Add modifications needed for L4re in libstd

This commit adds the needed modifications to compile the std crate
for the L4 Runtime environment (L4Re).

A target for the L4Re was introduced in commit:
c151220a84e40b65e45308cc0f3bbea4466d3acf

In many aspects implementations for linux also apply for the L4Re
microkernel.

Two uncommon characteristics had to be resolved:
* L4Re has no network funktionality
* L4Re has a maximum stacksize of 1Mb for threads

Co-authored-by: Sebastian Humenda <sebastian.humenda@tu-dresden.de>

8 files changed, 42 insertions, 8 deletions

diff --git a/src/libstd/sys/unix/args.rs b/src/libstd/sys/unix/args.rs
index 810d2d40c05..72169773df5 100644
--- a/src/libstd/sys/unix/args.rs
+++ b/src/libstd/sys/unix/args.rs
@@ -65,6 +65,7 @@ impl DoubleEndedIterator for Args {
           target_os = "solaris",
           target_os = "emscripten",
           target_os = "haiku",
+          target_os = "l4re",
           target_os = "fuchsia"))]
 mod imp {
     use os::unix::prelude::*;
diff --git a/src/libstd/sys/unix/condvar.rs b/src/libstd/sys/unix/condvar.rs
index b9ea573b323..89a44b97657 100644
--- a/src/libstd/sys/unix/condvar.rs
+++ b/src/libstd/sys/unix/condvar.rs
@@ -38,10 +38,16 @@ impl Condvar {
         Condvar { inner: UnsafeCell::new(libc::PTHREAD_COND_INITIALIZER) }
     }
 
-    #[cfg(any(target_os = "macos", target_os = "ios", target_os = "android"))]
+    #[cfg(any(target_os = "macos",
+              target_os = "ios",
+              target_os = "l4re",
+              target_os = "android"))]
     pub unsafe fn init(&mut self) {}
 
-    #[cfg(not(any(target_os = "macos", target_os = "ios", target_os = "android")))]
+    #[cfg(not(any(target_os = "macos",
+                  target_os = "ios",
+                  target_os = "l4re",
+                  target_os = "android")))]
     pub unsafe fn init(&mut self) {
         use mem;
         let mut attr: libc::pthread_condattr_t = mem::uninitialized();
diff --git a/src/libstd/sys/unix/env.rs b/src/libstd/sys/unix/env.rs
index eff3a8c2a34..3d9a06bedd5 100644
--- a/src/libstd/sys/unix/env.rs
+++ b/src/libstd/sys/unix/env.rs
@@ -182,3 +182,14 @@ pub mod os {
     pub const EXE_SUFFIX: &'static str = "";
     pub const EXE_EXTENSION: &'static str = "";
 }
+
+#[cfg(target_os = "l4re")]
+pub mod os {
+    pub const FAMILY: &'static str = "unix";
+    pub const OS: &'static str = "l4re";
+    pub const DLL_PREFIX: &'static str = "lib";
+    pub const DLL_SUFFIX: &'static str = ".so";
+    pub const DLL_EXTENSION: &'static str = "so";
+    pub const EXE_SUFFIX: &'static str = "";
+    pub const EXE_EXTENSION: &'static str = "";
+}
diff --git a/src/libstd/sys/unix/fd.rs b/src/libstd/sys/unix/fd.rs
index f50b093acc8..5dafc3251e7 100644
--- a/src/libstd/sys/unix/fd.rs
+++ b/src/libstd/sys/unix/fd.rs
@@ -144,6 +144,7 @@ impl FileDesc {
                   target_os = "solaris",
                   target_os = "emscripten",
                   target_os = "fuchsia",
+                  target_os = "l4re",
                   target_os = "haiku")))]
     pub fn set_cloexec(&self) -> io::Result<()> {
         unsafe {
@@ -155,6 +156,7 @@ impl FileDesc {
               target_os = "solaris",
               target_os = "emscripten",
               target_os = "fuchsia",
+              target_os = "l4re",
               target_os = "haiku"))]
     pub fn set_cloexec(&self) -> io::Result<()> {
         unsafe {
diff --git a/src/libstd/sys/unix/fs.rs b/src/libstd/sys/unix/fs.rs
index f94af491332..13112fc1fa5 100644
--- a/src/libstd/sys/unix/fs.rs
+++ b/src/libstd/sys/unix/fs.rs
@@ -23,19 +23,21 @@ use sys::time::SystemTime;
 use sys::{cvt, cvt_r};
 use sys_common::{AsInner, FromInner};
 
