
 }
 
-static bool isValidSwiftContextName(StringRef ContextName) {
-  // ContextName might be qualified, e.g. 'MyNamespace.MyStruct'.
-  SmallVector<StringRef, 1> ContextNameComponents;
-  ContextName.split(ContextNameComponents, '.');
-  return all_of(ContextNameComponents, [&](StringRef Component) {
-    return isValidAsciiIdentifier(Component);
-  });
-}
-
 void SemaSwift::handleAttrAttr(Decl *D, const ParsedAttr &AL) {
   if (AL.isInvalid() || AL.isUsedAsTypeAttr())
     return;
@@ -365,11 +356,11 @@ static bool validateSwiftFunctionName(Sema &S, const ParsedAttr &AL,
 
   // Split at the first '.', if it exists, which separates the context name
   // from the base name.
-  std::tie(ContextName, BaseName) = BaseName.rsplit('.');
+  std::tie(ContextName, BaseName) = BaseName.split('.');
   if (BaseName.empty()) {
     BaseName = ContextName;
     ContextName = StringRef();
-  } else if (ContextName.empty() || !isValidSwiftContextName(ContextName)) {
+  } else if (ContextName.empty() || !isValidAsciiIdentifier(ContextName)) {
     S.Diag(Loc, diag::warn_attr_swift_name_invalid_identifier)
         << AL << /*context*/ 1;
     return false;
@@ -593,11 +584,11 @@ bool SemaSwift::DiagnoseName(Decl *D, StringRef Name, SourceLocation Loc,
              !IsAsync) {
     StringRef ContextName, BaseName;
 
-    std::tie(ContextName, BaseName) = Name.rsplit('.');
+    std::tie(ContextName, BaseName) = Name.split('.');
     if (BaseName.empty()) {
       BaseName = ContextName;
       ContextName = StringRef();
-    } else if (!isValidSwiftContextName(ContextName)) {
+    } else if (!isValidAsciiIdentifier(ContextName)) {
       Diag(Loc, diag::warn_attr_swift_name_invalid_identifier)
           << AL << /*context*/ 1;
       return false;

clang/test/SemaObjCXX/attr-swift_name-cxx.mm

@@ -1,43 +1,7 @@
 // RUN: %clang_cc1 -verify -fsyntax-only -fobjc-arc -fblocks %s
 
-#define SWIFT_NAME(name) __attribute__((swift_name(name)))
 #define SWIFT_ASYNC_NAME(name) __attribute__((__swift_async_name__(name)))
 
-namespace MyNS {
-struct NestedStruct {};
-}
-
-void nestedStruct_method(MyNS::NestedStruct) SWIFT_NAME("MyNS.NestedStruct.method(self:)");
-void nestedStruct_methodConstRef(const MyNS::NestedStruct&) SWIFT_NAME("MyNS.NestedStruct.methodConstRef(self:)");
-void nestedStruct_invalidContext1(MyNS::NestedStruct) SWIFT_NAME(".MyNS.NestedStruct.invalidContext1(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the context name}}
-void nestedStruct_invalidContext2(MyNS::NestedStruct) SWIFT_NAME("MyNS::NestedStruct.invalidContext2(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the context name}}
-void nestedStruct_invalidContext3(MyNS::NestedStruct) SWIFT_NAME("::MyNS::NestedStruct.invalidContext3(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the context name}}
-void nestedStruct_invalidContext4(MyNS::NestedStruct) SWIFT_NAME("MyNS..NestedStruct.invalidContext4(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the context name}}
-void nestedStruct_invalidContext5(MyNS::NestedStruct) SWIFT_NAME("MyNS.NestedStruct.invalidContext5.(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the base name}}
-void nestedStruct_invalidContext6(MyNS::NestedStruct) SWIFT_NAME("MyNS.NestedStruct::invalidContext6(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the base name}}
-
-namespace MyNS {
-namespace MyDeepNS {
-struct DeepNestedStruct {};
-}
-}
-
-void deepNestedStruct_method(MyNS::MyDeepNS::DeepNestedStruct) SWIFT_NAME("MyNS.MyDeepNS.DeepNestedStruct.method(self:)");
-void deepNestedStruct_methodConstRef(const MyNS::MyDeepNS::DeepNestedStruct&) SWIFT_NAME("MyNS.MyDeepNS.DeepNestedStruct.methodConstRef(self:)");
-void deepNestedStruct_invalidContext(const MyNS::MyDeepNS::DeepNestedStruct&) SWIFT_NAME("MyNS::MyDeepNS::DeepNestedStruct.methodConstRef(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the context name}}
-
-typedef MyNS::MyDeepNS::DeepNestedStruct DeepNestedStructTypedef;
-
-void deepNestedStructTypedef_method(DeepNestedStructTypedef) SWIFT_NAME("DeepNestedStructTypedef.method(self:)");
-void deepNestedStructTypedef_methodQualName(MyNS::MyDeepNS::DeepNestedStruct) SWIFT_NAME("DeepNestedStructTypedef.method(self:)");
-
-struct TopLevelStruct {
-  struct StructInStruct {};
-};
-
-void structInStruct_method(TopLevelStruct::StructInStruct) SWIFT_NAME("TopLevelStruct.StructInStruct.method(self:)");
-void structInStruct_invalidContext(TopLevelStruct::StructInStruct) SWIFT_NAME("TopLevelStruct::StructInStruct.method(self:)"); // expected-warning {{'swift_name' attribute has invalid identifier for the context name}}
-
 typedef int (^CallbackTy)(void);
 
