Automerge: [clang] Simplify device kernel attributes (#137882)

We have multiple different attributes in clang representing device
kernels for specific targets/languages. Refactor them into one attribute
with different spellings to make it more easily scalable for new
languages/targets.

---------

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

clang-tools-extra/clang-tidy/altera/SingleWorkItemBarrierCheck.cpp

@@ -16,14 +16,14 @@ namespace clang::tidy::altera {
 
 void SingleWorkItemBarrierCheck::registerMatchers(MatchFinder *Finder) {
   // Find any function that calls barrier but does not call an ID function.
-  // hasAttr(attr::Kind::OpenCLKernel) restricts it to only kernel functions.
+  // hasAttr(attr::Kind::DeviceKernel) restricts it to only kernel functions.
   // FIXME: Have it accept all functions but check for a parameter that gets an
   // ID from one of the four ID functions.
   Finder->addMatcher(
       // Find function declarations...
       functionDecl(
-          // That are OpenCL kernels...
-          hasAttr(attr::Kind::OpenCLKernel),
+          // That are device kernels...
+          hasAttr(attr::Kind::DeviceKernel),
           // And call a barrier function (either 1.x or 2.x version)...
           forEachDescendant(callExpr(callee(functionDecl(hasAnyName(
                                          "barrier", "work_group_barrier"))))

clang/include/clang/AST/GlobalDecl.h

@@ -164,7 +164,7 @@ class GlobalDecl {
   }
 
   static KernelReferenceKind getDefaultKernelReference(const FunctionDecl *D) {
-    return (D->hasAttr<OpenCLKernelAttr>() || D->getLangOpts().CUDAIsDevice)
+    return (D->hasAttr<DeviceKernelAttr>() || D->getLangOpts().CUDAIsDevice)
                ? KernelReferenceKind::Kernel
                : KernelReferenceKind::Stub;
   }

clang/include/clang/Basic/Attr.td

@@ -196,8 +196,10 @@ def FunctionPointer : SubsetSubject<DeclBase,
                                     "functions pointers">;
 
 def OpenCLKernelFunction
-    : SubsetSubject<Function, [{S->hasAttr<OpenCLKernelAttr>()}],
-                    "kernel functions">;
+    : SubsetSubject<Function, [{S->getASTContext().getLangOpts().OpenCL &&
+                               DeviceKernelAttr::isOpenCLSpelling(
+			                 S->getAttr<DeviceKernelAttr>()}],
+                               "kernel functions">;
 
 // HasFunctionProto is a more strict version of FunctionLike, so it should
 // never be specified in a Subjects list along with FunctionLike (due to the
@@ -1515,12 +1517,6 @@ def CUDAGridConstant : InheritableAttr {
   let Documentation = [CUDAGridConstantAttrDocs];
 }
 
-def NVPTXKernel : InheritableAttr, TargetSpecificAttr<TargetNVPTX> {
-  let Spellings = [Clang<"nvptx_kernel">];
-  let Subjects = SubjectList<[Function]>;
-  let Documentation = [Undocumented];
-}
-
 def HIPManaged : InheritableAttr {
   let Spellings = [GNU<"managed">, Declspec<"__managed__">];
   let Subjects = SubjectList<[Var]>;
@@ -1555,11 +1551,52 @@ def CUDAShared : InheritableAttr {
 }
 def : MutualExclusions<[CUDAConstant, CUDAShared, HIPManaged]>;
 
