Fix compiling some rustc crates to wasm

src/librustc_data_structures/flock.rs

@@ -15,16 +15,15 @@
 //! librustdoc, it is not production quality at all.
 
 #![allow(non_camel_case_types)]
-use std::path::Path;
+#![allow(nonstandard_style)]
 
-pub use self::imp::Lock;
+use std::io;
+use std::path::Path;
 
-#[cfg(unix)]
-mod imp {
+cfg_if! {
+    if #[cfg(unix)] {
         use std::ffi::{CString, OsStr};
         use std::os::unix::prelude::*;
-    use std::path::Path;
-    use std::io;
         use libc;
 
         #[cfg(any(target_os = "linux", target_os = "android"))]
@@ -236,16 +235,10 @@ mod imp {
                 }
             }
         }
-}
-
-#[cfg(windows)]
-#[allow(nonstandard_style)]
-mod imp {
-    use std::io;
+    } else if #[cfg(windows)] {
         use std::mem;
         use std::os::windows::prelude::*;
         use std::os::windows::raw::HANDLE;
-    use std::path::Path;
         use std::fs::{File, OpenOptions};
         use std::os::raw::{c_ulong, c_int};
 
@@ -351,9 +344,22 @@ mod imp {
 
         // Note that we don't need a Drop impl on the Windows: The file is unlocked
         // automatically when it's closed.
+    } else {
+        #[derive(Debug)]
+        pub struct Lock(());
+
+        impl Lock {
+            pub fn new(_p: &Path, _wait: bool, _create: bool, _exclusive: bool)
+                -> io::Result<Lock>
+            {
+                let msg = "file locks not supported on this platform";
+                Err(io::Error::new(io::ErrorKind::Other, msg))
+            }
+        }
+    }
 }
 
-impl imp::Lock {
+impl Lock {
     pub fn panicking_new(p: &Path,
                          wait: bool,
                          create: bool,

src/librustc_errors/lock.rs

@@ -109,7 +109,7 @@ pub fn acquire_global_lock(name: &str) -> Box<dyn Any> {
     }
 }
 
-#[cfg(unix)]
+#[cfg(not(windows))]
 pub fn acquire_global_lock(_name: &str) -> Box<dyn Any> {
     Box::new(())
 }