1 files changed, 82 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 4df8687aff89..b6bd2e69629d 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -1001,6 +1001,84 @@ public:
 };
 }
 
+static void handleDiagnoseAsBuiltinAttr(Sema &S, Decl *D,
+                                        const ParsedAttr &AL) {
+  const auto *DeclFD = cast<FunctionDecl>(D);
+
+  if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(DeclFD))
+    if (!MethodDecl->isStatic()) {
+      S.Diag(AL.getLoc(), diag::err_attribute_no_member_function) << AL;
+      return;
+    }
+
+  auto DiagnoseType = [&](unsigned Index, AttributeArgumentNType T) {
+    SourceLocation Loc = [&]() {
+      auto Union = AL.getArg(Index - 1);
+      if (Union.is<Expr *>())
+        return Union.get<Expr *>()->getBeginLoc();
+      return Union.get<IdentifierLoc *>()->Loc;
+    }();
+
+    S.Diag(Loc, diag::err_attribute_argument_n_type) << AL << Index << T;
+  };
+
+  FunctionDecl *AttrFD = [&]() -> FunctionDecl * {
+    if (!AL.isArgExpr(0))
+      return nullptr;
+    auto *F = dyn_cast_or_null<DeclRefExpr>(AL.getArgAsExpr(0));
+    if (!F)
+      return nullptr;
+    return dyn_cast_or_null<FunctionDecl>(F->getFoundDecl());
+  }();
+
+  if (!AttrFD || !AttrFD->getBuiltinID(true)) {
+    DiagnoseType(1, AANT_ArgumentBuiltinFunction);
+    return;
+  }
+
+  if (AttrFD->getNumParams() != AL.getNumArgs() - 1) {
+    S.Diag(AL.getLoc(), diag::err_attribute_wrong_number_arguments_for)
+        << AL << AttrFD << AttrFD->getNumParams();
+    return;
+  }
+
+  SmallVector<unsigned, 8> Indices;
+
+  for (unsigned I = 1; I < AL.getNumArgs(); ++I) {
+    if (!AL.isArgExpr(I)) {
+      DiagnoseType(I + 1, AANT_ArgumentIntegerConstant);
+      return;
+    }
+
+    const Expr *IndexExpr = AL.getArgAsExpr(I);
+    uint32_t Index;
+
+    if (!checkUInt32Argument(S, AL, IndexExpr, Index, I + 1, false))
+      return;
+
+    if (Index > DeclFD->getNumParams()) {
+      S.Diag(AL.getLoc(), diag::err_attribute_bounds_for_function)
+          << AL << Index << DeclFD << DeclFD->getNumParams();
+      return;
+    }
+
+    QualType T1 = AttrFD->getParamDecl(I - 1)->getType();
+    QualType T2 = DeclFD->getParamDecl(Index - 1)->getType();
+
+    if (T1.getCanonicalType().getUnqualifiedType() !=
+        T2.getCanonicalType().getUnqualifiedType()) {
+      S.Diag(IndexExpr->getBeginLoc(), diag::err_attribute_parameter_types)
+          << AL << Index << DeclFD << T2 << I << AttrFD << T1;
+      return;
+    }
+
+    Indices.push_back(Index - 1);
+  }
+
+  D->addAttr(::new (S.Context) DiagnoseAsBuiltinAttr(
+      S.Context, AL, AttrFD, Indices.data(), Indices.size()));
+}
+
 static void handleDiagnoseIfAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   S.Diag(AL.getLoc(), diag::ext_clang_diagnose_if);
 
@@ -4502,7 +4580,7 @@ void Sema::AddModeAttr(Decl *D, const AttributeCommonInfo &CI,
     return;
   }
   bool IntegralOrAnyEnumType = (OldElemTy->isIntegralOrEnumerationType() &&
-                                !OldElemTy->isExtIntType()) ||
+                                !OldElemTy->isBitIntType()) ||
                                OldElemTy->getAs<EnumType>();
 
   if (!OldElemTy->getAs<BuiltinType>() && !OldElemTy->isComplexType() &&
@@ -8159,6 +8237,9 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
   case ParsedAttr::AT_DiagnoseIf:
     handleDiagnoseIfAttr(S, D, AL);
     break;
+  case ParsedAttr::AT_DiagnoseAsBuiltin:
+    handleDiagnoseAsBuiltinAttr(S, D, AL);
+    break;
   case ParsedAttr::AT_NoBuiltin:
     handleNoBuiltinAttr(S, D, AL);
     break;