Fix compilation on macOS and FreeBSD with --no-default-features. (bytecodealliance#966)

Author: sunfishcode

src/backend/libc/fs/syscalls.rs

@@ -10,7 +10,7 @@ use crate::backend::conv::ret_usize;
 use crate::backend::conv::{borrowed_fd, c_str, ret, ret_c_int, ret_off_t, ret_owned_fd};
 use crate::fd::{BorrowedFd, OwnedFd};
 use crate::ffi::CStr;
-#[cfg(apple)]
+#[cfg(all(apple, feature = "alloc"))]
 use crate::ffi::CString;
 #[cfg(not(any(target_os = "espidf", target_os = "vita")))]
 use crate::fs::Access;
@@ -73,7 +73,7 @@ use crate::io;
 use crate::timespec::LibcTimespec;
 #[cfg(not(target_os = "wasi"))]
 use crate::ugid::{Gid, Uid};
-#[cfg(apple)]
+#[cfg(all(apple, feature = "alloc"))]
 use alloc::vec;
 use core::mem::MaybeUninit;
 #[cfg(apple)]
@@ -2061,7 +2061,7 @@ pub(crate) unsafe fn copyfile_state_get(
     nonnegative_ret(copyfile_state_get(state, flag, dst))
 }
 
-#[cfg(apple)]
+#[cfg(all(apple, feature = "alloc"))]
 pub(crate) fn getpath(fd: BorrowedFd<'_>) -> io::Result<CString> {
     // The use of `PATH_MAX` is generally not encouraged, but it
     // is inevitable in this case because macOS defines `fcntl` with

src/fs/mod.rs

@@ -28,7 +28,7 @@ mod fcntl_apple;
 #[cfg(apple)]
 mod fcopyfile;
 pub(crate) mod fd;
-#[cfg(apple)]
+#[cfg(all(apple, feature = "alloc"))]
 mod getpath;
 #[cfg(not(target_os = "wasi"))] // WASI doesn't have get[gpu]id.
 mod id;
@@ -96,7 +96,7 @@ pub use fcntl_apple::*;
 #[cfg(apple)]
 pub use fcopyfile::*;
 pub use fd::*;
-#[cfg(apple)]
+#[cfg(all(apple, feature = "alloc"))]
 pub use getpath::getpath;
 #[cfg(not(target_os = "wasi"))]
 pub use id::*;

src/process/procctl.rs

@@ -5,8 +5,8 @@
 
 #![allow(unsafe_code)]
 
-use alloc::vec;
-use alloc::vec::Vec;
+#[cfg(feature = "alloc")]
+use alloc::{vec, vec::Vec};
 use core::mem::MaybeUninit;
 use core::ptr;
 
@@ -342,6 +342,7 @@ pub struct PidInfo {
 ///  - [FreeBSD: `procctl(PROC_REAP_GETPIDS,...)`]
 ///
 /// [FreeBSD: `procctl(PROC_REAP_GETPIDS,...)`]: https://man.freebsd.org/cgi/man.cgi?query=procctl&sektion=2
+#[cfg(feature = "alloc")]
 pub fn get_reaper_pids(process: ProcSelector) -> io::Result<Vec<PidInfo>> {
     // Sadly no better way to guarantee that we get all the results than to
     // allocate ~8MB of memory..