4 files changed, 41 insertions, 25 deletions
diff --git a/library/std/src/sys/pal/windows/c/README.md b/library/std/src/sys/pal/windows/c/README.md
new file mode 100644
index 00000000000..d458e55efbc
--- /dev/null
+++ b/library/std/src/sys/pal/windows/c/README.md
@@ -0,0 +1,9 @@
+The `windows_sys.rs` file is autogenerated from `bindings.txt` and must not
+be edited manually.
+
+To add bindings, edit `bindings.txt` then regenerate using the following command:
+
+    ./x run generate-windows-sys && ./x fmt library/std
+
+If you need to override generated functions or types then add them to
+`library/std/src/sys/pal/windows/c.rs`.
diff --git a/library/std/src/sys/pal/windows/c/windows_sys.lst b/library/std/src/sys/pal/windows/c/bindings.txt
index f91e1054a04..726f1c3df82 100644
--- a/library/std/src/sys/pal/windows/c/windows_sys.lst
+++ b/library/std/src/sys/pal/windows/c/bindings.txt
@@ -1,7 +1,6 @@
 --out windows_sys.rs
 --config flatten std
 --filter
-// tidy-alphabetical-start
 !Windows.Win32.Foundation.INVALID_HANDLE_VALUE
 Windows.Wdk.Storage.FileSystem.FILE_COMPLETE_IF_OPLOCKED
 Windows.Wdk.Storage.FileSystem.FILE_CONTAINS_EXTENDED_CREATE_INFORMATION
@@ -2592,5 +2591,3 @@ Windows.Win32.System.Threading.WakeAllConditionVariable
 Windows.Win32.System.Threading.WakeConditionVariable
 Windows.Win32.System.WindowsProgramming.PROGRESS_CONTINUE
 Windows.Win32.UI.Shell.GetUserProfileDirectoryW
-// tidy-alphabetical-end
-
diff --git a/library/std/src/sys/pal/windows/c/windows_sys.rs b/library/std/src/sys/pal/windows/c/windows_sys.rs
index b38b70c8983..c386b66a722 100644
--- a/library/std/src/sys/pal/windows/c/windows_sys.rs
+++ b/library/std/src/sys/pal/windows/c/windows_sys.rs
@@ -1,9 +1,3 @@
-// This file is autogenerated.
-//
-// To add bindings, edit windows_sys.lst then use `./x run generate-windows-sys` to
-// regenerate the bindings.
-//
-// ignore-tidy-filelength
 // Bindings generated by `windows-bindgen` 0.52.0
 
 #![allow(non_snake_case, non_upper_case_globals, non_camel_case_types, dead_code, clippy::all)]
@@ -4351,3 +4345,4 @@ impl ::core::clone::Clone for XSAVE_FORMAT {
         *self
     }
 }
+// ignore-tidy-filelength
diff --git a/src/tools/generate-windows-sys/src/main.rs b/src/tools/generate-windows-sys/src/main.rs
index dc95d969aed..c8913910bd6 100644
--- a/src/tools/generate-windows-sys/src/main.rs
+++ b/src/tools/generate-windows-sys/src/main.rs
@@ -1,34 +1,49 @@
 use std::env;
 use std::error::Error;
 use std::fs;
-use std::io::{self, Read, Seek, Write};
+use std::io::{Read, Seek, SeekFrom, Write};
 use std::path::PathBuf;
 
-/// This is printed to the file before the rest of the contents.
-const PRELUDE: &str = r#"// This file is autogenerated.
-//
-// To add bindings, edit windows_sys.lst then use `./x run generate-windows-sys` to
-// regenerate the bindings.
-//
-// ignore-tidy-filelength
-"#;
-
 fn main() -> Result<(), Box<dyn Error>> {
     let mut path: PathBuf =
         env::args_os().nth(1).expect("a path to the rust repository is required").into();
     path.push("library/std/src/sys/pal/windows/c");
     env::set_current_dir(&path)?;
 
-    let info = windows_bindgen::bindgen(["--etc", "windows_sys.lst"])?;
+    sort_bindings("bindings.txt")?;
+
+    let info = windows_bindgen::bindgen(["--etc", "bindings.txt"])?;
     println!("{info}");
 
-    // add some gunk to the output file.
-    let mut f = fs::File::options().read(true).write(true).open("windows_sys.rs")?;
+    let mut f = std::fs::File::options().append(true).open("windows_sys.rs")?;
+    writeln!(&mut f, "// ignore-tidy-filelength")?;
+
+    Ok(())
+}
+
+fn sort_bindings(file_name: &str) -> Result<(), Box<dyn Error>> {
+    let mut f = fs::File::options().read(true).write(true).open(file_name)?;
     let mut bindings = String::new();
     f.read_to_string(&mut bindings)?;
-    f.seek(io::SeekFrom::Start(0))?;
-    f.write_all(PRELUDE.as_bytes())?;
-    f.write_all(bindings.as_bytes())?;
+    f.set_len(0)?;
+    f.seek(SeekFrom::Start(0))?;
 
+    let mut lines = bindings.split_inclusive('\n');
+    for line in &mut lines {
+        f.write(line.as_bytes())?;
+        if line.contains("--filter") {
+            break;
+        }
+    }
+    let mut bindings = Vec::new();
+    for line in &mut lines {
+        if !line.trim().is_empty() {
+            bindings.push(line);
+        }
+    }
+    bindings.sort_by(|a, b| a.to_lowercase().cmp(&b.to_lowercase()));
+    for line in bindings {
+        f.write(line.as_bytes())?;
+    }
     Ok(())
 }