zig/std/os.zig
Andrew Kelley d6856859d3 improvements for windows and libc integration
* standard library knows if it is linking against libc and will
   sometimes call libc functions in that case instead of providing
   redundant definitions
 * fix infinite loop bug when resolving use declarations
 * allow calling the same C function from different C imports.
   closes #277
 * push more logic from compiler to std/bootstrap.zig
 * standard library provides way to access errno
   closes #274
 * fix compile error in standard library for windows
 * add implementation of getRandomBytes for windows
2017-03-23 02:59:58 -04:00

75 lines
2.6 KiB
Zig

const posix = switch(@compileVar("os")) {
Os.linux => @import("linux.zig"),
Os.darwin, Os.macosx, Os.ios => @import("darwin.zig"),
else => @compileError("Unsupported OS"),
};
const windows = @import("windows.zig");
const errno = @import("errno.zig");
const linking_libc = @import("build.zig").linking_libc;
const c = @import("c/index.zig");
error Unexpected;
/// Fills `buf` with random bytes. If linking against libc, this calls the
/// appropriate OS-specific library call. Otherwise it uses the zig standard
/// library implementation.
pub fn getRandomBytes(buf: []u8) -> %void {
while (true) {
const err = switch (@compileVar("os")) {
Os.linux => {
if (linking_libc) {
if (c.getrandom(buf.ptr, buf.len, 0) == -1) *c._errno() else 0
} else {
posix.getErrno(posix.getrandom(buf.ptr, buf.len, 0))
}
},
Os.darwin, Os.macosx, Os.ios => {
if (linking_libc) {
if (posix.getrandom(buf.ptr, buf.len) == -1) *c._errno() else 0
} else {
posix.getErrno(posix.getrandom(buf.ptr, buf.len))
}
},
Os.windows => {
var hCryptProv: windows.HCRYPTPROV = undefined;
if (!windows.CryptAcquireContext(&hCryptProv, null, null, windows.PROV_RSA_FULL, 0)) {
return error.Unexpected;
}
defer _ = windows.CryptReleaseContext(hCryptProv, 0);
if (!windows.CryptGenRandom(hCryptProv, windows.DWORD(buf.len), buf.ptr)) {
return error.Unexpected;
}
return;
},
else => @compileError("Unsupported OS"),
};
if (err > 0) {
return switch (err) {
errno.EINVAL => @unreachable(),
errno.EFAULT => @unreachable(),
errno.EINTR => continue,
else => error.Unexpected,
}
}
return;
}
}
/// Raises a signal in the current kernel thread, ending its execution.
/// If linking against libc, this calls the abort() libc function. Otherwise
/// it uses the zig standard library implementation.
pub coldcc fn abort() -> unreachable {
if (linking_libc) {
c.abort();
}
switch (@compileVar("os")) {
Os.linux => {
_ = posix.raise(posix.SIGABRT);
_ = posix.raise(posix.SIGKILL);
while (true) {}
},
else => @compileError("Unsupported OS"),
}
}