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Merged
merged 3 commits into from
May 28, 2025
Merged

Reland "Add macro to suppress -Wunnecessary-virtual-specifier" #141091

merged 3 commits into from
May 28, 2025

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DKLoehr
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@DKLoehr DKLoehr commented May 22, 2025

This fixes #139614 on non-clang compilers by moving __has_warning completely inside the #if defined(__clang__) block. This prevents a parse failure from compilers which don't recognize __has_warning.

Original description:
Followup to #138741.

This adds the requested macro to silence -Wunnecessary-virtual-specifier when declaring virtual anchor functions in final classes, per LLVM policy.

It also cleans up any remaining instances of the warning, allowing us to stop disabling it when we build LLVM.

@llvmbot llvmbot added cmake Build system in general and CMake in particular clang Clang issues not falling into any other category backend:AMDGPU backend:Hexagon backend:X86 clang:driver 'clang' and 'clang++' user-facing binaries. Not 'clang-cl' clang:frontend Language frontend issues, e.g. anything involving "Sema" clang:codegen IR generation bugs: mangling, exceptions, etc. llvm:support llvm:ir llvm:analysis Includes value tracking, cost tables and constant folding llvm:transforms clang:openmp OpenMP related changes to Clang clang:bytecode Issues for the clang bytecode constexpr interpreter labels May 22, 2025
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llvmbot commented May 22, 2025 •
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@llvm/pr-subscribers-backend-amdgpu
@llvm/pr-subscribers-llvm-ir
@llvm/pr-subscribers-clang-codegen
@llvm/pr-subscribers-llvm-transforms
@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-backend-hexagon

Author: Devon Loehr (DKLoehr)

Changes

This fixes #139614 on non-clang compilers by moving __has_warning completely inside the #if defined(__clang__) block. This prevents a parse failure from compilers which don't recognize __has_warning.

Original description:
Followup to #138741.

This adds the requested macro to silence -Wunnecessary-virtual-specifier when declaring virtual anchor functions in final classes, per LLVM policy.

It also cleans up any remaining instances of the warning, allowing us to stop disabling it when we build LLVM.

Full diff: https://github.com/llvm/llvm-project/pull/141091.diff

19 Files Affected:

  • (modified) clang/include/clang/AST/Decl.h (+3-3)
  • (modified) clang/include/clang/AST/DeclCXX.h (+1-1)
  • (modified) clang/include/clang/AST/DeclFriend.h (+1-1)
  • (modified) clang/include/clang/AST/DeclOpenMP.h (+3-3)
  • (modified) clang/include/clang/Driver/Action.h (+1-1)
  • (modified) clang/include/clang/Sema/Sema.h (+1-1)
  • (modified) clang/lib/AST/ByteCode/InterpFrame.h (+1-1)
  • (modified) clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp (+1-1)
  • (modified) clang/lib/CodeGen/CGStmtOpenMP.cpp (+1-1)
  • (modified) clang/lib/Driver/ToolChains/Hexagon.h (+2-2)
  • (modified) llvm/cmake/modules/HandleLLVMOptions.cmake (-5)
  • (modified) llvm/include/llvm/Analysis/InstSimplifyFolder.h (+1-1)
  • (modified) llvm/include/llvm/Analysis/TargetFolder.h (+1-1)
  • (modified) llvm/include/llvm/IR/ConstantFolder.h (+1-1)
  • (modified) llvm/include/llvm/IR/NoFolder.h (+1-1)
  • (modified) llvm/include/llvm/Support/Compiler.h (+24)
  • (modified) llvm/include/llvm/Transforms/Scalar/GVNExpression.h (+1-1)
  • (modified) llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp (+1-1)
  • (modified) llvm/lib/Target/X86/X86InstrInfo.h (+1-1)
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 9290ff3764c8c..69ad18f4c0581 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -173,7 +173,7 @@ class PragmaCommentDecl final
                     PragmaMSCommentKind CommentKind)
       : Decl(PragmaComment, TU, CommentLoc), CommentKind(CommentKind) {}
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   static PragmaCommentDecl *Create(const ASTContext &C, TranslationUnitDecl *DC,
@@ -207,7 +207,7 @@ class PragmaDetectMismatchDecl final
                            size_t ValueStart)
       : Decl(PragmaDetectMismatch, TU, Loc), ValueStart(ValueStart) {}
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   static PragmaDetectMismatchDecl *Create(const ASTContext &C,
@@ -5024,7 +5024,7 @@ class ImportDecl final : public Decl,
 ///   export void foo();
 /// \endcode
 class ExportDecl final : public Decl, public DeclContext {
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 private:
   friend class ASTDeclReader;
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index d40d11cbe1a3b..df76e6f5015b3 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -3297,7 +3297,7 @@ class LifetimeExtendedTemporaryDecl final
 
