Rollup merge of #22297 - nagisa:spring-cleanup, r=alexcrichton

 This PR replaces uses of `os::getenv` with newly introduced `env::var{,_os}`.

Mostly did this as a background activity to procrastinate from procrastinating.

Tests appear to build and run fine. This includes benchmarks from test/bench directory.

Author: Manishearth

src/librustc_back/target/mod.rs

@@ -384,8 +384,7 @@ impl Target {
             Path::new(target)
         };
 
-        let target_path = env::var_os("RUST_TARGET_PATH")
-                              .unwrap_or(OsString::from_str(""));
+        let target_path = env::var_os("RUST_TARGET_PATH").unwrap_or(OsString::from_str(""));
 
         // FIXME 16351: add a sane default search path?
 

src/libstd/sync/mpsc/mod.rs

@@ -1024,14 +1024,14 @@ impl fmt::Display for TryRecvError {
 mod test {
     use prelude::v1::*;
 
-    use os;
+    use std::env;
     use super::*;
     use thread::Thread;
 
     pub fn stress_factor() -> uint {
-        match os::getenv("RUST_TEST_STRESS") {
-            Some(val) => val.parse().unwrap(),
-            None => 1,
+        match env::var("RUST_TEST_STRESS") {
+            Ok(val) => val.parse().unwrap(),
+            Err(..) => 1,
         }
     }
 
@@ -1546,14 +1546,14 @@ mod test {
 mod sync_tests {
     use prelude::v1::*;
 
-    use os;
+    use std::env;
     use thread::Thread;
     use super::*;
 
     pub fn stress_factor() -> uint {
-        match os::getenv("RUST_TEST_STRESS") {
-            Some(val) => val.parse().unwrap(),
-            None => 1,
+        match env::var("RUST_TEST_STRESS") {
+            Ok(val) => val.parse().unwrap(),
+            Err(..) => 1,
         }
     }
 

src/test/bench/core-std.rs

@@ -17,6 +17,7 @@ use std::old_io::File;
 use std::iter::repeat;
 use std::mem::swap;
 use std::os;
+use std::env;
 use std::rand::Rng;
 use std::rand;
 use std::str;
@@ -46,7 +47,7 @@ fn main() {
 fn maybe_run_test<F>(argv: &[String], name: String, test: F) where F: FnOnce() {
     let mut run_test = false;
 
-    if os::getenv("RUST_BENCH").is_some() {
+    if env::var_os("RUST_BENCH").is_some() {
         run_test = true
     } else if argv.len() > 0 {
         run_test = argv.iter().any(|x| x == &"all".to_string()) || argv.iter().any(|x| x == &name)

src/test/bench/core-uint-to-str.rs

@@ -9,10 +9,11 @@
 // except according to those terms.
 
 use std::os;
+use std::env;
 
 fn main() {
     let args = os::args();
-    let args = if os::getenv("RUST_BENCH").is_some() {
+    let args = if env::var_os("RUST_BENCH").is_some() {
         vec!("".to_string(), "10000000".to_string())
     } else if args.len() <= 1u {
         vec!("".to_string(), "100000".to_string())

src/test/bench/msgsend-pipes-shared.rs

@@ -20,6 +20,7 @@
 
 use std::sync::mpsc::{channel, Sender, Receiver};
 use std::os;
+use std::env;
 use std::thread::Thread;
 use std::time::Duration;
 
@@ -94,7 +95,7 @@ fn run(args: &[String]) {
 
 fn main() {
     let args = os::args();
-    let args = if os::getenv("RUST_BENCH").is_some() {
+    let args = if env::var_os("RUST_BENCH").is_some() {
         vec!("".to_string(), "1000000".to_string(), "10000".to_string())
     } else if args.len() <= 1u {
         vec!("".to_string(), "10000".to_string(), "4".to_string())

src/test/bench/msgsend-pipes.rs

@@ -16,6 +16,7 @@
 
 use std::sync::mpsc::{channel, Sender, Receiver};
 use std::os;
+use std::env;
 use std::thread::Thread;
 use std::time::Duration;
 
@@ -101,7 +102,7 @@ fn run(args: &[String]) {
 
 fn main() {
     let args = os::args();
-    let args = if os::getenv("RUST_BENCH").is_some() {
+    let args = if env::var_os("RUST_BENCH").is_some() {
         vec!("".to_string(), "1000000".to_string(), "8".to_string())
     } else if args.len() <= 1u {
         vec!("".to_string(), "10000".to_string(), "4".to_string())

src/test/bench/msgsend-ring-mutex-arcs.rs

@@ -19,6 +19,7 @@
 // ignore-lexer-test FIXME #15679
 
 use std::os;
+use std::env;
 use std::sync::{Arc, Future, Mutex, Condvar};
 use std::time::Duration;
 
@@ -64,7 +65,7 @@ fn thread_ring(i: uint, count: uint, num_chan: pipe, num_port: pipe) {
 
 fn main() {
     let args = os::args();
-    let args = if os::getenv("RUST_BENCH").is_some() {
+    let args = if env::var_os("RUST_BENCH").is_some() {
         vec!("".to_string(), "100".to_string(), "10000".to_string())
     } else if args.len() <= 1u {
         vec!("".to_string(), "10".to_string(), "100".to_string())

src/test/bench/shootout-ackermann.rs

@@ -9,6 +9,7 @@
 // except according to those terms.
 
 use std::os;
+use std::env;
 
 fn ack(m: int, n: int) -> int {
     if m == 0 {
@@ -24,7 +25,7 @@ fn ack(m: int, n: int) -> int {
 
 fn main() {
     let args = os::args();
-    let args = if os::getenv("RUST_BENCH").is_some() {
+    let args = if env::var_os("RUST_BENCH").is_some() {
         vec!("".to_string(), "12".to_string())
     } else if args.len() <= 1u {
         vec!("".to_string(), "8".to_string())

src/test/bench/shootout-binarytrees.rs

@@ -86,7 +86,7 @@ fn inner(depth: i32, iterations: i32) -> String {
 fn main() {
     let args = std::os::args();
     let args = args;
-    let n = if std::os::getenv("RUST_BENCH").is_some() {
+    let n = if std::env::var_os("RUST_BENCH").is_some() {
         17
     } else if args.len() <= 1u {
         8

src/test/bench/shootout-chameneos-redux.rs

@@ -227,7 +227,7 @@ fn rendezvous(nn: uint, set: Vec<Color>) {
 }
 
 fn main() {
-    let nn = if std::os::getenv("RUST_BENCH").is_some() {
+    let nn = if std::env::var_os("RUST_BENCH").is_some() {
         200000
     } else {
         std::os::args()