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Auto merge of #46789 - Diggsey:command-env-capture, r=dtolnay 

Capture `Command` environment at spawn

Fixes #28975

This tracks a set of changes to the environment and then replays them at spawn time.
This commit is contained in:
bors 2017-12-24 20:57:20 +00:00
parent b9e4d3417f ccc91d7b48
commit c284f8807e
11 changed files with 320 additions and 166 deletions
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29
src/libstd/process.rs
View File

@ -513,7 +513,7 @@ impl Command {
pub fn env<K, V>(&mut self, key: K, val: V) -> &mut Command
where K: AsRef<OsStr>, V: AsRef<OsStr>
{
self.inner.env(key.as_ref(), val.as_ref());
self.inner.env_mut().set(key.as_ref(), val.as_ref());
self
}
@ -546,7 +546,7 @@ impl Command {
where I: IntoIterator<Item=(K, V)>, K: AsRef<OsStr>, V: AsRef<OsStr>
{
for (ref key, ref val) in vars {
self.inner.env(key.as_ref(), val.as_ref());
self.inner.env_mut().set(key.as_ref(), val.as_ref());
}
self
}
@ -567,7 +567,7 @@ impl Command {
/// ```
#[stable(feature = "process", since = "1.0.0")]
pub fn env_remove<K: AsRef<OsStr>>(&mut self, key: K) -> &mut Command {
self.inner.env_remove(key.as_ref());
self.inner.env_mut().remove(key.as_ref());
self
}
@ -587,7 +587,7 @@ impl Command {
/// ```
#[stable(feature = "process", since = "1.0.0")]
pub fn env_clear(&mut self) -> &mut Command {
self.inner.env_clear();
self.inner.env_mut().clear();
self
}
@ -1715,6 +1715,27 @@ mod tests {
"didn't find RUN_TEST_NEW_ENV inside of:\n\n{}", output);
}
#[test]
fn test_capture_env_at_spawn() {
use env;
let mut cmd = env_cmd();
cmd.env("RUN_TEST_NEW_ENV1", "123");
// This variable will not be present if the environment has already
// been captured above.
env::set_var("RUN_TEST_NEW_ENV2", "456");
let result = cmd.output().unwrap();
env::remove_var("RUN_TEST_NEW_ENV2");
let output = String::from_utf8_lossy(&result.stdout).to_string();
assert!(output.contains("RUN_TEST_NEW_ENV1=123"),
"didn't find RUN_TEST_NEW_ENV1 inside of:\n\n{}", output);
assert!(output.contains("RUN_TEST_NEW_ENV2=456"),
"didn't find RUN_TEST_NEW_ENV2 inside of:\n\n{}", output);
}
// Regression tests for #30858.
#[test]
fn test_interior_nul_in_progname_is_error() {

24
src/libstd/sys/redox/process.rs
View File

@ -8,8 +8,7 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use collections::hash_map::HashMap;
use env::{self, split_paths};
use env::{split_paths};
use ffi::OsStr;
use os::unix::ffi::OsStrExt;
use fmt;
@ -19,6 +18,7 @@ use sys::fd::FileDesc;
use sys::fs::{File, OpenOptions};
use sys::pipe::{self, AnonPipe};
use sys::{cvt, syscall};
use sys_common::process::{CommandEnv, DefaultEnvKey};
////////////////////////////////////////////////////////////////////////////////
// Command
@ -44,7 +44,7 @@ pub struct Command {
// other keys.
program: String,
args: Vec<String>,
env: HashMap<String, String>,
env: CommandEnv<DefaultEnvKey>,
cwd: Option<String>,
uid: Option<u32>,
@ -90,7 +90,7 @@ impl Command {
Command {
program: program.to_str().unwrap().to_owned(),
args: Vec::new(),
env: HashMap::new(),
env: Default::default(),
cwd: None,
uid: None,
gid: None,
@ -106,16 +106,8 @@ impl Command {
self.args.push(arg.to_str().unwrap().to_owned());
}
pub fn env(&mut self, key: &OsStr, val: &OsStr) {
self.env.insert(key.to_str().unwrap().to_owned(), val.to_str().unwrap().to_owned());
}
pub fn env_remove(&mut self, key: &OsStr) {
self.env.remove(key.to_str().unwrap());
}
pub fn env_clear(&mut self) {
self.env.clear();
pub fn env_mut(&mut self) -> &mut CommandEnv<DefaultEnvKey> {
&mut self.env
}
pub fn cwd(&mut self, dir: &OsStr) {
@ -309,9 +301,7 @@ impl Command {
args.push([arg.as_ptr() as usize, arg.len()]);
}
for (key, val) in self.env.iter() {
env::set_var(key, val);
}
self.env.apply();
let program = if self.program.contains(':') || self.program.contains('/') {
Some(PathBuf::from(&self.program))

