Index: llvm/include/llvm/TableGen/Record.h
===================================================================
--- llvm/include/llvm/TableGen/Record.h
+++ llvm/include/llvm/TableGen/Record.h
@@ -1471,7 +1471,16 @@
 
 class Record {
 public:
-  using AssertionTuple = std::tuple<SMLoc, Init *, Init *>;
+  struct AssertionInfo {
+    SMLoc Loc;
+    Init *Condition;
+    Init *Message;
+
+    // User-defined constructor to support std::make_unique(). It can be
+    // removed in C++20 when braced initialization is supported.
+    AssertionInfo(SMLoc Loc, Init *Condition, Init *Message)
+        : Loc(Loc), Condition(Condition), Message(Message) {}
+  };
 
 private:
   static unsigned LastID;
@@ -1482,8 +1491,7 @@
   SmallVector<SMLoc, 4> Locs;
   SmallVector<Init *, 0> TemplateArgs;
   SmallVector<RecordVal, 0> Values;
-  // Vector of [source location, condition Init, message Init].
-  SmallVector<AssertionTuple, 0> Assertions;
+  SmallVector<AssertionInfo, 0> Assertions;
 
   // All superclasses in the inheritance forest in post-order (yes, it
   // must be a forest; diamond-shaped inheritance is not allowed).
@@ -1558,7 +1566,7 @@
 
   ArrayRef<RecordVal> getValues() const { return Values; }
 
-  ArrayRef<AssertionTuple> getAssertions() const { return Assertions; }
+  ArrayRef<AssertionInfo> getAssertions() const { return Assertions; }
 
   ArrayRef<std::pair<Record *, SMRange>>  getSuperClasses() const {
     return SuperClasses;
@@ -1616,7 +1624,7 @@
   }
 
   void addAssertion(SMLoc Loc, Init *Condition, Init *Message) {
-    Assertions.push_back(std::make_tuple(Loc, Condition, Message));
+    Assertions.push_back(AssertionInfo(Loc, Condition, Message));
   }
 
   void appendAssertions(const Record *Rec) {
Index: llvm/lib/TableGen/Record.cpp
===================================================================
--- llvm/lib/TableGen/Record.cpp
+++ llvm/lib/TableGen/Record.cpp
@@ -2379,10 +2379,10 @@
 
   // Resolve the assertion expressions.
   for (auto &Assertion : Assertions) {
-    Init *Value = std::get<1>(Assertion)->resolveReferences(R);
-    std::get<1>(Assertion) = Value;
-    Value = std::get<2>(Assertion)->resolveReferences(R);
-    std::get<2>(Assertion) = Value;
+    Init *Value = Assertion.Condition->resolveReferences(R);
+    Assertion.Condition = Value;
+    Value = Assertion.Message->resolveReferences(R);
+    Assertion.Message = Value;
   }
 }
 
@@ -2634,9 +2634,9 @@
   R.setFinal(true);
 
   for (auto Assertion : getAssertions()) {
-    Init *Condition = std::get<1>(Assertion)->resolveReferences(R);
-    Init *Message = std::get<2>(Assertion)->resolveReferences(R);
-    CheckAssert(std::get<0>(Assertion), Condition, Message);
+    Init *Condition = Assertion.Condition->resolveReferences(R);
+    Init *Message = Assertion.Message->resolveReferences(R);
+    CheckAssert(Assertion.Loc, Condition, Message);
   }
 }
 
Index: llvm/lib/TableGen/TGParser.h
===================================================================
--- llvm/lib/TableGen/TGParser.h
+++ llvm/lib/TableGen/TGParser.h
@@ -37,20 +37,20 @@
   };
 
   /// RecordsEntry - Holds exactly one of a Record, ForeachLoop, or
-  /// assertion tuple.
+  /// AssertionInfo.
   struct RecordsEntry {
     std::unique_ptr<Record> Rec;
     std::unique_ptr<ForeachLoop> Loop;
-    std::unique_ptr<Record::AssertionTuple> Assertion;
+    std::unique_ptr<Record::AssertionInfo> Assertion;
 
     void dump() const;
 
     RecordsEntry() {}
     RecordsEntry(std::unique_ptr<Record> Rec) : Rec(std::move(Rec)) {}
     RecordsEntry(std::unique_ptr<ForeachLoop> Loop)
-      : Loop(std::move(Loop)) {}
-    RecordsEntry(std::unique_ptr<Record::AssertionTuple> Assertion)
-      : Assertion(std::move(Assertion)) {}
+        : Loop(std::move(Loop)) {}
+    RecordsEntry(std::unique_ptr<Record::AssertionInfo> Assertion)
+        : Assertion(std::move(Assertion)) {}
   };
 
   /// ForeachLoop - Record the iteration state associated with a for loop.
Index: llvm/lib/TableGen/TGParser.cpp
===================================================================
--- llvm/lib/TableGen/TGParser.cpp
+++ llvm/lib/TableGen/TGParser.cpp
@@ -365,8 +365,7 @@
 
   // If it is an assertion, then it's a top-level one, so check it.
   if (E.Assertion) {
-    CheckAssert(std::get<0>(*E.Assertion), std::get<1>(*E.Assertion), 
-                std::get<2>(*E.Assertion));
+    CheckAssert(E.Assertion->Loc, E.Assertion->Condition, E.Assertion->Message);
     return false;
   }
 
@@ -430,18 +429,14 @@
       MapResolver R;
       for (const auto &S : Substs)
         R.set(S.first, S.second);
-      Init *Condition = std::get<1>(*E.Assertion)->resolveReferences(R);
-      Init *Message = std::get<2>(*E.Assertion)->resolveReferences(R);
-
-      if (Dest) {
-        std::unique_ptr<Record::AssertionTuple> Tuple =
-            std::make_unique<Record::AssertionTuple>(std::get<0>(*E.Assertion),
-                                                     std::move(Condition),
-                                                     std::move(Message));
-        Dest->push_back(std::move(Tuple));
-      } else {
-        CheckAssert(std::get<0>(*E.Assertion), Condition, Message);
-      }
+      Init *Condition = E.Assertion->Condition->resolveReferences(R);
+      Init *Message = E.Assertion->Message->resolveReferences(R);
+
+      if (Dest)
+        Dest->push_back(std::make_unique<Record::AssertionInfo>(
+            E.Assertion->Loc, Condition, Message));
+      else
+        CheckAssert(E.Assertion->Loc, Condition, Message);
 
     } else {
       auto Rec = std::make_unique<Record>(*E.Rec);
@@ -3219,14 +3214,11 @@
   if (!consume(tgtok::semi))
     return TokError("expected ';'");
 
-  if (CurRec) {
+  if (CurRec)
     CurRec->addAssertion(ConditionLoc, Condition, Message);
-  } else {
-    std::unique_ptr<Record::AssertionTuple> Tuple =
-         std::make_unique<Record::AssertionTuple>(ConditionLoc, Condition, Message);
-    addEntry(std::move(Tuple));
-  }
- 
+  else
+    addEntry(std::make_unique<Record::AssertionInfo>(ConditionLoc, Condition,
+                                                     Message));
   return false;
 }