-def SYCLKernel : InheritableAttr {
-  let Spellings = [Clang<"sycl_kernel">];
-  let Subjects = SubjectList<[FunctionTmpl]>;
-  let LangOpts = [SYCLDevice];
-  let Documentation = [SYCLKernelDocs];
+def DeviceKernel : DeclOrTypeAttr {
+  let Spellings = [Clang<"device_kernel">, Clang<"sycl_kernel">,
+                   Clang<"nvptx_kernel">, Clang<"amdgpu_kernel">,
+                   CustomKeyword<"__kernel">, CustomKeyword<"kernel">];
+  let Documentation = [DeviceKernelDocs];
+  let AdditionalMembers =
+  [{
+    static inline bool isAMDGPUSpelling(const AttributeCommonInfo& A) {
+      return A.getAttributeSpellingListIndex() == GNU_amdgpu_kernel ||
+             A.getAttributeSpellingListIndex() == CXX11_clang_amdgpu_kernel ||
+             A.getAttributeSpellingListIndex() == C23_clang_amdgpu_kernel;
+    }
+    static inline bool isAMDGPUSpelling(const AttributeCommonInfo* A) {
+      if(!A) return false;
+      return isAMDGPUSpelling(*A);
+    }
+    static inline bool isNVPTXSpelling(const AttributeCommonInfo& A) {
+      return A.getAttributeSpellingListIndex() == GNU_nvptx_kernel ||
+             A.getAttributeSpellingListIndex() == CXX11_clang_nvptx_kernel ||
+             A.getAttributeSpellingListIndex() == C23_clang_nvptx_kernel;
+    }
+    static inline bool isNVPTXSpelling(const AttributeCommonInfo* A) {
+      if(!A) return false;
+      return isNVPTXSpelling(*A);
+    }
+    static inline bool isSYCLSpelling(const AttributeCommonInfo& A) {
+      return A.getAttributeSpellingListIndex() == GNU_sycl_kernel ||
+             A.getAttributeSpellingListIndex() == CXX11_clang_sycl_kernel ||
+             A.getAttributeSpellingListIndex() == C23_clang_sycl_kernel;
+    }
+    static inline bool isSYCLSpelling(const AttributeCommonInfo* A) {
+      if(!A) return false;
+      return isSYCLSpelling(*A);
+    }
+    static inline bool isOpenCLSpelling(const AttributeCommonInfo& A) {
+    // Tablegen trips underscores from spellings to build the spelling
+    // list, but here we have the same spelling with unscores and without,
+    // so handle that case manually.
+      return A.getAttributeSpellingListIndex() == Keyword_kernel ||
+      A.getAttrName()->getName() == "kernel";
+    }
+    static inline bool isOpenCLSpelling(const AttributeCommonInfo* A) {
+    if (!A) return false;
+    return isOpenCLSpelling(*A);
+    }
+}];
 }
 
 def SYCLKernelEntryPoint : InheritableAttr {
@@ -1625,15 +1662,6 @@ def Allocating : TypeAttr {
   let Documentation = [AllocatingDocs];
 }
 
-// Similar to CUDA, OpenCL attributes do not receive a [[]] spelling because
-// the specification does not expose them with one currently.
-def OpenCLKernel : InheritableAttr {
-  let Spellings = [CustomKeyword<"__kernel">, CustomKeyword<"kernel">];
-  let Subjects = SubjectList<[Function], ErrorDiag>;
-  let Documentation = [Undocumented];
-  let SimpleHandler = 1;
-}
-
 def OpenCLUnrollHint : StmtAttr {
   let Spellings = [GNU<"opencl_unroll_hint">];
   let Subjects = SubjectList<[ForStmt, CXXForRangeStmt, WhileStmt, DoStmt],
@@ -2370,11 +2398,6 @@ def AMDGPUMaxNumWorkGroups : InheritableAttr {
   let Subjects = SubjectList<[Function], ErrorDiag, "kernel functions">;
 }
 
-def AMDGPUKernelCall : DeclOrTypeAttr {
-  let Spellings = [Clang<"amdgpu_kernel">];
-  let Documentation = [Undocumented];
-}
-
 def BPFPreserveAccessIndex : InheritableAttr,
                              TargetSpecificAttr<TargetBPF>  {
   let Spellings = [Clang<"preserve_access_index">];

clang/include/clang/Basic/AttrDocs.td

@@ -396,9 +396,13 @@ any option of a multiversioned function is undefined.
   }];
 }
 
