[clang] [clang-format] Don't align comments over scopes (PR #68743)

[Owen Pan via cfe-commits]

================
@@ -1118,16 +1121,48 @@ void WhitespaceManager::alignTrailingComments() {
       }
     }
 
-    // We don't want to align namespace end comments.
-    const bool DontAlignThisComment =
-        I > 0 && C.NewlinesBefore == 0 &&
-        Changes[I - 1].Tok->is(TT_NamespaceRBrace);
-    if (Style.AlignTrailingComments.Kind == FormatStyle::TCAS_Never ||
-        DontAlignThisComment) {
+    // We don't want to align comments which end a scope, which are here
+    // identified by most closing braces.
+    auto DontAlignThisComment = [](const auto *Tok) {
+      if (Tok->is(tok::semi)) {
+        Tok = Tok->getPreviousNonComment();
+        if (!Tok)
+          return false;
+      }
+      if (Tok->is(tok::r_paren)) {
+        // Back up past the parentheses and a `TT_DoWhile` that may precede.
+        Tok = Tok->MatchingParen;
+        if (!Tok)
+          return false;
+        Tok = Tok->getPreviousNonComment();
+        if (!Tok)
+          return false;
+        if (Tok->is(TT_DoWhile)) {
+          auto Prev = Tok->getPreviousNonComment();
+          if (!Prev) {
+            // A do-while-loop without braces.
+            return Tok->NewlinesBefore > 0;
+          }
----------------
owenca wrote:

```suggestion
          const auto *Prev = Tok->getPreviousNonComment();
          if (!Prev)
            return true;
```
to cover the cases like `/**/ while (i > 0); //`.

https://github.com/llvm/llvm-project/pull/68743