[SYCL] Enable OpenCL diagnostics for sampler in SYCL mode

Selectively enabled a few OpenCL diagnostics for sampler type as some
diagnostics trigger on SYCL use cases.

For instance, OpenCL kernel in SYCL mode initializes lambda captures with
the kernel argument values. This initialization code for sampler emits
errors because OpenCL disallows sampler on the right hand side of the
binary operators - these are supposed to be used only by built-in
functions.

Another potential issue is the lambda object itself -
captured sampler is a member of the lambda object and OpenCL doesn't
allow composite types with samplers. SPIR-V produced from SYCL should be
okay as lambda object can be removed by standard LLVM transformation
passes.

Signed-off-by: Alexey Bader <alexey.bader@intel.com>

Author: bader

clang/lib/Sema/SemaDecl.cpp

@@ -6347,6 +6347,26 @@ NamedDecl *Sema::ActOnVariableDeclarator(
     return nullptr;
   }
 
+  if (R->isSamplerT()) {
+    // OpenCL v1.2 s6.9.b p4:
+    // The sampler type cannot be used with the __local and __global address
+    // space qualifiers.
+    if (R.getAddressSpace() == LangAS::opencl_local ||
+        R.getAddressSpace() == LangAS::opencl_global) {
+      Diag(D.getIdentifierLoc(), diag::err_wrong_sampler_addressspace);
+    }
+
+    // OpenCL v1.2 s6.12.14.1:
+    // A global sampler must be declared with either the constant address
+    // space qualifier or with the const qualifier.
+    if (DC->isTranslationUnit() &&
+        !(R.getAddressSpace() == LangAS::opencl_constant ||
+          R.isConstQualified())) {
+      Diag(D.getIdentifierLoc(), diag::err_opencl_nonconst_global_sampler);
+      D.setInvalidType();
+    }
+  }
+
   if (getLangOpts().OpenCL) {
     // OpenCL v2.0 s6.9.b - Image type can only be used as a function argument.
     // OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function
@@ -6392,26 +6412,6 @@ NamedDecl *Sema::ActOnVariableDeclarator(
       }
     }
 
-    if (R->isSamplerT()) {
-      // OpenCL v1.2 s6.9.b p4:
-      // The sampler type cannot be used with the __local and __global address
-      // space qualifiers.
-      if (R.getAddressSpace() == LangAS::opencl_local ||
-          R.getAddressSpace() == LangAS::opencl_global) {
-        Diag(D.getIdentifierLoc(), diag::err_wrong_sampler_addressspace);
-      }
-
-      // OpenCL v1.2 s6.12.14.1:
-      // A global sampler must be declared with either the constant address
-      // space qualifier or with the const qualifier.
-      if (DC->isTranslationUnit() &&
-          !(R.getAddressSpace() == LangAS::opencl_constant ||
-          R.isConstQualified())) {
-        Diag(D.getIdentifierLoc(), diag::err_opencl_nonconst_global_sampler);
-        D.setInvalidType();
-      }
-    }
-
     // OpenCL v1.2 s6.9.r:
     // The event type cannot be used with the __local, __constant and __global
     // address space qualifiers.

clang/lib/Sema/SemaExpr.cpp

@@ -13046,7 +13046,7 @@ ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc,
   bool CanOverflow = false;
 
   bool ConvertHalfVec = false;
-  if (getLangOpts().OpenCL) {
+  if (getLangOpts().OpenCL || getLangOpts().SYCLIsDevice) {
     QualType Ty = InputExpr->getType();
     // The only legal unary operation for atomics is '&'.
     if ((Opc != UO_AddrOf && Ty->isAtomicType()) ||

clang/lib/Sema/SemaInit.cpp

@@ -5319,9 +5319,9 @@ static bool TryOCLSamplerInitialization(Sema &S,
                                         InitializationSequence &Sequence,
                                         QualType DestType,
                                         Expr *Initializer) {
-  if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
+  if (!DestType->isSamplerT() ||
       (!Initializer->isIntegerConstantExpr(S.Context) &&
-      !Initializer->getType()->isSamplerT()))
+       !Initializer->getType()->isSamplerT()))
     return false;
 
   Sequence.AddOCLSamplerInitStep(DestType);
@@ -5634,6 +5634,9 @@ void InitializationSequence::InitializeFrom(Sema &S,
   bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
          Entity.isParameterKind();
 
+  if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
+    return;
+
   // We're at the end of the line for C: it's either a write-back conversion
   // or it's a C assignment. There's no need to check anything else.
   if (!S.getLangOpts().CPlusPlus) {
@@ -5643,9 +5646,6 @@ void InitializationSequence::InitializeFrom(Sema &S,
       return;
     }
 
-    if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
-      return;
-
     if (TryOCLZeroOpaqueTypeInitialization(S, *this, DestType, Initializer))
       return;
 

clang/lib/Sema/SemaType.cpp

@@ -2322,7 +2322,7 @@ QualType Sema::BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
   // OpenCL v2.0 s6.12.5 - Arrays of blocks are not supported.
   // OpenCL v2.0 s6.16.13.1 - Arrays of pipe type are not supported.
   // OpenCL v2.0 s6.9.b - Arrays of image/sampler type are not supported.
-  if (getLangOpts().OpenCL) {
+  if (getLangOpts().OpenCL || getLangOpts().SYCLIsDevice) {
     const QualType ArrType = Context.getBaseElementType(T);
     if (ArrType->isBlockPointerType() || ArrType->isPipeType() ||
         ArrType->isSamplerT() || ArrType->isImageType()) {
@@ -4409,7 +4409,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
       // OpenCL v2.0 s6.9b - Pointer to image/sampler cannot be used.
       // OpenCL v2.0 s6.13.16.1 - Pointer to pipe cannot be used.
       // OpenCL v2.0 s6.12.5 - Pointers to Blocks are not allowed.
-      if (LangOpts.OpenCL) {
+      if (LangOpts.OpenCL || LangOpts.SYCLIsDevice) {
         if (T->isImageType() || T->isSamplerT() || T->isPipeType() ||
             T->isBlockPointerType()) {
           S.Diag(D.getIdentifierLoc(), diag::err_opencl_pointer_to_type) << T;
@@ -4607,7 +4607,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
         }
       }
 
-      if (LangOpts.OpenCL) {
+      if (LangOpts.OpenCL || LangOpts.SYCLIsDevice) {
         // OpenCL v2.0 s6.12.5 - A block cannot be the return value of a
         // function.
         if (T->isBlockPointerType() || T->isImageType() || T->isSamplerT() ||
@@ -4619,7 +4619,9 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
         // OpenCL doesn't support variadic functions and blocks
         // (s6.9.e and s6.12.5 OpenCL v2.0) except for printf.
         // We also allow here any toolchain reserved identifiers.
+        // FIXME: Use deferred diagnostics engine to skip host side issues.
         if (FTI.isVariadic &&
+            !LangOpts.SYCLIsDevice &&
             !(D.getIdentifier() &&
               ((D.getIdentifier()->getName() == "printf" &&
                 (LangOpts.OpenCLCPlusPlus || LangOpts.OpenCLVersion >= 120)) ||