Provide C FFI types via core::ffi, not just in std
The ability to interoperate with C code via FFI is not limited to crates using std; this allows using these types without std. The existing types in `std::os::raw` become type aliases for the ones in `core::ffi`. This uses type aliases rather than re-exports, to allow the std types to remain stable while the core types are unstable. This also moves the currently unstable `NonZero_` variants and `c_size_t`/`c_ssize_t`/`c_ptrdiff_t` types to `core::ffi`, while leaving them unstable.
This commit is contained in:
Josh Triplett
parent
0f505c6377
commit
335c9609c6
16
library/core/src/ffi/c_void.md
Normal file
16
library/core/src/ffi/c_void.md
Normal file
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@ -0,0 +1,16 @@
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Equivalent to C's `void` type when used as a [pointer].
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In essence, `*const c_void` is equivalent to C's `const void*`
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and `*mut c_void` is equivalent to C's `void*`. That said, this is
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*not* the same as C's `void` return type, which is Rust's `()` type.
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To model pointers to opaque types in FFI, until `extern type` is
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stabilized, it is recommended to use a newtype wrapper around an empty
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byte array. See the [Nomicon] for details.
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One could use `std::os::raw::c_void` if they want to support old Rust
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compiler down to 1.1.0. After Rust 1.30.0, it was re-exported by
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this definition. For more information, please read [RFC 2521].
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[Nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
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[RFC 2521]: https://github.com/rust-lang/rfcs/blob/master/text/2521-c_void-reunification.md
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@ -1,28 +1,157 @@
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//! Platform-specific types, as defined by C.
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//!
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//! Code that interacts via FFI will almost certainly be using the
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//! base types provided by C, which aren't nearly as nicely defined
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//! as Rust's primitive types. This module provides types which will
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//! match those defined by C, so that code that interacts with C will
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//! refer to the correct types.
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#![stable(feature = "", since = "1.30.0")]
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#![allow(non_camel_case_types)]
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//! Utilities related to foreign function interface (FFI) bindings.
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use crate::fmt;
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use crate::marker::PhantomData;
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use crate::num::*;
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use crate::ops::{Deref, DerefMut};
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/// Equivalent to C's `void` type when used as a [pointer].
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macro_rules! type_alias_no_nz {
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{
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$Docfile:tt, $Alias:ident = $Real:ty;
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$( $Cfg:tt )*
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} => {
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#[doc = include_str!($Docfile)]
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$( $Cfg )*
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#[unstable(feature = "core_ffi_c", issue = "94501")]
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pub type $Alias = $Real;
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}
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}
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// To verify that the NonZero types in this file's macro invocations correspond
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//
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// perl -n < library/std/src/os/raw/mod.rs -e 'next unless m/type_alias\!/; die "$_ ?" unless m/, (c_\w+) = (\w+), NonZero_(\w+) = NonZero(\w+)/; die "$_ ?" unless $3 eq $1 and $4 eq ucfirst $2'
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//
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// NB this does not check that the main c_* types are right.
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macro_rules! type_alias {
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{
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$Docfile:tt, $Alias:ident = $Real:ty, $NZAlias:ident = $NZReal:ty;
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$( $Cfg:tt )*
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} => {
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type_alias_no_nz! { $Docfile, $Alias = $Real; $( $Cfg )* }
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#[doc = concat!("Type alias for `NonZero` version of [`", stringify!($Alias), "`]")]
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#[unstable(feature = "raw_os_nonzero", issue = "82363")]
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$( $Cfg )*
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pub type $NZAlias = $NZReal;
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}
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}
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type_alias! { "c_char.md", c_char = c_char_definition::c_char, NonZero_c_char = c_char_definition::NonZero_c_char;
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// Make this type alias appear cfg-dependent so that Clippy does not suggest
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// replacing `0 as c_char` with `0_i8`/`0_u8`. This #[cfg(all())] can be removed
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// after the false positive in https://github.com/rust-lang/rust-clippy/issues/8093
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// is fixed.
