[OpenCL] Support enum and typedef args in TableGen BIFs

[svenvh]

Summary

Add enum and typedef argument support to -fdeclare-opencl-builtins,
which was the last major missing feature.

Adding the remaining missing builtins is left as future work.

[Anastasia]

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

49

Should we add this conditionally if the base header is not included?

In the subsequent patches where you will add other functions, we should make sure that the base header indeed contains the declarations we use in tablegen.

clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp

640

I think we should add an assert that Result.getAsSingle<EnumDecl>() indeed holds. Consider if instead of using base header the types are defined manually and they are regular integers, not enums.

652

Same here, let's add an assert.

[svenvh]

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

49

Should we add this conditionally if the base header is not included?

It is already inside an #ifdef NO_HEADER, see line 21.

In the subsequent patches where you will add other functions, we should make sure that the base header indeed contains the declarations we use in tablegen.

Not sure what you mean... When we test a builtin function that relies on an enum or typedef from the base header, Sema won't succeed if the enum or typedef isn't available.

clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp

640

That is a good point. I think it would be even better to handle such a case properly with a diagnostic, and not rely on just an assert.

[svenvh]

Do not assume cast to Enum/TypedefDecl is always successful.

[Anastasia]

The change looks good, could we test the diagnostic that is added?

[svenvh]

Add test for new diagnostic.

[Anastasia]

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

27

Actually, could we remove the typedef from the diagnostic because it exposes the implementation details unnecessarily? I believe the spec doesn't say what the type is aside from enums? As a matter of fact, we have some types implemented as typedefs that should have been a native types e.g. vector types that we might change one day.

[svenvh]

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

27

I agree it's an implementation detail, but I can see reasons for keeping it: when there is an enum type with the same name available in the translation unit, then the message "type X not found" is not completely correct, because a type X exists, but it is of the wrong type. By prefixing "enum" or "typedef", the diagnostic is more accurate. This diagnostic is mainly targeted at Clang developers actually, because a user shouldn't see this diagnostic in any normal use case (with the driver setting both -fdeclare-opencl-builtins and -finclude-default-header).

[Anastasia]

LGTM! Thanks!

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

27

Ah, I see. Since the diagnostics are not going to be exposed during normal compilation it is less critical indeed... I guess the only issue is when we update the type implementation we might need more tests to change.

clang/include/clang/Basic/DiagnosticSemaKinds.td

 def err_opencl_invalid_type_array : Error<
   "array of %0 type is invalid in OpenCL">;
 def err_opencl_ternary_with_block : Error<
   "block type cannot be used as expression in ternary expression in OpenCL">;
 def err_opencl_pointer_to_type : Error<
   "pointer to type %0 is invalid in OpenCL">;
 def err_opencl_type_can_only_be_used_as_function_parameter : Error <
   "type %0 can only be used as a function parameter in OpenCL">;
+def err_opencl_type_not_found : Error<
+  "%0 type %1 not found; include the base header with -finclude-default-header">;
 def warn_opencl_attr_deprecated_ignored : Warning <
   "%0 attribute is deprecated and ignored in OpenCL version %1">,
   InGroup<IgnoredAttributes>;
 def err_opencl_variadic_function : Error<
   "invalid prototype, variadic arguments are not allowed in OpenCL">;
 def err_opencl_requires_extension : Error<
   "use of %select{type|declaration}0 %1 requires %2 extension to be enabled">;
 def warn_opencl_generic_address_space_arg : Warning<

clang/lib/Sema/OpenCLBuiltins.td

class ImageType<Type _Ty, string _AccessQualifier> :
   let AccessQualifier = _AccessQualifier;
   // Inherited fields
   let IsPointer = _Ty.IsPointer;
   let IsConst = _Ty.IsConst;
   let IsVolatile = _Ty.IsVolatile;
   let AddrSpace = _Ty.AddrSpace;
 }
 
+// OpenCL enum type (e.g. memory_scope).
+class EnumType<string _Name> :
+    Type<_Name, QualType<"getOpenCLEnumType(S, \"" # _Name # "\")", 0>> {
+}
+
+// OpenCL typedef type (e.g. cl_mem_fence_flags).
+class TypedefType<string _Name> :
+    Type<_Name, QualType<"getOpenCLTypedefType(S, \"" # _Name # "\")", 0>> {
+}
+
 // List of Types.
 class TypeList<list<Type> _Type> {
   list<Type> List = _Type;
 }
 
