diff --git a/clang/include/clang/Sema/ParsedAttr.h b/clang/include/clang/Sema/ParsedAttr.h
index 43c21faaece9fa..0d731d9150a8a3 100644
--- a/clang/include/clang/Sema/ParsedAttr.h
+++ b/clang/include/clang/Sema/ParsedAttr.h
@@ -573,6 +573,16 @@ class ParsedAttr final
     return MacroExpansionLoc;
   }
 
+  /// Check if the attribute has exactly as many args as Num. May output an
+  /// error. Returns false if a diagnostic is produced.
+  bool checkExactlyNumArgs(class Sema &S, unsigned Num) const;
+  /// Check if the attribute has at least as many args as Num. May output an
+  /// error. Returns false if a diagnostic is produced.
+  bool checkAtLeastNumArgs(class Sema &S, unsigned Num) const;
+  /// Check if the attribute has at most as many args as Num. May output an
+  /// error. Returns false if a diagnostic is produced.
+  bool checkAtMostNumArgs(class Sema &S, unsigned Num) const;
+
   bool isTargetSpecificAttr() const;
   bool isTypeAttr() const;
   bool isStmtAttr() const;
diff --git a/clang/lib/Sema/ParsedAttr.cpp b/clang/lib/Sema/ParsedAttr.cpp
index 3ef8498baffdf8..c6a3d7c4342c9b 100644
--- a/clang/lib/Sema/ParsedAttr.cpp
+++ b/clang/lib/Sema/ParsedAttr.cpp
@@ -204,3 +204,35 @@ bool ParsedAttr::hasVariadicArg() const {
   // whether it's truly variadic or not.
   return getInfo().OptArgs == 15;
 }
+
+static unsigned getNumAttributeArgs(const ParsedAttr &AL) {
+  // FIXME: Include the type in the argument list.
+  return AL.getNumArgs() + AL.hasParsedType();
+}
+
+template <typename Compare>
+static bool checkAttributeNumArgsImpl(Sema &S, const ParsedAttr &AL,
+                                      unsigned Num, unsigned Diag,
+                                      Compare Comp) {
+  if (Comp(getNumAttributeArgs(AL), Num)) {
+    S.Diag(AL.getLoc(), Diag) << AL << Num;
+    return false;
+  }
+  return true;
+}
+
+bool ParsedAttr::checkExactlyNumArgs(Sema &S, unsigned Num) const {
+  return checkAttributeNumArgsImpl(S, *this, Num,
+                                   diag::err_attribute_wrong_number_arguments,
+                                   std::not_equal_to<unsigned>());
+}
+bool ParsedAttr::checkAtLeastNumArgs(Sema &S, unsigned Num) const {
+  return checkAttributeNumArgsImpl(S, *this, Num,
+                                   diag::err_attribute_too_few_arguments,
+                                   std::less<unsigned>());
+}
+bool ParsedAttr::checkAtMostNumArgs(Sema &S, unsigned Num) const {
+  return checkAttributeNumArgsImpl(S, *this, Num,
+                                   diag::err_attribute_too_many_arguments,
+                                   std::greater<unsigned>());
+}
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 4376342185fb67..5b9acda6738ebc 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -191,44 +191,6 @@ static unsigned getNumAttributeArgs(const ParsedAttr &AL) {
   return AL.getNumArgs() + AL.hasParsedType();
 }
 
