Change wait_with_output to borrow instead of taking ownership

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1613,7 +1613,7 @@ fn exec_linker(
     // will read all its options out of there instead of looking at the command line.
     if !cmd.very_likely_to_exceed_some_spawn_limit() {
         match cmd.command().stdout(Stdio::piped()).stderr(Stdio::piped()).spawn() {
-            Ok(child) => {
+            Ok(mut child) => {
                 let output = child.wait_with_output();
                 flush_linked_file(&output, out_filename)?;
                 return output;

library/std/src/process.rs

@@ -2238,7 +2238,7 @@ impl Child {
     /// ```should_panic
     /// use std::process::{Command, Stdio};
     ///
-    /// let child = Command::new("/bin/cat")
+    /// let mut child = Command::new("/bin/cat")
     ///     .arg("file.txt")
     ///     .stdout(Stdio::piped())
     ///     .spawn()
@@ -2252,7 +2252,7 @@ impl Child {
     /// ```
     ///
     #[stable(feature = "process", since = "1.0.0")]
-    pub fn wait_with_output(mut self) -> io::Result<Output> {
+    pub fn wait_with_output(&mut self) -> io::Result<Output> {
         drop(self.stdin.take());
 
         let (mut stdout, mut stderr) = (Vec::new(), Vec::new());

library/std/src/process/tests.rs

@@ -233,7 +233,7 @@ fn test_finish_twice() {
 #[test]
 #[cfg_attr(any(target_os = "vxworks"), ignore)]
 fn test_wait_with_output_once() {
-    let prog = if cfg!(target_os = "windows") {
+    let mut prog = if cfg!(target_os = "windows") {
         Command::new("cmd").args(&["/C", "echo hello"]).stdout(Stdio::piped()).spawn().unwrap()
     } else {
         shell_cmd().arg("-c").arg("echo hello").stdout(Stdio::piped()).spawn().unwrap()

tests/ui/backtrace/backtrace.rs

@@ -25,7 +25,9 @@ fn double() {
     struct Double;
 
     impl Drop for Double {
-        fn drop(&mut self) { panic!("twice") }
+        fn drop(&mut self) {
+            panic!("twice")
+        }
     }
 
     let _d = Double;
@@ -35,9 +37,7 @@ fn double() {
 
 fn template(me: &str) -> Command {
     let mut m = Command::new(me);
-    m.env("IS_TEST", "1")
-     .stdout(Stdio::piped())
-     .stderr(Stdio::piped());
+    m.env("IS_TEST", "1").stdout(Stdio::piped()).stderr(Stdio::piped());
     return m;
 }
 
@@ -63,65 +63,61 @@ fn contains_verbose_expected(s: &str, fn_name: &str) -> bool {
 
 fn runtest(me: &str) {
     // Make sure that the stack trace is printed
-    let p = template(me).arg("fail").env("RUST_BACKTRACE", "1").spawn().unwrap();
+    let mut p = template(me).arg("fail").env("RUST_BACKTRACE", "1").spawn().unwrap();
     let out = p.wait_with_output().unwrap();
     assert!(!out.status.success());
     let s = str::from_utf8(&out.stderr).unwrap();
-    assert!(s.contains("stack backtrace") && s.contains(&expected("foo")),
-            "bad output: {}", s);
+    assert!(s.contains("stack backtrace") && s.contains(&expected("foo")), "bad output: {}", s);
     assert!(s.contains(" 0:"), "the frame number should start at 0");
 
     // Make sure the stack trace is *not* printed
     // (Remove RUST_BACKTRACE from our own environment, in case developer
     // is running `make check` with it on.)
-    let p = template(me).arg("fail").env_remove("RUST_BACKTRACE").spawn().unwrap();
+    let mut p = template(me).arg("fail").env_remove("RUST_BACKTRACE").spawn().unwrap();
     let out = p.wait_with_output().unwrap();
     assert!(!out.status.success());
     let s = str::from_utf8(&out.stderr).unwrap();
-    assert!(!s.contains("stack backtrace") && !s.contains(&expected("foo")),
-            "bad output2: {}", s);
+    assert!(!s.contains("stack backtrace") && !s.contains(&expected("foo")), "bad output2: {}", s);
 
     // Make sure the stack trace is *not* printed
     // (RUST_BACKTRACE=0 acts as if it were unset from our own environment,
     // in case developer is running `make check` with it set.)
-    let p = template(me).arg("fail").env("RUST_BACKTRACE","0").spawn().unwrap();
+    let mut p = template(me).arg("fail").env("RUST_BACKTRACE", "0").spawn().unwrap();
     let out = p.wait_with_output().unwrap();
     assert!(!out.status.success());
     let s = str::from_utf8(&out.stderr).unwrap();
-    assert!(!s.contains("stack backtrace") && !s.contains(" - foo"),
-            "bad output3: {}", s);
+    assert!(!s.contains("stack backtrace") && !s.contains(" - foo"), "bad output3: {}", s);
 
     #[cfg(not(panic = "abort"))]
     {
         // Make sure a stack trace is printed
-        let p = template(me).arg("double-fail").env("RUST_BACKTRACE","0").spawn().unwrap();
+        let mut p = template(me).arg("double-fail").env("RUST_BACKTRACE", "0").spawn().unwrap();
         let out = p.wait_with_output().unwrap();
         assert!(!out.status.success());
         let s = str::from_utf8(&out.stderr).unwrap();
         // loosened the following from double::h to double:: due to
         // spurious failures on mac, 32bit, optimized
         assert!(
-            s.contains("stack backtrace") &&
-                s.contains("panic in a destructor during cleanup") &&
-                contains_verbose_expected(s, "double"),
-            "bad output3: {}", s
+            s.contains("stack backtrace")
+                && s.contains("panic in a destructor during cleanup")
+                && contains_verbose_expected(s, "double"),
+            "bad output3: {}",
+            s
         );
         // Make sure it's only one stack trace.
         assert_eq!(s.split("stack backtrace").count(), 2);
 
         // Make sure a stack trace isn't printed too many times
         // even with RUST_BACKTRACE=1. It should be printed twice.
-        let p = template(me).arg("double-fail")
-                                    .env("RUST_BACKTRACE", "1").spawn().unwrap();
+        let mut p = template(me).arg("double-fail").env("RUST_BACKTRACE", "1").spawn().unwrap();
         let out = p.wait_with_output().unwrap();
         assert!(!out.status.success());
         let s = str::from_utf8(&out.stderr).unwrap();
         let mut i = 0;
         for _ in 0..2 {
             i += s[i + 10..].find("stack backtrace").unwrap() + 10;
         }
-        assert!(s[i + 10..].find("stack backtrace").is_none(),
-                "bad output4: {}", s);
+        assert!(s[i + 10..].find("stack backtrace").is_none(), "bad output4: {}", s);
     }
 }