[clang-tidy] Bugfix for readability-redundant-control-flow check

[malcolm.parsons]

Summary

This check did not create FixItHints when the statement before the redundant control flow was not followed by a semicolon.

[alexfh]

LG. If there's a related buganizer item, please mention it in the commit message.

[malcolm.parsons]

I didn't report a bug for this issue, and there isn't an existing one.

I don't have commit access, so please commit it for me.

[omtcyfz]

In D24500#542284, @malcolm.parsons wrote:

I didn't report a bug for this issue, and there isn't an existing one.

I don't have commit access, so please commit it for me.

Since Alex is away at the moment I landed it.

clang-tidy/readability/RedundantControlFlowCheck.cpp

void RedundantControlFlowCheck::issueDiagnostic(
 
   CompoundStmt::const_reverse_body_iterator Previous = ++Block->body_rbegin();
   SourceLocation Start;
   if (Previous != Block->body_rend())
     Start = Lexer::findLocationAfterToken(
         dyn_cast<Stmt>(*Previous)->getLocEnd(), tok::semi, SM,
         Result.Context->getLangOpts(),
         /*SkipTrailingWhitespaceAndNewLine=*/true);
-  else
+  if (!Start.isValid())
     Start = StmtRange.getBegin();
   auto RemovedRange = CharSourceRange::getCharRange(
       Start,
       Lexer::findLocationAfterToken(StmtRange.getEnd(), tok::semi, SM,
                                     Result.Context->getLangOpts(),
                                     /*SkipTrailingWhitespaceAndNewLine=*/true));
 
   diag(StmtRange.getBegin(), Diag) << FixItHint::CreateRemoval(RemovedRange);
 }
 
 } // namespace readability
 } // namespace tidy
 } // namespace clang

test/clang-tidy/readability-redundant-control-flow.cpp

if (check < T(0)) {
     return;
   }
   return;
 }
 // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: redundant return statement
 // CHECK-FIXES: {{^}}  if (check < T(0)) {{{$}}
 // CHECK-FIXES-NEXT: {{^    return;$}}
 // CHECK-FIXES-NEXT: {{^ *}$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
 
 template <>
 void template_return(int check) {
   if (check < 0) {
     return;
   }
   return;
 }
 // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: redundant return statement
 // CHECK-FIXES: {{^}}  if (check < 0) {{{$}}
 // CHECK-FIXES-NEXT: {{^    return;$}}
 // CHECK-FIXES-NEXT: {{^ *}$}}
+// CHECK-FIXES-NEXT: {{^ *}$}}
 
 template <typename T>
 void template_loop(T end) {
   for (T i = 0; i < end; ++i) {
     continue;
   }
 }
 // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: redundant continue statement