143
src/libstd/sys/unix/process/process_common.rs
View File

@ -10,8 +10,6 @@
use os::unix::prelude::*;
use collections::hash_map::{HashMap, Entry};
use env;
use ffi::{OsString, OsStr, CString, CStr};
use fmt;
use io;
@ -20,6 +18,8 @@ use ptr;
use sys::fd::FileDesc;
use sys::fs::{File, OpenOptions};
use sys::pipe::{self, AnonPipe};
use sys_common::process::{CommandEnv, DefaultEnvKey};
use collections::BTreeMap;
////////////////////////////////////////////////////////////////////////////////
// Command
@ -45,9 +45,8 @@ pub struct Command {
// other keys.
program: CString,
args: Vec<CString>,
env: Option<HashMap<OsString, (usize, CString)>>,
argv: Vec<*const c_char>,
envp: Option<Vec<*const c_char>>,
env: CommandEnv<DefaultEnvKey>,
cwd: Option<CString>,
uid: Option<uid_t>,
@ -96,8 +95,7 @@ impl Command {
argv: vec![program.as_ptr(), ptr::null()],
program,
args: Vec::new(),
env: None,
envp: None,
env: Default::default(),
cwd: None,
uid: None,
gid: None,
@ -121,68 +119,6 @@ impl Command {
self.args.push(arg);
}
fn init_env_map(&mut self) -> (&mut HashMap<OsString, (usize, CString)>,
&mut Vec<*const c_char>) {
if self.env.is_none() {
let mut map = HashMap::new();
let mut envp = Vec::new();
for (k, v) in env::vars_os() {
let s = pair_to_key(&k, &v, &mut self.saw_nul);
envp.push(s.as_ptr());
map.insert(k, (envp.len() - 1, s));
}
envp.push(ptr::null());
self.env = Some(map);
self.envp = Some(envp);
}
(self.env.as_mut().unwrap(), self.envp.as_mut().unwrap())
}
pub fn env(&mut self, key: &OsStr, val: &OsStr) {
let new_key = pair_to_key(key, val, &mut self.saw_nul);
let (map, envp) = self.init_env_map();
// If `key` is already present then we just update `envp` in place
// (and store the owned value), but if it's not there we override the
// trailing NULL pointer, add a new NULL pointer, and store where we
// were located.
match map.entry(key.to_owned()) {
Entry::Occupied(mut e) => {
let (i, ref mut s) = *e.get_mut();
envp[i] = new_key.as_ptr();
*s = new_key;
}
Entry::Vacant(e) => {
let len = envp.len();
envp[len - 1] = new_key.as_ptr();
envp.push(ptr::null());
e.insert((len - 1, new_key));
}
}
}
pub fn env_remove(&mut self, key: &OsStr) {
let (map, envp) = self.init_env_map();
// If we actually ended up removing a key, then we need to update the
// position of all keys that come after us in `envp` because they're all
// one element sooner now.
if let Some((i, _)) = map.remove(key) {
envp.remove(i);
for (_, &mut (ref mut j, _)) in map.iter_mut() {
if *j >= i {
*j -= 1;
}
}
}
}