   mutable APValue *Value = nullptr;
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
   LifetimeExtendedTemporaryDecl(Expr *Temp, ValueDecl *EDecl, unsigned Mangling)
       : Decl(Decl::LifetimeExtendedTemporary, EDecl->getDeclContext(),
diff --git a/clang/include/clang/AST/DeclFriend.h b/clang/include/clang/AST/DeclFriend.h
index 1644e2de98f80..1f8c210263677 100644
--- a/clang/include/clang/AST/DeclFriend.h
+++ b/clang/include/clang/AST/DeclFriend.h
@@ -52,7 +52,7 @@ class ASTContext;
 class FriendDecl final
     : public Decl,
       private llvm::TrailingObjects<FriendDecl, TemplateParameterList *> {
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   using FriendUnion = llvm::PointerUnion<NamedDecl *, TypeSourceInfo *>;
diff --git a/clang/include/clang/AST/DeclOpenMP.h b/clang/include/clang/AST/DeclOpenMP.h
index cf383889c0ad9..2d07f9d9f5d8c 100644
--- a/clang/include/clang/AST/DeclOpenMP.h
+++ b/clang/include/clang/AST/DeclOpenMP.h
@@ -110,7 +110,7 @@ template <typename U> class OMPDeclarativeDirective : public U {
 class OMPThreadPrivateDecl final : public OMPDeclarativeDirective<Decl> {
   friend class OMPDeclarativeDirective<Decl>;
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
   OMPThreadPrivateDecl(DeclContext *DC = nullptr,
                        SourceLocation L = SourceLocation())
@@ -418,7 +418,7 @@ class OMPRequiresDecl final : public OMPDeclarativeDirective<Decl> {
   friend class OMPDeclarativeDirective<Decl>;
   friend class ASTDeclReader;
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
   OMPRequiresDecl(DeclContext *DC, SourceLocation L)
       : OMPDeclarativeDirective<Decl>(OMPRequires, DC, L) {}
@@ -475,7 +475,7 @@ class OMPAllocateDecl final : public OMPDeclarativeDirective<Decl> {
   friend class OMPDeclarativeDirective<Decl>;
   friend class ASTDeclReader;
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
   OMPAllocateDecl(DeclContext *DC, SourceLocation L)
       : OMPDeclarativeDirective<Decl>(OMPAllocate, DC, L) {}
diff --git a/clang/include/clang/Driver/Action.h b/clang/include/clang/Driver/Action.h
index 92bb19314e3d6..7aecfd886adb8 100644
--- a/clang/include/clang/Driver/Action.h
+++ b/clang/include/clang/Driver/Action.h
@@ -267,7 +267,7 @@ class BindArchAction : public Action {
 /// programming model implementation needs and propagates the offloading kind to
 /// its dependences.
 class OffloadAction final : public Action {
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   /// Type used to communicate device actions. It associates bound architecture,
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index fe93df94438cb..9c48d6122a7f0 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -895,7 +895,7 @@ class Sema final : public SemaBase {
   /// with a vtable when the vtable is emitted. Sema is final and not
   /// polymorphic, but the debug info size savings are so significant that it is
   /// worth adding a vtable just to take advantage of this optimization.
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
   const LangOptions &getLangOpts() const { return LangOpts; }
   OpenCLOptions &getOpenCLOptions() { return OpenCLFeatures; }
diff --git a/clang/lib/AST/ByteCode/InterpFrame.h b/clang/lib/AST/ByteCode/InterpFrame.h
index 360e6bff12327..cfebe936cd468 100644
--- a/clang/lib/AST/ByteCode/InterpFrame.h
+++ b/clang/lib/AST/ByteCode/InterpFrame.h
@@ -119,7 +119,7 @@ class InterpFrame final : public Frame {
   CodePtr getRetPC() const { return RetPC; }
 