-def SYCLKernelDocs : Documentation {
+def DeviceKernelDocs : Documentation {
   let Category = DocCatFunction;
+  let Heading = "device_kernel, sycl_kernel, nvptx_kernel, amdgpu_kernel, "
+                "kernel, __kernel";
   let Content = [{
+These attributes specify that the function represents a kernel for device offloading.
+The specific semantics depend on the offloading language, target, and attribute spelling.
 The ``sycl_kernel`` attribute specifies that a function template will be used
 to outline device code and to generate an OpenCL kernel.
 Here is a code example of the SYCL program, which demonstrates the compiler's

clang/include/clang/Basic/Specifiers.h

@@ -289,14 +289,13 @@ namespace clang {
     CC_AAPCS_VFP,          // __attribute__((pcs("aapcs-vfp")))
     CC_IntelOclBicc,       // __attribute__((intel_ocl_bicc))
     CC_SpirFunction,       // default for OpenCL functions on SPIR target
-    CC_OpenCLKernel,       // inferred for OpenCL kernels
+    CC_DeviceKernel,       // __attribute__((device_kernel))
     CC_Swift,              // __attribute__((swiftcall))
     CC_SwiftAsync,         // __attribute__((swiftasynccall))
     CC_PreserveMost,       // __attribute__((preserve_most))
     CC_PreserveAll,        // __attribute__((preserve_all))
     CC_AArch64VectorCall,  // __attribute__((aarch64_vector_pcs))
     CC_AArch64SVEPCS,      // __attribute__((aarch64_sve_pcs))
-    CC_AMDGPUKernelCall,   // __attribute__((amdgpu_kernel))
     CC_M68kRTD,            // __attribute__((m68k_rtd))
     CC_PreserveNone,       // __attribute__((preserve_none))
     CC_RISCVVectorCall,    // __attribute__((riscv_vector_cc))
@@ -326,7 +325,7 @@ namespace clang {
     case CC_X86Pascal:
     case CC_X86VectorCall:
     case CC_SpirFunction:
-    case CC_OpenCLKernel:
+    case CC_DeviceKernel:
     case CC_Swift:
     case CC_SwiftAsync:
     case CC_M68kRTD:

clang/lib/AST/Decl.cpp

@@ -3541,7 +3541,7 @@ bool FunctionDecl::isExternC() const {
 }
 
 bool FunctionDecl::isInExternCContext() const {
-  if (hasAttr<OpenCLKernelAttr>())
+  if (DeviceKernelAttr::isOpenCLSpelling(getAttr<DeviceKernelAttr>()))
     return true;
   return getLexicalDeclContext()->isExternCContext();
 }
@@ -5510,7 +5510,8 @@ FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
 }
 
 bool FunctionDecl::isReferenceableKernel() const {
-  return hasAttr<CUDAGlobalAttr>() || hasAttr<OpenCLKernelAttr>();
+  return hasAttr<CUDAGlobalAttr>() ||
+         DeviceKernelAttr::isOpenCLSpelling(getAttr<DeviceKernelAttr>());
 }
 
 BlockDecl *BlockDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {

clang/lib/AST/ItaniumMangle.cpp

@@ -1557,7 +1557,8 @@ void CXXNameMangler::mangleUnqualifiedName(
           FD && FD->hasAttr<CUDAGlobalAttr>() &&
           GD.getKernelReferenceKind() == KernelReferenceKind::Stub;
       bool IsOCLDeviceStub =
-          FD && FD->hasAttr<OpenCLKernelAttr>() &&
+          FD &&
+          DeviceKernelAttr::isOpenCLSpelling(FD->getAttr<DeviceKernelAttr>()) &&
           GD.getKernelReferenceKind() == KernelReferenceKind::Stub;
       if (IsDeviceStub)
         mangleDeviceStubName(II);
@@ -3532,10 +3533,9 @@ StringRef CXXNameMangler::getCallingConvQualifierName(CallingConv CC) {
   case CC_AAPCS_VFP:
   case CC_AArch64VectorCall:
   case CC_AArch64SVEPCS:
-  case CC_AMDGPUKernelCall:
   case CC_IntelOclBicc:
   case CC_SpirFunction:
-  case CC_OpenCLKernel:
+  case CC_DeviceKernel:
   case CC_PreserveMost:
   case CC_PreserveAll:
   case CC_M68kRTD:

