[llvm-branch-commits] [clang] [Clang] [C++26] Expansion Statements (Part 3: Enumerating Expansion Statements) (PR #169682)

[via llvm-branch-commits]

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@@ -64,13 +103,144 @@ StmtResult Sema::ActOnCXXExpansionStmtPattern(
     Expr *ExpansionInitializer, SourceLocation LParenLoc,
     SourceLocation ColonLoc, SourceLocation RParenLoc,
     ArrayRef<MaterializeTemporaryExpr *> LifetimeExtendTemps) {
+  if (!ExpansionInitializer || !ExpansionVarStmt)
+    return StmtError();
+
+  assert(CurContext->isExpansionStmt());
+  auto *DS = cast<DeclStmt>(ExpansionVarStmt);
+  if (!DS->isSingleDecl()) {
+    Diag(DS->getBeginLoc(), diag::err_type_defined_in_for_range);
+    return StmtError();
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Sirraide wrote:

Hmm, well actually that diagnostic says ‘types may not be defined in a for range declaration’, and in the standard, _for-range-declaration_ is a grammar production that is also used for expansion statements; we can change to ‘in the declaration of an expansion variable’ maybe, but I’m not sure if that’s better

https://github.com/llvm/llvm-project/pull/169682