   /// Map a location to a source.
-  virtual SourceInfo getSource(CodePtr PC) const;
+  SourceInfo getSource(CodePtr PC) const;
   const Expr *getExpr(CodePtr PC) const;
   SourceLocation getLocation(CodePtr PC) const;
   SourceRange getRange(CodePtr PC) const;
diff --git a/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp b/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
index f746b483b2b91..9e27e634676dc 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
@@ -323,7 +323,7 @@ class CheckVarsEscapingDeclContext final
   CheckVarsEscapingDeclContext(CodeGenFunction &CGF,
                                ArrayRef<const ValueDecl *> TeamsReductions)
       : CGF(CGF), EscapedDecls(llvm::from_range, TeamsReductions) {}
-  virtual ~CheckVarsEscapingDeclContext() = default;
+  ~CheckVarsEscapingDeclContext() = default;
   void VisitDeclStmt(const DeclStmt *S) {
     if (!S)
       return;
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 803c7ed37635e..89a79a7579e03 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -4783,7 +4783,7 @@ class CheckVarsEscapingUntiedTaskDeclContext final
 
 public:
   explicit CheckVarsEscapingUntiedTaskDeclContext() = default;
-  virtual ~CheckVarsEscapingUntiedTaskDeclContext() = default;
+  ~CheckVarsEscapingUntiedTaskDeclContext() = default;
   void VisitDeclStmt(const DeclStmt *S) {
     if (!S)
       return;
diff --git a/clang/lib/Driver/ToolChains/Hexagon.h b/clang/lib/Driver/ToolChains/Hexagon.h
index e35a224dced41..033d9b48cae10 100644
--- a/clang/lib/Driver/ToolChains/Hexagon.h
+++ b/clang/lib/Driver/ToolChains/Hexagon.h
@@ -42,8 +42,8 @@ class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
   bool hasIntegratedCPP() const override { return false; }
   bool isLinkJob() const override { return true; }
 
-  virtual void RenderExtraToolArgs(const JobAction &JA,
-                                   llvm::opt::ArgStringList &CmdArgs) const;
+  void RenderExtraToolArgs(const JobAction &JA,
+                           llvm::opt::ArgStringList &CmdArgs) const;
   void ConstructJob(Compilation &C, const JobAction &JA,
                     const InputInfo &Output, const InputInfoList &Inputs,
                     const llvm::opt::ArgList &TCArgs,
diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 2912f45953c41..9721dacbcbe84 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -882,11 +882,6 @@ if (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
   # The LLVM libraries have no stable C++ API, so -Wnoexcept-type is not useful.
   append("-Wno-noexcept-type" CMAKE_CXX_FLAGS)
 
-  # LLVM has a policy of including virtual "anchor" functions to control
-  # where the vtable is emitted. In `final` classes, these are exactly what
-  # this warning detects: unnecessary virtual methods.
-  add_flag_if_supported("-Wno-unnecessary-virtual-specifier" CXX_SUPPORTS_UNNECESSARY_VIRTUAL_FLAG)
-
   if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     append("-Wnon-virtual-dtor" CMAKE_CXX_FLAGS)
   endif()
diff --git a/llvm/include/llvm/Analysis/InstSimplifyFolder.h b/llvm/include/llvm/Analysis/InstSimplifyFolder.h
index d4ae4dcc918cf..fbf6764212167 100644
--- a/llvm/include/llvm/Analysis/InstSimplifyFolder.h
+++ b/llvm/include/llvm/Analysis/InstSimplifyFolder.h
@@ -36,7 +36,7 @@ class InstSimplifyFolder final : public IRBuilderFolder {
   TargetFolder ConstFolder;
   SimplifyQuery SQ;
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   explicit InstSimplifyFolder(const DataLayout &DL) : ConstFolder(DL), SQ(DL) {}
diff --git a/llvm/include/llvm/Analysis/TargetFolder.h b/llvm/include/llvm/Analysis/TargetFolder.h
index 4c78211b5c935..57a883e16dd25 100644
--- a/llvm/include/llvm/Analysis/TargetFolder.h
+++ b/llvm/include/llvm/Analysis/TargetFolder.h
@@ -39,7 +39,7 @@ class TargetFolder final : public IRBuilderFolder {
     return ConstantFoldConstant(C, DL);
   }
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   explicit TargetFolder(const DataLayout &DL) : DL(DL) {}
diff --git a/llvm/include/llvm/IR/ConstantFolder.h b/llvm/include/llvm/IR/ConstantFolder.h
index a75cdf97f6ed3..a1d9a8faf69e1 100644
--- a/llvm/include/llvm/IR/ConstantFolder.h
+++ b/llvm/include/llvm/IR/ConstantFolder.h
@@ -28,7 +28,7 @@ namespace llvm {
 
