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Don't link to libresolv
in libstd on Darwin
#102766
Conversation
Hey! It looks like you've submitted a new PR for the library teams! If this PR contains changes to any Examples of
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(rust-highfive has picked a reviewer for you, use r? to override) |
+1 to relnotes; thanks for tagging. No particular opinion on the change itself but it seems reasonable to me. The code change itself looks OK. |
👍 for making this change and documenting it in compatibility notes. |
We discussed this in today's @rust-lang/libs meeting, and agreed that we can make this change. We should document this in the release notes. |
r=me per discussion in meeting (as noted above), not sure if we were blocking on anything else |
We aren't, the discussion in the meeting was that we should just land it, and that it did not need FCP. @bors r=Mark-Simulacrum |
…acrum Don't link to `libresolv` in libstd on Darwin Currently we link `libresolv` into every Rust program on apple targets despite never using it (as of rust-lang#44965). I had thought we needed this for `getaddrinfo` or something, but we do not / cannot safely use it. I'd like to fix this for `libiconv` too (the other library we pull in. that's harder since it's coming in through `libc`, which is rust-lang/libc#2944)). --- This may warrant release notes. I'm not sure but I've added the flag regardless -- It's a change to the list of dylibs every Rust program pulls in, so it's worth mentioning. It's pretty unlikely anybody was relying on this being pulled in, and `std` does not guarantee that it will link (and thus transitively provide access to) any particular system library -- anybody relying on that behavior would already be broken when dynamically linking std. That is, there's an outside chance something will fail to link on macOS and iOS because it was accidentally relying on our unnecessary dependency. (If that *does* happen, that project could be easily fixed by linking libresolv explicitly on those platforms, probably via `#[link(name = "resolv")] extern {}`,` -Crustc-link-lib=resolv`, `println!("cargo:rustc-link-lib=resolv")`, or one of several places in `.config/cargo.toml`) --- I'm also going to preemptively add the nomination for discussing this in the libs meeting. Basically: Do we care about programs that assume we will bring libraries in that we do not use. `libresolv` and `libiconv` on macOS/iOS are in this camp (`libresolv` because we used to use it, and `libiconv` because the `libc` crate was unintentionally(?) pulling it in to every Rust program). I'd like to remove them both, but this may cause link issues programs that are relying on `std` to depend on them transitively. (Relying on std for this does not work in all build configurations, so this seems very fragile, and like a use case we should not support). More generally, IMO we should not guarantee the specific set of system-provided libraries we use (beyond what is implied by an OS version requirement), which means we'd be free to remove this cruft.
…acrum Don't link to `libresolv` in libstd on Darwin Currently we link `libresolv` into every Rust program on apple targets despite never using it (as of rust-lang#44965). I had thought we needed this for `getaddrinfo` or something, but we do not / cannot safely use it. I'd like to fix this for `libiconv` too (the other library we pull in. that's harder since it's coming in through `libc`, which is rust-lang/libc#2944)). --- This may warrant release notes. I'm not sure but I've added the flag regardless -- It's a change to the list of dylibs every Rust program pulls in, so it's worth mentioning. It's pretty unlikely anybody was relying on this being pulled in, and `std` does not guarantee that it will link (and thus transitively provide access to) any particular system library -- anybody relying on that behavior would already be broken when dynamically linking std. That is, there's an outside chance something will fail to link on macOS and iOS because it was accidentally relying on our unnecessary dependency. (If that *does* happen, that project could be easily fixed by linking libresolv explicitly on those platforms, probably via `#[link(name = "resolv")] extern {}`,` -Crustc-link-lib=resolv`, `println!("cargo:rustc-link-lib=resolv")`, or one of several places in `.config/cargo.toml`) --- I'm also going to preemptively add the nomination for discussing this in the libs meeting. Basically: Do we care about programs that assume we will bring libraries in that we do not use. `libresolv` and `libiconv` on macOS/iOS are in this camp (`libresolv` because we used to use it, and `libiconv` because the `libc` crate was unintentionally(?) pulling it in to every Rust program). I'd like to remove them both, but this may cause link issues programs that are relying on `std` to depend on them transitively. (Relying on std for this does not work in all build configurations, so this seems very fragile, and like a use case we should not support). More generally, IMO we should not guarantee the specific set of system-provided libraries we use (beyond what is implied by an OS version requirement), which means we'd be free to remove this cruft.