 // A GenericType is an abstract type that defines a set of types as a
 // combination of Types and vector sizes.
 //

 def Image2dMsaaDepth      : Type<"image2d_msaa_depth_t", QualType<"Context.OCLImage2dMSAADepth", 1>>;
 def Image2dArrayMsaaDepth : Type<"image2d_array_msaa_depth_t", QualType<"Context.OCLImage2dArrayMSAADepth", 1>>;
 
 def Sampler               : Type<"sampler_t", QualType<"Context.OCLSamplerTy">>;
 def ClkEvent              : Type<"clk_event_t", QualType<"Context.OCLClkEventTy">>;
 def Event                 : Type<"event_t", QualType<"Context.OCLEventTy">>;
 def Queue                 : Type<"queue_t", QualType<"Context.OCLQueueTy">>;
 def ReserveId             : Type<"reserve_id_t", QualType<"Context.OCLReserveIDTy">>;
+def MemFenceFlags         : TypedefType<"cl_mem_fence_flags">;
 
 // OpenCL v2.0 s6.13.11: Atomic integer and floating-point types.
 def AtomicInt             : Type<"atomic_int", QualType<"Context.getAtomicType(Context.IntTy)">>;
 def AtomicUInt            : Type<"atomic_uint", QualType<"Context.getAtomicType(Context.UnsignedIntTy)">>;
 def AtomicLong            : Type<"atomic_long", QualType<"Context.getAtomicType(Context.LongTy)">>;
 def AtomicULong           : Type<"atomic_ulong", QualType<"Context.getAtomicType(Context.UnsignedLongTy)">>;
 def AtomicFloat           : Type<"atomic_float", QualType<"Context.getAtomicType(Context.FloatTy)">>;
 def AtomicDouble          : Type<"atomic_double", QualType<"Context.getAtomicType(Context.DoubleTy)">>;
 def AtomicIntPtr          : Type<"atomic_intptr_t", QualType<"Context.getAtomicType(Context.getIntPtrType())">>;
 def AtomicUIntPtr         : Type<"atomic_uintptr_t", QualType<"Context.getAtomicType(Context.getUIntPtrType())">>;
 def AtomicSize            : Type<"atomic_size_t", QualType<"Context.getAtomicType(Context.getSizeType())">>;
 def AtomicPtrDiff         : Type<"atomic_ptrdiff_t", QualType<"Context.getAtomicType(Context.getPointerDiffType())">>;
 
+def MemoryOrder           : EnumType<"memory_order">;
+def MemoryScope           : EnumType<"memory_scope">;
+
 //===----------------------------------------------------------------------===//
 //                 Definitions of OpenCL gentype variants
 //===----------------------------------------------------------------------===//
 // The OpenCL specification often uses "gentype" in builtin function
 // declarations to indicate that a builtin function is available with various
 // argument and return types.  The types represented by "gentype" vary between
 // different parts of the specification.  The following definitions capture
 // the different type lists for gentypes in different parts of the
foreach AS = [ConstantAS] in {
   def : Builtin<"vloada_half", [Float, Size, PointerType<ConstType<Half>, AS>]>;
   foreach VSize = [2, 3, 4, 8, 16] in {
     foreach name = ["vload_half" # VSize] in {
       def : Builtin<name, [VectorType<Float, VSize>, Size, PointerType<ConstType<Half>, AS>]>;
     }
   }
 }
 
