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2025-03-21Rollup merge of #138713 - RalfJung:memory-hook-pointers, r=oli-obkMatthias Krüger-2/+23
interpret memory access hooks: also pass through the Pointer used for the access In some ongoing work on the Miri side, we need the absolute address that the memory access occurred at. That is non-trivial to obtain since we don't have an `ecx`. So pass through the `Pointer` used for the access, which contains the address, and which is available everywhere we are calling these hooks. r? `@oli-obk`
2025-03-20interpret memory access hooks: also pass through the Pointer used for the accessRalf Jung-2/+23
2025-03-20Use def_path_str for def id arg in UnsupportedOpInfoMichael Goulet-3/+4
2025-03-15Stop relying on rustc_type_ir in non-type-system cratesMichael Goulet-19/+14
2025-03-13Rollup merge of #138417 - RalfJung:interpret-cleanup, r=oli-obkMatthias Krüger-41/+25
minor interpreter cleanups - remove the `eval_inline_asm` hook that `@saethlin` added; the usage never materialized and he agreed with removing it - I tried merging `init_alloc_extra` and `adjust_global_allocation` and it didn't work; leave a comment as to why. Also, make the allocation code path a bit more clear by renaming `init_alloc_extra` to `init_local_allocation`. r? `@oli-obk`
2025-03-13Auto merge of #138416 - Manishearth:rollup-fejor9p, r=Manishearthbors-1/+1
Rollup of 12 pull requests Successful merges: - #134076 (Stabilize `std::io::ErrorKind::InvalidFilename`) - #137504 (Move methods from Map to TyCtxt, part 4.) - #138175 (Support rmeta inputs for --crate-type=bin --emit=obj) - #138259 (Disentangle `ForwardGenericParamBan` and `ConstParamTy` ribs) - #138280 (fix ICE in pretty-printing `global_asm!`) - #138318 (Rustdoc: remove a bunch of `@ts-expect-error` from main.js) - #138331 (Use `RUSTC_LINT_FLAGS` more) - #138357 (merge `TypeChecker` and `TypeVerifier`) - #138394 (remove unnecessary variant) - #138403 (Delegation: one more ICE fix for `MethodCall` generation) - #138407 (Delegation: reject C-variadics) - #138409 (Use sa_sigaction instead of sa_union.__su_sigaction for AIX) r? `@ghost` `@rustbot` modify labels: rollup
2025-03-12minor interpret cleanupsRalf Jung-41/+25
2025-03-12Auto merge of #138414 - matthiaskrgr:rollup-9ablqdb, r=matthiaskrgrbors-1/+0
Rollup of 7 pull requests Successful merges: - #137314 (change definitely unproductive cycles to error) - #137701 (Convert `ShardedHashMap` to use `hashbrown::HashTable`) - #138269 (uefi: fs: Implement FileType, FilePermissions and FileAttr) - #138331 (Use `RUSTC_LINT_FLAGS` more) - #138345 (Some autodiff cleanups) - #138387 (intrinsics: remove unnecessary leading underscore from argument names) - #138390 (fix incorrect tracing log) r? `@ghost` `@rustbot` modify labels: rollup
2025-03-12Rollup merge of #138331 - nnethercote:use-RUSTC_LINT_FLAGS-more, ↵Manish Goregaokar-1/+0
r=onur-ozkan,jieyouxu Use `RUSTC_LINT_FLAGS` more An alternative to the failed #138084. Fixes #138106. r? `````@jieyouxu`````
2025-03-12Rollup merge of #137504 - nnethercote:remove-Map-4, r=ZalatharManish Goregaokar-1/+1
Move methods from Map to TyCtxt, part 4. A follow-up to https://github.com/rust-lang/rust/pull/137350. r? ```@Zalathar```
2025-03-12Rollup merge of #138331 - nnethercote:use-RUSTC_LINT_FLAGS-more, ↵Matthias Krüger-1/+0
r=onur-ozkan,jieyouxu Use `RUSTC_LINT_FLAGS` more An alternative to the failed #138084. Fixes #138106. r? ````@jieyouxu````
2025-03-12Auto merge of #138083 - nnethercote:rm-NtItem-NtStmt, r=petrochenkovbors-0/+1
Remove `NtItem` and `NtStmt` Another piece of #124141. r? `@petrochenkov`
2025-03-12Move methods from `Map` to `TyCtxt`, part 4.Nicholas Nethercote-1/+1
Continuing the work from #137350. Removes the unused methods: `expect_variant`, `expect_field`, `expect_foreign_item`. Every method gains a `hir_` prefix.
