[clang][Interp] Handle CXXUuidofExprs

Allocate storage and initialize it with the given APValue contents.

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -2059,6 +2059,66 @@ bool ByteCodeExprGen<Emitter>::VisitExpressionTraitExpr(
   return this->emitConstBool(E->getValue(), E);
 }
 
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
+  if (DiscardResult)
+    return true;
+  assert(!Initializing);
+
+  std::optional<unsigned> GlobalIndex = P.getOrCreateGlobal(E->getGuidDecl());
+  if (!GlobalIndex)
+    return false;
+  if (!this->emitGetPtrGlobal(*GlobalIndex, E))
+    return false;
+
+  const Record *R = this->getRecord(E->getType());
+  assert(R);
+
+  const APValue &V = E->getGuidDecl()->getAsAPValue();
+  if (V.getKind() == APValue::None)
+    return true;
+
+  assert(V.isStruct());
+  assert(V.getStructNumBases() == 0);
+  // FIXME: This could be useful in visitAPValue, too.
+  for (unsigned I = 0, N = V.getStructNumFields(); I != N; ++I) {
+    const APValue &F = V.getStructField(I);
+    const Record::Field *RF = R->getField(I);
+
+    if (F.isInt()) {
+      PrimType T = classifyPrim(RF->Decl->getType());
+      if (!this->visitAPValue(F, T, E))
+        return false;
+      if (!this->emitInitField(T, RF->Offset, E))
+        return false;
+    } else if (F.isArray()) {
+      assert(RF->Desc->isPrimitiveArray());
+      const auto *ArrType = RF->Decl->getType()->getAsArrayTypeUnsafe();
+      PrimType ElemT = classifyPrim(ArrType->getElementType());
+      assert(ArrType);
+
+      if (!this->emitDupPtr(E))
+        return false;
+      if (!this->emitGetPtrField(RF->Offset, E))
+        return false;
+
+      for (unsigned A = 0, AN = F.getArraySize(); A != AN; ++A) {
+        if (!this->visitAPValue(F.getArrayInitializedElt(A), ElemT, E))
+          return false;
+        if (!this->emitInitElem(ElemT, A, E))
+          return false;
+      }
+
+      if (!this->emitPopPtr(E))
+        return false;
+    } else {
+      assert(false && "I don't think this should be possible");
+    }
+  }
+
+  return this->emitInitPtr(E);
+}
+
 template <class Emitter> bool ByteCodeExprGen<Emitter>::discard(const Expr *E) {
   if (E->containsErrors())
     return false;

clang/lib/AST/Interp/ByteCodeExprGen.h

@@ -113,6 +113,7 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
   bool VisitObjCBoolLiteralExpr(const ObjCBoolLiteralExpr *E);
   bool VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
   bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E);
+  bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
 
 protected:
   bool visitExpr(const Expr *E) override;

clang/lib/AST/Interp/Program.cpp

@@ -169,7 +169,7 @@ std::optional<unsigned> Program::createGlobal(const ValueDecl *VD,
   if (const auto *Var = dyn_cast<VarDecl>(VD)) {
     IsStatic = Context::shouldBeGloballyIndexed(VD);
     IsExtern = !Var->getAnyInitializer();
-  } else if (isa<UnnamedGlobalConstantDecl>(VD)) {
+  } else if (isa<UnnamedGlobalConstantDecl, MSGuidDecl>(VD)) {
     IsStatic = true;
     IsExtern = false;
   } else {

clang/test/AST/Interp/literals.cpp

@@ -915,6 +915,13 @@ static_assert(ignoredDecls() == 12, "");
 namespace DiscardExprs {
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-value"
+  typedef struct _GUID {
+    __UINT32_TYPE__ Data1;
+    __UINT16_TYPE__ Data2;
+    __UINT16_TYPE__ Data3;
+    __UINT8_TYPE__ Data4[8];
+  } GUID;
+  class __declspec(uuid("000000A0-0000-0000-C000-000000000049")) GuidType;
 
   struct A{ int a; };
   constexpr int ignoredExprs() {
@@ -951,6 +958,8 @@ namespace DiscardExprs {
     (float)1;
     (double)1.0f;
     (signed)4u;
+    __uuidof(GuidType);
+    __uuidof(number); // both-error {{cannot call operator __uuidof on a type with no GUID}}
 
     return 0;
   }

clang/test/SemaCXX/PR40395.cpp

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++17 -fms-extensions -triple=x86_64-pc-win32 -verify %s
+// RUN: %clang_cc1 -std=c++17 -fms-extensions -triple=x86_64-pc-win32 -verify %s -fexperimental-new-constant-interpreter
 // expected-no-diagnostics
 
 // PR40395 - ConstantExpr shouldn't cause the template object to infinitely

clang/test/SemaCXX/ms-uuid.cpp

@@ -1,5 +1,7 @@
 // RUN: %clang_cc1 -fsyntax-only -verify -fms-extensions %s -Wno-deprecated-declarations
+// RUN: %clang_cc1 -fsyntax-only -verify -fms-extensions %s -Wno-deprecated-declarations -fexperimental-new-constant-interpreter
 // RUN: %clang_cc1 -fsyntax-only -std=c++17 -verify -fms-extensions %s -Wno-deprecated-declarations
+// RUN: %clang_cc1 -fsyntax-only -std=c++17 -verify -fms-extensions %s -Wno-deprecated-declarations -fexperimental-new-constant-interpreter
 
 typedef struct _GUID {
   __UINT32_TYPE__ Data1;