-template <typename Compare>
-static bool checkAttributeNumArgsImpl(Sema &S, const ParsedAttr &AL,
-                                      unsigned Num, unsigned Diag,
-                                      Compare Comp) {
-  if (Comp(getNumAttributeArgs(AL), Num)) {
-    S.Diag(AL.getLoc(), Diag) << AL << Num;
-    return false;
-  }
-
-  return true;
-}
-
-/// Check if the attribute has exactly as many args as Num. May
-/// output an error.
-static bool checkAttributeNumArgs(Sema &S, const ParsedAttr &AL, unsigned Num) {
-  return checkAttributeNumArgsImpl(S, AL, Num,
-                                   diag::err_attribute_wrong_number_arguments,
-                                   std::not_equal_to<unsigned>());
-}
-
-/// Check if the attribute has at least as many args as Num. May
-/// output an error.
-static bool checkAttributeAtLeastNumArgs(Sema &S, const ParsedAttr &AL,
-                                         unsigned Num) {
-  return checkAttributeNumArgsImpl(S, AL, Num,
-                                   diag::err_attribute_too_few_arguments,
-                                   std::less<unsigned>());
-}
-
-/// Check if the attribute has at most as many args as Num. May
-/// output an error.
-static bool checkAttributeAtMostNumArgs(Sema &S, const ParsedAttr &AL,
-                                        unsigned Num) {
-  return checkAttributeNumArgsImpl(S, AL, Num,
-                                   diag::err_attribute_too_many_arguments,
-                                   std::greater<unsigned>());
-}
-
 /// A helper function to provide Attribute Location for the Attr types
 /// AND the ParsedAttr.
 template <typename AttrInfo>
@@ -771,7 +733,7 @@ static void handlePtGuardedByAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
 static bool checkAcquireOrderAttrCommon(Sema &S, Decl *D, const ParsedAttr &AL,
                                         SmallVectorImpl<Expr *> &Args) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return false;
 
   // Check that this attribute only applies to lockable types.
@@ -867,8 +829,7 @@ static bool checkParamIsIntegerType(Sema &S, const FunctionDecl *FD,
 }
 
 static void handleAllocSizeAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1) ||
-      !checkAttributeAtMostNumArgs(S, AL, 2))
+  if (!AL.checkAtLeastNumArgs(S, 1) || !AL.checkAtMostNumArgs(S, 2))
     return;
 
   const auto *FD = cast<FunctionDecl>(D);
@@ -904,7 +865,7 @@ static void handleAllocSizeAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
 static bool checkTryLockFunAttrCommon(Sema &S, Decl *D, const ParsedAttr &AL,
                                       SmallVectorImpl<Expr *> &Args) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return false;
 
   if (!isIntOrBool(AL.getArgAsExpr(0))) {
@@ -951,7 +912,7 @@ static void handleLockReturnedAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 }
 
 static void handleLocksExcludedAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   // check that all arguments are lockable objects
@@ -1193,7 +1154,7 @@ static bool checkForConsumableClass(Sema &S, const CXXMethodDecl *MD,
 }
 
 static void handleCallableWhenAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   if (!checkForConsumableClass(S, cast<CXXMethodDecl>(D), AL))
@@ -2016,7 +1977,7 @@ static void handleCPUSpecificAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     }
   }
 
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   SmallVector<IdentifierInfo *, 8> CPUs;
@@ -2120,7 +2081,7 @@ static void handleNoCfCheckAttr(Sema &S, Decl *D, const ParsedAttr &Attrs) {
 }
 
 bool Sema::CheckAttrNoArgs(const ParsedAttr &Attrs) {
-  if (!checkAttributeNumArgs(*this, Attrs, 0)) {
+  if (!Attrs.checkExactlyNumArgs(*this, 0)) {
     Attrs.setInvalid();
     return true;
   }
@@ -2492,7 +2453,7 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(
 }
 
 static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeNumArgs(S, AL, 1))
+  if (!AL.checkExactlyNumArgs(S, 1))
     return;
   IdentifierLoc *Platform = AL.getArgAsIdent(0);
 
@@ -2600,10 +2561,8 @@ static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
 static void handleExternalSourceSymbolAttr(Sema &S, Decl *D,
                                            const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1) || !AL.checkAtMostNumArgs(S, 3))
     return;
-  assert(checkAttributeAtMostNumArgs(S, AL, 3) &&
-         "Invalid number of arguments in an external_source_symbol attribute");
 
