[clang][Interp] Implement __builtin_sycl_unique_stable_name

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -1594,6 +1594,30 @@ bool ByteCodeExprGen<Emitter>::VisitStringLiteral(const StringLiteral *E) {
   return true;
 }
 
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitSYCLUniqueStableNameExpr(
+    const SYCLUniqueStableNameExpr *E) {
+  if (DiscardResult)
+    return true;
+
+  assert(!Initializing);
+
+  auto &A = Ctx.getASTContext();
+  std::string ResultStr = E->ComputeName(A);
+
+  QualType CharTy = A.CharTy.withConst();
+  APInt Size(A.getTypeSize(A.getSizeType()), ResultStr.size() + 1);
+  QualType ArrayTy = A.getConstantArrayType(CharTy, Size, nullptr,
+                                            ArraySizeModifier::Normal, 0);
+
+  StringLiteral *SL =
+      StringLiteral::Create(A, ResultStr, StringLiteralKind::Ordinary,
+                            /*Pascal=*/false, ArrayTy, E->getLocation());
+
+  unsigned StringIndex = P.createGlobalString(SL);
+  return this->emitGetPtrGlobal(StringIndex, E);
+}
+
 template <class Emitter>
 bool ByteCodeExprGen<Emitter>::VisitCharacterLiteral(
     const CharacterLiteral *E) {

clang/lib/AST/Interp/ByteCodeExprGen.h

@@ -90,6 +90,7 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
   bool VisitOpaqueValueExpr(const OpaqueValueExpr *E);
   bool VisitAbstractConditionalOperator(const AbstractConditionalOperator *E);
   bool VisitStringLiteral(const StringLiteral *E);
+  bool VisitSYCLUniqueStableNameExpr(const SYCLUniqueStableNameExpr *E);
   bool VisitCharacterLiteral(const CharacterLiteral *E);
   bool VisitCompoundAssignOperator(const CompoundAssignOperator *E);
   bool VisitFloatCompoundAssignOperator(const CompoundAssignOperator *E);

clang/test/AST/Interp/sycl.cpp

@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -std=c++17 -triple x86_64-linux-gnu -fsycl-is-device -verify=both,ref -fsyntax-only -Wno-unused
+// RUN: %clang_cc1 %s -std=c++17 -triple x86_64-linux-gnu -fsycl-is-device -verify=both,expected -fsyntax-only -Wno-unused -fexperimental-new-constant-interpreter
+
+// both-no-diagnostics
+
+constexpr int a = 0;
+constexpr const char *a_name = __builtin_sycl_unique_stable_name(decltype(a));
+static_assert(__builtin_strcmp(a_name, "_ZTSKi") == 0);
+