 class CXXClass {

libcxx/include/CMakeLists.txt

@@ -847,6 +847,7 @@ set(files
   __type_traits/is_member_pointer.h
   __type_traits/is_nothrow_assignable.h
   __type_traits/is_nothrow_constructible.h
+  __type_traits/is_nothrow_convertible.h
   __type_traits/is_nothrow_destructible.h
   __type_traits/is_null_pointer.h
   __type_traits/is_object.h

libcxx/include/__algorithm/sort.h

@@ -359,10 +359,10 @@ inline _LIBCPP_HIDE_FROM_ABI void __swap_bitmap_pos(
   // Swap one pair on each iteration as long as both bitsets have at least one
   // element for swapping.
   while (__left_bitset != 0 && __right_bitset != 0) {
-    difference_type __tz_left  = std::__countr_zero(__left_bitset);
-    __left_bitset              = std::__libcpp_blsr(__left_bitset);
-    difference_type __tz_right = std::__countr_zero(__right_bitset);
-    __right_bitset             = std::__libcpp_blsr(__right_bitset);
+    difference_type __tz_left  = __libcpp_ctz(__left_bitset);
+    __left_bitset              = __libcpp_blsr(__left_bitset);
+    difference_type __tz_right = __libcpp_ctz(__right_bitset);
+    __right_bitset             = __libcpp_blsr(__right_bitset);
     _Ops::iter_swap(__first + __tz_left, __last - __tz_right);
   }
 }
@@ -458,7 +458,7 @@ inline _LIBCPP_HIDE_FROM_ABI void __swap_bitmap_pos_within(
     // Swap within the left side.  Need to find set positions in the reverse
     // order.
     while (__left_bitset != 0) {
-      difference_type __tz_left = __detail::__block_size - 1 - std::__countl_zero(__left_bitset);
+      difference_type __tz_left = __detail::__block_size - 1 - __libcpp_clz(__left_bitset);
       __left_bitset &= (static_cast<uint64_t>(1) << __tz_left) - 1;
       _RandomAccessIterator __it = __first + __tz_left;
       if (__it != __lm1) {
@@ -471,7 +471,7 @@ inline _LIBCPP_HIDE_FROM_ABI void __swap_bitmap_pos_within(
     // Swap within the right side.  Need to find set positions in the reverse
     // order.
     while (__right_bitset != 0) {
-      difference_type __tz_right = __detail::__block_size - 1 - std::__countl_zero(__right_bitset);
+      difference_type __tz_right = __detail::__block_size - 1 - __libcpp_clz(__right_bitset);
       __right_bitset &= (static_cast<uint64_t>(1) << __tz_right) - 1;
       _RandomAccessIterator __it = __lm1 - __tz_right;
       if (__it != __first) {

libcxx/include/__bit/countl.h

@@ -6,9 +6,13 @@
 //
 //===----------------------------------------------------------------------===//
 
+// TODO: __builtin_clzg is available since Clang 19 and GCC 14. When support for older versions is dropped, we can
+//  refactor this code to exclusively use __builtin_clzg.
+
 #ifndef _LIBCPP___BIT_COUNTL_H
 #define _LIBCPP___BIT_COUNTL_H
 