+// OpenCL v3.0 s6.15.8 - Synchronization Functions.
+def : Builtin<"barrier", [Void, MemFenceFlags], Attr.Convergent>;
+
 //--------------------------------------------------------------------
 // OpenCL v1.1 s6.11.10, v1.2 s6.12.10, v2.0 s6.13.10: Async Copies from Global to Local Memory, Local to Global Memory, and Prefetch
 // OpenCL Extension v2.0 s5.1.7 and s6.1.7: Async Copies from Global to Local Memory, Local to Global Memory, and Prefetch
 // --- Table 18 ---
 foreach name = ["async_work_group_copy"] in {
   def : Builtin<name, [Event, PointerType<AGenTypeN, LocalAS>, PointerType<ConstType<AGenTypeN>, GlobalAS>, Size, Event]>;
   def : Builtin<name, [Event, PointerType<AGenTypeN, GlobalAS>, PointerType<ConstType<AGenTypeN>, LocalAS>, Size, Event]>;
 }
foreach TypePair = [[AtomicInt, Int], [AtomicUInt, UInt],
     def : Builtin<"atomic_load",
         [TypePair[1], PointerType<VolatileType<TypePair[0]>, GenericAS>]>;
     def : Builtin<"atomic_exchange",
         [TypePair[1], PointerType<VolatileType<TypePair[0]>, GenericAS>, TypePair[1]]>;
     foreach Variant = ["weak", "strong"] in {
       def : Builtin<"atomic_compare_exchange_" # Variant,
           [Bool, PointerType<VolatileType<TypePair[0]>, GenericAS>,
            PointerType<TypePair[1], GenericAS>, TypePair[1]]>;
+      def : Builtin<"atomic_compare_exchange_" # Variant # "_explicit",
+          [Bool, PointerType<VolatileType<TypePair[0]>, GenericAS>,
+           PointerType<TypePair[1], GenericAS>, TypePair[1], MemoryOrder, MemoryOrder]>;
+      def : Builtin<"atomic_compare_exchange_" # Variant # "_explicit",
+          [Bool, PointerType<VolatileType<TypePair[0]>, GenericAS>,
+           PointerType<TypePair[1], GenericAS>, TypePair[1], MemoryOrder, MemoryOrder, MemoryScope]>;
     }
   }
 
   foreach TypePair = [[AtomicInt, Int, Int], [AtomicUInt, UInt, UInt],
                       [AtomicLong, Long, Long], [AtomicULong, ULong, ULong],
                       [AtomicIntPtr, IntPtr, PtrDiff],
                       [AtomicUIntPtr, UIntPtr, PtrDiff]] in {
     foreach ModOp = ["add", "sub"] in {

clang/lib/Sema/SemaLookup.cpp

 
 LLVM_DUMP_METHOD void LookupResult::dump() {
   llvm::errs() << "lookup results for " << getLookupName().getAsString()
                << ":\n";
   for (NamedDecl *D : *this)
     D->dump();
 }
 
+/// Diagnose a missing builtin type.
+static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass,
+                                           llvm::StringRef Name) {
+  S.Diag(SourceLocation(), diag::err_opencl_type_not_found)
+      << TypeClass << Name;
+  return S.Context.VoidTy;
+}
+
+/// Lookup an OpenCL enum type.
+static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) {
+  LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
+                      Sema::LookupTagName);
+  S.LookupName(Result, S.TUScope);
+  if (Result.empty())
+    return diagOpenCLBuiltinTypeError(S, "enum", Name);
+  EnumDecl *Decl = Result.getAsSingle<EnumDecl>();
+  if (!Decl)
+    return diagOpenCLBuiltinTypeError(S, "enum", Name);
+  return S.Context.getEnumType(Decl);
+}
+
+/// Lookup an OpenCL typedef type.
+static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) {
+  LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
+                      Sema::LookupOrdinaryName);
+  S.LookupName(Result, S.TUScope);
+  if (Result.empty())
+    return diagOpenCLBuiltinTypeError(S, "typedef", Name);
+  TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>();
+  if (!Decl)
+    return diagOpenCLBuiltinTypeError(S, "typedef", Name);
+  return S.Context.getTypedefType(Decl);
+}
+
 /// Get the QualType instances of the return type and arguments for an OpenCL
 /// builtin function signature.
-/// \param Context (in) The Context instance.
+/// \param S (in) The Sema instance.
 /// \param OpenCLBuiltin (in) The signature currently handled.
 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
 ///        type used as return type or as argument.
 ///        Only meaningful for generic types, otherwise equals 1.
 /// \param RetTypes (out) List of the possible return types.
 /// \param ArgTypes (out) List of the possible argument types.  For each
 ///        argument, ArgTypes contains QualTypes for the Cartesian product
 ///        of (vector sizes) x (types) .
 static void GetQualTypesForOpenCLBuiltin(
-    ASTContext &Context, const OpenCLBuiltinStruct &OpenCLBuiltin,
-    unsigned &GenTypeMaxCnt, SmallVector<QualType, 1> &RetTypes,
+    Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt,
+    SmallVector<QualType, 1> &RetTypes,
     SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
   // Get the QualType instances of the return types.
   unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
-  OCL2Qual(Context, TypeTable[Sig], RetTypes);
+  OCL2Qual(S, TypeTable[Sig], RetTypes);
   GenTypeMaxCnt = RetTypes.size();
 