 /// ConstantFolder - Create constants with minimum, target independent, folding.
 class ConstantFolder final : public IRBuilderFolder {
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   explicit ConstantFolder() = default;
diff --git a/llvm/include/llvm/IR/NoFolder.h b/llvm/include/llvm/IR/NoFolder.h
index c4631a9ba1cbf..2a2318dfd7863 100644
--- a/llvm/include/llvm/IR/NoFolder.h
+++ b/llvm/include/llvm/IR/NoFolder.h
@@ -33,7 +33,7 @@ namespace llvm {
 
 /// NoFolder - Create "constants" (actually, instructions) with no folding.
 class NoFolder final : public IRBuilderFolder {
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
 public:
   explicit NoFolder() = default;
diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h
index 4864071ed87a8..89b925da75338 100644
--- a/llvm/include/llvm/Support/Compiler.h
+++ b/llvm/include/llvm/Support/Compiler.h
@@ -710,4 +710,28 @@ void AnnotateIgnoreWritesEnd(const char *file, int line);
 #define LLVM_PREFERRED_TYPE(T)
 #endif
 
+/// \macro LLVM_VIRTUAL_ANCHOR_FUNCTION
+/// This macro is used to adhere to LLVM's policy that each class with a vtable
+/// must have at least one out-of-line virtual function. This macro allows us
+/// to declare such a function in `final` classes without triggering a warning.
+// clang-format off
+// Autoformatting makes this look awful.
+#if defined(__clang__)
+  // Make sure this is only parsed if __clang__ is defined
+  #if __has_warning("-Wunnecessary-virtual-specifier")
+    #define LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION()                            \
+      _Pragma("clang diagnostic push")                                        \
+      _Pragma("clang diagnostic ignored \"-Wunnecessary-virtual-specifier\"") \
+      virtual void anchor()                                                   \
+      _Pragma("clang diagnostic pop")
+  #else // __has_warning
+    #define LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION()                            \
+      virtual void anchor()
+  #endif
+#else // defined(__clang__)
+  #define LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION()                              \
+    virtual void anchor()
+#endif
+// clang-format on
+
 #endif
diff --git a/llvm/include/llvm/Transforms/Scalar/GVNExpression.h b/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
index 50cd6ceb9fc0d..1629aacbae45c 100644
--- a/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
+++ b/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
@@ -452,7 +452,7 @@ class AggregateValueExpression final : public BasicExpression {
     IntOperands[NumIntOperands++] = IntOperand;
   }
 
-  virtual void allocateIntOperands(BumpPtrAllocator &Allocator) {
+  void allocateIntOperands(BumpPtrAllocator &Allocator) {
     assert(!IntOperands && "Operands already allocated");
     IntOperands = Allocator.Allocate<unsigned>(MaxIntOperands);
   }
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
index 20ccdcaa0e9a0..48ea2d5a48829 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
@@ -1212,7 +1212,7 @@ class FatPtrConstMaterializer final : public ValueMaterializer {
                           ValueToValueMapTy &UnderlyingMap)
       : TypeMap(TypeMap),
         InternalMapper(UnderlyingMap, RF_None, TypeMap, this) {}
-  virtual ~FatPtrConstMaterializer() = default;
+  ~FatPtrConstMaterializer() = default;
 
   Value *materialize(Value *V) override;
 };
diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h
index e53f2566dd892..9dc5f4b0e086e 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -225,7 +225,7 @@ class X86InstrInfo final : public X86GenInstrInfo {
   X86Subtarget &Subtarget;
   const X86RegisterInfo RI;
 
-  virtual void anchor();
+  LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
 
   bool analyzeBranchImpl(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
                          MachineBasicBlock *&FBB,

@DKLoehr DKLoehr mentioned this pull request May 22, 2025
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@zyn0217
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zyn0217 commented May 28, 2025

@cor3ntin can we merge it? building clang with ToT clang results in a lot of warnings now.