clang/lib/AST/MicrosoftMangle.cpp

@@ -1164,7 +1164,9 @@ void MicrosoftCXXNameMangler::mangleUnqualifiedName(GlobalDecl GD,
                   ->hasAttr<CUDAGlobalAttr>())) &&
             GD.getKernelReferenceKind() == KernelReferenceKind::Stub;
         bool IsOCLDeviceStub =
-            ND && isa<FunctionDecl>(ND) && ND->hasAttr<OpenCLKernelAttr>() &&
+            ND && isa<FunctionDecl>(ND) &&
+            DeviceKernelAttr::isOpenCLSpelling(
+                ND->getAttr<DeviceKernelAttr>()) &&
             GD.getKernelReferenceKind() == KernelReferenceKind::Stub;
         if (IsDeviceStub)
           mangleSourceName(

clang/lib/AST/Type.cpp

@@ -3606,14 +3606,12 @@ StringRef FunctionType::getNameForCallConv(CallingConv CC) {
     return "aarch64_vector_pcs";
   case CC_AArch64SVEPCS:
     return "aarch64_sve_pcs";
-  case CC_AMDGPUKernelCall:
-    return "amdgpu_kernel";
   case CC_IntelOclBicc:
     return "intel_ocl_bicc";
   case CC_SpirFunction:
     return "spir_function";
-  case CC_OpenCLKernel:
-    return "opencl_kernel";
+  case CC_DeviceKernel:
+    return "device_kernel";
   case CC_Swift:
     return "swiftcall";
   case CC_SwiftAsync:
@@ -4328,7 +4326,7 @@ bool AttributedType::isCallingConv() const {
   case attr::VectorCall:
   case attr::AArch64VectorPcs:
   case attr::AArch64SVEPcs:
-  case attr::AMDGPUKernelCall:
+  case attr::DeviceKernel:
   case attr::Pascal:
   case attr::MSABI:
   case attr::SysVABI:

clang/lib/AST/TypePrinter.cpp

@@ -1100,8 +1100,8 @@ void TypePrinter::printFunctionAfter(const FunctionType::ExtInfo &Info,
     case CC_AArch64SVEPCS:
       OS << "__attribute__((aarch64_sve_pcs))";
       break;
-    case CC_AMDGPUKernelCall:
-      OS << "__attribute__((amdgpu_kernel))";
+    case CC_DeviceKernel:
+      OS << "__attribute__((device_kernel))";
       break;
     case CC_IntelOclBicc:
       OS << " __attribute__((intel_ocl_bicc))";
@@ -1116,7 +1116,6 @@ void TypePrinter::printFunctionAfter(const FunctionType::ExtInfo &Info,
       OS << " __attribute__((regcall))";
       break;
     case CC_SpirFunction:
-    case CC_OpenCLKernel:
       // Do nothing. These CCs are not available as attributes.
       break;
     case CC_Swift:
@@ -2069,7 +2068,9 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   }
   case attr::AArch64VectorPcs: OS << "aarch64_vector_pcs"; break;
   case attr::AArch64SVEPcs: OS << "aarch64_sve_pcs"; break;
-  case attr::AMDGPUKernelCall: OS << "amdgpu_kernel"; break;
+  case attr::DeviceKernel:
+    OS << T->getAttr()->getSpelling();
+    break;
   case attr::IntelOclBicc: OS << "inteloclbicc"; break;
   case attr::PreserveMost:
     OS << "preserve_most";