…acrum Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin) This is to pull in rust-lang/libc#2944. It's related to rust-lang#102766, in that they both remove unused dylibs from libstd on Darwin platforms. As a result, I'm marking this as relnotes since everybody agreed it was good to add it to the other as well. (The note should be about no longer linking against libiconv -- the libc update is irrelevant). Might as well have the same reviewer too. r? `@Mark-Simulacrum`
Rollup of 7 pull requests Successful merges: - rust-lang#99578 (Remove redundant lifetime bound from `impl Borrow for Cow`) - rust-lang#99939 (Sort tests at compile time, not at startup) - rust-lang#102271 (Stabilize `duration_checked_float`) - rust-lang#102766 (Don't link to `libresolv` in libstd on Darwin) - rust-lang#103277 (Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin)) - rust-lang#103437 (Sync rustc_codegen_cranelift) - rust-lang#103466 (Fix grammar in docs for std::io::Read) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
Perform a bunch of pkglint cleanup while here, and bump bootstrap kits to 1.65.0. Version 1.66.0 (2022-12-15) ========================== Language -------- - [Permit specifying explicit discriminants on all `repr(Int)` enums](rust-lang/rust#95710) ```rust #[repr(u8)] enum Foo { A(u8) = 0, B(i8) = 1, C(bool) = 42, } ``` - [Allow transmutes between the same type differing only in lifetimes](rust-lang/rust#101520) - [Change constant evaluation errors from a deny-by-default lint to a hard error](rust-lang/rust#102091) - [Trigger `must_use` on `impl Trait` for supertraits](rust-lang/rust#102287) This makes `impl ExactSizeIterator` respect the existing `#[must_use]` annotation on `Iterator`. - [Allow `..X` and `..=X` in patterns](rust-lang/rust#102275) - [Uplift `clippy::for_loops_over_fallibles` lint into rustc](rust-lang/rust#99696) - [Stabilize `sym` operands in inline assembly](rust-lang/rust#103168) - [Update to Unicode 15](rust-lang/rust#101912) - [Opaque types no longer imply lifetime bounds](rust-lang/rust#95474) This is a soundness fix which may break code that was erroneously relying on this behavior. Compiler -------- - [Add armv5te-none-eabi and thumbv5te-none-eabi tier 3 targets](rust-lang/rust#101329) - Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. - [Add support for linking against macOS universal libraries](rust-lang/rust#98736) Libraries --------- - [Fix `#[derive(Default)]` on a generic `#[default]` enum adding unnecessary `Default` bounds](rust-lang/rust#101040) - [Update to Unicode 15](rust-lang/rust#101821) Stabilized APIs --------------- - [`proc_macro::Span::source_text`](https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.source_text) - [`uX::{checked_add_signed, overflowing_add_signed, saturating_add_signed, wrapping_add_signed}`](https://doc.rust-lang.org/stable/std/primitive.u8.html#method.checked_add_signed) - [`iX::{checked_add_unsigned, overflowing_add_unsigned, saturating_add_unsigned, wrapping_add_unsigned}`](https://doc.rust-lang.org/stable/std/primitive.i8.html#method.checked_add_unsigned) - [`iX::{checked_sub_unsigned, overflowing_sub_unsigned, saturating_sub_unsigned, wrapping_sub_unsigned}`](https://doc.rust-lang.org/stable/std/primitive.i8.html#method.checked_sub_unsigned) - [`BTreeSet::{first, last, pop_first, pop_last}`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeSet.html#method.first) - [`BTreeMap::{first_key_value, last_key_value, first_entry, last_entry, pop_first, pop_last}`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html#method.first_key_value) - [Add `AsFd` implementations for stdio lock types on WASI.](rust-lang/rust#101768) - [`impl TryFrom<Vec<T>> for Box<[T; N]>`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#impl-TryFrom%3CVec%3CT%2C%20Global%3E%3E-for-Box%3C%5BT%3B%20N%5D%2C%20Global%3E) - [`core::hint::black_box`](https://doc.rust-lang.org/stable/std/hint/fn.black_box.html) - [`Duration::try_from_secs_{f32,f64}`](https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.try_from_secs_f32) - [`Option::unzip`](https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.unzip) - [`std::os::fd`](https://doc.rust-lang.org/stable/std/os/fd/index.html) Rustdoc ------- - [Add Rustdoc warning for invalid HTML tags in the documentation](rust-lang/rust#101720) Cargo ----- - [Added `cargo remove` to remove dependencies from Cargo.toml](https://doc.rust-lang.org/nightly/cargo/commands/cargo-remove.html) - [`cargo publish` now waits for the new version to be downloadable before exiting](rust-lang/cargo#11062) See [detailed release notes](https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-166-2022-12-15) for more. Compatibility Notes ------------------- - [Only apply `ProceduralMasquerade` hack to older versions of `rental`](rust-lang/rust#94063) - [Don't export `__heap_base` and `__data_end` on wasm32-wasi.](rust-lang/rust#102385) - [Don't export `__wasm_init_memory` on WebAssembly.](rust-lang/rust#102426) - [Only export `__tls_*` on wasm32-unknown-unknown.](rust-lang/rust#102440) - [Don't link to `libresolv` in libstd on Darwin](rust-lang/rust#102766) - [Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin)](rust-lang/rust#103277) - [Opaque types no longer imply lifetime bounds](rust-lang/rust#95474) This is a soundness fix which may break code that was erroneously relying on this behavior. - [Make `order_dependent_trait_objects` show up in future-breakage reports](rust-lang/rust#102635) - [Change std::process::Command spawning to default to inheriting the parent's signal mask](rust-lang/rust#101077) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Enable BOLT for LLVM compilation](rust-lang/rust#94381) - [Enable LTO for rustc_driver.so](rust-lang/rust#101403)
Pkgsrc changes: * pkglint cleanups, bump bootstrap kits to 1.65.0. * New target: mipsel-unknown-netbsd, for cpu=mips32 with soft-float. * Managed to retain the build of aarch64_be, llvm needed a patch to avoid use of neon instructions in the BE case (llvm doesn't support use of neon in BE mode). Ref. patch to src/llvm-project/llvm/lib/Support/BLAKE3/blake3_impl.h. Also submitted upstream of LLVM to the BLAKE3 maintainers. * The minimum gcc version is now 7.x, and that includes the cross-compiler for the targets. For i386 this also needs to /usr/include/gcc-7 include files in the target root, because immintrin.h from gcc 5 is not compatible with gcc 7.x. This applies for the targets where we build against a root from netbsd-8 (sparc64, powerpc, i386), and files/gcc-wrap gets a hack for this. * Pick up tweak for -latomic inclusion from rust-lang/rust#104220 and rust-lang/rust#104572 * Retain ability to do 32-bit NetBSD, by changing from 64 to 32 bit types in library/std/src/sys/unix/thread_parker/netbsd.rs. * I've tried to get the "openssl-src" build with -latomic where it's needed. I've introduced the "NetBSD-generic32" system type and use it for the NetBSD mipsel target. There is another attempt to do the same in the patch to vendor/openssl-sys/build/main.rs. Upstream changes: Version 1.66.1 (2023-01-10) =========================== - Added validation of SSH host keys for git URLs in Cargo ([CVE-2022-46176](https://www.cve.org/CVERecord?id=CVE-2022-46176)) Version 1.66.0 (2022-12-15) =========================== Language -------- - [Permit specifying explicit discriminants on all `repr(Int)` enums](rust-lang/rust#95710) ```rust #[repr(u8)] enum Foo { A(u8) = 0, B(i8) = 1, C(bool) = 42, } ``` - [Allow transmutes between the same type differing only in lifetimes](rust-lang/rust#101520) - [Change constant evaluation errors from a deny-by-default lint to a hard error](rust-lang/rust#102091) - [Trigger `must_use` on `impl Trait` for supertraits](rust-lang/rust#102287) This makes `impl ExactSizeIterator` respect the existing `#[must_use]` annotation on `Iterator`. - [Allow `..X` and `..