   // Get the QualType instances of the arguments.
   // First type is the return type, skip it.
   for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
     SmallVector<QualType, 1> Ty;
-    OCL2Qual(Context,
-        TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], Ty);
+    OCL2Qual(S, TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]],
+             Ty);
     GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
     ArgTypes.push_back(std::move(Ty));
   }
 }
 
 /// Create a list of the candidate function overloads for an OpenCL builtin
 /// function.
 /// \param Context (in) The ASTContext instance.
for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
     StringRef Ext = FunctionExtensionTable[OpenCLBuiltin.Extension];
     if (!Ext.empty() && !S.getPreprocessor().isMacroDefined(Ext))
       continue;
 
     SmallVector<QualType, 1> RetTypes;
     SmallVector<SmallVector<QualType, 1>, 5> ArgTypes;
 
     // Obtain QualType lists for the function signature.
-    GetQualTypesForOpenCLBuiltin(Context, OpenCLBuiltin, GenTypeMaxCnt,
-                                 RetTypes, ArgTypes);
+    GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes,
+                                 ArgTypes);
     if (GenTypeMaxCnt > 1) {
       HasGenType = true;
     }
 
     // Create function overload for each type combination.
     std::vector<QualType> FunctionList;
     GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
                                  ArgTypes);

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

 // this test should cover different functional aspects of the TableGen builtin
 // function machinery.
 
 #pragma OPENCL EXTENSION cl_khr_fp16 : enable
 #if __OPENCL_C_VERSION__ < CL_VERSION_1_2
 #pragma OPENCL EXTENSION cl_khr_fp64 : enable
 #endif
 
+// First, test that Clang gracefully handles missing types.
+#ifdef NO_HEADER
+void test_without_header() {
+  barrier(0);
+  // expected-note@-1 0+{{candidate function not viable}}
+  // expected-error@-2 0+{{argument type 'void' is incomplete}}
+  // expected-error@-3 0+{{no matching function for call to 'barrier'}}
+  // expected-error@* {{typedef type cl_mem_fence_flags not found; include the base header with -finclude-default-header}}
+}
+#endif
+
 // Provide typedefs when invoking clang without -finclude-default-header.
 #ifdef NO_HEADER
 typedef unsigned char uchar;
 typedef unsigned int uint;
 typedef unsigned long ulong;
 typedef unsigned short ushort;
 typedef __SIZE_TYPE__ size_t;
 typedef char char2 __attribute__((ext_vector_type(2)));
 typedef char char4 __attribute__((ext_vector_type(4)));
 typedef uchar uchar4 __attribute__((ext_vector_type(4)));
 typedef float float4 __attribute__((ext_vector_type(4)));
 typedef half half4 __attribute__((ext_vector_type(4)));
 typedef int int2 __attribute__((ext_vector_type(2)));
 typedef int int4 __attribute__((ext_vector_type(4)));
 typedef uint uint4 __attribute__((ext_vector_type(4)));
 typedef long long2 __attribute__((ext_vector_type(2)));
 
+typedef uint cl_mem_fence_flags;
+#define CLK_GLOBAL_MEM_FENCE 0x02
+
 // Enable extensions that are enabled in opencl-c-base.h.
 #if (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 200)
 #define cl_khr_subgroup_extended_types 1
 #define cl_khr_subgroup_ballot 1
 #define cl_khr_subgroup_non_uniform_arithmetic 1
 #define cl_khr_subgroup_clustered_reduce 1
 #endif
 #endif
 
 kernel void test_pointers(volatile global void *global_p, global const int4 *a) {
   int i;
   unsigned int ui;
 
   prefetch(a, 2);
 
   atom_add((volatile __global int *)global_p, i);
   atom_cmpxchg((volatile __global unsigned int *)global_p, ui, ui);
 }
 