pub fn env_clear(&mut self) {
self.env = Some(HashMap::new());
self.envp = Some(vec![ptr::null()]);
}
pub fn cwd(&mut self, dir: &OsStr) {
self.cwd = Some(os2c(dir, &mut self.saw_nul));
}
@ -196,9 +132,6 @@ impl Command {
pub fn saw_nul(&self) -> bool {
self.saw_nul
}
pub fn get_envp(&self) -> &Option<Vec<*const c_char>> {
&self.envp
}
pub fn get_argv(&self) -> &Vec<*const c_char> {
&self.argv
}
@ -237,6 +170,15 @@ impl Command {
self.stderr = Some(stderr);
}
pub fn env_mut(&mut self) -> &mut CommandEnv<DefaultEnvKey> {
&mut self.env
}
pub fn capture_env(&mut self) -> Option<CStringArray> {
let maybe_env = self.env.capture_if_changed();
maybe_env.map(|env| construct_envp(env, &mut self.saw_nul))
}
pub fn setup_io(&self, default: Stdio, needs_stdin: bool)
-> io::Result<(StdioPipes, ChildPipes)> {
let null = Stdio::Null;
@ -268,6 +210,53 @@ fn os2c(s: &OsStr, saw_nul: &mut bool) -> CString {
})
}
// Helper type to manage ownership of the strings within a C-style array.
pub struct CStringArray {
items: Vec<CString>,
ptrs: Vec<*const c_char>
}
impl CStringArray {
pub fn with_capacity(capacity: usize) -> Self {
let mut result = CStringArray {
items: Vec::with_capacity(capacity),
ptrs: Vec::with_capacity(capacity+1)
};
result.ptrs.push(ptr::null());
result
}
pub fn push(&mut self, item: CString) {
let l = self.ptrs.len();
self.ptrs[l-1] = item.as_ptr();
self.ptrs.push(ptr::null());
self.items.push(item);
}
pub fn as_ptr(&self) -> *const *const c_char {
self.ptrs.as_ptr()
}
}
fn construct_envp(env: BTreeMap<DefaultEnvKey, OsString>, saw_nul: &mut bool) -> CStringArray {
let mut result = CStringArray::with_capacity(env.len());
for (k, v) in env {
let mut k: OsString = k.into();
// Reserve additional space for '=' and null terminator
k.reserve_exact(v.len() + 2);
k.push("=");
k.push(&v);
// Add the new entry into the array
if let Ok(item) = CString::new(k.into_vec()) {
result.push(item);
} else {
*saw_nul = true;
}
}
result
}
impl Stdio {
pub fn to_child_stdio(&self, readable: bool)
-> io::Result<(ChildStdio, Option<AnonPipe>)> {
@ -337,18 +326,6 @@ impl ChildStdio {
}
}
fn pair_to_key(key: &OsStr, value: &OsStr, saw_nul: &mut bool) -> CString {
let (key, value) = (key.as_bytes(), value.as_bytes());
let mut v = Vec::with_capacity(key.len() + value.len() + 1);
v.extend(key);
v.push(b'=');
v.extend(value);
CString::new(v).unwrap_or_else(|_e| {
*saw_nul = true;
CString::new("foo=bar").unwrap()
})
}
impl fmt::Debug for Command {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{:?}", self.program)?;