+#include <__bit/rotate.h>
 #include <__config>
 #include <__type_traits/integer_traits.h>
 #include <limits>
@@ -22,10 +26,69 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned __x) _NOEXCEPT {
+  return __builtin_clz(__x);
+}
+
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned long __x) _NOEXCEPT {
+  return __builtin_clzl(__x);
+}
+
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned long long __x) _NOEXCEPT {
+  return __builtin_clzll(__x);
+}
+
+#if _LIBCPP_HAS_INT128
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(__uint128_t __x) _NOEXCEPT {
+#  if __has_builtin(__builtin_clzg)
+  return __builtin_clzg(__x);
+#  else
+  // The function is written in this form due to C++ constexpr limitations.
+  // The algorithm:
+  // - Test whether any bit in the high 64-bits is set
+  // - No bits set:
+  //   - The high 64-bits contain 64 leading zeros,
+  //   - Add the result of the low 64-bits.
+  // - Any bits set:
+  //   - The number of leading zeros of the input is the number of leading
+  //     zeros in the high 64-bits.
+  return ((__x >> 64) == 0) ? (64 + __builtin_clzll(static_cast<unsigned long long>(__x)))
+                            : __builtin_clzll(static_cast<unsigned long long>(__x >> 64));
+#  endif
+}
+#endif // _LIBCPP_HAS_INT128
+
 template <class _Tp>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __countl_zero(_Tp __t) _NOEXCEPT {
   static_assert(__is_unsigned_integer_v<_Tp>, "__countl_zero requires an unsigned integer type");
+#if __has_builtin(__builtin_clzg)
   return __builtin_clzg(__t, numeric_limits<_Tp>::digits);
+#else  // __has_builtin(__builtin_clzg)
+  if (__t == 0)
+    return numeric_limits<_Tp>::digits;
+
+  if (sizeof(_Tp) <= sizeof(unsigned int))
+    return std::__libcpp_clz(static_cast<unsigned int>(__t)) -
+           (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits);
+  else if (sizeof(_Tp) <= sizeof(unsigned long))
+    return std::__libcpp_clz(static_cast<unsigned long>(__t)) -
+           (numeric_limits<unsigned long>::digits - numeric_limits<_Tp>::digits);
+  else if (sizeof(_Tp) <= sizeof(unsigned long long))
+    return std::__libcpp_clz(static_cast<unsigned long long>(__t)) -
+           (numeric_limits<unsigned long long>::digits - numeric_limits<_Tp>::digits);
+  else {
+    int __ret                      = 0;
+    int __iter                     = 0;
+    const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
+    while (true) {
+      __t = std::__rotl(__t, __ulldigits);
+      if ((__iter = std::__countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits)
+        break;
+      __ret += __iter;
+    }
+    return __ret + __iter;
+  }
+#endif // __has_builtin(__builtin_clzg)
 }
 
 #if _LIBCPP_STD_VER >= 20

libcxx/include/__bit/countr.h

@@ -6,11 +6,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+// TODO: __builtin_ctzg is available since Clang 19 and GCC 14. When support for older versions is dropped, we can
+//  refactor this code to exclusively use __builtin_ctzg.
+
 #ifndef _LIBCPP___BIT_COUNTR_H
 #define _LIBCPP___BIT_COUNTR_H
 
+#include <__bit/rotate.h>
 #include <__config>
 #include <__type_traits/integer_traits.h>
+#include <__type_traits/is_unsigned.h>
 #include <limits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -22,10 +27,55 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_ctz(unsigned __x) _NOEXCEPT {
+  return __builtin_ctz(__x);
+}
+
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_ctz(unsigned long __x) _NOEXCEPT {
+  return __builtin_ctzl(__x);
+}
+
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_ctz(unsigned long long __x) _NOEXCEPT {
+  return __builtin_ctzll(__x);
+}
+
+// A constexpr implementation for C++11 and later (using clang extensions for constexpr support)
+// Precondition: __t != 0 (the caller __countr_zero handles __t == 0 as a special case)
+template <class _Tp>
+[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero_impl(_Tp __t) _NOEXCEPT {
+  _LIBCPP_ASSERT_INTERNAL(__t != 0, "__countr_zero_impl called with zero value");
+  static_assert(is_unsigned<_Tp>::value, "__countr_zero_impl only works with unsigned types");
+  if _LIBCPP_CONSTEXPR (sizeof(_Tp) <= sizeof(unsigned int)) {
+    return std::__libcpp_ctz(static_cast<unsigned int>(__t));
+  } else if _LIBCPP_CONSTEXPR (sizeof(_Tp) <= sizeof(unsigned long)) {
+    return std::__libcpp_ctz(static_cast<unsigned long>(__t));
+  } else if _LIBCPP_CONSTEXPR (sizeof(_Tp) <= sizeof(unsigned long long)) {
+    return std::__libcpp_ctz(static_cast<unsigned long long>(__t));
+  } else {
+#if _LIBCPP_STD_VER == 11
+    unsigned long long __ull       = static_cast<unsigned long long>(__t);
+    const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
+    return __ull == 0ull ? __ulldigits + std::__countr_zero_impl<_Tp>(__t >> __ulldigits) : std::__libcpp_ctz(__ull);
+#else
+    int __ret                      = 0;
+    const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
+    while (static_cast<unsigned long long>(__t) == 0uLL) {
+      __ret += __ulldigits;
+      __t >>= __ulldigits;
+    }
+    return __ret + std::__libcpp_ctz(static_cast<unsigned long long>(__t));
+#endif
+  }
+}
+
 template <class _Tp>
 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __countr_zero(_Tp __t) _NOEXCEPT {
-  static_assert(__is_unsigned_integer_v<_Tp>, "__countr_zero only works with unsigned types");
+  static_assert(is_unsigned<_Tp>::value, "__countr_zero only works with unsigned types");
+#if __has_builtin(__builtin_ctzg) // TODO (LLVM 21): This can be dropped once we only support Clang >= 19.
   return __builtin_ctzg(__t, numeric_limits<_Tp>::digits);
+#else
+  return __t != 0 ? std::__countr_zero_impl(__t) : numeric_limits<_Tp>::digits;
+#endif
 }
 
 #if _LIBCPP_STD_VER >= 20