Index: clang-tidy/modernize/MakeSmartPtrCheck.cpp
===================================================================
--- clang-tidy/modernize/MakeSmartPtrCheck.cpp
+++ clang-tidy/modernize/MakeSmartPtrCheck.cpp
@@ -241,6 +241,10 @@
   SourceLocation NewStart = New->getSourceRange().getBegin();
   SourceLocation NewEnd = New->getSourceRange().getEnd();
 
+  // Skip when the source location of the new expression is invalid.
+  if (NewStart.isInvalid() || NewEnd.isInvalid())
+    return false;
+
   std::string ArraySizeExpr;
   if (const auto* ArraySize = New->getArraySize()) {
     ArraySizeExpr = Lexer::getSourceText(CharSourceRange::getTokenRange(
Index: test/clang-tidy/modernize-make-unique.cpp
===================================================================
--- test/clang-tidy/modernize-make-unique.cpp
+++ test/clang-tidy/modernize-make-unique.cpp
@@ -498,3 +498,12 @@
   Foo* foo;
   template_fun(foo);
 }
+
+void no_fix_for_invalid_new_loc() {
+  // FIXME: Although the code is valid, the end location of `new struct Base` is
+  // invalid. Correct it once https://bugs.llvm.org/show_bug.cgi?id=35952 is
+  // fixed.
+  auto T = std::unique_ptr<Base>(new struct Base);
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use std::make_unique instead
+  // CHECK-FIXES: auto T = std::unique_ptr<Base>(new struct Base);
+}