[clang] [clang] Fix crashes when passing VLA to va_arg (PR #119563)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-codegen

Author: 天音あめ (amane-ame)

<details>
<summary>Changes</summary>

Closes #<!-- -->119360.

---
Full diff: https://github.com/llvm/llvm-project/pull/119563.diff


1 Files Affected:

- (modified) clang/lib/CodeGen/CGExprAgg.cpp (+2) 


``````````diff
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 2ad6587089f101..a4111cb65c8b1c 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -2201,6 +2201,8 @@ void CodeGenFunction::EmitAggregateCopy(LValue Dest, LValue Src, QualType Ty,
     // But note that getTypeInfo returns 0 for a VLA.
     if (auto *VAT = dyn_cast_or_null<VariableArrayType>(
             getContext().getAsArrayType(Ty))) {
+      assert(Ty->isVariableArrayType());
+      EmitVariablyModifiedType(Ty);
       QualType BaseEltTy;
       SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr);
       TypeInfo = getContext().getTypeInfoInChars(BaseEltTy);

``````````

</details>


https://github.com/llvm/llvm-project/pull/119563