Rollup merge of #102641 - eholk:dyn-star-box, r=compiler-errors
Support casting boxes to dyn* Boxes have a pointer type at codegen time which LLVM does not allow to be transparently converted to an integer. Work around this by inserting a `ptrtoint` instruction if the argument is a pointer. r? ``@compiler-errors`` Fixes #102427
This commit is contained in:
commit
6755c2a89d
@ -14,6 +14,7 @@ use rustc_middle::ty::cast::{CastTy, IntTy};
|
||||
use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
|
||||
use rustc_middle::ty::{self, adjustment::PointerCast, Instance, Ty, TyCtxt};
|
||||
use rustc_span::source_map::{Span, DUMMY_SP};
|
||||
use rustc_target::abi::Size;
|
||||
|
||||
impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
|
||||
#[instrument(level = "trace", skip(self, bx))]
|
||||
@ -285,6 +286,14 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
|
||||
bug!("Only valid to do a DynStar cast into a DynStar type")
|
||||
};
|
||||
let vtable = get_vtable(bx.cx(), source.ty(self.mir, bx.tcx()), trait_ref);
|
||||
let vtable = bx.pointercast(vtable, bx.cx().type_ptr_to(bx.cx().type_isize()));
|
||||
// FIXME(dyn-star): this is probably not the best way to check if this is
|
||||
// a pointer, and really we should ensure that the value is a suitable
|
||||
// pointer earlier in the compilation process.
|
||||
let data = match operand.layout.pointee_info_at(bx.cx(), Size::ZERO) {
|
||||
Some(_) => bx.ptrtoint(data, bx.cx().type_isize()),
|
||||
None => data,
|
||||
};
|
||||
OperandValue::Pair(data, vtable)
|
||||
}
|
||||
mir::CastKind::Pointer(
|
||||
|
17
src/test/ui/dyn-star/box.rs
Normal file
17
src/test/ui/dyn-star/box.rs
Normal file
@ -0,0 +1,17 @@
|
||||
// run-pass
|
||||
// compile-flags: -C opt-level=0
|
||||
|
||||
#![feature(dyn_star)]
|
||||
#![allow(incomplete_features)]
|
||||
|
||||
use std::fmt::Display;
|
||||
|
||||
fn make_dyn_star() -> dyn* Display {
|
||||
Box::new(42) as dyn* Display
|
||||
}
|
||||
|
||||
fn main() {
|
||||
let x = make_dyn_star();
|
||||
|
||||
println!("{x}");
|
||||
}
|
Loading…
x
Reference in New Issue
Block a user