Auto merge of #38401 - redox-os:redox_cross, r=brson

Redox Cross Compilation

I will admit - there are things here that I wish I did not have to do. This completes the ability to create a cross compiler from the rust repository for `x86_64-unknown-redox`. I will document this PR with inline comments explaining some things.

[View this gist to see how a cross compiler is built](https://gist.github.com/jackpot51/6680ad973986e84d69c79854249f2b7e)

Prior discussion of a smaller change is here: #38366

mk/cfg/x86_64-unknown-redox.mk

@@ -0,0 +1 @@
+# rustbuild-only target

src/liballoc_jemalloc/build.rs

@@ -36,7 +36,8 @@ fn main() {
     // targets, which means we have to build the alloc_jemalloc crate
     // for targets like emscripten, even if we don't use it.
     if target.contains("rumprun") || target.contains("bitrig") || target.contains("openbsd") ||
-       target.contains("msvc") || target.contains("emscripten") || target.contains("fuchsia") {
+       target.contains("msvc") || target.contains("emscripten") || target.contains("fuchsia") ||
+       target.contains("redox") {
         println!("cargo:rustc-cfg=dummy_jemalloc");
         return;
     }

src/liballoc_system/lib.rs

@@ -19,7 +19,7 @@
             issue = "27783")]
 #![feature(allocator)]
 #![feature(staged_api)]
-#![cfg_attr(unix, feature(libc))]
+#![cfg_attr(any(unix, target_os = "redox"), feature(libc))]
 
 // The minimum alignment guaranteed by the architecture. This value is used to
 // add fast paths for low alignment values. In practice, the alignment is a
@@ -71,7 +71,7 @@ pub extern "C" fn __rust_usable_size(size: usize, align: usize) -> usize {
     imp::usable_size(size, align)
 }
 
-#[cfg(unix)]
+#[cfg(any(unix, target_os = "redox"))]
 mod imp {
     extern crate libc;
 
@@ -87,7 +87,7 @@ mod imp {
         }
     }
 
-    #[cfg(target_os = "android")]
+    #[cfg(any(target_os = "android", target_os = "redox"))]
     unsafe fn aligned_malloc(size: usize, align: usize) -> *mut u8 {
         // On android we currently target API level 9 which unfortunately
         // doesn't have the `posix_memalign` API used below. Instead we use
@@ -109,7 +109,7 @@ mod imp {
         libc::memalign(align as libc::size_t, size as libc::size_t) as *mut u8
     }
 
-    #[cfg(not(target_os = "android"))]
+    #[cfg(not(any(target_os = "android", target_os = "redox")))]
     unsafe fn aligned_malloc(size: usize, align: usize) -> *mut u8 {
         let mut out = ptr::null_mut();
         let ret = libc::posix_memalign(&mut out, align as libc::size_t, size as libc::size_t);

src/libcompiler_builtins/build.rs

@@ -242,7 +242,7 @@ fn main() {
                          "atomic_thread_fence.c"]);
     }
 
-    if !target.contains("windows") {
+    if !target.contains("redox") && !target.contains("windows") {
         sources.extend(&["emutls.c"]);
     }
 

src/librustc/session/config.rs

@@ -945,26 +945,20 @@ pub fn default_configuration(sess: &Session) -> ast::CrateConfig {
     let vendor = &sess.target.target.target_vendor;
     let max_atomic_width = sess.target.target.max_atomic_width();
 
-    let fam = if let Some(ref fam) = sess.target.target.options.target_family {
-        Symbol::intern(fam)
-    } else if sess.target.target.options.is_like_windows {
-        Symbol::intern("windows")
-    } else {
-        Symbol::intern("unix")
-    };
-
     let mut ret = HashSet::new();
     // Target bindings.
     ret.insert((Symbol::intern("target_os"), Some(Symbol::intern(os))));
-    ret.insert((Symbol::intern("target_family"), Some(fam)));
+    if let Some(ref fam) = sess.target.target.options.target_family {
+        ret.insert((Symbol::intern("target_family"), Some(Symbol::intern(fam))));
+        if fam == "windows" || fam == "unix" {
+            ret.insert((Symbol::intern(fam), None));
+        }
+    }
     ret.insert((Symbol::intern("target_arch"), Some(Symbol::intern(arch))));
     ret.insert((Symbol::intern("target_endian"), Some(Symbol::intern(end))));
     ret.insert((Symbol::intern("target_pointer_width"), Some(Symbol::intern(wordsz))));
     ret.insert((Symbol::intern("target_env"), Some(Symbol::intern(env))));
     ret.insert((Symbol::intern("target_vendor"), Some(Symbol::intern(vendor))));
-    if fam == "windows" || fam == "unix" {
-        ret.insert((fam, None));
-    }
     if sess.target.target.options.has_elf_tls {
         ret.insert((Symbol::intern("target_thread_local"), None));
     }