10
src/libstd/sys/unix/process/process_fuchsia.rs
View File

@ -23,6 +23,8 @@ use sys::process::process_common::*;
impl Command {
pub fn spawn(&mut self, default: Stdio, needs_stdin: bool)
-> io::Result<(Process, StdioPipes)> {
let envp = self.capture_env();
if self.saw_nul() {
return Err(io::Error::new(io::ErrorKind::InvalidInput,
"nul byte found in provided data"));
@ -30,7 +32,7 @@ impl Command {
let (ours, theirs) = self.setup_io(default, needs_stdin)?;
let process_handle = unsafe { self.do_exec(theirs)? };
let process_handle = unsafe { self.do_exec(theirs, envp.as_ref())? };
Ok((Process { handle: Handle::new(process_handle) }, ours))
}
@ -50,13 +52,13 @@ impl Command {
}
}
unsafe fn do_exec(&mut self, stdio: ChildPipes)
unsafe fn do_exec(&mut self, stdio: ChildPipes, maybe_envp: Option<&CStringArray>)
-> io::Result<zx_handle_t> {
use sys::process::zircon::*;
let job_handle = zx_job_default();
let envp = match *self.get_envp() {
Some(ref envp) => envp.as_ptr(),
let envp = match maybe_envp {
Some(envp) => envp.as_ptr(),
None => ptr::null(),
};

16
src/libstd/sys/unix/process/process_unix.rs
View File

@ -26,6 +26,8 @@ impl Command {
const CLOEXEC_MSG_FOOTER: &'static [u8] = b"NOEX";
let envp = self.capture_env();
if self.saw_nul() {
return Err(io::Error::new(ErrorKind::InvalidInput,
"nul byte found in provided data"));
@ -38,7 +40,7 @@ impl Command {
match cvt(libc::fork())? {
0 => {
drop(input);
let err = self.do_exec(theirs);
let err = self.do_exec(theirs, envp.as_ref());
let errno = err.raw_os_error().unwrap_or(libc::EINVAL) as u32;
let bytes = [
(errno >> 24) as u8,
@ -99,13 +101,15 @@ impl Command {
}
pub fn exec(&mut self, default: Stdio) -> io::Error {
let envp = self.capture_env();
if self.saw_nul() {
return io::Error::new(ErrorKind::InvalidInput,
"nul byte found in provided data")
}
match self.setup_io(default, true) {
Ok((_, theirs)) => unsafe { self.do_exec(theirs) },
Ok((_, theirs)) => unsafe { self.do_exec(theirs, envp.as_ref()) },
Err(e) => e,
}
}
@ -140,7 +144,11 @@ impl Command {
// allocation). Instead we just close it manually. This will never
// have the drop glue anyway because this code never returns (the
// child will either exec() or invoke libc::exit)
unsafe fn do_exec(&mut self, stdio: ChildPipes) -> io::Error {
unsafe fn do_exec(
&mut self,
stdio: ChildPipes,
maybe_envp: Option<&CStringArray>
) -> io::Error {
use sys::{self, cvt_r};
macro_rules! t {
@ -180,7 +188,7 @@ impl Command {
if let Some(ref cwd) = *self.get_cwd() {
t!(cvt(libc::chdir(cwd.as_ptr())));
}
if let Some(ref envp) = *self.get_envp() {
if let Some(envp) = maybe_envp {
*sys::os::environ() = envp.as_ptr();
}

15
src/libstd/sys/wasm/process.rs
View File

@ -14,12 +14,14 @@ use io;
use sys::fs::File;
use sys::pipe::AnonPipe;
use sys::{unsupported, Void};
use sys_common::process::{CommandEnv, DefaultEnvKey};
////////////////////////////////////////////////////////////////////////////////
// Command
////////////////////////////////////////////////////////////////////////////////
pub struct Command {
env: CommandEnv<DefaultEnvKey>
}
// passed back to std::process with the pipes connected to the child, if any
@ -38,19 +40,16 @@ pub enum Stdio {
impl Command {
pub fn new(_program: &OsStr) -> Command {
Command {}
Command {
env: Default::default()
}
}
pub fn arg(&mut self, _arg: &OsStr) {
}
pub fn env(&mut self, _key: &OsStr, _val: &OsStr) {
}
pub fn env_remove(&mut self, _key: &OsStr) {
}
pub fn env_clear(&mut self) {
pub fn env_mut(&mut self) -> &mut CommandEnv<DefaultEnvKey> {
&mut self.env
}
pub fn cwd(&mut self, _dir: &OsStr) {

