Auto merge of #130803 - cuviper:file-buffered, r=joshtriplett

Add `File` constructors that return files wrapped with a buffer

In addition to the light convenience, these are intended to raise visibility that buffering is something you should consider when opening a file, since unbuffered I/O is a common performance footgun to Rust newcomers.

ACP: https://github.com/rust-lang/libs-team/issues/446
Tracking Issue: #130804

2 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_mir_dataflow/src/framework/engine.rs b/compiler/rustc_mir_dataflow/src/framework/engine.rs
index 947bdf860b5..da01a974094 100644
--- a/compiler/rustc_mir_dataflow/src/framework/engine.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/engine.rs
@@ -266,7 +266,7 @@ where
     A::Domain: DebugWithContext<A>,
 {
     use std::fs;
-    use std::io::{self, Write};
+    use std::io::Write;
 
     let def_id = body.source.def_id();
     let Ok(attrs) = RustcMirAttrs::parse(tcx, def_id) else {
@@ -281,8 +281,7 @@ where
                 if let Some(parent) = path.parent() {
                     fs::create_dir_all(parent)?;
                 }
-                let f = fs::File::create(&path)?;
-                io::BufWriter::new(f)
+                fs::File::create_buffered(&path)?
             }
 
             None if dump_enabled(tcx, A::NAME, def_id) => {
diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs
index cb7c7edc413..cd926c07641 100644
--- a/compiler/rustc_mir_dataflow/src/lib.rs
+++ b/compiler/rustc_mir_dataflow/src/lib.rs
@@ -3,6 +3,7 @@
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]
+#![feature(file_buffered)]
 #![feature(let_chains)]
 #![feature(try_blocks)]
 #![warn(unreachable_pub)]