=X` in patterns](rust-lang/rust#102275) - [Uplift `clippy::for_loops_over_fallibles` lint into rustc](rust-lang/rust#99696) - [Stabilize `sym` operands in inline assembly](rust-lang/rust#103168) - [Update to Unicode 15](rust-lang/rust#101912) - [Opaque types no longer imply lifetime bounds](rust-lang/rust#95474) This is a soundness fix which may break code that was erroneously relying on this behavior. Compiler -------- - [Add armv5te-none-eabi and thumbv5te-none-eabi tier 3 targets](rust-lang/rust#101329) - Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. - [Add support for linking against macOS universal libraries](rust-lang/rust#98736) Libraries --------- - [Fix `#[derive(Default)]` on a generic `#[default]` enum adding unnecessary `Default` bounds](rust-lang/rust#101040) - [Update to Unicode 15](rust-lang/rust#101821) Stabilized APIs --------------- - [`proc_macro::Span::source_text`](https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.source_text) - [`uX::{checked_add_signed, overflowing_add_signed, saturating_add_signed, wrapping_add_signed}`](https://doc.rust-lang.org/stable/std/primitive.u8.html#method.checked_add_signed) - [`iX::{checked_add_unsigned, overflowing_add_unsigned, saturating_add_unsigned, wrapping_add_unsigned}`](https://doc.rust-lang.org/stable/std/primitive.i8.html#method.checked_add_unsigned) - [`iX::{checked_sub_unsigned, overflowing_sub_unsigned, saturating_sub_unsigned, wrapping_sub_unsigned}`](https://doc.rust-lang.org/stable/std/primitive.i8.html#method.checked_sub_unsigned) - [`BTreeSet::{first, last, pop_first, pop_last}`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeSet.html#method.first) - [`BTreeMap::{first_key_value, last_key_value, first_entry, last_entry, pop_first, pop_last}`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html#method.first_key_value) - [Add `AsFd` implementations for stdio lock types on WASI.](rust-lang/rust#101768) - [`impl TryFrom<Vec<T>> for Box<[T; N]>`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#impl-TryFrom%3CVec%3CT%2C%20Global%3E%3E-for-Box%3C%5BT%3B%20N%5D%2C%20Global%3E) - [`core::hint::black_box`](https://doc.rust-lang.org/stable/std/hint/fn.black_box.html) - [`Duration::try_from_secs_{f32,f64}`](https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.try_from_secs_f32) - [`Option::unzip`](https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.unzip) - [`std::os::fd`](https://doc.rust-lang.org/stable/std/os/fd/index.html) Rustdoc ------- - [Add Rustdoc warning for invalid HTML tags in the documentation](rust-lang/rust#101720) Cargo ----- - [Added `cargo remove` to remove dependencies from Cargo.toml](https://doc.rust-lang.org/nightly/cargo/commands/cargo-remove.html) - [`cargo publish` now waits for the new version to be downloadable before exiting](rust-lang/cargo#11062) See [detailed release notes](https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-166-2022-12-15) for more. Compatibility Notes ------------------- - [Only apply `ProceduralMasquerade` hack to older versions of `rental`](rust-lang/rust#94063) - [Don't export `__heap_base` and `__data_end` on wasm32-wasi.](rust-lang/rust#102385) - [Don't export `__wasm_init_memory` on WebAssembly.](rust-lang/rust#102426) - [Only export `__tls_*` on wasm32-unknown-unknown.](rust-lang/rust#102440) - [Don't link to `libresolv` in libstd on Darwin](rust-lang/rust#102766) - [Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin)](rust-lang/rust#103277) - [Opaque types no longer imply lifetime bounds](rust-lang/rust#95474) This is a soundness fix which may break code that was erroneously relying on this behavior. - [Make `order_dependent_trait_objects` show up in future-breakage reports](rust-lang/rust#102635) - [Change std::process::Command spawning to default to inheriting the parent's signal mask](rust-lang/rust#101077) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Enable BOLT for LLVM compilation](rust-lang/rust#94381) - [Enable LTO for rustc_driver.so](rust-lang/rust#101403) Version 1.65.0 (2022-11-03) ========================== Language -------- - [Error on `as` casts of enums with `#[non_exhaustive]` variants] (rust-lang/rust#92744) - [Stabilize `let else`](rust-lang/rust#93628) - [Stabilize generic associated types (GATs)] (rust-lang/rust#96709) - [Add lints `let_underscore_drop`, `let_underscore_lock`, and `let_underscore_must_use` from Clippy] (rust-lang/rust#97739) - [Stabilize `break`ing from arbitrary labeled blocks ("label-break-value")] (rust-lang/rust#99332) - [Uninitialized integers, floats, and raw pointers are now considered immediate UB](rust-lang/rust#98919). Usage of `MaybeUninit` is the correct way to work with uninitialized memory. - [Stabilize raw-dylib for Windows x86_64, aarch64, and thumbv7a] (rust-lang/rust#99916) - [Do not allow `Drop` impl on foreign ADTs] (rust-lang/rust#99576) Compiler -------- - [Stabilize -Csplit-debuginfo on Linux] (rust-lang/rust#98051) - [Use niche-filling optimization even when multiple variants have data] (rust-lang/rust#94075) - [Associated type projections are now verified to be well-formed prior to resolving the underlying type] (rust-lang/rust#99217) - [Stringify non-shorthand visibility correctly] (rust-lang/rust#100350) - [Normalize struct field types when unsizing] (rust-lang/rust#101831) - [Update to LLVM 15](rust-lang/rust#99464) - [Fix aarch64 call abi to correctly zeroext when needed] (rust-lang/rust#97800) - [debuginfo: Generalize C++-like encoding for enums] (rust-lang/rust#98393) - [Add `special_module_name` lint] (rust-lang/rust#94467) - [Add support for generating unique profraw files by default when using `-C instrument-coverage`] (rust-lang/rust#100384) - [Allow dynamic linking for iOS/tvOS targets] (rust-lang/rust#100636) New targets: - [Add armv4t-none-eabi as a tier 3 target] (rust-lang/rust#100244) - [Add powerpc64-unknown-openbsd and riscv64-unknown-openbsd as tier 3 targets] (rust-lang/rust#101025) - Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Don't generate `PartialEq::ne` in derive(PartialEq)] (rust-lang/rust#98655) - [Windows RNG: Use `BCRYPT_RNG_ALG_HANDLE` by default] (rust-lang/rust#101325) - [Forbid mixing `System` with direct system allocator calls] (rust-lang/rust#101394) - [Document no support for writing to non-blocking stdio/stderr] (rust-lang/rust#101416) - [`std::layout::Layout` size must not overflow `isize::MAX` when rounded up to `align`](rust-lang/rust#95295) This also changes the safety conditions on `Layout::from_size_align_unchecked`. Stabilized APIs --------------- - [`std::backtrace::Backtrace`] (https://doc.rust-lang.org/stable/std/backtrace/struct.Backtrace.html) - [`Bound::as_ref`] (https://doc.rust-lang.org/stable/std/ops/enum.Bound.html#method.as_ref) - [`std::io::read_to_string`] (https://doc.rust-lang.org/stable/std/io/fn.read_to_string.html) - [`<*const T>::cast_mut`] (https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.cast_mut) - [`<*mut T>::cast_const`] (https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.cast_const) These APIs are now stable in const contexts: - [`<*const T>::offset_from`] (https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.offset_from) - [`<*mut T>::offset_from`] (https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.offset_from) Cargo ----- - [Apply GitHub fast path even for partial hashes] (rust-lang/cargo#10807) - [Do not add home bin path to PATH if it's already there] (rust-lang/cargo#11023) - [Take priority into account within the pending queue] (rust-lang/cargo#11032). This slightly optimizes job scheduling by Cargo, with typically small improvements on larger crate graph builds. Compatibility Notes ------------------- - [`std::layout::Layout` size must not overflow `isize::MAX` when rounded up to `align`] (rust-lang/rust#95295). This also changes the safety conditions on `Layout::from_size_align_unchecked`. - [`PollFn` now only implements `Unpin` if the closure is `Unpin`] (rust-lang/rust#102737). This is a possible breaking change if users were relying on the blanket unpin implementation. See discussion on the PR for details of why this change was made. - [Drop ExactSizeIterator impl from std::char::EscapeAscii] (rust-lang/rust#99880) This is a backwards-incompatible change to the standard library's surface area, but is unlikely to affect real world usage. - [Do not consider a single repeated lifetime eligible for elision in the return type] (rust-lang/rust#103450) This behavior was unintentionally changed in 1.64.0, and this release reverts that change by making this an error again. - [Reenable disabled early syntax gates as future-incompatibility lints] (rust-lang/rust#99935) - [Update the minimum external LLVM to 13] (rust-lang/rust#100460) - [Don't duplicate file descriptors into stdio fds] (rust-lang/rust#101426) - [Sunset RLS](rust-lang/rust#100863) - [Deny usage of `#![cfg_attr(..., crate_type = ...)]