8
src/libstd/sys/windows/os_str.rs
View File

@ -17,7 +17,7 @@ use sys_common::wtf8::{Wtf8, Wtf8Buf};
use mem;
use rc::Rc;
use sync::Arc;
use sys_common::{AsInner, IntoInner};
use sys_common::{AsInner, IntoInner, FromInner};
#[derive(Clone, Hash)]
pub struct Buf {
@ -30,6 +30,12 @@ impl IntoInner<Wtf8Buf> for Buf {
}
}
impl FromInner<Wtf8Buf> for Buf {
fn from_inner(inner: Wtf8Buf) -> Self {
Buf { inner }
}
}
impl AsInner<Wtf8> for Buf {
fn as_inner(&self) -> &Wtf8 {
&self.inner

96
src/libstd/sys/windows/process.rs
View File

@ -8,9 +8,10 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![unstable(feature = "process_internals", issue = "0")]
use ascii::AsciiExt;
use collections::HashMap;
use collections;
use collections::BTreeMap;
use env::split_paths;
use env;
use ffi::{OsString, OsStr};
@ -28,19 +29,42 @@ use sys::fs::{OpenOptions, File};
use sys::handle::Handle;
use sys::pipe::{self, AnonPipe};
use sys::stdio;
use sys::{self, cvt};
use sys_common::{AsInner, FromInner};
use sys::cvt;
use sys_common::{AsInner, FromInner, IntoInner};
use sys_common::process::{CommandEnv, EnvKey};
use alloc::borrow::Borrow;
////////////////////////////////////////////////////////////////////////////////
// Command
////////////////////////////////////////////////////////////////////////////////
fn mk_key(s: &OsStr) -> OsString {
FromInner::from_inner(sys::os_str::Buf {
inner: s.as_inner().inner.to_ascii_uppercase()
})
#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
#[doc(hidden)]
pub struct WindowsEnvKey(OsString);
impl From<OsString> for WindowsEnvKey {
fn from(k: OsString) -> Self {
let mut buf = k.into_inner().into_inner();
buf.make_ascii_uppercase();
WindowsEnvKey(FromInner::from_inner(FromInner::from_inner(buf)))
}
}
impl From<WindowsEnvKey> for OsString {
fn from(k: WindowsEnvKey) -> Self { k.0 }
}
impl Borrow<OsStr> for WindowsEnvKey {
fn borrow(&self) -> &OsStr { &self.0 }
}
impl AsRef<OsStr> for WindowsEnvKey {
fn as_ref(&self) -> &OsStr { &self.0 }
}
impl EnvKey for WindowsEnvKey {}
fn ensure_no_nuls<T: AsRef<OsStr>>(str: T) -> io::Result<T> {
if str.as_ref().encode_wide().any(|b| b == 0) {
Err(io::Error::new(ErrorKind::InvalidInput, "nul byte found in provided data"))
@ -52,7 +76,7 @@ fn ensure_no_nuls<T: AsRef<OsStr>>(str: T) -> io::Result<T> {
pub struct Command {
program: OsString,
args: Vec<OsString>,
env: Option<HashMap<OsString, OsString>>,
env: CommandEnv<WindowsEnvKey>,
cwd: Option<OsString>,
flags: u32,
detach: bool, // not currently exposed in std::process
@ -83,7 +107,7 @@ impl Command {
Command {
program: program.to_os_string(),
args: Vec::new(),
env: None,
env: Default::default(),
cwd: None,
flags: 0,
detach: false,
@ -96,23 +120,8 @@ impl Command {
pub fn arg(&mut self, arg: &OsStr) {