@cor3ntin cor3ntin merged commit 63de20c into llvm:main May 28, 2025
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llvm-ci commented May 28, 2025

LLVM Buildbot has detected a new failure on builder clang-s390x-linux-lnt running on systemz-1 while building clang,llvm at step 13 "setup lit".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/136/builds/4070

Here is the relevant piece of the build log for the reference 
Step 13 (setup lit) failure: '/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/bin/python /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/lnt/setup.py ...' (failure)
...
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2009u is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2010e is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2010g is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2010h is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2010k is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2010l is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2010o is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011d is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011e is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011g is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011h is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011j is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011k is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2011n is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2012d is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2012f is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2012g is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2012h is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2012j is an invalid version and will not be supported in a future release
  warnings.warn(
/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: 2013d is an invalid version and will not be supported in a future release
  warnings.warn(
Downloading https://files.pythonhosted.org/packages/f5/fa/4a9aefc206aa49a4b5e0a72f013df1f471b4714cdbe6d78f0134feeeecdb/pytz-2016.10-py2.py3-none-any.whl#sha256=a1ea35e87a63c7825846d5b5c81d23d668e8a102d3b1b465ce95afe1b3a2e065
Best match: pytz 2016.10
Processing pytz-2016.10-py2.py3-none-any.whl
Installing pytz-2016.10-py2.py3-none-any.whl to /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages
Adding pytz 2016.10 to easy-install.pth file

Installed /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/test/sandbox/lib/python3.10/site-packages/pytz-2016.10-py3.10.egg
Searching for python-gnupg==0.3.7
Reading https://pypi.org/simple/python-gnupg/
error: The read operation timed out

nico
nico reviewed May 28, 2025
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llvm/include/llvm/Support/Compiler.h
// clang-format off
// Autoformatting makes this look awful.
#if defined(__clang__)
// Make sure this is only parsed if __clang__ is defined
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(I think some clangs on some bots don't have __has_warning; I ran into that recently too: c2a62af I'll push a similar commit for this.)

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Hm, actually I wonder if we should add __has_warning to the defines further up.

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Went with that in 4a44e00. With that, it's probably safe to put defined(__clang__) && __has_warning("-Wunnecessary-virtual-specifier") on one line again.

nico added a commit that referenced this pull request May 28, 2025
@nico
[llvm] Define __has_warning in Compiler.h if it isn't defined
4a44e00 
Follow-up to #141091.
sivan-shani pushed a commit to sivan-shani/llvm-project that referenced this pull request Jun 3, 2025
@DKLoehr @sivan-shani
Reland "Add macro to suppress -Wunnecessary-virtual-specifier" (llvm#…
2d0940f 
…141091)

This fixes llvm#139614 on non-clang compilers by moving `__has_warning`
completely inside the `#if defined(__clang__)` block. This prevents a
parse failure from compilers which don't recognize `__has_warning`.

Original description:
Followup to llvm#138741.

This adds the requested macro to silence
`-Wunnecessary-virtual-specifier` when declaring virtual anchor
functions in `final` classes, per [LLVM
policy](https://llvm.org/docs/CodingStandards.html#provide-a-virtual-method-anchor-for-classes-in-headers).

It also cleans up any remaining instances of the warning, allowing us to
stop disabling it when we build LLVM.
sivan-shani pushed a commit to sivan-shani/llvm-project that referenced this pull request Jun 3, 2025
@nico @sivan-shani
[llvm] Define __has_warning in Compiler.h if it isn't defined
fc1714c 
Follow-up to llvm#141091.
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backend:AMDGPU backend:Hexagon backend:X86 clang:bytecode Issues for the clang bytecode constexpr interpreter clang:codegen IR generation bugs: mangling, exceptions, etc. clang:driver 'clang' and 'clang++' user-facing binaries. Not 'clang-cl' clang:frontend Language frontend issues, e.g. anything involving "Sema" clang:openmp OpenMP related changes to Clang clang Clang issues not falling into any other category cmake Build system in general and CMake in particular llvm:analysis Includes value tracking, cost tables and constant folding llvm:ir llvm:support llvm:transforms
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@DKLoehr @llvmbot @zyn0217 @llvm-ci @nico @cor3ntin