Proper ctrl+c handling in Windows (fix #508)

Cargo.lock

@@ -1843,6 +1843,7 @@ dependencies = [
  "toml",
  "walkdir",
  "which",
+ "winapi 0.3.9",
 ]
 
 [[package]]

Cargo.toml

@@ -43,6 +43,7 @@ self_update_crate = { version = "0.19.0", optional = true, package =  "self_upda
 
 [target.'cfg(windows)'.dependencies]
 self_update_crate = { version = "0.19.0", optional = true, package =  "self_update", features = ["archive-zip", "compression-zip-deflate"] }
+winapi = "0.3.9"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 rust-ini = "0.15.0"

src/ctrlc/interrupted.rs

@@ -0,0 +1,22 @@
+use lazy_static::lazy_static;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+lazy_static! {
+    /// A global variable telling whether the application has been interrupted.
+    static ref INTERRUPTED: AtomicBool = AtomicBool::new(false);
+}
+
+/// Tells whether the program has been interrupted
+pub fn interrupted() -> bool {
+    INTERRUPTED.load(Ordering::SeqCst)
+}
+
+/// Clears the interrupted flag
+pub fn unset_interrupted() {
+    debug_assert!(INTERRUPTED.load(Ordering::SeqCst));
+    INTERRUPTED.store(false, Ordering::SeqCst)
+}
+
+pub fn set_interrupted() {
+    INTERRUPTED.store(true, Ordering::SeqCst)
+}

src/ctrlc/mod.rs

@@ -1,11 +1,13 @@
-//! Provides handling for process interruption.
-//! There's no actual handling for Windows at the moment.
+mod interrupted;
+
 #[cfg(unix)]
 mod unix;
 #[cfg(unix)]
-pub use self::unix::*;
+pub use self::unix::set_handler;
 
 #[cfg(windows)]
 mod windows;
 #[cfg(windows)]
-pub use self::windows::*;
+pub use self::windows::set_handler;
+
+pub use self::interrupted::*;

src/ctrlc/unix.rs

@@ -1,27 +1,10 @@
 //! SIGINT handling in Unix systems.
-use lazy_static::lazy_static;
+use crate::ctrlc::interrupted::set_interrupted;
 use nix::sys::signal;
-use std::sync::atomic::{AtomicBool, Ordering};
-
-lazy_static! {
-    /// A global variable telling whether the application has been interrupted.
-    static ref INTERRUPTED: AtomicBool = AtomicBool::new(false);
-}
-
-/// Tells whether the program has been interrupted
-pub fn interrupted() -> bool {
-    INTERRUPTED.load(Ordering::SeqCst)
-}
-
-/// Clears the interrupted flag
-pub fn unset_interrupted() {
-    debug_assert!(INTERRUPTED.load(Ordering::SeqCst));
-    INTERRUPTED.store(false, Ordering::SeqCst)
-}
 
 /// Handle SIGINT. Set the interruption flag.
 extern "C" fn handle_sigint(_: i32) {
-    INTERRUPTED.store(true, Ordering::SeqCst)
+    set_interrupted()
 }
 
 /// Set the necessary signal handlers.

src/ctrlc/windows.rs

@@ -1,9 +1,21 @@
 //! A stub for Ctrl + C handling.
+use crate::ctrlc::interrupted::set_interrupted;
+use winapi::shared::minwindef::{BOOL, DWORD, FALSE, TRUE};
+use winapi::um::consoleapi::SetConsoleCtrlHandler;
+use winapi::um::wincon::CTRL_C_EVENT;
 
-pub fn interrupted() -> bool {
-    false
+extern "system" fn handler(ctrl_type: DWORD) -> BOOL {
+    match ctrl_type {
+        CTRL_C_EVENT => {
+            set_interrupted();
+            TRUE
+        }
+        _ => FALSE,
+    }
 }
 
-pub fn unset_interrupted() {}
-
-pub fn set_handler() {}
+pub fn set_handler() {
+    if 0 == unsafe { SetConsoleCtrlHandler(Some(handler), TRUE) } {
+        log::error!("Cannot set a control C handler")
+    }
+}

src/terminal.rs

@@ -211,13 +211,9 @@ impl Terminal {
             .write_fmt(format_args!(
                 "\n{}",
                 style(format!(
-                    "{}Retry? (y)es/(N)o/(s)hell {}",
+                    "{}Retry? (y)es/(N)o/(s)hell{}",
                     self.prefix,
-                    if interrupted {
-                        "(Press Ctrl+C again to stop Topgrade) "
-                    } else {
-                        ""
-                    }
+                    if interrupted { "/(q)uit" } else { "" }
                 ))
                 .yellow()
                 .bold()
@@ -233,7 +229,8 @@ impl Terminal {
                     break Ok(true);
                 }
                 'n' | 'N' | '\r' | '\n' => break Ok(false),
-                _ => (),
+                'q' | 'Q' => return Err(io::Error::from(io::ErrorKind::Interrupted)),
+                _ => println!("hi"),
             }
         };