+// Only test enum arguments when the base header is included, because we need
+// the enum declarations.
+#if !defined(NO_HEADER) && (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 200)
+kernel void test_enum_args(volatile global atomic_int *global_p, global int *expected) {
+  int desired;
+  atomic_compare_exchange_strong_explicit(global_p, expected, desired,
+                                          memory_order_acq_rel,
+                                          memory_order_relaxed,
+                                          memory_scope_work_group);
+}
+#endif
+
 kernel void basic_conversion() {
   double d;
   float f;
   char2 c2;
   long2 l2;
   float4 f4;
   int4 i4;
 
#endif
   vload8(s, (const __global long *) global_p);
   vload2(s, (const __local uint *) local_p);
   vload16(s, (const __private float *) private_p);
 }
 
 kernel void basic_work_item() {
   uint ui;
 
+  barrier(CLK_GLOBAL_MEM_FENCE);
+
   get_enqueued_local_size(ui);
 #if !defined(__OPENCL_CPP_VERSION__) && __OPENCL_C_VERSION__ < CL_VERSION_2_0
 // expected-error@-2{{implicit declaration of function 'get_enqueued_local_size' is invalid in OpenCL}}
 #endif
 }

clang/utils/TableGen/ClangOpenCLBuiltinEmitter.cpp

 //  * OpenCLBuiltinStruct BuiltinTable[]
 //    Each entry represents one overload of an OpenCL builtin function and
 //    consists of an index into the SignatureTable and the number of arguments.
 //
 //  * std::pair<unsigned, unsigned> isOpenCLBuiltin(llvm::StringRef Name)
 //    Find out whether a string matches an existing OpenCL builtin function
 //    name and return an index into BuiltinTable and the number of overloads.
 //
-//  * void OCL2Qual(ASTContext&, OpenCLTypeStruct, std::vector<QualType>&)
+//  * void OCL2Qual(Sema&, OpenCLTypeStruct, std::vector<QualType>&)
 //    Convert an OpenCLTypeStruct type to a list of QualType instances.
 //    One OpenCLTypeStruct can represent multiple types, primarily when using
 //    GenTypes.
 //
 //===----------------------------------------------------------------------===//
 
 #include "TableGenBackends.h"
 #include "llvm/ADT/MapVector.h"
)";
 
   OS << "  return std::make_pair(0, 0);\n";
   OS << "} // isOpenCLBuiltin\n";
 }
 
 void BuiltinNameEmitter::EmitQualTypeFinder() {
   OS << R"(
 
+static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name);
+static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name);
+
 // Convert an OpenCLTypeStruct type to a list of QualTypes.
 // Generic types represent multiple types and vector sizes, thus a vector
 // is returned. The conversion is done in two steps:
 // Step 1: A switch statement fills a vector with scalar base types for the
 //         Cartesian product of (vector sizes) x (types) for generic types,
 //         or a single scalar type for non generic types.
 // Step 2: Qualifiers and other type properties such as vector size are
 //         applied.
-static void OCL2Qual(ASTContext &Context, const OpenCLTypeStruct &Ty,
+static void OCL2Qual(Sema &S, const OpenCLTypeStruct &Ty,
                      llvm::SmallVectorImpl<QualType> &QT) {
+  ASTContext &Context = S.Context;
   // Number of scalar types in the GenType.
   unsigned GenTypeNumTypes;
   // Pointer to the list of vector sizes for the GenType.
   llvm::ArrayRef<unsigned> GenVectorSizes;
 )";
 
   // Generate list of vector sizes for each generic type.
   for (const auto *VectList : Records.getAllDerivedDefinitions("IntList")) {
     OS << "  constexpr unsigned List"
        << VectList->getValueAsString("Name") << "[] = {";
     for (const auto V : VectList->getValueAsListOfInts("List")) {
       OS << V << ", ";
     }
     OS << "};\n";
   }