[PATCH] D144164: [clang][Interp] Handle PtrMemOps

[Timm Bäder via Phabricator via cfe-commits]

tbaeder marked an inline comment as done.
tbaeder added inline comments.


================
Comment at: clang/lib/AST/Interp/ByteCodeExprGen.cpp:213-214
 
+  if (BO->isPtrMemOp())
+    return this->visit(RHS);
+
----------------
aaron.ballman wrote:
> tbaeder wrote:
> > aaron.ballman wrote:
> > > Do we need similar changes for unary operators, pointer arithmetic operators, etc?
> > In what case would we need similar changes for those?
> I could use some more explanation for the changes here then; I thought this was to support overloaded binary operators. e.g.,
> ```
> struct S {
>   virtual constexpr int operator+(S s) const {
>     return 12;
>   }
> };
> 
> struct T : S {
>   constexpr int operator+(S s) const override {
>     return 100;
>   }
> };
> 
> constexpr T t1, t2;
> constexpr const S &s1 = t1, &s2 = t2;
> constexpr const S s3, s4;
> static_assert(s1 + s2 == 100);
> static_assert(s3 + s4 == 12);
> ```
For this snippet from the tests:
```
  constexpr S s;
  constexpr decltype(&S::func) foo = &S::func;
  constexpr int value = (s.*foo)();
  static_assert(value == 1);
```
`value` is:

```
VarDecl 0x6210000a5180 <array.cpp:131:3, col:34> col:17 value 'const int' constexpr cinit
`-CXXMemberCallExpr 0x6210000a52d8 <col:25, col:34> 'int'
  `-ParenExpr 0x6210000a52b0 <col:25, col:32> '<bound member function type>'
    `-BinaryOperator 0x6210000a5288 <col:26, col:29> '<bound member function type>' '.*'
      |-DeclRefExpr 0x6210000a51f0 <col:26> 'const S':'const S' lvalue Var 0x6210000a0cf8 's' 'const S':'const S'
      `-ImplicitCastExpr 0x6210000a5268 <col:29> 'decltype(&S::func)':'int (S::*)() const' <LValueToRValue>
        `-DeclRefExpr 0x6210000a5240 <col:29> 'const decltype(&S::func)':'int (S::*const)() const' lvalue Var 0x6210000a0fc0 'foo' 'const decltype(&S::func)':'int (S::*const)() const' non_odr_use_constant
```

notice the `BinaryOperator`.


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  https://reviews.llvm.org/D144164/new/

https://reviews.llvm.org/D144164