2025-03-11miri native_calls: ensure we actually expose *mutable* provenance to the ↵Ralf Jung-0/+4
memory FFI can access
2025-03-11Remove `#![warn(unreachable_pub)]` from all `compiler/` crates.Nicholas Nethercote-1/+0
It's no longer necessary now that `-Wunreachable_pub` is being passed.
2025-03-10Revert "Use workspace lints for crates in `compiler/` #138084"许杰友 Jieyou Xu (Joe)-0/+1
Revert <https://github.com/rust-lang/rust/pull/138084> to buy time to consider options that avoids breaking downstream usages of cargo on distributed `rustc-src` artifacts, where such cargo invocations fail due to inability to inherit `lints` from workspace root manifest's `workspace.lints` (this is only valid for the source rust-lang/rust workspace, but not really the distributed `rustc-src` artifacts). This breakage was reported in <https://github.com/rust-lang/rust/issues/138304>. This reverts commit 48caf81484b50dca5a5cebb614899a3df81ca898, reversing changes made to c6662879b27f5161e95f39395e3c9513a7b97028.
2025-03-09Rollup merge of #138084 - nnethercote:workspace-lints, r=jieyouxuMatthias Krüger-1/+0
Use workspace lints for crates in `compiler/` This is nicer and hopefully less error prone than specifying lints via bootstrap. r? ``@jieyouxu``
2025-03-08Remove `#![warn(unreachable_pub)]` from all `compiler/` crates.Nicholas Nethercote-1/+0
(Except for `rustc_codegen_cranelift`.) It's no longer necessary now that `unreachable_pub` is in the workspace lints.
2025-03-07Pass `Option<Symbol>` to `def_path_data`/`create_def` methods.Nicholas Nethercote-1/+1
It's clearer than using `kw::Empty` to mean `None`.
2025-03-07Increase recursion_limit in numerous crates.Nicholas Nethercote-0/+1
This is temporarily needed for `x doc compiler` to work. They can be removed once the `Nonterminal` is removed (#124141).
2025-03-06Rollup merge of #137802 - RalfJung:miri-native-call-exposed, r=oli-obkMichael Goulet-10/+5
miri native-call support: all previously exposed provenance is accessible to the callee When Miri invokes a native C function, the memory C can access needs to be "prepared": to avoid false positives, we need to consider all that memory initialized, and we need to consider it to have arbitrary provenance. So far we did this for all pointers passed to C, but not for pointers that were exposed already before the native call. This PR adjusts the logic so that we now "prepare" all memory that has ever been exposed. This fixes cases such as: - cast a pointer to integer, send that integer to C, and access the memory there (`test_pass_ptr_as_int`) - send a pointer to some memory to C, which stores it somewhere; then in Rust store another pointer in that memory, and access that via C (`test_pass_ptr_via_previously_shared_mem`) r? `````@oli-obk`````
2025-03-01Rollup merge of #137804 - RalfJung:backend-repr-simd-vector, r=workingjubileeMatthias Krüger-2/+2
rename BackendRepr::Vector → SimdVector For many Rustaceans, "vector" does not imply "SIMD", so let's be more clear in this type that is used pervasively in the compiler. r? `@workingjubilee`
2025-03-01Rollup merge of #136503 - estebank:const-panic, r=RalfJungMatthias Krüger-10/+46
Tweak output of const panic diagnostic ### Shorten span of panic failures in const context Previously, we included a redundant prefix on the panic message and a postfix of the location of the panic. The prefix didn't carry any additional information beyond "something failed", and the location of the panic is redundant with the diagnostic's span, which gets printed out even if its code is not shown. ``` error[E0080]: evaluation of constant value failed --> $DIR/assert-type-intrinsics.rs:11:9 | LL | MaybeUninit::<!>::uninit().assume_init(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ panic: aborted execution: attempted to instantiate uninhabited type `!` ``` ``` error[E0080]: evaluation of `Fail::<i32>::C` failed --> $DIR/collect-in-dead-closure.rs:9:19 | LL | const C: () = panic!