   StringRef Language;
   if (const auto *SE = dyn_cast_or_null<StringLiteral>(AL.getArgAsExpr(0)))
@@ -4690,7 +4649,7 @@ static void handleCallConvAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 }
 
 static void handleSuppressAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   std::vector<StringRef> DiagnosticIdentifiers;
@@ -4780,7 +4739,7 @@ bool Sema::CheckCallingConvAttr(const ParsedAttr &Attrs, CallingConv &CC,
   }
 
   unsigned ReqArgs = Attrs.getKind() == ParsedAttr::AT_Pcs ? 1 : 0;
-  if (!checkAttributeNumArgs(*this, Attrs, ReqArgs)) {
+  if (!Attrs.checkExactlyNumArgs(*this, ReqArgs)) {
     Attrs.setInvalid();
     return true;
   }
@@ -5008,7 +4967,7 @@ bool Sema::CheckRegparmAttr(const ParsedAttr &AL, unsigned &numParams) {
   if (AL.isInvalid())
     return true;
 
-  if (!checkAttributeNumArgs(*this, AL, 1)) {
+  if (!AL.checkExactlyNumArgs(*this, 1)) {
     AL.setInvalid();
     return true;
   }
@@ -5097,8 +5056,7 @@ void Sema::AddLaunchBoundsAttr(Decl *D, const AttributeCommonInfo &CI,
 }
 
 static void handleLaunchBoundsAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1) ||
-      !checkAttributeAtMostNumArgs(S, AL, 2))
+  if (!AL.checkAtLeastNumArgs(S, 1) || !AL.checkAtMostNumArgs(S, 2))
     return;
 
   S.AddLaunchBoundsAttr(D, AL, AL.getArgAsExpr(0),
@@ -5145,7 +5103,7 @@ static void handleTypeTagForDatatypeAttr(Sema &S, Decl *D,
     return;
   }
 
-  if (!checkAttributeNumArgs(S, AL, 1))
+  if (!AL.checkExactlyNumArgs(S, 1))
     return;
 
   if (!isa<VarDecl>(D)) {
@@ -5952,7 +5910,7 @@ static void handleSwiftAsyncError(Sema &S, Decl *D, const ParsedAttr &AL) {
   switch (ConvKind) {
   case SwiftAsyncErrorAttr::ZeroArgument:
   case SwiftAsyncErrorAttr::NonZeroArgument: {
-    if (!checkAttributeNumArgs(S, AL, 2))
+    if (!AL.checkExactlyNumArgs(S, 2))
       return;
 
     Expr *IdxExpr = AL.getArgAsExpr(1);
@@ -5962,7 +5920,7 @@ static void handleSwiftAsyncError(Sema &S, Decl *D, const ParsedAttr &AL) {
   }
   case SwiftAsyncErrorAttr::NonNullError:
   case SwiftAsyncErrorAttr::None: {
-    if (!checkAttributeNumArgs(S, AL, 1))
+    if (!AL.checkExactlyNumArgs(S, 1))
       return;
     break;
   }
@@ -6288,7 +6246,7 @@ static void handleSwiftAsyncName(Sema &S, Decl *D, const ParsedAttr &AL) {
 
 static void handleSwiftNewType(Sema &S, Decl *D, const ParsedAttr &AL) {
   // Make sure that there is an identifier as the annotation's single argument.
-  if (!checkAttributeNumArgs(S, AL, 1))
+  if (!AL.checkExactlyNumArgs(S, 1))
     return;
 
   if (!AL.isArgIdent(0)) {
@@ -6330,11 +6288,11 @@ static void handleSwiftAsyncAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   ParamIdx Idx;
   if (Kind == SwiftAsyncAttr::None) {
     // If this is 'none', then there shouldn't be any additional arguments.
-    if (!checkAttributeNumArgs(S, AL, 1))
+    if (!AL.checkExactlyNumArgs(S, 1))
       return;
   } else {
     // Non-none swift_async requires a completion handler index argument.
-    if (!checkAttributeNumArgs(S, AL, 2))
+    if (!AL.checkExactlyNumArgs(S, 2))
       return;
 
     Expr *HandlerIdx = AL.getArgAsExpr(1);
@@ -6498,7 +6456,7 @@ static void handleAbiTagAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     }
     if (AL.getNumArgs() == 0)
       Tags.push_back(NS->getName());
-  } else if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  } else if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   // Store tags sorted and without duplicates.
@@ -6556,7 +6514,7 @@ static void handleMSP430InterruptAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   }
 