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#[cfg(all())]
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#[doc(cfg(all()))] }
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type_alias! { "c_schar.md", c_schar = i8, NonZero_c_schar = NonZeroI8; }
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type_alias! { "c_uchar.md", c_uchar = u8, NonZero_c_uchar = NonZeroU8; }
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type_alias! { "c_short.md", c_short = i16, NonZero_c_short = NonZeroI16; }
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type_alias! { "c_ushort.md", c_ushort = u16, NonZero_c_ushort = NonZeroU16; }
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type_alias! { "c_int.md", c_int = i32, NonZero_c_int = NonZeroI32; }
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type_alias! { "c_uint.md", c_uint = u32, NonZero_c_uint = NonZeroU32; }
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type_alias! { "c_long.md", c_long = i32, NonZero_c_long = NonZeroI32;
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#[doc(cfg(all()))]
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#[cfg(any(target_pointer_width = "32", windows))] }
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type_alias! { "c_ulong.md", c_ulong = u32, NonZero_c_ulong = NonZeroU32;
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#[doc(cfg(all()))]
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#[cfg(any(target_pointer_width = "32", windows))] }
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type_alias! { "c_long.md", c_long = i64, NonZero_c_long = NonZeroI64;
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#[doc(cfg(all()))]
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#[cfg(all(target_pointer_width = "64", not(windows)))] }
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type_alias! { "c_ulong.md", c_ulong = u64, NonZero_c_ulong = NonZeroU64;
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#[doc(cfg(all()))]
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#[cfg(all(target_pointer_width = "64", not(windows)))] }
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type_alias! { "c_longlong.md", c_longlong = i64, NonZero_c_longlong = NonZeroI64; }
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type_alias! { "c_ulonglong.md", c_ulonglong = u64, NonZero_c_ulonglong = NonZeroU64; }
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type_alias_no_nz! { "c_float.md", c_float = f32; }
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type_alias_no_nz! { "c_double.md", c_double = f64; }
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/// Equivalent to C's `size_t` type, from `stddef.h` (or `cstddef` for C++).
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///
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/// In essence, `*const c_void` is equivalent to C's `const void*`
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/// and `*mut c_void` is equivalent to C's `void*`. That said, this is
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/// *not* the same as C's `void` return type, which is Rust's `()` type.
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/// This type is currently always [`usize`], however in the future there may be
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/// platforms where this is not the case.
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#[unstable(feature = "c_size_t", issue = "88345")]
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pub type c_size_t = usize;
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/// Equivalent to C's `ptrdiff_t` type, from `stddef.h` (or `cstddef` for C++).
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///
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/// To model pointers to opaque types in FFI, until `extern type` is
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/// stabilized, it is recommended to use a newtype wrapper around an empty
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/// byte array. See the [Nomicon] for details.
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/// This type is currently always [`isize`], however in the future there may be
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/// platforms where this is not the case.
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#[unstable(feature = "c_size_t", issue = "88345")]
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pub type c_ptrdiff_t = isize;
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/// Equivalent to C's `ssize_t` (on POSIX) or `SSIZE_T` (on Windows) type.
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///
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/// One could use `std::os::raw::c_void` if they want to support old Rust
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/// compiler down to 1.1.0. After Rust 1.30.0, it was re-exported by
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/// this definition. For more information, please read [RFC 2521].
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///
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/// [Nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
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/// [RFC 2521]: https://github.com/rust-lang/rfcs/blob/master/text/2521-c_void-reunification.md
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/// This type is currently always [`isize`], however in the future there may be
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/// platforms where this is not the case.
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#[unstable(feature = "c_size_t", issue = "88345")]
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pub type c_ssize_t = isize;
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mod c_char_definition {
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cfg_if! {
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// These are the targets on which c_char is unsigned.
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if #[cfg(any(
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all(
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target_os = "linux",
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any(
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target_arch = "aarch64",
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target_arch = "arm",
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target_arch = "hexagon",
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target_arch = "powerpc",
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target_arch = "powerpc64",
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target_arch = "s390x",
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target_arch = "riscv64",
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target_arch = "riscv32"
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)
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),
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all(target_os = "android", any(target_arch = "aarch64", target_arch = "arm")),
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all(target_os = "l4re", target_arch = "x86_64"),
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all(
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target_os = "freebsd",
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any(
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target_arch = "aarch64",
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target_arch = "arm",
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target_arch = "powerpc",
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target_arch = "powerpc64",
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target_arch = "riscv64"
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)
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),
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all(
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target_os = "netbsd",
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any(target_arch = "aarch64", target_arch = "arm", target_arch = "powerpc")
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),
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all(target_os = "openbsd", target_arch = "aarch64"),
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all(
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target_os = "vxworks",
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any(
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target_arch = "aarch64",
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target_arch = "arm",
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target_arch = "powerpc64",
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target_arch = "powerpc"
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)
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),
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all(target_os = "fuchsia", target_arch = "aarch64")
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))] {
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pub type c_char = u8;
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pub type NonZero_c_char = crate::num::NonZeroU8;
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} else {
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// On every other target, c_char is signed.
