Reject incomplete types and vlas

Author: Sirraide

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -3702,6 +3702,10 @@ def err_conflicting_codeseg_attribute : Error<
 def warn_duplicate_codeseg_attribute : Warning<
   "duplicate code segment specifiers">, InGroup<Section>;
 
+def err_expansion_stmt_vla : Error<
+  "cannot expand variable length array type %0">;
+def err_expansion_stmt_incomplete : Error<
+  "cannot expand expression of incomplete type %0">;
 def err_expansion_stmt_lambda : Error<
   "cannot expand lambda closure type">;
 

clang/lib/Sema/SemaExpand.cpp

@@ -287,6 +287,17 @@ StmtResult Sema::BuildNonEnumeratingCXXExpansionStmtPattern(
         RParenLoc);
   }
 
+  if (RequireCompleteType(ExpansionInitializer->getExprLoc(),
+                          ExpansionInitializer->getType(),
+                          diag::err_expansion_stmt_incomplete))
+    return StmtError();
+
+  if (ExpansionInitializer->getType()->isVariableArrayType()) {
+    Diag(ExpansionInitializer->getExprLoc(), diag::err_expansion_stmt_vla)
+        << ExpansionInitializer->getType();
+    return StmtError();
+  }
+
   // Otherwise, if it can be an iterating expansion statement, it is one.
   DeclRefExpr *Index = BuildIndexDRE(*this, ESD);
   IterableExpansionStmtData Data = TryBuildIterableExpansionStmtInitializer(