Matthias Krüger 6d7d366fd3 Rollup merge of #141260 - LuigiPiucco:volatile-null, r=RalfJung ...

Allow volatile access to non-Rust memory, including address 0

This PR relaxes the `ub_check` in the `read_volatile`/`write_volatile` pointer operations to allow passing null. This is needed to support processors which hard-code peripheral registers on address 0, like the AVR chip ATtiny1626. LLVM understands this as valid and handles it correctly, as tested in my [PR to add a note about it](6387c82255 (diff-81bbb96298c32fa901beb82ab3b97add27a410c01d577c1f8c01000ed2055826)) (rustc generates the same LLVM IR as expected there when this PR is applied, and consequently the same AVR assembly).

Follow-up and implementation of the discussions in:
- https://internals.rust-lang.org/t/pre-rfc-conditionally-supported-volatile-access-to-address-0/12881/7
- https://github.com/Rahix/avr-device/pull/185;
- [#t-lang > Adding the possibility of volatile access to address 0](https://rust-lang.zulipchat.com/#narrow/channel/213817-t-lang/topic/Adding.20the.20possibility.20of.20volatile.20access.20to.20address.200/with/513303502)
- https://discourse.llvm.org/t/rfc-volatile-access-to-non-dereferenceable-memory-may-be-well-defined/86303

r? ````@RalfJung````

Also fixes https://github.com/rust-lang/unsafe-code-guidelines/issues/29 (about as good as it'll get, null will likely never be a "normal" address in Rust)

2025-07-20 08:56:05 +02:00

..

early

Implement resolver warnings about reexporting private dependencies

2025-07-15 15:44:25 +02:00

nonstandard_style

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types

added error for invalid char cast

2025-07-10 15:44:36 +05:00

async_closures.rs

Move some Map methods onto TyCtxt.

2025-02-17 13:21:02 +11:00

async_fn_in_trait.rs

…

autorefs.rs

setup CI and tidy to use typos for spellchecking and fix few typos

2025-07-03 10:51:06 +03:00

builtin.rs

Rollup merge of #144008 - anatawa12:fix-double-negations, r=compiler-errors

2025-07-18 04:27:53 +02:00

context.rs

Add track_caller attributes to trace origin of Clippy lints

2025-07-02 11:50:25 +02:00

dangling.rs

Port #[rustc_as_ptr] to the new attribute system

2025-06-16 18:13:27 +03:00

default_could_be_derived.rs

Port #[automatically_derived] to the new attribute parsing infrastructure

2025-07-12 17:48:50 +02:00

deref_into_dyn_supertrait.rs

Retire hir::*ItemRef.

2025-07-13 13:50:01 +00:00

drop_forget_useless.rs

Move methods from Map to TyCtxt, part 3.

2025-02-21 14:31:09 +11:00

early.rs

early linting: avoid redundant calls to check_id

2025-06-12 19:01:19 +08:00

enum_intrinsics_non_enums.rs

Fold visit into ty

2025-03-15 06:34:36 +00:00

errors.rs

Move eager translation to a method on Diag

2025-04-16 21:38:59 -04:00

expect.rs

Reduce uses of hir_crate.

2025-06-18 15:46:19 +00:00

for_loops_over_fallibles.rs

Use span before macro expansion in lint for-loops-over-falibles

2025-05-08 21:17:33 +08:00

foreign_modules.rs

Port #[link_name] to the new attribute parsing infrastructure

2025-06-28 13:53:37 +02:00

if_let_rescope.rs

setup CI and tidy to use typos for spellchecking and fix few typos

2025-07-03 10:51:06 +03:00

impl_trait_overcaptures.rs

Same for types

2025-07-04 18:26:09 +00:00

internal.rs

Implement lint against direct uses of rustc_type_ir in compiler crates

2025-06-18 16:01:41 +02:00

invalid_from_utf8.rs

Introduce ByteSymbol.

2025-06-30 20:42:27 +10:00

late.rs

Introduce ByteSymbol.

2025-06-30 20:42:27 +10:00

let_underscore.rs

Rustfmt

2025-02-08 22:12:13 +00:00

levels.rs

Port #[automatically_derived] to the new attribute parsing infrastructure

2025-07-12 17:48:50 +02:00

lib.rs

Reword mismatched-lifetime-syntaxes text based on feedback

2025-07-14 09:52:58 -04:00

lifetime_syntax.rs

Reword mismatched-lifetime-syntaxes text based on feedback

2025-07-14 09:52:58 -04:00

lints.rs

Rollup merge of #143914 - shepmaster:mismatched-lifetime-syntaxes-rewording, r=traviscross,jieyouxu

2025-07-17 10:41:47 +02:00

macro_expr_fragment_specifier_2024_migration.rs

Rename RefTokenTreeCursor.

2024-12-18 10:39:07 +11:00

map_unit_fn.rs

Stop using Key trait randomly

2025-07-05 18:37:11 +00:00

multiple_supertrait_upcastable.rs

parse const trait Trait

2025-07-17 18:06:26 +08:00

non_ascii_idents.rs

Make LevelAndSource a struct

2025-04-03 09:17:55 +00:00

non_fmt_panic.rs

Use Option<Symbol> in panic_call.

2025-03-25 16:14:27 +11:00

non_local_def.rs

Reorder fields in hir::ItemKind variants.

2025-05-30 02:23:20 +10:00

nonstandard_style.rs

Allow Early stage to emit errors

2025-07-15 09:01:03 +02:00

noop_method_call.rs

Rustfmt

2025-02-08 22:12:13 +00:00

opaque_hidden_inferred_bound.rs

Squash fold into ty

2025-03-15 06:34:36 +00:00

pass_by_value.rs

Port #[rustc_pass_by_value] to the new attribute system

2025-07-04 00:07:56 +03:00

passes.rs

Introduce ByteSymbol.

2025-06-30 20:42:27 +10:00

precedence.rs

…

ptr_nulls.rs

fix: don't panic on volatile access to null

2025-07-18 13:41:34 -03:00

redundant_semicolon.rs

Dont suggest remove semi inside macro expansion for redundant semi lint

2025-06-18 00:36:51 +08:00

reference_casting.rs

setup CI and tidy to use typos for spellchecking and fix few typos

2025-07-03 10:51:06 +03:00

shadowed_into_iter.rs

Use is_lang_item and as_lang_item instead of handrolling their logic

2025-04-22 11:02:37 +00:00

static_mut_refs.rs

Fix error message for static references or mutable references

2025-04-26 14:48:30 +09:00

tests.rs

update cfg(bootstrap)

2025-01-08 21:26:39 +01:00

traits.rs

Rustfmt

2025-02-08 22:12:13 +00:00

transmute.rs

Make UNNECESSARY_TRANSMUTES into a HIR lint

2025-05-25 15:57:48 +00:00

types.rs

improve lint doc text

2025-07-09 09:08:56 +00:00

unit_bindings.rs

Rustfmt

2025-02-08 22:12:13 +00:00

unqualified_local_imports.rs

Overhaul UsePath.

2025-06-03 08:23:21 +10:00

unused.rs

Remove uncessary parens in closure body with unused lint

2025-07-10 09:25:56 +08:00

utils.rs

Uplift clippy::invalid_null_ptr_usage as invalid_null_arguments

2025-03-30 19:33:15 +02:00