Auto merge of #47225 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 5 pull requests

- Successful merges: #46987, #47165, #47173, #47202, #47216
- Failed merges:

3 files changed, 28 insertions, 32 deletions

diff --git a/src/libstd/env.rs b/src/libstd/env.rs
index 457c6e1409d..ed34c1204b3 100644
--- a/src/libstd/env.rs
+++ b/src/libstd/env.rs
@@ -571,8 +571,11 @@ pub fn temp_dir() -> PathBuf {
 
 /// Returns the full filesystem path of the current running executable.
 ///
-/// The path returned is not necessarily a "real path" of the executable as
-/// there may be intermediate symlinks.
+/// # Platform-specific behavior
+///
+/// If the executable was invoked through a symbolic link, some platforms will
+/// return the path of the symbolic link and other platforms will return the
+/// path of the symbolic link’s target.
 ///
 /// # Errors
 ///
@@ -599,14 +602,14 @@ pub fn temp_dir() -> PathBuf {
 /// Ok("/home/alex/foo")
 /// ```
 ///
-/// And you make a symbolic link of the program:
+/// And you make a hard link of the program:
 ///
 /// ```bash
 /// $ ln foo bar
 /// ```
 ///
-/// When you run it, you won't get the original executable, you'll get the
-/// symlink:
+/// When you run it, you won’t get the path of the original executable, you’ll
+/// get the path of the hard link:
 ///
 /// ```bash
 /// $ ./bar
@@ -614,9 +617,9 @@ pub fn temp_dir() -> PathBuf {
 /// ```
 ///
 /// This sort of behavior has been known to [lead to privilege escalation] when
-/// used incorrectly, for example.
+/// used incorrectly.
 ///
-/// [lead to privilege escalation]: http://securityvulns.com/Wdocument183.html
+/// [lead to privilege escalation]: https://securityvulns.com/Wdocument183.html
 ///
 /// # Examples
 ///
@@ -625,7 +628,7 @@ pub fn temp_dir() -> PathBuf {
 ///
 /// match env::current_exe() {
 ///     Ok(exe_path) => println!("Path of this executable is: {}",
-///                               exe_path.display()),
+///                              exe_path.display()),
 ///     Err(e) => println!("failed to get current exe path: {}", e),
 /// };
 /// ```
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index e9b707c57eb..ad9cf1eed70 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -601,7 +601,7 @@ pub trait Read {
         read_to_end(self, buf)
     }
 
-    /// Read all bytes until EOF in this source, placing them into `buf`.
+    /// Read all bytes until EOF in this source, appending them to `buf`.
     ///
     /// If successful, this function returns the number of bytes which were read
     /// and appended to `buf`.
diff --git a/src/libstd/sys/unix/args.rs b/src/libstd/sys/unix/args.rs
index 72169773df5..e1c7ffc19e5 100644
--- a/src/libstd/sys/unix/args.rs
+++ b/src/libstd/sys/unix/args.rs
@@ -69,7 +69,7 @@ impl DoubleEndedIterator for Args {
           target_os = "fuchsia"))]
 mod imp {
     use os::unix::prelude::*;
-    use mem;
+    use ptr;
     use ffi::{CStr, OsString};
     use marker::PhantomData;
     use libc;
@@ -77,49 +77,42 @@ mod imp {
 
     use sys_common::mutex::Mutex;
 
-    static mut GLOBAL_ARGS_PTR: usize = 0;
+    static mut ARGC: isize = 0;
+    static mut ARGV: *const *const u8 = ptr::null();
     static LOCK: Mutex = Mutex::new();
 
     pub unsafe fn init(argc: isize, argv: *const *const u8) {
-        let args = (0..argc).map(|i| {
-            CStr::from_ptr(*argv.offset(i) as *const libc::c_char).to_bytes().to_vec()
-        }).collect();
-
         LOCK.lock();
-        let ptr = get_global_ptr();
-        assert!((*ptr).is_none());
-        (*ptr) = Some(box args);
+        ARGC = argc;
+        ARGV = argv;
         LOCK.unlock();
     }
 
     pub unsafe fn cleanup() {
         LOCK.lock();
-        *get_global_ptr() = None;
+        ARGC = 0;
+        ARGV = ptr::null();
         LOCK.unlock();
     }
 
     pub fn args() -> Args {
-        let bytes = clone().unwrap_or(Vec::new());
-        let v: Vec<OsString> = bytes.into_iter().map(|v| {
-            OsStringExt::from_vec(v)
-        }).collect();
-        Args { iter: v.into_iter(), _dont_send_or_sync_me: PhantomData }
+        Args {
+            iter: clone().into_iter(),
+            _dont_send_or_sync_me: PhantomData
+        }
     }
 
-    fn clone() -> Option<Vec<Vec<u8>>> {
+    fn clone() -> Vec<OsString> {
         unsafe {
             LOCK.lock();
-            let ptr = get_global_ptr();
-            let ret = (*ptr).as_ref().map(|s| (**s).clone());
+            let ret = (0..ARGC).map(|i| {
+                let cstr = CStr::from_ptr(*ARGV.offset(i) as *const libc::c_char);
+                OsStringExt::from_vec(cstr.to_bytes().to_vec())
+            }).collect();
             LOCK.unlock();
             return ret
         }
     }
-
-    fn get_global_ptr() -> *mut Option<Box<Vec<Vec<u8>>>> {
-        unsafe { mem::transmute(&GLOBAL_ARGS_PTR) }
-    }
-
 }
 
 #[cfg(any(target_os = "macos",