Merge remote-tracking branch 'upstream/main' into delayed_privatization_15

Author: ergawy

.github/CODEOWNERS

@@ -35,6 +35,10 @@
 clang/lib/AST/Interp/ @tbaederr
 clang/test/AST/Interp/ @tbaederr
 
+/clang/include/clang/CIR @lanza @bcardosolopes
+/clang/lib/CIR @lanza @bcardosolopes
+/clang/tools/cir-* @lanza @bcardosolopes
+
 /lldb/ @JDevlieghere
 
 # MLIR Interfaces.

clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.h

@@ -19,7 +19,7 @@ class UseNullptrCheck : public ClangTidyCheck {
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     // FIXME this should be CPlusPlus11 but that causes test cases to
     // erroneously fail.
-    return LangOpts.CPlusPlus;
+    return LangOpts.CPlusPlus || LangOpts.C23;
   }
   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;

clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp

@@ -64,8 +64,11 @@ void AvoidReturnWithVoidValueCheck::check(
            << BraceInsertionHints.closingBraceFixIt();
   }
   Diag << FixItHint::CreateRemoval(VoidReturn->getReturnLoc());
-  if (!Result.Nodes.getNodeAs<FunctionDecl>("function_parent") ||
-      SurroundingBlock->body_back() != VoidReturn)
+  const auto *FunctionParent =
+      Result.Nodes.getNodeAs<FunctionDecl>("function_parent");
+  if (!FunctionParent ||
+      (SurroundingBlock && SurroundingBlock->body_back() != VoidReturn))
+    // If this is not the last statement in a function body, we add a `return`.
     Diag << FixItHint::CreateInsertion(SemicolonPos.getLocWithOffset(1),
                                        " return;", true);
 }

clang-tools-extra/docs/ReleaseNotes.rst

@@ -100,13 +100,15 @@ Improvements to clang-tidy
 - Improved :program:`run-clang-tidy.py` script. Added argument `-source-filter`
   to filter source files from the compilation database, via a RegEx. In a
   similar fashion to what `-header-filter` does for header files.
+
 - Improved :program:`check_clang_tidy.py` script. Added argument `-export-fixes`
   to aid in clang-tidy and test development.
+
 - Fixed bug where big values for unsigned check options overflowed into negative values
-  when being printed with ``--dump-config``.
+  when being printed with `--dump-config`.
 
-- Fixed ``--verify-config`` option not properly parsing checks when using the 
-  literal operator in the ``.clang-tidy`` config.
+- Fixed `--verify-config` option not properly parsing checks when using the
+  literal operator in the `.clang-tidy` config.
 
 New checks
 ^^^^^^^^^^
@@ -236,7 +238,7 @@ Changes in existing checks
 
 - Improved :doc:`google-explicit-constructor
   <clang-tidy/checks/google/explicit-constructor>` check to better handle
-  ``C++-20`` `explicit(bool)`.
+  C++20 `explicit(bool)`.
 
 - Improved :doc:`google-global-names-in-headers
   <clang-tidy/checks/google/global-names-in-headers>` check by replacing the local
@@ -249,6 +251,10 @@ Changes in existing checks
   check by ignoring other functions with same prefixes as the target specific
   functions.
 
+- Improved :doc:`linuxkernel-must-check-errs
+  <clang-tidy/checks/linuxkernel/must-check-errs>` check documentation to
+  consistently use the check's proper name.
+
 - Improved :doc:`llvm-header-guard
   <clang-tidy/checks/llvm/header-guard>` check by replacing the local
   option `HeaderFileExtensions` by the global option of the same name.
@@ -281,6 +287,10 @@ Changes in existing checks
   don't remove parentheses used in ``sizeof`` calls when they have array index
   accesses as arguments.
 
+- Improved :doc:`modernize-use-nullptr
+  <clang-tidy/checks/modernize/use-nullptr>` check to include support for C23,
+  which also has introduced the ``nullptr`` keyword.
+
 - Improved :doc:`modernize-use-override
   <clang-tidy/checks/modernize/use-override>` check to also remove any trailing
   whitespace when deleting the ``virtual`` keyword.
@@ -336,13 +346,9 @@ Miscellaneous
 ^^^^^^^^^^^^^
 
 - Fixed incorrect formatting in :program:`clang-apply-replacements` when no
-  ``--format`` option is specified. Now :program:`clang-apply-replacements`
+  `--format` option is specified. Now :program:`clang-apply-replacements`
   applies formatting only with the option.
 
-- Fixed the :doc:`linuxkernel-must-check-errs
-  <clang-tidy/checks/linuxkernel/must-check-errs>` documentation to consistently
-  use the check's proper name.
-
 Improvements to include-fixer
 -----------------------------
 

clang-tools-extra/docs/clang-tidy/checks/modernize/use-nullptr.rst

@@ -4,7 +4,7 @@ modernize-use-nullptr
 =====================
 
 The check converts the usage of null pointer constants (e.g. ``NULL``, ``0``)
-to use the new C++11 ``nullptr`` keyword.
+to use the new C++11 and C23 ``nullptr`` keyword.
 
