Module rustix::backend::conv

Convert values to ArgReg and from RetReg.

System call arguments and return values are all communicated with inline asm and FFI as *mut Opaque. To protect these raw pointers from escaping or being accidentally misused as they travel through the code, we wrap them in ArgReg and RetReg structs. This file provides From implementations and explicit conversion functions for converting values into and out of these wrapper structs.

Safety

Some of this code is unsafe in order to work with raw file descriptors, and some is unsafe to interpret the values in a RetReg.

Modules

• fs 🔒

Functions

• by_mut 🔒
• by_ref 🔒
• c_int 🔒
  Convert a c_int into an ArgReg.
• c_uint 🔒
  Convert a c_uint into an ArgReg.
• dev_t 🔒
• loff_t 🔒
• loff_t_from_u64 🔒
• negative_pid 🔒
• no_fd 🔒
  Deliberately pass -1 to a file-descriptor argument, for system calls like mmap where this indicates the argument is omitted.
• opt_mut 🔒
  Convert an optional mutable reference into a usize for passing to a syscall.
• pass_usize 🔒
  Pass an arbitrary usize value.
• raw_fd 🔒 ^⚠
  Pass a raw file-descriptor argument. Most users should use ArgReg::from instead, to preserve I/O safety as long as possible.
• ret 🔒 ^⚠
  Convert a usize returned from a syscall that effectively returns () on success.
• ret_c_int 🔒
  Convert a usize returned from a syscall that effectively returns a c_int on success.
• ret_c_int_infallible 🔒 ^⚠
  Convert a c_int returned from a syscall that effectively always returns a c_int.
• ret_c_uint 🔒
  Convert a usize returned from a syscall that effectively returns a c_uint on success.
• ret_c_uint_infallible 🔒 ^⚠
  Convert a c_uint returned from a syscall that effectively always returns a c_uint.
• ret_discarded_fd 🔒 ^⚠
  Convert the return value of dup2 and dup3.
• ret_error 🔒 ^⚠
  Convert a usize returned from a syscall that doesn’t return on success.
• ret_infallible 🔒 ^⚠
  Convert a usize returned from a syscall that effectively always returns ().
• ret_owned_fd 🔒 ^⚠
  Convert a usize returned from a syscall that effectively returns an OwnedFd on success.
• ret_u64 🔒
  Convert a usize returned from a syscall that effectively returns a u64 on success.
• ret_usize 🔒
  Convert a usize returned from a syscall that effectively returns a usize on success.
• ret_usize_infallible 🔒 ^⚠
  Convert a usize returned from a syscall that effectively always returns a usize.
• ret_void_star 🔒
  Convert a usize returned from a syscall that effectively returns a *mut c_void on success.
• size_of 🔒
  Pass the mem::size_of of a type.
• slice 🔒
• slice_just_addr 🔒
• slice_just_addr_mut 🔒
• slice_mut 🔒
• socklen_t 🔒
• zero 🔒
  Pass a zero, or null, argument.