[clang-tidy] Fix handling of methods with try-statement as a body in modernize-use-override

[idlecode]

Summary

Fix generated by modernize-use-override caused syntax error when method
used try-statement as a body. override keyword was inserted after last
declaration token which happened to be a try keyword.

This fixes PR27119.

[alexfh]

LG

clang-tidy/modernize/UseOverrideCheck.cpp

if (!HasFinal && !HasOverride) {
     }
 
     if (InsertLoc.isInvalid() && Method->doesThisDeclarationHaveABody() &&
         Method->getBody() && !Method->isDefaulted()) {
       // For methods with inline definition, add the override keyword at the
       // end of the declaration of the function, but prefer to put it on the
       // same line as the declaration if the beginning brace for the start of
       // the body falls on the next line.
-      Token LastNonCommentToken;
-      for (Token T : Tokens) {
-        if (!T.is(tok::comment)) {
-          LastNonCommentToken = T;
-        }
-      }
-      InsertLoc = LastNonCommentToken.getEndLoc();
       ReplacementText = " override";
+      auto LastTokenIter = std::prev(Tokens.end());
+      // When try statement is used instead of compound statement as
+      // method body - insert override keyword before it.
+      if (LastTokenIter->is(tok::kw_try))
+        LastTokenIter = std::prev(LastTokenIter);
+      InsertLoc = LastTokenIter->getEndLoc();
     }
 
     if (!InsertLoc.isValid()) {
       // For declarations marked with "= 0" or "= [default|delete]", the end
       // location will point until after those markings. Therefore, the override
       // keyword shouldn't be inserted at the end, but before the '='.
       if (Tokens.size() > 2 && (GetText(Tokens.back(), Sources) == "0" ||
                                 Tokens.back().is(tok::kw_default) ||

test/clang-tidy/modernize-use-override.cpp

 template <int I>
 struct MembersOfSpecializations : public Base2 {
   void a() override;
   // CHECK-MESSAGES-NOT: warning:
   // CHECK-FIXES: {{^}}  void a() override;
 };
 template <> void MembersOfSpecializations<3>::a() {}
 void ff() { MembersOfSpecializations<3>().a(); };
+
+// In case try statement is used as a method body,
+// make sure that override fix is placed before try keyword.
+struct TryStmtAsBody : public Base {
+  void a() try
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: annotate this
+  // CHECK-FIXES: {{^}}  void a() override try
+  { b(); } catch(...) { c(); }
+
+  virtual void d() try
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: prefer using
+  // CHECK-FIXES: {{^}}  void d() override try
+  { e(); } catch(...) { f(); }
+};