 Example
 -------

clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr-c23.c

@@ -0,0 +1,139 @@
+// RUN: %check_clang_tidy %s modernize-use-nullptr %t -- -- -std=c23
+
+#define NULL 0
+
+void test_assignment() {
+  int *p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr [modernize-use-nullptr]
+  // CHECK-FIXES: int *p1 = nullptr;
+  p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p1 = nullptr;
+
+  int *p2 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: int *p2 = nullptr;
+
+  p2 = p1;
+  // CHECK-FIXES: p2 = p1;
+
+  const int null = 0;
+  int *p3 = &null;
+
+  p3 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p3 = nullptr;
+
+  int *p4 = p3;
+
+  int i1 = 0;
+
+  int i2 = NULL;
+
+  int i3 = null;
+
+  int *p5, *p6, *p7;
+  p5 = p6 = p7 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use nullptr
+  // CHECK-FIXES: p5 = p6 = p7 = nullptr;
+}
+
+void test_function(int *p) {}
+
+void test_function_no_ptr_param(int i) {}
+
+void test_function_call() {
+  test_function(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function_no_ptr_param(0);
+}
+
+char *test_function_return1() {
+  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+void *test_function_return2() {
+  return NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+int test_function_return4() {
+  return 0;
+}
+
+int test_function_return5() {
+  return NULL;
+}
+
+int *test_function_return_cast1() {
+  return(int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+int *test_function_return_cast2() {
+#define RET return
+  RET(int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use nullptr
+  // CHECK-FIXES: RET nullptr;
+#undef RET
+}
+
+// Test parentheses expressions resulting in a nullptr.
+int *test_parentheses_expression1() {
+  return(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return(nullptr);
+}
+
+int *test_parentheses_expression2() {
+  return((int)(0.0f));
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return(nullptr);
+}
+
+int *test_nested_parentheses_expression() {
+  return((((0))));
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: return((((nullptr))));
+}
+
+void test_const_pointers() {
+  const int *const_p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p1 = nullptr;
+  const int *const_p2 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p2 = nullptr;
+  const int *const_p3 = (int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p3 = nullptr;
+  const int *const_p4 = (int)0.0f;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p4 = nullptr;
+}
+
+void test_nested_implicit_cast_expr() {
+  int func0(void*, void*);
+  int func1(int, void*, void*);
+
+  (double)func1(0, 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-2]]:23: warning: use nullptr
+  // CHECK-FIXES: (double)func1(0, nullptr, nullptr);
+  (double)func1(func0(0, 0), 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-2]]:26: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-3]]:30: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-4]]:33: warning: use nullptr
+  // CHECK-FIXES: (double)func1(func0(nullptr, nullptr), nullptr, nullptr);
+}

clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr.c

@@ -1,4 +1,4 @@
-// RUN: clang-tidy %s -checks=-*,modernize-use-nullptr -- | count 0
+// RUN: clang-tidy %s -checks=-*,modernize-use-nullptr -- -std=c17 | count 0
 
 // Note: this test expects no diagnostics, but FileCheck cannot handle that,
 // hence the use of | count 0.

clang/cmake/caches/Release.cmake

@@ -82,6 +82,7 @@ set(LLVM_ENABLE_PROJECTS ${STAGE1_PROJECTS} CACHE STRING "")
 # stage2-instrumented and Final Stage Config:
 # Options that need to be set in both the instrumented stage (if we are doing
 # a pgo build) and the final stage.
+set_instrument_and_final_stage_var(CMAKE_POSITION_INDEPENDENT_CODE "ON" STRING)
 set_instrument_and_final_stage_var(LLVM_ENABLE_LTO "${LLVM_RELEASE_ENABLE_LTO}" STRING)
 if (LLVM_RELEASE_ENABLE_LTO)
   set_instrument_and_final_stage_var(LLVM_ENABLE_LLD "ON" BOOL)

clang/docs/LanguageExtensions.rst

@@ -1493,6 +1493,7 @@ Conditional ``explicit``                     __cpp_conditional_explicit       C+
 ``if consteval``                             __cpp_if_consteval               C++23         C++20
 ``static operator()``                        __cpp_static_call_operator       C++23         C++03
 Attributes on Lambda-Expressions                                              C++23         C++11
+Attributes on Structured Bindings            __cpp_structured_bindings        C++26         C++03
 ``= delete ("should have a reason");``       __cpp_deleted_function           C++26         C++03
 -------------------------------------------- -------------------------------- ------------- -------------
 Designated initializers (N494)                                                C99           C89

clang/docs/ReleaseNotes.rst

@@ -143,6 +143,8 @@ C++2c Feature Support
 
 - Implemented `P2573R2: = delete("should have a reason"); <https://wg21.link/P2573R2>`_
 
