Replace internal atty module with atty crate.

This removes all use of explicit unsafe in ripgrep proper except for
one: accessing the contents of a memory map. (Which may never go away.)

src/args.rs

@@ -394,8 +394,8 @@ impl<'a> ArgMatches<'a> {
             self.values_of_os("file").map_or(false, |mut files| {
                 files.any(|f| f == "-")
             });
-        let search_cwd = atty::on_stdin()
-            || !atty::stdin_is_readable()
+        let search_cwd = atty::is(atty::Stream::Stdin)
+            || !stdin_is_readable()
             || (self.is_present("file") && file_is_stdin)
             || self.is_present("files")
             || self.is_present("type-list");
@@ -584,7 +584,7 @@ impl<'a> ArgMatches<'a> {
         } else {
             self.is_present("line-number")
             || self.is_present("column")
-            || atty::on_stdout()
+            || atty::is(atty::Stream::Stdout)
             || self.is_present("pretty")
             || self.is_present("vimgrep")
         }
@@ -602,7 +602,7 @@ impl<'a> ArgMatches<'a> {
             false
         } else {
             self.is_present("heading")
-            || atty::on_stdout()
+            || atty::is(atty::Stream::Stdout)
             || self.is_present("pretty")
         }
     }
@@ -667,7 +667,7 @@ impl<'a> ArgMatches<'a> {
         } else if self.is_present("vimgrep") {
             false
         } else if preference == "auto" {
-            atty::on_stdout() || self.is_present("pretty")
+            atty::is(atty::Stream::Stdout) || self.is_present("pretty")
         } else {
             false
         }
@@ -687,7 +687,7 @@ impl<'a> ArgMatches<'a> {
         } else if self.is_present("vimgrep") {
             termcolor::ColorChoice::Never
         } else if preference == "auto" {
-            if atty::on_stdout() || self.is_present("pretty") {
+            if atty::is(atty::Stream::Stdout) || self.is_present("pretty") {
                 termcolor::ColorChoice::Auto
             } else {
                 termcolor::ColorChoice::Never
@@ -869,3 +869,24 @@ impl QuietMatched {
         }
     }
 }
+
+/// Returns true if and only if stdin is deemed searchable.
+#[cfg(unix)]
+fn stdin_is_readable() -> bool {
+    use std::os::unix::fs::FileTypeExt;
+    use same_file::Handle;
+
+    let ft = match Handle::stdin().and_then(|h| h.as_file().metadata()) {
+        Err(_) => return false,
+        Ok(md) => md.file_type(),
+    };
+    ft.is_file() || ft.is_fifo()
+}
+
+/// Returns true if and only if stdin is deemed searchable.
+#[cfg(windows)]
+fn stdin_is_readable() -> bool {
+    // On Windows, it's not clear what the possibilities are to me, so just
+    // always return true.
+    true
+}

