[PATCH] D32372: Arrays of unknown bound in constant expressions

[Richard Smith via Phabricator via cfe-commits]

rsmith added a comment.

Thanks, this looks good, just a couple of minor things and then it should be ready to land.

Do you have commit access or will you need someone else to commit this for you?



================
Comment at: lib/AST/ExprConstant.cpp:152
+                           uint64_t &ArraySize, QualType &Type, bool &IsArray,
+                           bool &isUnsizedArray) {
     // This only accepts LValueBases from APValues, and APValues don't support
----------------
Please start variable names with an uppercase letter.


================
Comment at: lib/AST/ExprConstant.cpp:168
+          ArraySize = 0;
+          isUnsizedArray = true;
+        }
----------------
The other 'most derived' paths through here should set this back to `false` (a sized array in a field in an element of an unsized array does not give an unsized array).


================
Comment at: lib/AST/ExprConstant.cpp:1301
     void addUnsizedArray(EvalInfo &Info, QualType ElemTy) {
-      assert(Designator.Entries.empty() && getType(Base)->isPointerType());
-      assert(isBaseAnAllocSizeCall(Base) &&
-             "Only alloc_size bases can have unsized arrays");
-      Designator.FirstEntryIsAnUnsizedArray = true;
       Designator.addUnsizedArrayUnchecked(ElemTy);
     }
----------------
We should call `checkSubobject` here, for cases like:

```
void f(int n) {
  int arr[2][n];
  constexpr int *p = &arr[2][0];
}
```

... which we should reject because `arr[2]` is a one-past-the-end lvalue, so cannot be indexed (we reject this if `n` is instead a constant).


https://reviews.llvm.org/D32372