src/librustc_back/target/apple_base.rs

@@ -37,6 +37,7 @@ pub fn opts() -> TargetOptions {
         function_sections: false,
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         is_like_osx: true,
         has_rpath: true,
         dll_prefix: "lib".to_string(),

src/librustc_back/target/bitrig_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         position_independent_executables: true,

src/librustc_back/target/dragonfly_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         pre_link_args: vec![

src/librustc_back/target/freebsd_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         pre_link_args: vec![

src/librustc_back/target/fuchsia_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         pre_link_args: vec![

src/librustc_back/target/haiku_base.rs

@@ -17,6 +17,7 @@ pub fn opts() -> TargetOptions {
         dynamic_linking: true,
         executables: true,
         has_rpath: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         .. Default::default()
     }

src/librustc_back/target/linux_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         pre_link_args: vec![

src/librustc_back/target/mod.rs

@@ -69,6 +69,7 @@ mod windows_base;
 mod windows_msvc_base;
 mod thumb_base;
 mod fuchsia_base;
+mod redox_base;
 
 pub type TargetResult = Result<Target, String>;
 
@@ -184,6 +185,8 @@ supported_targets! {
     ("aarch64-unknown-fuchsia", aarch64_unknown_fuchsia),
     ("x86_64-unknown-fuchsia", x86_64_unknown_fuchsia),
 
+    ("x86_64-unknown-redox", x86_64_unknown_redox),
+
     ("i386-apple-ios", i386_apple_ios),
     ("x86_64-apple-ios", x86_64_apple_ios),
     ("aarch64-apple-ios", aarch64_apple_ios),

src/librustc_back/target/netbsd_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         pre_link_args: vec![

src/librustc_back/target/openbsd_base.rs

@@ -15,6 +15,7 @@ pub fn opts() -> TargetOptions {
     TargetOptions {
         dynamic_linking: true,
         executables: true,
+        target_family: Some("unix".to_string()),
         linker_is_gnu: true,
         has_rpath: true,
         is_like_openbsd: true,

src/librustc_back/target/redox_base.rs

@@ -0,0 +1,50 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use PanicStrategy;
+use target::TargetOptions;
+use std::default::Default;
+
+pub fn opts() -> TargetOptions {
+    TargetOptions {
+        pre_link_args: vec![
+            // We want to be able to strip as much executable code as possible
+            // from the linker command line, and this flag indicates to the
+            // linker that it can avoid linking in dynamic libraries that don't
+            // actually satisfy any symbols up to that point (as with many other
+            // resolutions the linker does). This option only applies to all
+            // following libraries so we're sure to pass it as one of the first
+            // arguments.
+            "-Wl,--as-needed".to_string(),
+
+            // Always enable NX protection when it is available
+            "-Wl,-z,noexecstack".to_string(),
+
+            // Static link
+            "-static".to_string()
+        ],
+        late_link_args: vec![
+            "-lc".to_string(),
+            "-lm".to_string()
+        ],
+        executables: true,
+        relocation_model: "static".to_string(),
+        disable_redzone: true,
+        eliminate_frame_pointer: false,
+        target_family: None,
+        linker_is_gnu: true,
+        no_default_libraries: true,
+        lib_allocation_crate: "alloc_system".to_string(),
+        exe_allocation_crate: "alloc_system".to_string(),
+        has_elf_tls: true,
+        panic_strategy: PanicStrategy::Abort,
+        .. Default::default()
+    }
+}

src/librustc_back/target/solaris_base.rs

@@ -16,6 +16,7 @@ pub fn opts() -> TargetOptions {
         dynamic_linking: true,
         executables: true,
         has_rpath: true,
+        target_family: Some("unix".to_string()),
         is_like_solaris: true,
         exe_allocation_crate: super::maybe_jemalloc(),
 

src/librustc_back/target/windows_base.rs

@@ -24,6 +24,7 @@ pub fn opts() -> TargetOptions {
         staticlib_prefix: "".to_string(),
         staticlib_suffix: ".lib".to_string(),
         no_default_libraries: true,
+        target_family: Some("windows".to_string()),
         is_like_windows: true,
         allows_weak_linkage: false,
         pre_link_args: vec![

src/librustc_back/target/windows_msvc_base.rs

@@ -53,6 +53,7 @@ pub fn opts() -> TargetOptions {
         exe_suffix: ".exe".to_string(),
         staticlib_prefix: "".to_string(),
         staticlib_suffix: ".lib".to_string(),
+        target_family: Some("windows".to_string()),
         is_like_windows: true,
         is_like_msvc: true,
         pre_link_args: vec![