self.args.push(arg.to_os_string())
}
fn init_env_map(&mut self){
if self.env.is_none() {
self.env = Some(env::vars_os().map(|(key, val)| {
(mk_key(&key), val)
}).collect());
}
}
pub fn env(&mut self, key: &OsStr, val: &OsStr) {
self.init_env_map();
self.env.as_mut().unwrap().insert(mk_key(key), val.to_os_string());
}
pub fn env_remove(&mut self, key: &OsStr) {
self.init_env_map();
self.env.as_mut().unwrap().remove(&mk_key(key));
}
pub fn env_clear(&mut self) {
self.env = Some(HashMap::new())
pub fn env_mut(&mut self) -> &mut CommandEnv<WindowsEnvKey> {
&mut self.env
}
pub fn cwd(&mut self, dir: &OsStr) {
self.cwd = Some(dir.to_os_string())
@ -132,13 +141,12 @@ impl Command {
pub fn spawn(&mut self, default: Stdio, needs_stdin: bool)
-> io::Result<(Process, StdioPipes)> {
let maybe_env = self.env.capture_if_changed();
// To have the spawning semantics of unix/windows stay the same, we need
// to read the *child's* PATH if one is provided. See #15149 for more
// details.
let program = self.env.as_ref().and_then(|env| {
for (key, v) in env {
if OsStr::new("PATH") != &**key { continue }
let program = maybe_env.as_ref().and_then(|env| {
if let Some(v) = env.get(OsStr::new("PATH")) {
// Split the value and test each path to see if the
// program exists.
for path in split_paths(&v) {
@ -148,7 +156,6 @@ impl Command {
return Some(path.into_os_string())
}
}
break
}
None
});
@ -167,7 +174,7 @@ impl Command {
flags |= c::DETACHED_PROCESS | c::CREATE_NEW_PROCESS_GROUP;
}
let (envp, _data) = make_envp(self.env.as_ref())?;
let (envp, _data) = make_envp(maybe_env)?;
let (dirp, _data) = make_dirp(self.cwd.as_ref())?;
let mut pi = zeroed_process_information();
@ -488,25 +495,24 @@ fn make_command_line(prog: &OsStr, args: &[OsString]) -> io::Result<Vec<u16>> {
}
}
fn make_envp(env: Option<&collections::HashMap<OsString, OsString>>)
fn make_envp(maybe_env: Option<BTreeMap<WindowsEnvKey, OsString>>)
-> io::Result<(*mut c_void, Vec<u16>)> {
// On Windows we pass an "environment block" which is not a char**, but
// rather a concatenation of null-terminated k=v\0 sequences, with a final
// \0 to terminate.
match env {
Some(env) => {
let mut blk = Vec::new();
if let Some(env) = maybe_env {
let mut blk = Vec::new();
for pair in env {
blk.extend(ensure_no_nuls(pair.0)?.encode_wide());
blk.push('=' as u16);
blk.extend(ensure_no_nuls(pair.1)?.encode_wide());
blk.push(0);
}
for (k, v) in env {
blk.extend(ensure_no_nuls(k.0)?.encode_wide());
blk.push('=' as u16);
blk.extend(ensure_no_nuls(v)?.encode_wide());
blk.push(0);
Ok((blk.as_mut_ptr() as *mut c_void, blk))
}
_ => Ok((ptr::null_mut(), Vec::new()))
blk.push(0);
Ok((blk.as_mut_ptr() as *mut c_void, blk))
} else {
Ok((ptr::null_mut(), Vec::new()))
}
}

