Index: clang-tidy/readability/BracesAroundStatementsCheck.cpp
===================================================================
--- clang-tidy/readability/BracesAroundStatementsCheck.cpp
+++ clang-tidy/readability/BracesAroundStatementsCheck.cpp
@@ -176,6 +176,11 @@
   if (S->getLocStart().isMacroID())
     return SourceLocation();
 
+  // Ignore cases that there are parsing errors in condition expression of
+  // IfStmt. Avoid triggering assert failure.
+  if (isa<OpaqueValueExpr>(S->getCond()))
+    return SourceLocation();
+
   SourceLocation CondEndLoc = S->getCond()->getLocEnd();
   if (const DeclStmt *CondVar = S->getConditionVariableDeclStmt())
     CondEndLoc = CondVar->getLocEnd();
Index: test/clang-tidy/readability-braces-around-statements-assert-failure.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/readability-braces-around-statements-assert-failure.cpp
@@ -0,0 +1,7 @@
+// RUN: %check_clang_tidy %s readability-braces-around-statements %t
+
+int test_failure() {
+  if (std::rand()) {
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: error: use of undeclared identifier 'std'
+  }
+}