` to set the crate type] (rust-lang/rust#99784) This strengthens the forward compatibility lint deprecated_cfg_attr_crate_type_name to deny. - [`llvm-has-rust-patches` allows setting the build system to treat the LLVM as having Rust-specific patches] (rust-lang/rust#101072) This option may need to be set for distributions that are building Rust with a patched LLVM via `llvm-config`, not the built-in LLVM. Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Add `x.sh` and `x.ps1` shell scripts] (rust-lang/rust#99992) - [compiletest: use target cfg instead of hard-coded tables] (rust-lang/rust#100260) - [Use object instead of LLVM for reading bitcode from rlibs] (rust-lang/rust#98100) - [Enable MIR inlining for optimized compilations] (rust-lang/rust#91743) This provides a 3-10% improvement in compiletimes for real world crates. See [perf results] (https://perf.rust-lang.org/compare.html?start=aedf78e56b2279cc869962feac5153b6ba7001ed&end=0075bb4fad68e64b6d1be06bf2db366c30bc75e1&stat=instructions:u).
Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin) This is to pull in rust-lang/libc#2944. It's related to rust-lang/rust#102766, in that they both remove unused dylibs from libstd on Darwin platforms. As a result, I'm marking this as relnotes since everybody agreed it was good to add it to the other as well. (The note should be about no longer linking against libiconv -- the libc update is irrelevant). Might as well have the same reviewer too. r? `@Mark-Simulacrum`
Currently we link
libresolv
into every Rust program on apple targets despite never using it (as of #44965). I had thought we needed this forgetaddrinfo
or something, but we do not / cannot safely use it.I'd like to fix this for
libiconv
too (the other library we pull in. that's harder since it's coming in throughlibc
, which is rust-lang/libc#2944)).This may warrant release notes. I'm not sure but I've added the flag regardless -- It's a change to the list of dylibs every Rust program pulls in, so it's worth mentioning.
It's pretty unlikely anybody was relying on this being pulled in, and
std
does not guarantee that it will link (and thus transitively provide access to) any particular system library -- anybody relying on that behavior would already be broken when dynamically linking std. That is, there's an outside chance something will fail to link on macOS and iOS because it was accidentally relying on our unnecessary dependency.(If that does happen, that project could be easily fixed by linking libresolv explicitly on those platforms, probably via
#[link(name = "resolv")] extern {}
,-Crustc-link-lib=resolv
,println!("cargo:rustc-link-lib=resolv")
, or one of several places in.config/cargo.toml
)I'm also going to preemptively add the nomination for discussing this in the libs meeting. Basically: Do we care about programs that assume we will bring libraries in that we do not use.
libresolv
andlibiconv
on macOS/iOS are in this camp (libresolv
because we used to use it, andlibiconv
because thelibc
crate was unintentionally(?) pulling it in to every Rust program).I'd like to remove them both, but this may cause link issues programs that are relying on
std
to depend on them transitively. (Relying on std for this does not work in all build configurations, so this seems very fragile, and like a use case we should not support).More generally, IMO we should not guarantee the specific set of system-provided libraries we use (beyond what is implied by an OS version requirement), which means we'd be free to remove this cruft.