bjoernager/rust
bjoernager/rust
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Auto merge of #96800 - nbdd0121:const, r=nagisa

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Permit `asm_const` and `asm_sym` to reference generic params

Related #96557

These constructs will be allowed:
```rust
fn foofoo<const N: usize>() {}

unsafe fn foo<const N: usize>() {
    asm!("/* {0} */", const N);
    asm!("/* {0} */", const N + 1);
    asm!("/* {0} */", sym foofoo::<N>);
}

fn barbar<T>() {}

unsafe fn bar<T>() {
    asm!("/* {0} */", const std::mem::size_of::<T>());
    asm!("/* {0} */", const std::mem::size_of::<(T, T)>());
    asm!("/* {0} */", sym barbar::<T>);
    asm!("/* {0} */", sym barbar::<(T, T)>);
}
```

`@Amanieu,` I didn't switch inline asms to use `DefKind::InlineAsm`, as I see little value doing that; given that no type inference is needed, it will only make typecking slower and more complex but will have no real gains. I did switch them to follow the same code path as inline asm during symbol resolution, though.
The `error: unconstrained generic constant` you mentioned in #76001 is due to the fact that `to_const` will actually add a wfness obligation to the constant, which we don't need for `asm_const`, so I have that removed.

`@rustbot` label: +A-inline-assembly +F-asm
This commit is contained in:
bors 2022-05-18 15:07:47 +00:00
commit 10d9ecda48
12 changed files with 117 additions and 59 deletions
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4
compiler/rustc_ast/src/visit.rs
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@ -326,7 +326,7 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
ItemKind::ForeignMod(ref foreign_module) => {
walk_list!(visitor, visit_foreign_item, &foreign_module.items);
}
ItemKind::GlobalAsm(ref asm) => walk_inline_asm(visitor, asm),
ItemKind::GlobalAsm(ref asm) => visitor.visit_inline_asm(asm),
ItemKind::TyAlias(box TyAlias { ref generics, ref bounds, ref ty, .. }) => {
visitor.visit_generics(generics);
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
@ -897,7 +897,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
}
ExprKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
ExprKind::Paren(ref subexpression) => visitor.visit_expr(subexpression),
ExprKind::InlineAsm(ref asm) => walk_inline_asm(visitor, asm),
ExprKind::InlineAsm(ref asm) => visitor.visit_inline_asm(asm),
ExprKind::Yield(ref optional_expression) => {
walk_list!(visitor, visit_expr, optional_expression);
}