src/atty.rs

@@ -1,145 +0,0 @@
-/*!
-This atty module contains functions for detecting whether ripgrep is being fed
-from (or to) a terminal. Windows and Unix do this differently, so implement
-both here.
-*/
-
-#[cfg(windows)]
-use winapi::minwindef::DWORD;
-#[cfg(windows)]
-use winapi::winnt::HANDLE;
-
-#[cfg(unix)]
-pub fn stdin_is_readable() -> bool {
-    use std::os::unix::fs::FileTypeExt;
-    use same_file::Handle;
-
-    let ft = match Handle::stdin().and_then(|h| h.as_file().metadata()) {
-        Err(_) => return false,
-        Ok(md) => md.file_type(),
-    };
-    ft.is_file() || ft.is_fifo()
-}
-
-#[cfg(windows)]
-pub fn stdin_is_readable() -> bool {
-    // ???
-    true
-}
-
-/// Returns true if there is a tty on stdin.
-#[cfg(unix)]
-pub fn on_stdin() -> bool {
-    use libc;
-    0 < unsafe { libc::isatty(libc::STDIN_FILENO) }
-}
-
-/// Returns true if there is a tty on stdout.
-#[cfg(unix)]
-pub fn on_stdout() -> bool {
-    use libc;
-    0 < unsafe { libc::isatty(libc::STDOUT_FILENO) }
-}
-
-/// Returns true if there is a tty on stdin.
-#[cfg(windows)]
-pub fn on_stdin() -> bool {
-    use kernel32::GetStdHandle;
-    use winapi::winbase::{
-        STD_INPUT_HANDLE, STD_OUTPUT_HANDLE, STD_ERROR_HANDLE,
-    };
-
-    unsafe {
-        let stdin = GetStdHandle(STD_INPUT_HANDLE);
-        if console_on_handle(stdin) {
-            // False positives aren't possible. If we got a console then
-            // we definitely have a tty on stdin.
-            return true;
-        }
-        // Otherwise, it's possible to get a false negative. If we know that
-        // there's a console on stdout or stderr however, then this is a true
-        // negative.
-        if console_on_fd(STD_OUTPUT_HANDLE)
-            || console_on_fd(STD_ERROR_HANDLE) {
-            return false;
-        }
-        // Otherwise, we can't really tell, so we do a weird hack.
-        msys_tty_on_handle(stdin)
-    }
-}
-
-/// Returns true if there is a tty on stdout.
-#[cfg(windows)]
-pub fn on_stdout() -> bool {
-    use kernel32::GetStdHandle;
-    use winapi::winbase::{
-        STD_INPUT_HANDLE, STD_OUTPUT_HANDLE, STD_ERROR_HANDLE,
-    };
-
-    unsafe {
-        let stdout = GetStdHandle(STD_OUTPUT_HANDLE);
-        if console_on_handle(stdout) {
-            // False positives aren't possible. If we got a console then
-            // we definitely have a tty on stdout.
-            return true;
-        }
-        // Otherwise, it's possible to get a false negative. If we know that
-        // there's a console on stdin or stderr however, then this is a true
-        // negative.
-        if console_on_fd(STD_INPUT_HANDLE) || console_on_fd(STD_ERROR_HANDLE) {
-            return false;
-        }
-        // Otherwise, we can't really tell, so we do a weird hack.
-        msys_tty_on_handle(stdout)
-    }
-}
-
-/// Returns true if there is an MSYS tty on the given handle.
-#[cfg(windows)]
-unsafe fn msys_tty_on_handle(handle: HANDLE) -> bool {
-    use std::ffi::OsString;
-    use std::mem;
-    use std::os::raw::c_void;
-    use std::os::windows::ffi::OsStringExt;
-    use std::slice;
-
-    use kernel32::{GetFileInformationByHandleEx};
-    use winapi::fileapi::FILE_NAME_INFO;
-    use winapi::minwinbase::FileNameInfo;
-    use winapi::minwindef::MAX_PATH;
-
-    let size = mem::size_of::<FILE_NAME_INFO>();
-    let mut name_info_bytes = vec![0u8; size + MAX_PATH];
-    let res = GetFileInformationByHandleEx(
-        handle,
-        FileNameInfo,
-        &mut *name_info_bytes as *mut _ as *mut c_void,
-        name_info_bytes.len() as u32);
-    if res == 0 {
-        return true;
-    }
-    let name_info: FILE_NAME_INFO =
-        *(name_info_bytes[0..size].as_ptr() as *const FILE_NAME_INFO);
-    let name_bytes =
-        &name_info_bytes[size..size + name_info.FileNameLength as usize];
-    let name_u16 = slice::from_raw_parts(
-        name_bytes.as_ptr() as *const u16, name_bytes.len() / 2);
-    let name = OsString::from_wide(name_u16)
-        .as_os_str().to_string_lossy().into_owned();
-    name.contains("msys-") || name.contains("-pty")
-}
-
-/// Returns true if there is a console on the given file descriptor.
-#[cfg(windows)]
-unsafe fn console_on_fd(fd: DWORD) -> bool {
-    use kernel32::GetStdHandle;
-    console_on_handle(GetStdHandle(fd))
-}
-
-/// Returns true if there is a console on the given handle.
-#[cfg(windows)]
-unsafe fn console_on_handle(handle: HANDLE) -> bool {
-    use kernel32::GetConsoleMode;
-    let mut out = 0;
-    GetConsoleMode(handle, &mut out) != 0
-}

src/main.rs

@@ -1,3 +1,4 @@
+extern crate atty;
 extern crate bytecount;
 #[macro_use]
 extern crate clap;
@@ -46,7 +47,6 @@ macro_rules! eprintln {
 
 mod app;
 mod args;
-mod atty;
 mod pathutil;
 mod printer;
 mod search_buffer;