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pub type c_char = i8;
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pub type NonZero_c_char = crate::num::NonZeroI8;
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}
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}
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}
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// N.B., for LLVM to recognize the void pointer type and by extension
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// functions like malloc(), we need to have it represented as i8* in
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// LLVM bitcode. The enum used here ensures this and prevents misuse
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@ -31,6 +160,7 @@ use crate::ops::{Deref, DerefMut};
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// otherwise and we need at least one variant as otherwise the enum
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// would be uninhabited and at least dereferencing such pointers would
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// be UB.
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#[doc = include_str!("c_void.md")]
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#[repr(u8)]
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#[stable(feature = "core_c_void", since = "1.30.0")]
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pub enum c_void {
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@ -261,6 +261,7 @@
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#![feature(const_socketaddr)]
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#![feature(const_trait_impl)]
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#![feature(container_error_extra)]
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#![feature(core_ffi_c)]
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#![feature(core_intrinsics)]
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#![feature(core_panic)]
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#![feature(custom_test_frameworks)]
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@ -315,6 +316,7 @@
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#![feature(prelude_import)]
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#![feature(ptr_as_uninit)]
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#![feature(ptr_internals)]
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#![feature(raw_os_nonzero)]
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#![feature(rustc_attrs)]
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#![feature(rustc_private)]
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#![feature(saturating_int_impl)]
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@ -1,156 +1,31 @@
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//! Platform-specific types, as defined by C.
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//!
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//! Code that interacts via FFI will almost certainly be using the
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//! base types provided by C, which aren't nearly as nicely defined
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//! as Rust's primitive types. This module provides types which will
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//! match those defined by C, so that code that interacts with C will
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//! refer to the correct types.
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//! Compatibility module for C platform-specific types. Use [`core::ffi`] instead.
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#![stable(feature = "raw_os", since = "1.1.0")]
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#[cfg(test)]
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mod tests;
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use core::num::*;
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macro_rules! type_alias_no_nz {
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{
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$Docfile:tt, $Alias:ident = $Real:ty;
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$( $Cfg:tt )*
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} => {
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#[doc = include_str!($Docfile)]
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$( $Cfg )*
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macro_rules! alias_core_ffi {
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($($t:ident)*) => {$(
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#[stable(feature = "raw_os", since = "1.1.0")]
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pub type $Alias = $Real;
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}
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#[doc = include_str!(concat!("../../../../core/src/ffi/", stringify!($t), ".md"))]
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// Make this type alias appear cfg-dependent so that Clippy does not suggest
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// replacing expressions like `0 as c_char` with `0_i8`/`0_u8`. This #[cfg(all())] can be
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// removed after the false positive in https://github.com/rust-lang/rust-clippy/issues/8093
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// is fixed.
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#[cfg(all())]
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#[doc(cfg(all()))]
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pub type $t = core::ffi::$t;
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)*}
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}
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// To verify that the NonZero types in this file's macro invocations correspond
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//
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// perl -n < library/std/src/os/raw/mod.rs -e 'next unless m/type_alias\!/; die "$_ ?" unless m/, (c_\w+) = (\w+), NonZero_(\w+) = NonZero(\w+)/; die "$_ ?" unless $3 eq $1 and $4 eq ucfirst $2'
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//
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// NB this does not check that the main c_* types are right.
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macro_rules! type_alias {
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{
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$Docfile:tt, $Alias:ident = $Real:ty, $NZAlias:ident = $NZReal:ty;
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$( $Cfg:tt )*
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} => {
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type_alias_no_nz! { $Docfile, $Alias = $Real; $( $Cfg )* }
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#[doc = concat!("Type alias for `NonZero` version of [`", stringify!($Alias), "`]")]
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#[unstable(feature = "raw_os_nonzero", issue = "82363")]
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$( $Cfg )*
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pub type $NZAlias = $NZReal;
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}
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}
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type_alias! { "char.md", c_char = c_char_definition::c_char, NonZero_c_char = c_char_definition::NonZero_c_char;
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// Make this type alias appear cfg-dependent so that Clippy does not suggest
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// replacing `0 as c_char` with `0_i8`/`0_u8`. This #[cfg(all())] can be removed
|
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// after the false positive in https://github.com/rust-lang/rust-clippy/issues/8093
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// is fixed.
