[clang-tidy] Fix an assert failure in 'readability-braces-around-statements' check.

[hokein]

Summary

The check will trigger a assert failure("CondEndLoc.isValid") when
checking the IfStmt whose condition expression is not parsed.

In this case, we should ignore that.

[hokein]

Minor update.

[alexfh]

Looks good with one possible improvement. Thank you!

clang-tidy/readability/BracesAroundStatementsCheck.cpp

181

Maybe just replace the assertion with

if (!CondEndLoc.isValid())
  return SourceLocation();

?

[hokein]

Address review comment.

clang-tidy/readability/BracesAroundStatementsCheck.cpp

BracesAroundStatementsCheck::findRParenLoc(const IfOrWhileStmt *S,
                                            const SourceManager &SM,
                                            const ASTContext *Context) {
   // Skip macros.
   if (S->getLocStart().isMacroID())
     return SourceLocation();
 
   SourceLocation CondEndLoc = S->getCond()->getLocEnd();
   if (const DeclStmt *CondVar = S->getConditionVariableDeclStmt())
     CondEndLoc = CondVar->getLocEnd();
 
-  assert(CondEndLoc.isValid());
+  if (!CondEndLoc.isValid()) {
+    return SourceLocation();
+  }
+
   SourceLocation PastCondEndLoc =
       Lexer::getLocForEndOfToken(CondEndLoc, 0, SM, Context->getLangOpts());
   if (PastCondEndLoc.isInvalid())
     return SourceLocation();
   SourceLocation RParenLoc =
       forwardSkipWhitespaceAndComments(PastCondEndLoc, SM, Context);
   if (RParenLoc.isInvalid())
     return SourceLocation();

test/clang-tidy/readability-braces-around-statements-assert-failure.cpp

+// 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'
+  }
+}