-#[cfg(any(target_os = "linux", target_os = "emscripten"))]
+#[cfg(any(target_os = "linux", target_os = "emscripten", target_os = "l4re"))]
 use libc::{stat64, fstat64, lstat64, off64_t, ftruncate64, lseek64, dirent64, readdir64_r, open64};
 #[cfg(target_os = "android")]
 use libc::{stat as stat64, fstat as fstat64, lstat as lstat64, lseek64,
            dirent as dirent64, open as open64};
 #[cfg(not(any(target_os = "linux",
               target_os = "emscripten",
+              target_os = "l4re",
               target_os = "android")))]
 use libc::{stat as stat64, fstat as fstat64, lstat as lstat64, off_t as off64_t,
            ftruncate as ftruncate64, lseek as lseek64, dirent as dirent64, open as open64};
 #[cfg(not(any(target_os = "linux",
               target_os = "emscripten",
               target_os = "solaris",
+              target_os = "l4re",
               target_os = "fuchsia")))]
 use libc::{readdir_r as readdir64_r};
 
@@ -316,6 +318,7 @@ impl DirEntry {
               target_os = "android",
               target_os = "solaris",
               target_os = "haiku",
+              target_os = "l4re",
               target_os = "fuchsia"))]
     pub fn ino(&self) -> u64 {
         self.entry.d_ino as u64
@@ -346,6 +349,7 @@ impl DirEntry {
     #[cfg(any(target_os = "android",
               target_os = "linux",
               target_os = "emscripten",
+              target_os = "l4re",
               target_os = "haiku"))]
     fn name_bytes(&self) -> &[u8] {
         unsafe {
diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs
index efa14964604..697e9b962b1 100644
--- a/src/libstd/sys/unix/mod.rs
+++ b/src/libstd/sys/unix/mod.rs
@@ -28,6 +28,7 @@ use libc;
 #[cfg(all(not(dox), target_os = "solaris"))]   pub use os::solaris as platform;
 #[cfg(all(not(dox), target_os = "emscripten"))] pub use os::emscripten as platform;
 #[cfg(all(not(dox), target_os = "fuchsia"))]   pub use os::fuchsia as platform;
+#[cfg(all(not(dox), target_os = "l4re"))]      pub use os::linux as platform;
 
 #[macro_use]
 pub mod weak;
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index 8e41fd009be..5ef98d24710 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -38,7 +38,10 @@ static ENV_LOCK: Mutex = Mutex::new();
 
 extern {
     #[cfg(not(target_os = "dragonfly"))]
-    #[cfg_attr(any(target_os = "linux", target_os = "emscripten", target_os = "fuchsia"),
+    #[cfg_attr(any(target_os = "linux",
+                   target_os = "emscripten",
+                   target_os = "fuchsia",
+                   target_os = "l4re"),
                link_name = "__errno_location")]
     #[cfg_attr(any(target_os = "bitrig",
                    target_os = "netbsd",
@@ -346,10 +349,10 @@ pub fn current_exe() -> io::Result<PathBuf> {
     }
 }
 
-#[cfg(target_os = "fuchsia")]
+#[cfg(any(target_os = "fuchsia", target_os = "l4re"))]
 pub fn current_exe() -> io::Result<PathBuf> {
     use io::ErrorKind;
-    Err(io::Error::new(ErrorKind::Other, "Not yet implemented on fuchsia"))
+    Err(io::Error::new(ErrorKind::Other, "Not yet implemented!"))
 }
 
 pub struct Env {
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index 40f1d6a6db1..5e2610736a8 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -52,6 +52,11 @@ impl Thread {
         assert_eq!(libc::pthread_attr_init(&mut attr), 0);
 
         let stack_size = cmp::max(stack, min_stack_size(&attr));
+
+        // L4Re only supports a maximum of 1Mb per default.
+        #[cfg(target_os = "l4re")]
+        let stack_size = cmp::min(stack_size, 1024 * 1024);
+
         match pthread_attr_setstacksize(&mut attr,
                                         stack_size) {
             0 => {}
@@ -131,6 +136,7 @@ impl Thread {
     #[cfg(any(target_env = "newlib",
               target_os = "solaris",
               target_os = "haiku",
+              target_os = "l4re",
               target_os = "emscripten"))]
     pub fn set_name(_name: &CStr) {
         // Newlib, Illumos, Haiku, and Emscripten have no way to set a thread name.
@@ -226,7 +232,7 @@ pub mod guard {
     }
 
     #[cfg(any(target_os = "android", target_os = "freebsd",
-              target_os = "linux", target_os = "netbsd"))]
+              target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
     unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
         let mut ret = None;
         let mut attr: libc::pthread_attr_t = ::mem::zeroed();
@@ -328,7 +334,7 @@ pub mod guard {
     }
 
     #[cfg(any(target_os = "android", target_os = "freebsd",
-              target_os = "linux", target_os = "netbsd"))]
+              target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
     pub unsafe fn current() -> Option<usize> {
         let mut ret = None;
         let mut attr: libc::pthread_attr_t = ::mem::zeroed();