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#[cfg(all())]
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#[doc(cfg(all()))] }
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type_alias! { "schar.md", c_schar = i8, NonZero_c_schar = NonZeroI8; }
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type_alias! { "uchar.md", c_uchar = u8, NonZero_c_uchar = NonZeroU8; }
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type_alias! { "short.md", c_short = i16, NonZero_c_short = NonZeroI16; }
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type_alias! { "ushort.md", c_ushort = u16, NonZero_c_ushort = NonZeroU16; }
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type_alias! { "int.md", c_int = i32, NonZero_c_int = NonZeroI32; }
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type_alias! { "uint.md", c_uint = u32, NonZero_c_uint = NonZeroU32; }
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type_alias! { "long.md", c_long = i32, NonZero_c_long = NonZeroI32;
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#[doc(cfg(all()))]
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#[cfg(any(target_pointer_width = "32", windows))] }
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type_alias! { "ulong.md", c_ulong = u32, NonZero_c_ulong = NonZeroU32;
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#[doc(cfg(all()))]
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#[cfg(any(target_pointer_width = "32", windows))] }
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type_alias! { "long.md", c_long = i64, NonZero_c_long = NonZeroI64;
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#[doc(cfg(all()))]
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#[cfg(all(target_pointer_width = "64", not(windows)))] }
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type_alias! { "ulong.md", c_ulong = u64, NonZero_c_ulong = NonZeroU64;
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#[doc(cfg(all()))]
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#[cfg(all(target_pointer_width = "64", not(windows)))] }
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type_alias! { "longlong.md", c_longlong = i64, NonZero_c_longlong = NonZeroI64; }
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type_alias! { "ulonglong.md", c_ulonglong = u64, NonZero_c_ulonglong = NonZeroU64; }
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type_alias_no_nz! { "float.md", c_float = f32; }
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type_alias_no_nz! { "double.md", c_double = f64; }
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#[stable(feature = "raw_os", since = "1.1.0")]
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#[doc(no_inline)]
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pub use core::ffi::c_void;
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|
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/// Equivalent to C's `size_t` type, from `stddef.h` (or `cstddef` for C++).
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///
|
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/// This type is currently always [`usize`], however in the future there may be
|
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/// platforms where this is not the case.
|
||||
#[unstable(feature = "c_size_t", issue = "88345")]
|
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pub type c_size_t = usize;
|
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|
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/// Equivalent to C's `ptrdiff_t` type, from `stddef.h` (or `cstddef` for C++).
|
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///
|
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/// This type is currently always [`isize`], however in the future there may be
|
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/// platforms where this is not the case.
|
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#[unstable(feature = "c_size_t", issue = "88345")]
|
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pub type c_ptrdiff_t = isize;
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|
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/// Equivalent to C's `ssize_t` (on POSIX) or `SSIZE_T` (on Windows) type.
|
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///
|
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/// This type is currently always [`isize`], however in the future there may be
|
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/// platforms where this is not the case.
|
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#[unstable(feature = "c_size_t", issue = "88345")]
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pub type c_ssize_t = isize;
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|
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mod c_char_definition {
|
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cfg_if::cfg_if! {
|
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// These are the targets on which c_char is unsigned.
|
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if #[cfg(any(
|
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all(
|
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target_os = "linux",
|
||||
any(
|
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target_arch = "aarch64",
|
||||
target_arch = "arm",
|
||||
target_arch = "hexagon",
|
||||
target_arch = "powerpc",
|
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target_arch = "powerpc64",
|
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target_arch = "s390x",
|
||||
target_arch = "riscv64",
|
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target_arch = "riscv32"
|
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)
|
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),
|
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all(target_os = "android", any(target_arch = "aarch64", target_arch = "arm")),
|
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all(target_os = "l4re", target_arch = "x86_64"),
|
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all(
|
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target_os = "freebsd",
|
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any(
|
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target_arch = "aarch64",
|
||||
target_arch = "arm",
|
||||
target_arch = "powerpc",
|
||||
target_arch = "powerpc64",
|
||||
target_arch = "riscv64"
|
||||
)
|
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),
|
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all(
|
||||
target_os = "netbsd",
|
||||
any(target_arch = "aarch64", target_arch = "arm", target_arch = "powerpc")
|
||||
),
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all(target_os = "openbsd", target_arch = "aarch64"),
|
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all(
|
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target_os = "vxworks",
|
||||
any(
|
||||
target_arch = "aarch64",
|
||||
target_arch = "arm",
|
||||
target_arch = "powerpc64",
|
||||
target_arch = "powerpc"
|
||||
)
|
||||
),
|
||||
all(target_os = "fuchsia", target_arch = "aarch64")
|
||||
))] {
|
||||
pub type c_char = u8;
|
||||
pub type NonZero_c_char = core::num::NonZeroU8;
|
||||
} else {
|
||||
// On every other target, c_char is signed.