+- Implemented `P0609R3: Attributes for Structured Bindings <https://wg21.link/P0609R3>`_
+
 
 Resolutions to C++ Defect Reports
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/AST/DeclContextInternals.h

@@ -42,11 +42,12 @@ class StoredDeclsList {
   /// external declarations.
   DeclsAndHasExternalTy Data;
 
-  template<typename Fn>
-  void erase_if(Fn ShouldErase) {
+  template <typename Fn> DeclListNode::Decls *erase_if(Fn ShouldErase) {
     Decls List = Data.getPointer();
+
     if (!List)
-      return;
+      return nullptr;
+
     ASTContext &C = getASTContext();
     DeclListNode::Decls NewHead = nullptr;
     DeclListNode::Decls *NewLast = nullptr;
@@ -79,6 +80,17 @@ class StoredDeclsList {
     Data.setPointer(NewHead);
 
     assert(llvm::none_of(getLookupResult(), ShouldErase) && "Still exists!");
+
+    if (!Data.getPointer())
+      // All declarations are erased.
+      return nullptr;
+    else if (NewHead.is<NamedDecl *>())
+      // The list only contains a declaration, the header itself.
+      return (DeclListNode::Decls *)&Data;
+    else {
+      assert(NewLast && NewLast->is<NamedDecl *>() && "Not the tail?");
+      return NewLast;
+    }
   }
 
   void erase(NamedDecl *ND) {
@@ -160,12 +172,16 @@ class StoredDeclsList {
 
   void replaceExternalDecls(ArrayRef<NamedDecl*> Decls) {
     // Remove all declarations that are either external or are replaced with
-    // external declarations.
-    erase_if([Decls](NamedDecl *ND) {
+    // external declarations with higher visibilities.
+    DeclListNode::Decls *Tail = erase_if([Decls](NamedDecl *ND) {
       if (ND->isFromASTFile())
         return true;
+      // FIXME: Can we get rid of this loop completely?
       for (NamedDecl *D : Decls)
-        if (D->declarationReplaces(ND, /*IsKnownNewer=*/false))
+        // Only replace the local declaration if the external declaration has
+        // higher visibilities.
+        if (D->getModuleOwnershipKind() <= ND->getModuleOwnershipKind() &&
+            D->declarationReplaces(ND, /*IsKnownNewer=*/false))
           return true;
       return false;
     });
@@ -185,24 +201,15 @@ class StoredDeclsList {
       DeclsAsList = Node;
     }
 
-    DeclListNode::Decls Head = Data.getPointer();
-    if (Head.isNull()) {
+    if (!Data.getPointer()) {
       Data.setPointer(DeclsAsList);
       return;
     }
 
-    // Find the end of the existing list.
-    // FIXME: It would be possible to preserve information from erase_if to
-    // avoid this rescan looking for the end of the list.
-    DeclListNode::Decls *Tail = &Head;
-    while (DeclListNode *Node = Tail->dyn_cast<DeclListNode *>())
-      Tail = &Node->Rest;
-
     // Append the Decls.
     DeclListNode *Node = C.AllocateDeclListNode(Tail->get<NamedDecl *>());
     Node->Rest = DeclsAsList;
     *Tail = Node;
-    Data.setPointer(Head);
   }
 
   /// Return the list of all the decls.

clang/include/clang/Basic/Attr.td

@@ -3211,7 +3211,7 @@ def ObjCRequiresPropertyDefs : InheritableAttr {
 def Unused : InheritableAttr {
   let Spellings = [CXX11<"", "maybe_unused", 201603>, GCC<"unused">,
                    C23<"", "maybe_unused", 202106>];
-  let Subjects = SubjectList<[Var, ObjCIvar, Type, Enum, EnumConstant, Label,
+  let Subjects = SubjectList<[Var, Binding, ObjCIvar, Type, Enum, EnumConstant, Label,
                               Field, ObjCMethod, FunctionLike]>;
   let Documentation = [WarnMaybeUnusedDocs];
 }

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -478,6 +478,15 @@ def ext_decomp_decl_empty : ExtWarn<
   "ISO C++17 does not allow a decomposition group to be empty">,
   InGroup<DiagGroup<"empty-decomposition">>;
 
+// C++26 structured bindings
+def ext_decl_attrs_on_binding : ExtWarn<
+  "an attribute specifier sequence attached to a structured binding declaration "
+  "is a C++2c extension">, InGroup<CXX26>;
+def warn_cxx23_compat_decl_attrs_on_binding : Warning<
+  "an attribute specifier sequence attached to a structured binding declaration "
+  "is incompatible with C++ standards before C++2c">,
+  InGroup<CXXPre26Compat>, DefaultIgnore;
+
 /// Objective-C parser diagnostics
 def err_expected_minus_or_plus : Error<
   "method type specifier must start with '-' or '+'">;