(); | ^^^^^^^^ explicit panic | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` ``` error[E0080]: evaluation of constant value failed --> $DIR/uninhabited.rs:87:9 | LL | assert!(false); | ^^^^^^^^^^^^^^ assertion failed: false | = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info) ``` ### Remove duplicated span from const eval frame list When the primary span for a const error is the same as the first frame in the const error report, skip it. ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ the failure occurred here = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ note: inside `_CONST` --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) note: erroneous constant encountered --> $DIR/issue-88434-removal-index-should-be-less.rs:3:23 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^^ ``` r? ``@oli-obk``
2025-02-28Shorten span of panic failures in const contextEsteban Küber-10/+46
Previously, we included a redundant prefix on the panic message and a postfix of the location of the panic. The prefix didn't carry any additional information beyond "something failed", and the location of the panic is redundant with the diagnostic's span, which gets printed out even if its code is not shown. ``` error[E0080]: evaluation of constant value failed --> $DIR/assert-type-intrinsics.rs:11:9 | LL | MaybeUninit::<!>::uninit().assume_init(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation panicked: aborted execution: attempted to instantiate uninhabited type `!` ``` ``` error[E0080]: evaluation of `Fail::<i32>::C` failed --> $DIR/collect-in-dead-closure.rs:9:19 | LL | const C: () = panic!(); | ^^^^^^^^ evaluation panicked: explicit panic | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` ``` error[E0080]: evaluation of constant value failed --> $DIR/uninhabited.rs:41:9 | LL | assert!(false); | ^^^^^^^^^^^^^^ evaluation panicked: assertion failed: false | = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info) ``` --- When the primary span for a const error is the same as the first frame in the const error report, skip it. ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ evaluation panicked: explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ the failure occurred here = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ note: inside `_CONST` --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` --- Revert order of constant evaluation errors Point at the code the user wrote first and std functions last. ``` error[E0080]: evaluation of constant value failed --> $DIR/const-errs-dont-conflict-103369.rs:5:25 | LL | impl ConstGenericTrait<{my_fn(1)}> for () {} | ^^^^^^^^ evaluation panicked: Some error occurred | note: called from `my_fn` --> $DIR/const-errs-dont-conflict-103369.rs:10:5 | LL | panic!("Some error occurred"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/const-errs-dont-conflict-103369.rs:10:5 | LL | panic!("Some error occurred"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Some error occurred | note: called from `<() as ConstGenericTrait<{my_fn(1)}>>::{constant#0}` --> $DIR/const-errs-dont-conflict-103369.rs:5:25 | LL | impl ConstGenericTrait<{my_fn(1)}> for () {} | ^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ```
2025-02-28rename BackendRepr::Vector → SimdVectorRalf Jung-2/+2
2025-02-28miri native-call support: all previously exposed provenance is accessible to ↵Ralf Jung-10/+5
the callee
2025-02-27require trait impls to have matching const stabilities as the traitsDeadbeef-0/+5
2025-02-25Teach structured errors to display short `Ty`Esteban Küber-5/+5
Make it so that every structured error annotated with `#[derive(Diagnostic)]` that has a field of type `Ty<'_>`, the printing of that value into a `String` will look at the thread-local storage `TyCtxt` in order to shorten to a length appropriate with the terminal width. When this happen, the resulting error will have a note with the file where the full type name was written to. ``` error[E0618]: expected function, found `((..., ..., ..., ...), ..., ..., ...)`` --> long.rs:7:5 | 6 | fn foo(x: D) { //~ `x` has type `(... | - `x` has type `((..., ..., ..., ...), ..., ..., ...)` 7 | x(); //~ ERROR expected function, found `(... | ^-- | | | call expression requires function | = note: the full name for the type has been written to 'long.long-type-14182675702747116984.txt' = note: consider using `--verbose` to print the full type name to the console ```