   // The attribute takes one integer argument.
-  if (!checkAttributeNumArgs(S, AL, 1))
+  if (!AL.checkExactlyNumArgs(S, 1))
     return;
 
   if (!AL.isArgExpr(0)) {
@@ -6642,7 +6600,7 @@ static void handleMipsInterruptAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 }
 
 static void handleM68kInterruptAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeNumArgs(S, AL, 1))
+  if (!AL.checkExactlyNumArgs(S, 1))
     return;
 
   if (!AL.isArgExpr(0)) {
@@ -6745,7 +6703,7 @@ static void handleAVRInterruptAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     return;
   }
 
-  if (!checkAttributeNumArgs(S, AL, 0))
+  if (!AL.checkExactlyNumArgs(S, 0))
     return;
 
   handleSimpleAttribute<AVRInterruptAttr>(S, D, AL);
@@ -6758,7 +6716,7 @@ static void handleAVRSignalAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     return;
   }
 
-  if (!checkAttributeNumArgs(S, AL, 0))
+  if (!AL.checkExactlyNumArgs(S, 0))
     return;
 
   handleSimpleAttribute<AVRSignalAttr>(S, D, AL);
@@ -6889,7 +6847,7 @@ static void handleRISCVInterruptAttr(Sema &S, Decl *D,
   }
 
   // Check the attribute argument. Argument is optional.
-  if (!checkAttributeAtMostNumArgs(S, AL, 1))
+  if (!AL.checkAtMostNumArgs(S, 1))
     return;
 
   StringRef Str;
@@ -7062,8 +7020,7 @@ void Sema::addAMDGPUWavesPerEUAttr(Decl *D, const AttributeCommonInfo &CI,
 }
 
 static void handleAMDGPUWavesPerEUAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1) ||
-      !checkAttributeAtMostNumArgs(S, AL, 2))
+  if (!AL.checkAtLeastNumArgs(S, 1) || !AL.checkAtMostNumArgs(S, 2))
     return;
 
   Expr *MinExpr = AL.getArgAsExpr(0);
@@ -7286,7 +7243,7 @@ static void handleReleaseCapabilityAttr(Sema &S, Decl *D,
 
 static void handleRequiresCapabilityAttr(Sema &S, Decl *D,
                                          const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   // check that all arguments are lockable objects
@@ -7320,7 +7277,7 @@ static void handleDeprecatedAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
   // Only support a single optional message for Declspec and CXX11.
   if (AL.isDeclspecAttribute() || AL.isCXX11Attribute())
-    checkAttributeAtMostNumArgs(S, AL, 1);
+    AL.checkAtMostNumArgs(S, 1);
   else if (AL.isArgExpr(1) && AL.getArgAsExpr(1) &&
            !S.checkStringLiteralArgumentAttr(AL, 1, Replacement))
     return;
@@ -7338,7 +7295,7 @@ static bool isGlobalVar(const Decl *D) {
 }
 
 static void handleNoSanitizeAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
-  if (!checkAttributeAtLeastNumArgs(S, AL, 1))
+  if (!AL.checkAtLeastNumArgs(S, 1))
     return;
 
   std::vector<StringRef> Sanitizers;
@@ -7433,15 +7390,14 @@ static bool handleCommonAttributeFeatures(Sema &S, Decl *D,
   if (AL.getMinArgs() == AL.getMaxArgs()) {
     // If there are no optional arguments, then checking for the argument count
     // is trivial.
-    if (!checkAttributeNumArgs(S, AL, AL.getMinArgs()))
+    if (!AL.checkExactlyNumArgs(S, AL.getMinArgs()))
       return true;
   } else {
     // There are optional arguments, so checking is slightly more involved.
-    if (AL.getMinArgs() &&
-        !checkAttributeAtLeastNumArgs(S, AL, AL.getMinArgs()))
+    if (AL.getMinArgs() && !AL.checkAtLeastNumArgs(S, AL.getMinArgs()))
       return true;
     else if (!AL.hasVariadicArg() && AL.getMaxArgs() &&
-             !checkAttributeAtMostNumArgs(S, AL, AL.getMaxArgs()))
+             !AL.checkAtMostNumArgs(S, AL.getMaxArgs()))
       return true;
   }