[clang] [clang][Parser] Warn when the body of expansion statement is not a compound statement (PR #209229)

[Corentin Jabot via cfe-commits]

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@@ -2379,6 +2383,9 @@ StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc,
       return StmtError();
     }
 
+    if (!isa<CompoundStmt>(Body.get()) || BodyStartsWithSquare)
+      Diag(BodyBeginLoc, diag::ext_expansion_stmt_missing_braces);
+
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cor3ntin wrote:

although, you could check for `AttributedStmt`, i think this would be cleaner than looking for a `[`

https://github.com/llvm/llvm-project/pull/209229