diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -602,6 +602,13 @@
       MostRecentLocation = *StartLoc;
     }
 
+    // If the either location is invalid, set it to std::nullopt to avoid
+    // letting users of RegionStack think that region has a valid start/end
+    // location.
+    if (StartLoc && StartLoc->isInvalid())
+      StartLoc = std::nullopt;
+    if (EndLoc && EndLoc->isInvalid())
+      EndLoc = std::nullopt;
     RegionStack.emplace_back(Count, FalseCount, StartLoc, EndLoc);
 
     return RegionStack.size() - 1;
@@ -624,7 +631,8 @@
     assert(RegionStack.size() >= ParentIndex && "parent not in stack");
     while (RegionStack.size() > ParentIndex) {
       SourceMappingRegion &Region = RegionStack.back();
-      if (Region.hasStartLoc()) {
+      if (Region.hasStartLoc() &&
+          (Region.hasEndLoc() || RegionStack[ParentIndex].hasEndLoc())) {
         SourceLocation StartLoc = Region.getBeginLoc();
         SourceLocation EndLoc = Region.hasEndLoc()
                                     ? Region.getEndLoc()
@@ -691,7 +699,7 @@
         assert(SM.isWrittenInSameFile(Region.getBeginLoc(), EndLoc));
         assert(SpellingRegion(SM, Region).isInSourceOrder());
         SourceRegions.push_back(Region);
-        }
+      }
       RegionStack.pop_back();
     }
   }