[clang] [Clang] [C++26] Expansion Statements (Part 1: AST) (PR #169680)

[Erich Keane via cfe-commits]

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@@ -204,6 +204,13 @@ void CodeGenFunction::EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs) {
   case Stmt::CXXForRangeStmtClass:
     EmitCXXForRangeStmt(cast<CXXForRangeStmt>(*S), Attrs);
     break;
+  case Stmt::CXXEnumeratingExpansionStmtPatternClass:
+  case Stmt::CXXIteratingExpansionStmtPatternClass:
+  case Stmt::CXXDestructuringExpansionStmtPatternClass:
+  case Stmt::CXXDependentExpansionStmtPatternClass:
+    llvm_unreachable("unexpanded expansion statements should not be emitted");
+  case Stmt::CXXExpansionStmtInstantiationClass:
+    llvm_unreachable("Todo");
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erichkeane wrote:

I think we have an error mechanism for this?  Also, it should be `TODO`, capital makes these sorts of things greppable.

https://github.com/llvm/llvm-project/pull/169680