2025-02-24Introduce new-style attribute parsers for several attributesJana Dönszelmann-2/+4
note: compiler compiles but librustdoc and clippy don't
2025-02-22Greatly simplify lifetime captures in edition 2024Michael Goulet-2/+2
2025-02-22Fix binding mode problemsMichael Goulet-6/+4
2025-02-20fine-tune commentRalf Jung-6/+5
2025-02-20Remove `BackendRepr::Uninhabited`, replaced with an `uninhabited: bool` ↵Zachary S-12/+14
field in `LayoutData`. Also update comments that refered to BackendRepr::Uninhabited.
2025-02-20Rollup merge of #135296 - lukas-code:dyn-leak-check, r=compiler-errorsMatthias Krüger-56/+14
interpret: adjust vtable validity check for higher-ranked types ## What Transmuting between trait objects where a generic argument or associated type only differs in bound regions (not bound at or above the trait object's binder) is now UB. For example * transmuting between `&dyn Trait<for<'a> fn(&'a u8)>` and `&dyn Trait<fn(&'static u8)>` is UB. * transmuting between `&dyn Trait<Assoc = for<'a> fn(&'a u8)>` and `&dyn Trait<Assoc = fn(&'static u8)>` is UB. * transmuting between `&dyn Trait<for<'a> fn(&'a u8) -> (&'a u8, &'static u8)>` and `&dyn Trait<for<'a> fn(&'a u8) -> (&'static u8, &'a u8)>` is UB. Transmuting between subtypes (in either direction) is still allowed, which means that bound regions that are bound at or above the trait object's binder can still be changed: * transmuting between `&dyn for<'a> Trait<fn(&'a u8)>` and `&dyn for Trait<fn(&'static u8)>` is fine. * transmuting between `&dyn for<'a> Trait<dyn Trait<fn(&'a u8)>>` and `&dyn for Trait<dyn Trait<fn(&'static u8)>>` is fine. ## Why Very similar to https://github.com/rust-lang/rust/issues/120217 and https://github.com/rust-lang/rust/issues/120222, changing a trait object's generic argument to a type that only differs in bound regions can still affect the vtable layout and lead to segfaults at runtime (for an example see `src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.rs`). Since we already already require that the trait object predicates must be equal modulo bound regions, it is only natural to extend this check to also require type equality considering bound regions. However, it also makes sense to allow transmutes between a type and a subtype thereof. For example `&dyn for<'a> Trait<&'a u8>` is a subtype of `&dyn Trait<&'static ()>` and they are guaranteed to have the same vtable, so it makes sense to allow this transmute. So that's why bound lifetimes that are bound to the trait object itself are treated as free lifetime for the purpose of this check. Note that codegen already relies on the property that subtyping cannot change the the vtable and this is asserted here (note the leak check): https://github.com/rust-lang/rust/blob/251206c27b619ccf3a08e2ac4c525dc343f08492/compiler/rustc_codegen_ssa/src/base.rs#L106-L153 Furthermore, we allow some pointer-to-pointer casts like `*const dyn for<'a> Trait<&'a u8>` to `*const Wrapper<dyn Trait<&'static u8>>` that instantiate the trait object binder and are currently lowered to a single pointer-to-pointer cast in MIR (`CastKind::PtrToPtr`) and *not* an unsizing coercion (`CastKind::PointerCoercion(Unsize)`), so the current MIR lowering of these would be UB if we didn't allow subtyping transmutes. --- fixes https://github.com/rust-lang/rust/issues/135230 cc `@rust-lang/opsem` r? `@compiler-errors` for the implementation
2025-02-18Move methods from `Map` to `TyCtxt`, part 2.Nicholas Nethercote-1/+1
Continuing the work started in #136466. Every method gains a `hir_` prefix, though for the ones that already have a `par_` or `try_par_` prefix I added the `hir_` after that.
