src/libstd/sys/wasm/mod.rs

   1 //! System bindings for the wasm/web platform
   2 //!
   3 //! This module contains the facade (aka platform-specific) implementations of
   4 //! OS level functionality for wasm. Note that this wasm is *not* the emscripten
   5 //! wasm, so we have no runtime here.
   6 //!
   7 //! This is all super highly experimental and not actually intended for
   8 //! wide/production use yet, it's still all in the experimental category. This
   9 //! will likely change over time.
  10 //!
  11 //! Currently all functions here are basically stubs that immediately return
  12 //! errors. The hope is that with a portability lint we can turn actually just
  13 //! remove all this and just omit parts of the standard library if we're
  14 //! compiling for wasm. That way it's a compile time error for something that's
  15 //! guaranteed to be a runtime error!
  16
  17 use crate::os::raw::c_char;
  18
  19 pub mod alloc;
  20 pub mod args;
  21 pub mod cmath;
  22 pub mod env;
  23 pub mod fast_thread_local;
  24 pub mod fs;
  25 pub mod io;
  26 pub mod memchr;
  27 pub mod net;
  28 pub mod os;
  29 pub mod path;
  30 pub mod pipe;
  31 pub mod process;
  32 pub mod stack_overflow;
  33 pub mod stdio;
  34 pub mod thread;
  35 pub mod thread_local;
  36 pub mod time;
  37
  38 pub use crate::sys_common::os_str_bytes as os_str;
  39
  40 cfg_if::cfg_if! {
  41     if #[cfg(target_feature = "atomics")] {
  42         #[path = "condvar_atomics.rs"]
  43         pub mod condvar;
  44         #[path = "mutex_atomics.rs"]
  45         pub mod mutex;
  46         #[path = "rwlock_atomics.rs"]
  47         pub mod rwlock;
  48     } else {
  49         pub mod condvar;
  50         pub mod mutex;
  51         pub mod rwlock;
  52     }
  53 }
  54
  55 #[cfg(not(test))]
  56 pub fn init() {}
  57
  58 pub fn unsupported<T>() -> crate::io::Result<T> {
  59     Err(unsupported_err())
  60 }
  61
  62 pub fn unsupported_err() -> crate::io::Error {
  63     crate::io::Error::new(crate::io::ErrorKind::Other, "operation not supported on wasm yet")
  64 }
  65
  66 pub fn decode_error_kind(_code: i32) -> crate::io::ErrorKind {
  67     crate::io::ErrorKind::Other
  68 }
  69
  70 // This enum is used as the storage for a bunch of types which can't actually
  71 // exist.
  72 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
  73 pub enum Void {}
  74
  75 pub unsafe fn strlen(mut s: *const c_char) -> usize {
  76     let mut n = 0;
  77     while *s != 0 {
  78         n += 1;
  79         s = s.offset(1);
  80     }
  81     return n;
  82 }
  83
  84 pub fn abort_internal() -> ! {
  85     unsafe { crate::arch::wasm32::unreachable() }
  86 }
  87
  88 // We don't have randomness yet, but I totally used a random number generator to
  89 // generate these numbers.
  90 //
  91 // More seriously though this is just for DOS protection in hash maps. It's ok
  92 // if we don't do that on wasm just yet.
  93 pub fn hashmap_random_keys() -> (u64, u64) {
  94     (1, 2)
  95 }