|
||||
pub type c_char = i8;
|
||||
pub type NonZero_c_char = core::num::NonZeroI8;
|
||||
}
|
||||
}
|
||||
alias_core_ffi! {
|
||||
c_char c_schar c_uchar
|
||||
c_short c_ushort
|
||||
c_int c_uint
|
||||
c_long c_ulong
|
||||
c_longlong c_ulonglong
|
||||
c_float
|
||||
c_double
|
||||
c_void
|
||||
}
|
||||
|
|
|
|||
|
|
@ -3,11 +3,11 @@ use crate::fmt;
|
|||
use crate::io::{self, Error, ErrorKind};
|
||||
use crate::mem;
|
||||
use crate::num::NonZeroI32;
|
||||
use crate::os::raw::NonZero_c_int;
|
||||
use crate::ptr;
|
||||
use crate::sys;
|
||||
use crate::sys::cvt;
|
||||
use crate::sys::process::process_common::*;
|
||||
use core::ffi::NonZero_c_int;
|
||||
|
||||
#[cfg(target_os = "linux")]
|
||||
use crate::os::linux::process::PidFd;
|
||||
|
|
|
|||
|
|
@ -3,12 +3,12 @@ use crate::fmt;
|
|||
use crate::io;
|
||||
use crate::io::ErrorKind;
|
||||
use crate::num::NonZeroI32;
|
||||
use crate::os::raw::NonZero_c_int;
|
||||
use crate::sys;
|
||||
use crate::sys::cvt;
|
||||
use crate::sys::pipe::AnonPipe;
|
||||
use crate::sys::process::process_common::*;
|
||||
use crate::sys::unix::unsupported::*;
|
||||
use core::ffi::NonZero_c_int;
|
||||
|
||||
use libc::{c_int, pid_t};
|
||||
|
||||
|
|
|
|||
|
|
@ -2,11 +2,11 @@ use crate::convert::{TryFrom, TryInto};
|
|||
use crate::fmt;
|
||||
use crate::io::{self, Error, ErrorKind};
|
||||
use crate::num::NonZeroI32;
|
||||
use crate::os::raw::NonZero_c_int;
|
||||
use crate::sys;
|
||||
use crate::sys::cvt;
|
||||
use crate::sys::process::process_common::*;
|
||||
use crate::sys_common::thread;
|
||||
use core::ffi::NonZero_c_int;
|
||||
use libc::RTP_ID;
|
||||
use libc::{self, c_char, c_int};
|
||||
|
||||
|
|
|
|||
|
|
@ -5,9 +5,9 @@
|
|||
#![unstable(issue = "none", feature = "windows_c")]
|
||||
|
||||
use crate::mem;
|
||||
use crate::os::raw::NonZero_c_ulong;
|
||||
use crate::os::raw::{c_char, c_int, c_long, c_longlong, c_uint, c_ulong, c_ushort};
|
||||
use crate::ptr;
|
||||
use core::ffi::NonZero_c_ulong;
|
||||
|
||||
use libc::{c_void, size_t, wchar_t};
|
||||
|
||||
|
|
|
|||
|
|
@ -46,7 +46,7 @@ const EXCEPTION_PATHS: &[&str] = &[
|
|||
// pointer regardless of the target architecture. As a result,
|
||||
// we must use `#[cfg(windows)]` to conditionally compile the
|
||||
// correct `VaList` structure for windows.
|
||||
"library/core/src/ffi.rs",
|
||||
"library/core/src/ffi/mod.rs",
|
||||
"library/std/src/sys/", // Platform-specific code for std lives here.
|
||||
"library/std/src/os", // Platform-specific public interfaces
|
||||
// Temporary `std` exceptions
|
||||
|
|
|
|||
Loading…
Reference in a new issue