src/librustc_back/target/x86_64_unknown_redox.rs

@@ -0,0 +1,30 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use target::{Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::redox_base::opts();
+    base.cpu = "x86-64".to_string();
+    base.max_atomic_width = Some(64);
+    base.pre_link_args.push("-m64".to_string());
+
+    Ok(Target {
+        llvm_target: "x86_64-unknown-redox".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        data_layout: "e-m:e-i64:64-f80:128-n8:16:32:64-S128".to_string(),
+        arch: "x86_64".to_string(),
+        target_os: "redox".to_string(),
+        target_env: "".to_string(),
+        target_vendor: "unknown".to_string(),
+        options: base,
+    })
+}

src/libstd/build.rs

@@ -26,7 +26,7 @@ fn main() {
     let target = env::var("TARGET").expect("TARGET was not set");
     let host = env::var("HOST").expect("HOST was not set");
     if cfg!(feature = "backtrace") && !target.contains("apple") && !target.contains("msvc") &&
-        !target.contains("emscripten") && !target.contains("fuchsia") {
+        !target.contains("emscripten") && !target.contains("fuchsia") && !target.contains("redox") {
         build_libbacktrace(&host, &target);
     }
 

src/libstd/sys/redox/ext/io.rs

@@ -13,8 +13,9 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use fs;
+use net;
 use sys;
-use sys_common::{AsInner, FromInner, IntoInner};
+use sys_common::{self, AsInner, FromInner, IntoInner};
 
 /// Raw file descriptors.
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -89,58 +90,62 @@ impl IntoRawFd for fs::File {
     }
 }
 
-/*
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRawFd for net::TcpStream {
-    fn as_raw_fd(&self) -> RawFd { *self.as_inner().socket().as_inner() }
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_inner().fd().raw()
+    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRawFd for net::TcpListener {
-    fn as_raw_fd(&self) -> RawFd { *self.as_inner().socket().as_inner() }
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_inner().fd().raw()
+    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsRawFd for net::UdpSocket {
-    fn as_raw_fd(&self) -> RawFd { *self.as_inner().socket().as_inner() }
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_inner().fd().raw()
+    }
 }
 
 #[stable(feature = "from_raw_os", since = "1.1.0")]
 impl FromRawFd for net::TcpStream {
     unsafe fn from_raw_fd(fd: RawFd) -> net::TcpStream {
-        let socket = sys::net::Socket::from_inner(fd);
-        net::TcpStream::from_inner(sys_common::net::TcpStream::from_inner(socket))
+        let file = sys::fs::File::from_inner(fd);
+        net::TcpStream::from_inner(sys_common::net::TcpStream::from_inner(file))
     }
 }
 #[stable(feature = "from_raw_os", since = "1.1.0")]
 impl FromRawFd for net::TcpListener {
     unsafe fn from_raw_fd(fd: RawFd) -> net::TcpListener {
-        let socket = sys::net::Socket::from_inner(fd);
-        net::TcpListener::from_inner(sys_common::net::TcpListener::from_inner(socket))
+        let file = sys::fs::File::from_inner(fd);
+        net::TcpListener::from_inner(sys_common::net::TcpListener::from_inner(file))
     }
 }
 #[stable(feature = "from_raw_os", since = "1.1.0")]
 impl FromRawFd for net::UdpSocket {
     unsafe fn from_raw_fd(fd: RawFd) -> net::UdpSocket {
-        let socket = sys::net::Socket::from_inner(fd);
-        net::UdpSocket::from_inner(sys_common::net::UdpSocket::from_inner(socket))
+        let file = sys::fs::File::from_inner(fd);
+        net::UdpSocket::from_inner(sys_common::net::UdpSocket::from_inner(file))
     }
 }
 
 #[stable(feature = "into_raw_os", since = "1.4.0")]
 impl IntoRawFd for net::TcpStream {
     fn into_raw_fd(self) -> RawFd {
-        self.into_inner().into_socket().into_inner()
+        self.into_inner().into_inner().into_fd().into_raw()
     }
 }
 #[stable(feature = "into_raw_os", since = "1.4.0")]
 impl IntoRawFd for net::TcpListener {
     fn into_raw_fd(self) -> RawFd {
-        self.into_inner().into_socket().into_inner()
+        self.into_inner().into_inner().into_fd().into_raw()
     }
 }
 #[stable(feature = "into_raw_os", since = "1.4.0")]
 impl IntoRawFd for net::UdpSocket {
     fn into_raw_fd(self) -> RawFd {
-        self.into_inner().into_socket().into_inner()
+        self.into_inner().into_inner().into_fd().into_raw()
     }
 }
-*/