[PATCH] D136920: [clang][Interp] Array initialization via CXXConstructExpr

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


================
Comment at: clang/lib/AST/Interp/ByteCodeExprGen.cpp:962-963
+  } else if (const auto *Ctor = dyn_cast<CXXConstructExpr>(Initializer)) {
+    const ArrayType *AT = Ctor->getType()->getAsArrayTypeUnsafe();
+    const auto *CAT = cast<ConstantArrayType>(AT);
+    size_t NumElems = CAT->getSize().getZExtValue();
----------------
This should go through `ASTContext::getConstantArrayType()`. It may also be worth a comment mentioning that VLAs can't have initializers and an unbounded array has known bounds if it has an initializer, as I suspect that's the reason you're not handling either of those here?


================
Comment at: clang/test/AST/Interp/arrays.cpp:188-200
+class A {
+public:
+  int a;
+  constexpr A(int m = 2) : a(10 + m) {}
+};
+class B {
+public:
----------------
I'd like to see a test for when the class ends with a flexible array member (ctor shouldn't be called for that case because we don't know how many trailing objects there will be). That could show up as an unbounded member.

Also, a test case where the ctor will execute UB, to demonstrate we properly diagnose arrays of default-constructed objects.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136920/new/

https://reviews.llvm.org/D136920