Rollup merge of #67219 - jsgf:command-argv0-debug, r=joshtriplett

Fix up Command Debug output when arg0 is specified.

PR https://github.com/rust-lang/rust/pull/66512 added the ability to set argv[0] on
Command. As a side effect, it changed the Debug output to print both the program and
argv[0], which in practice results in stuttery output (`"echo" "echo" "foo"`).

This PR reverts the behaviour to the the old one, so that the command is only printed
once - unless arg0 has been set. In that case it emits `"[command]" "arg0" "arg1" ...`.

5 files changed, 311 insertions, 0 deletions

diff --git a/src/test/ui/command/command-argv0-debug.rs b/src/test/ui/command/command-argv0-debug.rs
new file mode 100644
index 00000000000..133d2ada2b2
--- /dev/null
+++ b/src/test/ui/command/command-argv0-debug.rs
@@ -0,0 +1,24 @@
+// run-pass
+
+// ignore-windows - this is a unix-specific test
+// ignore-cloudabi no processes
+// ignore-emscripten no processes
+// ignore-sgx no processes
+#![feature(process_set_argv0)]
+
+use std::os::unix::process::CommandExt;
+use std::process::Command;
+
+fn main() {
+    let mut command = Command::new("some-boring-name");
+
+    assert_eq!(format!("{:?}", command), r#""some-boring-name""#);
+
+    command.args(&["1", "2", "3"]);
+
+    assert_eq!(format!("{:?}", command), r#""some-boring-name" "1" "2" "3""#);
+
+    command.arg0("exciting-name");
+
+    assert_eq!(format!("{:?}", command), r#"["some-boring-name"] "exciting-name" "1" "2" "3""#);
+}
diff --git a/src/test/ui/command/command-argv0.rs b/src/test/ui/command/command-argv0.rs
new file mode 100644
index 00000000000..56a9fb4d391
--- /dev/null
+++ b/src/test/ui/command/command-argv0.rs
@@ -0,0 +1,33 @@
+// run-pass
+
+// ignore-windows - this is a unix-specific test
+// ignore-cloudabi no processes
+// ignore-emscripten no processes
+// ignore-sgx no processes
+#![feature(process_set_argv0)]
+
+use std::env;
+use std::os::unix::process::CommandExt;
+use std::process::Command;
+
+fn main() {
+    let args: Vec<_> = env::args().collect();
+
+    if args.len() > 1 {
+        assert_eq!(args[1], "doing-test");
+        assert_eq!(args[0], "i have a silly name");
+
+        println!("passed");
+        return;
+    }
+
+    let output =
+        Command::new(&args[0]).arg("doing-test").arg0("i have a silly name").output().unwrap();
+    assert!(
+        output.stderr.is_empty(),
+        "Non-empty stderr: {}",
+        String::from_utf8_lossy(&output.stderr)
+    );
+    assert!(output.status.success());
+    assert_eq!(output.stdout, b"passed\n");
+}
diff --git a/src/test/ui/command/command-exec.rs b/src/test/ui/command/command-exec.rs
new file mode 100644
index 00000000000..568be67abe3
--- /dev/null
+++ b/src/test/ui/command/command-exec.rs
@@ -0,0 +1,104 @@
+// run-pass
+
+#![allow(stable_features)]
+// ignore-windows - this is a unix-specific test
+// ignore-pretty issue #37199
+// ignore-cloudabi no processes
+// ignore-emscripten no processes
+// ignore-sgx no processes
+
+#![feature(process_exec)]
+
+use std::env;
+use std::os::unix::process::CommandExt;
+use std::process::Command;
+
+fn main() {
+    let mut args = env::args();
+    let me = args.next().unwrap();
+
+    if let Some(arg) = args.next() {
+        match &arg[..] {
+            "test1" => println!("passed"),
+
+            "exec-test1" => {
+                let err = Command::new(&me).arg("test1").exec();
+                panic!("failed to spawn: {}", err);
+            }
+
+            "exec-test2" => {
+                Command::new("/path/to/nowhere").exec();
+                println!("passed");
+            }
+
+            "exec-test3" => {
+                Command::new(&me).arg("bad\0").exec();
+                println!("passed");
+            }
+
+            "exec-test4" => {
+                Command::new(&me).current_dir("/path/to/nowhere").exec();
+                println!("passed");
+            }
+
+            "exec-test5" => {
+                env::set_var("VARIABLE", "ABC");
+                Command::new("definitely-not-a-real-binary").env("VARIABLE", "XYZ").exec();
+                assert_eq!(env::var("VARIABLE").unwrap(), "ABC");
+                println!("passed");
+            }
+
+            "exec-test6" => {
+                let err = Command::new("echo").arg("passed").env_clear().exec();
+                panic!("failed to spawn: {}", err);
+            }
+
+            "exec-test7" => {
+                let err = Command::new("echo").arg("passed").env_remove("PATH").exec();
+                panic!("failed to spawn: {}", err);
+            }
+
+            _ => panic!("unknown argument: {}", arg),
+        }
+        return
+    }
+
+    let output = Command::new(&me).arg("exec-test1").output().unwrap();
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert_eq!(output.stdout, b"passed\n");
+
+    let output = Command::new(&me).arg("exec-test2").output().unwrap();
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert_eq!(output.stdout, b"passed\n");
+
+    let output = Command::new(&me).arg("exec-test3").output().unwrap();
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert_eq!(output.stdout, b"passed\n");
+
