[clang][Interp] Fix assertion in InitElem{,Pop} ops

... when the pointer is an unknown size array.
llvm · Mar 4, 2024 · c089fa5 · c089fa5
1 parent 7d55a3b
commit c089fa5
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diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h
@@ -1448,6 +1448,8 @@ template <PrimType Name, class T = typename PrimConv<Name>::T>
 bool InitElem(InterpState &S, CodePtr OpPC, uint32_t Idx) {
   const T &Value = S.Stk.pop<T>();
   const Pointer &Ptr = S.Stk.peek<Pointer>().atIndex(Idx);
+  if (Ptr.isUnknownSizeArray())
+    return false;
   if (!CheckInit(S, OpPC, Ptr))
     return false;
   Ptr.initialize();
@@ -1460,6 +1462,8 @@ template <PrimType Name, class T = typename PrimConv<Name>::T>
 bool InitElemPop(InterpState &S, CodePtr OpPC, uint32_t Idx) {
   const T &Value = S.Stk.pop<T>();
   const Pointer &Ptr = S.Stk.pop<Pointer>().atIndex(Idx);
+  if (Ptr.isUnknownSizeArray())
+    return false;
   if (!CheckInit(S, OpPC, Ptr))
     return false;
   Ptr.initialize();

diff --git a/clang/test/AST/Interp/arrays.cpp b/clang/test/AST/Interp/arrays.cpp
@@ -138,6 +138,8 @@ constexpr int dependent[4] = {
 static_assert(dependent[2] == dependent[0], "");
 static_assert(dependent[3] == dependent[1], "");
 
+union { char x[]; } r = {0};
+
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wc99-extensions"
 #pragma clang diagnostic ignored "-Winitializer-overrides"