Rollup merge of #55182 - jD91mZM2:rebased, r=alexcrichton

Redox: Update to new changes

These are all cherry-picked from our fork:

 - Remove the `env:` scheme
 - Update `execve` system call to `fexec`
 - Interpret shebangs: these are no longer handled by the kernel, which like usual tries to be as minimal as possible

3 files changed, 48 insertions, 11 deletions

diff --git a/src/libstd/sys/redox/syscall/call.rs b/src/libstd/sys/redox/syscall/call.rs
index f9a8bd61ac8..61cd97d6d43 100644
--- a/src/libstd/sys/redox/syscall/call.rs
+++ b/src/libstd/sys/redox/syscall/call.rs
@@ -82,12 +82,6 @@ pub fn dup2(fd: usize, newfd: usize, buf: &[u8]) -> Result<usize> {
     unsafe { syscall4(SYS_DUP2, fd, newfd, buf.as_ptr() as usize, buf.len()) }
 }
 
-/// Replace the current process with a new executable
-pub fn execve<T: AsRef<[u8]>>(path: T, args: &[[usize; 2]]) -> Result<usize> {
-    unsafe { syscall4(SYS_EXECVE, path.as_ref().as_ptr() as usize,
-                      path.as_ref().len(), args.as_ptr() as usize, args.len()) }
-}
-
 /// Exit the current process
 pub fn exit(status: usize) -> Result<usize> {
     unsafe { syscall1(SYS_EXIT, status) }
@@ -110,9 +104,10 @@ pub fn fcntl(fd: usize, cmd: usize, arg: usize) -> Result<usize> {
     unsafe { syscall3(SYS_FCNTL, fd, cmd, arg) }
 }
 
-/// Register a file for event-based I/O
-pub fn fevent(fd: usize, flags: usize) -> Result<usize> {
-    unsafe { syscall2(SYS_FEVENT, fd, flags) }
+/// Replace the current process with a new executable
+pub fn fexec(fd: usize, args: &[[usize; 2]], vars: &[[usize; 2]]) -> Result<usize> {
+    unsafe { syscall5(SYS_FEXEC, fd, args.as_ptr() as usize, args.len(),
+                      vars.as_ptr() as usize, vars.len()) }
 }
 
 /// Map a file into memory
diff --git a/src/libstd/sys/redox/syscall/flag.rs b/src/libstd/sys/redox/syscall/flag.rs
index 0f61b9fa77b..0f1a2c23159 100644
--- a/src/libstd/sys/redox/syscall/flag.rs
+++ b/src/libstd/sys/redox/syscall/flag.rs
@@ -113,4 +113,46 @@ pub const SA_RESTART: usize =   0x10000000;
 pub const SA_NODEFER: usize =   0x40000000;
 pub const SA_RESETHAND: usize = 0x80000000;
 
-pub const WNOHANG: usize = 1;
+pub const WNOHANG: usize =    0x01;
+pub const WUNTRACED: usize =  0x02;
+pub const WCONTINUED: usize = 0x08;
+
+/// True if status indicates the child is stopped.
+pub fn wifstopped(status: usize) -> bool {
+    (status & 0xff) == 0x7f
+}
+
+/// If wifstopped(status), the signal that stopped the child.
+pub fn wstopsig(status: usize) -> usize {
+    (status >> 8) & 0xff
+}
+
+/// True if status indicates the child continued after a stop.
+pub fn wifcontinued(status: usize) -> bool {
+    status == 0xffff
+}
+
+/// True if STATUS indicates termination by a signal.
+pub fn wifsignaled(status: usize) -> bool {
+    ((status & 0x7f) + 1) as i8 >= 2
+}
+
+/// If wifsignaled(status), the terminating signal.
+pub fn wtermsig(status: usize) -> usize {
+    status & 0x7f
+}
+
+/// True if status indicates normal termination.
+pub fn wifexited(status: usize) -> bool {
+    wtermsig(status) == 0
+}
+
+/// If wifexited(status), the exit status.
+pub fn wexitstatus(status: usize) -> usize {
+    (status >> 8) & 0xff
+}
+
+/// True if status indicates a core dump was created.
+pub fn wcoredump(status: usize) -> bool {
+    (status & 0x80) != 0
+}
diff --git a/src/libstd/sys/redox/syscall/number.rs b/src/libstd/sys/redox/syscall/number.rs
index 45cb40e3908..1e187565a67 100644
--- a/src/libstd/sys/redox/syscall/number.rs
+++ b/src/libstd/sys/redox/syscall/number.rs
@@ -36,6 +36,7 @@ pub const SYS_FCHMOD: usize =   SYS_CLASS_FILE | 94;
 pub const SYS_FCHOWN: usize =   SYS_CLASS_FILE | 207;
 pub const SYS_FCNTL: usize =    SYS_CLASS_FILE | 55;
 pub const SYS_FEVENT: usize =   SYS_CLASS_FILE | 927;
+pub const SYS_FEXEC: usize =    SYS_CLASS_FILE | 11;
 pub const SYS_FMAP: usize =     SYS_CLASS_FILE | 90;
 pub const SYS_FUNMAP: usize =   SYS_CLASS_FILE | 91;
 pub const SYS_FPATH: usize =    SYS_CLASS_FILE | SYS_ARG_MSLICE | 928;
@@ -50,7 +51,6 @@ pub const SYS_BRK: usize =      45;
 pub const SYS_CHDIR: usize =    12;
 pub const SYS_CLOCK_GETTIME: usize = 265;
 pub const SYS_CLONE: usize =    120;
-pub const SYS_EXECVE: usize =   11;
 pub const SYS_EXIT: usize =     1;
 pub const SYS_FUTEX: usize =    240;
 pub const SYS_GETCWD: usize =   183;