ahatanak added inline comments.
================
Comment at: clang/lib/Sema/SemaExpr.cpp:5917
if (auto *BE = dyn_cast<BlockExpr>(Arg->IgnoreParenNoopCasts(Context)))
BE->getBlockDecl()->setDoesNotEscape();
----------------
rjmccall wrote:
> We need to be checking that the parameter type is a block pointer type. A
> parameter of a type like `id` or `void*` does not have the enhanced semantics
> of `noescape` for blocks.
>
> The inevitable weird C++ test case is:
>
> ```
> struct NoescapeCtor {
> NoescapeCtor(__attribute__((noescape)) void (^)());
> };
> struct EscapeCtor {
> EscapeCtor(void (^)());
> };
>
> void helper1(NoescapeCtor a);
> void test1() { helper1(^{}); } // <- should be noescape
>
> void helper2(NoescapeCtor &&a);
> void test2() { helper2(^{}); } // <- should be noescape
>
> void helper3(__attribute__((noescape)) EscapeCtor &&a);
> void test3() { helper3(^{}); } // <- should not be noescape
> ```
>
> You should probably also test that calls to function templates behave
> according to the instantiated type of the parameter. I expect that that
> should just fall out from this implementation, which I think only triggers on
> non-dependent calls.
I understand why the blocks should or shouldn't be `noescape` in the C++
example, but I'm not sure I understand the comment about `id` and `void*`.
Do you mean the `DoesNotEscape` bit shouldn't be set in the following example?
```
void helper(__attribute__((noescape)) id);
void test() {
S s;
helper(^{ (void)s; });
}
```
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D101097/new/
https://reviews.llvm.org/D101097
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