+    let output = Command::new(&me).arg("exec-test4").output().unwrap();
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert_eq!(output.stdout, b"passed\n");
+
+    let output = Command::new(&me).arg("exec-test5").output().unwrap();
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert_eq!(output.stdout, b"passed\n");
+
+    if cfg!(target_os = "linux") {
+        let output = Command::new(&me).arg("exec-test6").output().unwrap();
+        println!("{:?}", output);
+        assert!(output.status.success());
+        assert!(output.stderr.is_empty());
+        assert_eq!(output.stdout, b"passed\n");
+
+        let output = Command::new(&me).arg("exec-test7").output().unwrap();
+        println!("{:?}", output);
+        assert!(output.status.success());
+        assert!(output.stderr.is_empty());
+        assert_eq!(output.stdout, b"passed\n");
+    }
+}
diff --git a/src/test/ui/command/command-pre-exec.rs b/src/test/ui/command/command-pre-exec.rs
new file mode 100644
index 00000000000..c0fc554183a
--- /dev/null
+++ b/src/test/ui/command/command-pre-exec.rs
@@ -0,0 +1,118 @@
+// run-pass
+
+#![allow(stable_features)]
+// ignore-windows - this is a unix-specific test
+// ignore-cloudabi no processes
+// ignore-emscripten no processes
+// ignore-sgx no processes
+#![feature(process_exec, rustc_private)]
+
+extern crate libc;
+
+use std::env;
+use std::io::Error;
+use std::os::unix::process::CommandExt;
+use std::process::Command;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+
+fn main() {
+    if let Some(arg) = env::args().nth(1) {
+        match &arg[..] {
+            "test1" => println!("hello2"),
+            "test2" => assert_eq!(env::var("FOO").unwrap(), "BAR"),
+            "test3" => assert_eq!(env::current_dir().unwrap().to_str().unwrap(), "/"),
+            "empty" => {}
+            _ => panic!("unknown argument: {}", arg),
+        }
+        return;
+    }
+
+    let me = env::current_exe().unwrap();
+
+    let output = unsafe {
+        Command::new(&me)
+            .arg("test1")
+            .pre_exec(|| {
+                println!("hello");
+                Ok(())
+            })
+            .output()
+            .unwrap()
+    };
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert_eq!(output.stdout, b"hello\nhello2\n");
+
+    let output = unsafe {
+        Command::new(&me)
+            .arg("test2")
+            .pre_exec(|| {
+                env::set_var("FOO", "BAR");
+                Ok(())
+            })
+            .output()
+            .unwrap()
+    };
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert!(output.stdout.is_empty());
+
+    let output = unsafe {
+        Command::new(&me)
+            .arg("test3")
+            .pre_exec(|| {
+                env::set_current_dir("/").unwrap();
+                Ok(())
+            })
+            .output()
+            .unwrap()
+    };
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert!(output.stdout.is_empty());
+
+    let output = unsafe {
+        Command::new(&me)
+            .arg("bad")
+            .pre_exec(|| Err(Error::from_raw_os_error(102)))
+            .output()
+            .unwrap_err()
+    };
+    assert_eq!(output.raw_os_error(), Some(102));
+
+    let pid = unsafe { libc::getpid() };
+    assert!(pid >= 0);
+    let output = unsafe {
+        Command::new(&me)
+            .arg("empty")
+            .pre_exec(move || {
+                let child = libc::getpid();
+                assert!(child >= 0);
+                assert!(pid != child);
+                Ok(())
+            })
+            .output()
+            .unwrap()
+    };
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert!(output.stdout.is_empty());
+
+    let mem = Arc::new(AtomicUsize::new(0));
+    let mem2 = mem.clone();
+    let output = unsafe {
+        Command::new(&me)
+            .arg("empty")
+            .pre_exec(move || {
+                assert_eq!(mem2.fetch_add(1, Ordering::SeqCst), 0);
+                Ok(())
+            })
+            .output()
+            .unwrap()
+    };
+    assert!(output.status.success());
+    assert!(output.stderr.is_empty());
+    assert!(output.stdout.is_empty());
+    assert_eq!(mem.load(Ordering::SeqCst), 0);
+}
diff --git a/src/test/ui/command/command-uid-gid.rs b/src/test/ui/command/command-uid-gid.rs
new file mode 100644
index 00000000000..f867106c35d
--- /dev/null
+++ b/src/test/ui/command/command-uid-gid.rs
@@ -0,0 +1,32 @@
+// run-pass
+// ignore-android
+// ignore-cloudabi
+// ignore-emscripten
+// ignore-sgx
+
+#![feature(rustc_private)]
+
+fn main() {
+    #[cfg(unix)]
+    run()
+}
+
+#[cfg(unix)]
+fn run() {
+    extern crate libc;
+    use std::process::Command;
+    use std::os::unix::prelude::*;
+
+    let mut p = Command::new("/bin/sh")
+        .arg("-c").arg("true")
+        .uid(unsafe { libc::getuid() })
+        .gid(unsafe { libc::getgid() })
+        .spawn().unwrap();
+    assert!(p.wait().unwrap().success());
+
+    // if we're already root, this isn't a valid test. Most of the bots run
+    // as non-root though (android is an exception).
+    if unsafe { libc::getuid() != 0 } {
+        assert!(Command::new("/bin/ls").uid(0).gid(0).spawn().is_err());
+    }
+}