1
src/libstd/sys_common/mod.rs
View File

@ -44,6 +44,7 @@ pub mod thread_local;
pub mod util;
pub mod wtf8;
pub mod bytestring;
pub mod process;
cfg_if! {
if #[cfg(any(target_os = "redox", target_os = "l4re"))] {

124
src/libstd/sys_common/process.rs Normal file
View File

@ -0,0 +1,124 @@
// 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.
#![allow(dead_code)]
#![unstable(feature = "process_internals", issue = "0")]
use ffi::{OsStr, OsString};
use env;
use collections::BTreeMap;
use alloc::borrow::Borrow;
pub trait EnvKey:
From<OsString> + Into<OsString> +
Borrow<OsStr> + Borrow<Self> + AsRef<OsStr> +
Ord + Clone {}
// Implement a case-sensitive environment variable key
#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
pub struct DefaultEnvKey(OsString);
impl From<OsString> for DefaultEnvKey {
fn from(k: OsString) -> Self { DefaultEnvKey(k) }
}
impl From<DefaultEnvKey> for OsString {
fn from(k: DefaultEnvKey) -> Self { k.0 }
}
impl Borrow<OsStr> for DefaultEnvKey {
fn borrow(&self) -> &OsStr { &self.0 }
}
impl AsRef<OsStr> for DefaultEnvKey {
fn as_ref(&self) -> &OsStr { &self.0 }
}
impl EnvKey for DefaultEnvKey {}
// Stores a set of changes to an environment
#[derive(Clone, Debug)]
pub struct CommandEnv<K> {
clear: bool,
vars: BTreeMap<K, Option<OsString>>
}
impl<K: EnvKey> Default for CommandEnv<K> {
fn default() -> Self {
CommandEnv {
clear: false,
vars: Default::default()
}
}
}
impl<K: EnvKey> CommandEnv<K> {
// Capture the current environment with these changes applied
pub fn capture(&self) -> BTreeMap<K, OsString> {
let mut result = BTreeMap::<K, OsString>::new();
if !self.clear {
for (k, v) in env::vars_os() {
result.insert(k.into(), v);
}
}
for (k, maybe_v) in &self.vars {
if let &Some(ref v) = maybe_v {
result.insert(k.clone(), v.clone());
} else {
result.remove(k);
}
}
result
}
// Apply these changes directly to the current environment
pub fn apply(&self) {
if self.clear {
for (k, _) in env::vars_os() {
env::remove_var(k);
}
}
for (key, maybe_val) in self.vars.iter() {
if let &Some(ref val) = maybe_val {
env::set_var(key, val);
} else {
env::remove_var(key);
}
}
}
pub fn is_unchanged(&self) -> bool {
!self.clear && self.vars.is_empty()
}
pub fn capture_if_changed(&self) -> Option<BTreeMap<K, OsString>> {
if self.is_unchanged() {
None
} else {
Some(self.capture())
}
}
// The following functions build up changes
pub fn set(&mut self, key: &OsStr, value: &OsStr) {
self.vars.insert(key.to_owned().into(), Some(value.to_owned()));
}
pub fn remove(&mut self, key: &OsStr) {
if self.clear {
self.vars.remove(key);
} else {
self.vars.insert(key.to_owned().into(), None);
}
}
pub fn clear(&mut self) {
self.clear = true;
self.vars.clear();
}
}

20
src/libstd/sys_common/wtf8.rs
View File

@ -134,6 +134,12 @@ impl ops::Deref for Wtf8Buf {
}
}
impl ops::DerefMut for Wtf8Buf {
fn deref_mut(&mut self) -> &mut Wtf8 {
self.as_mut_slice()
}
}
/// Format the string with double quotes,
/// and surrogates as `\u` followed by four hexadecimal digits.
/// Example: `"a\u{D800}"` for a string with code points [U+0061, U+D800]
@ -221,6 +227,11 @@ impl Wtf8Buf {
unsafe { Wtf8::from_bytes_unchecked(&self.bytes) }
}
#[inline]
pub fn as_mut_slice(&mut self) -> &mut Wtf8 {
unsafe { Wtf8::from_mut_bytes_unchecked(&mut self.bytes) }
}
/// Reserves capacity for at least `additional` more bytes to be inserted
/// in the given `Wtf8Buf`.
/// The collection may reserve more space to avoid frequent reallocations.
@ -486,6 +497,15 @@ impl Wtf8 {
mem::transmute(value)
}
/// Creates a mutable WTF-8 slice from a mutable WTF-8 byte slice.
///
/// Since the byte slice is not checked for valid WTF-8, this functions is
/// marked unsafe.
#[inline]
unsafe fn from_mut_bytes_unchecked(value: &mut [u8]) -> &mut Wtf8 {
mem::transmute(value)
}
/// Returns the length, in WTF-8 bytes.
#[inline]
pub fn len(&self) -> usize {