Reland "Add macro to suppress -Wunnecessary-virtual-specifier" (#141091)
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](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.
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 9290ff3..69ad18f 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -173,7 +173,7 @@
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 @@
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 @@
/// 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 d40d11c..df76e6f 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -3297,7 +3297,7 @@
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 1644e2d..1f8c210 100644
--- a/clang/include/clang/AST/DeclFriend.h
+++ b/clang/include/clang/AST/DeclFriend.h
@@ -52,7 +52,7 @@
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 cf38388..2d07f9d 100644
--- a/clang/include/clang/AST/DeclOpenMP.h
+++ b/clang/include/clang/AST/DeclOpenMP.h
@@ -110,7 +110,7 @@
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 @@
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 @@
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 92bb193..7aecfd8 100644
--- a/clang/include/clang/Driver/Action.h
+++ b/clang/include/clang/Driver/Action.h
@@ -267,7 +267,7 @@
/// 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 6680a45..b423e2a 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -895,7 +895,7 @@
/// 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 360e6bf..cfebe93 100644
--- a/clang/lib/AST/ByteCode/InterpFrame.h
+++ b/clang/lib/AST/ByteCode/InterpFrame.h
@@ -119,7 +119,7 @@
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 f746b48..9e27e63 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
@@ -323,7 +323,7 @@
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 803c7ed..89a79a7 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -4783,7 +4783,7 @@
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 e35a224..033d9b4 100644
--- a/clang/lib/Driver/ToolChains/Hexagon.h
+++ b/clang/lib/Driver/ToolChains/Hexagon.h
@@ -42,8 +42,8 @@
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 2912f45..9721dac 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -882,11 +882,6 @@
# 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 d60c516..58793ed 100644
--- a/llvm/include/llvm/Analysis/InstSimplifyFolder.h
+++ b/llvm/include/llvm/Analysis/InstSimplifyFolder.h
@@ -37,7 +37,7 @@
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 54433b13..d27455c 100644
--- a/llvm/include/llvm/Analysis/TargetFolder.h
+++ b/llvm/include/llvm/Analysis/TargetFolder.h
@@ -40,7 +40,7 @@
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 a75cdf97..a1d9a8f 100644
--- a/llvm/include/llvm/IR/ConstantFolder.h
+++ b/llvm/include/llvm/IR/ConstantFolder.h
@@ -28,7 +28,7 @@
/// 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 c4631a9..2a2318d 100644
--- a/llvm/include/llvm/IR/NoFolder.h
+++ b/llvm/include/llvm/IR/NoFolder.h
@@ -33,7 +33,7 @@
/// 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 4864071..89b925d 100644
--- a/llvm/include/llvm/Support/Compiler.h
+++ b/llvm/include/llvm/Support/Compiler.h
@@ -710,4 +710,28 @@
#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 50cd6ce..1629aac 100644
--- a/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
+++ b/llvm/include/llvm/Transforms/Scalar/GVNExpression.h
@@ -452,7 +452,7 @@
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 517f368..3835f4c 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerBufferFatPointers.cpp
@@ -1211,7 +1211,7 @@
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 e53f256..9dc5f4b 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -225,7 +225,7 @@
X86Subtarget &Subtarget;
const X86RegisterInfo RI;
- virtual void anchor();
+ LLVM_DECLARE_VIRTUAL_ANCHOR_FUNCTION();
bool analyzeBranchImpl(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