2025-02-15add a doc commentRalf Jung-0/+1
2025-02-15made check_argument_compat publicgeetanshjuneja-1/+1
2025-02-13Auto merge of #136593 - lukas-code:ty-value-perf, r=oli-obkbors-27/+21
valtree performance tuning Summary: This PR makes type checking of code with many type-level constants faster. After https://github.com/rust-lang/rust/pull/136180 was merged, we observed a small perf regression (https://github.com/rust-lang/rust/pull/136318#issuecomment-2635562821). This happened because that PR introduced additional copies in the fast reject code path for consts, which is very hot for certain crates: https://github.com/rust-lang/rust/blob/6c1d960d88dd3755548b3818630acb63fa98187e/compiler/rustc_type_ir/src/fast_reject.rs#L486-L487 This PR improves the performance again by properly interning the valtrees so that copying and comparing them becomes faster. This will become especially useful with `feature(adt_const_params)`, so the fast reject code doesn't have to do a deep compare of the valtrees. Note that we can't just compare the interned consts themselves in the fast reject, because sometimes `'static` lifetimes in the type are be replaced with inference variables (due to canonicalization) on one side but not the other. A less invasive alternative that I considered is simply avoiding copies introduced by https://github.com/rust-lang/rust/pull/136180 and comparing the valtrees it in-place (see commit: https://github.com/rust-lang/rust/commit/9e91e50ac5920f0b9b4a3b1e0880c85336ba5c64 / perf results: https://github.com/rust-lang/rust/pull/136593#issuecomment-2642303245), however that was still measurably slower than interning. There are some minor regressions in secondary benchmarks: These happen due to changes in memory allocations and seem acceptable to me. The crates that make heavy use of valtrees show no significant changes in memory usage.
2025-02-13simplify valtree branches constructionLukas Markeffsky-15/+12
2025-02-13intern valtreesLukas Markeffsky-14/+11
2025-02-12Auto merge of #135994 - 1c3t3a:rename-unsafe-ptr, r=oli-obkbors-4/+4
Rename rustc_middle::Ty::is_unsafe_ptr to is_raw_ptr The wording unsafe pointer is less common and not mentioned in a lot of places, instead this is usually called a "raw pointer". For the sake of uniformity, we rename this method. This came up during the review of https://github.com/rust-lang/rust/pull/134424. r? `@Noratrieb`
2025-02-11Rollup merge of #136833 - workingjubilee:let-the-impossible-be-impossible, ↵Matthias Krüger-13/+0
r=compiler-errors compiler: die immediately instead of handling unknown target codegen We cannot produce anything useful if asked to compile unknown targets. We should handle the error immediately at the point of discovery instead of propagating it upward, and preferably in the simplest way: Die. This allows cleaning up our "error-handling" spread across 5 crates.
2025-02-11fix ensure_monomorphic_enoughLukas Markeffsky-41/+3
2025-02-10compiler: die immediately instead of handling unknown target codegenJubilee Young-13/+0
We cannot produce anything useful if asked to compile unknown targets. We should handle the error immediately at the point of discovery instead of propagating it upward, and preferably in the simplest way: Die. This allows cleaning up our "error-handling" spread across 5 crates.
2025-02-10Rename rustc_middle::Ty::is_unsafe_ptr to is_raw_ptrBastian Kersting-4/+4
The wording unsafe pointer is less common and not mentioned in a lot of places, instead this is usually called a "raw pointer". For the sake of uniformity, we rename this method. This came up during the review of https://github.com/rust-lang/rust/pull/134424.
2025-02-08Rustfmtbjorn3-36/+46
2025-02-06Rollup merge of #136235 - oli-obk:transmuty-pat-tys, r=RalfJungMatthias Krüger-13/+44
Pretty print pattern type values with transmute if they don't satisfy their pattern Instead of printing `0_u32 is 1..`, we now print the default fallback rendering that we also use for invalid bools, chars, ...: `{transmute(0x00000000): (u32) is 1..=}`. These cases can occur in mir dumps when const prop propagates a constant across a safety check that would prevent the actually UB value from existing. That's fine though, as it's dead code and we always need to allow UB in dead code. follow-up to https://github.com/rust-lang/rust/pull/136176 cc ``@compiler-errors`` ``@scottmcm`` r? ``@RalfJung`` because of the interpreter changes
2025-02-05Pretty print pattern type values with `transmute` if they don't satisfy ↵Oli Scherer-13/+44
their pattern
2025-02-05Rollup merge of #128045 - pnkfelix:rustc-contracts, r=oli-obkLeón Orell Valerian Liehr-1/+16
#[contracts::requires(...)] + #[contracts::ensures(...)] cc https://github.com/rust-lang/rust/issues/128044 Updated contract support: attribute syntax for preconditions and postconditions, implemented via a series of desugarings that culminates in: 1. a compile-time flag (`-Z contract-checks`) that, similar to `-Z ub-checks`, attempts to ensure that the decision of enabling/disabling contract checks is delayed until the end user program is compiled, 2. invocations of lang-items that handle invoking the precondition, building a checker for the post-condition, and invoking that post-condition checker at the return sites for the function, and 3. intrinsics for the actual evaluation of pre- and post-condition predicates that third-party verification tools can intercept and reinterpret for their own purposes (e.g. creating shims of behavior that abstract away the function body and replace it solely with the pre- and post-conditions). Known issues: * My original intent, as described in the MCP (https://github.com/rust-lang/compiler-team/issues/759) was to have a rustc-prefixed attribute namespace (like rustc_contracts::requires). But I could not get things working when I tried to do rewriting via a rustc-prefixed builtin attribute-macro. So for now it is called `contracts::requires`. * Our attribute macro machinery does not provide direct support for attribute arguments that are parsed like rust expressions. I spent some time trying to add that (e.g. something that would parse the attribute arguments as an AST while treating the remainder of the items as a token-tree), but its too big a lift for me to undertake. So instead I hacked in something approximating that goal, by semi-trivially desugaring the token-tree attribute contents into internal AST constucts. This may be too fragile for the long-term. * (In particular, it *definitely* breaks when you try to add a contract to a function like this: `fn foo1(x: i32) -> S<{ 23 }> { ... }`, because its token-tree based search for where to inject the internal AST constructs cannot immediately see that the `{ 23 }` is within a generics list. I think we can live for this for the short-term, i.e. land the work, and continue working on it while in parallel adding a new attribute variant that takes a token-tree attribute alongside an AST annotation, which would completely resolve the issue here.) * the *intent* of `-Z contract-checks` is that it behaves like `-Z ub-checks`, in that we do not prematurely commit to including or excluding the contract evaluation in upstream crates (most notably, `core` and `std`). But the current test suite does not actually *check* that this is the case. Ideally the test suite would be extended with a multi-crate test that explores the matrix of enabling/disabling contracts on both the upstream lib and final ("leaf") bin crates.
2025-02-03Contracts core intrinsics.Felix S. Klock II-1/+16
These are hooks to: 1. control whether contract checks are run 2. allow 3rd party tools to intercept and reintepret the results of running contracts.