transpile: Run rustfmt on generated .rs files

c2rust-transpile/src/build_files/mod.rs

@@ -11,10 +11,10 @@ use serde_json::json;
 
 use super::compile_cmds::LinkCmd;
 use super::TranspilerConfig;
-use crate::get_module_name;
 use crate::CrateSet;
 use crate::ExternCrateDetails;
 use crate::PragmaSet;
+use crate::{get_module_name, rustfmt};
 
 #[derive(Debug, Copy, Clone)]
 pub enum BuildDirectoryContents {
@@ -225,7 +225,10 @@ fn emit_build_rs(
     });
     let output = reg.render("build.rs", &json).unwrap();
     let output_path = build_dir.join("build.rs");
-    maybe_write_to_file(&output_path, output, tcfg.overwrite_existing)
+    let path = maybe_write_to_file(&output_path, output, tcfg.overwrite_existing)?;
+    rustfmt(&output_path, build_dir);
+
+    Some(path)
 }
 
 /// Emit lib.rs (main.rs) for a library (binary). Returns `Some(path)`
@@ -252,8 +255,10 @@ fn emit_lib_rs(
 
     let output_path = build_dir.join(file_name);
     let output = reg.render("lib.rs", &json).unwrap();
+    let path = maybe_write_to_file(&output_path, output, tcfg.overwrite_existing)?;
+    rustfmt(&output_path, build_dir);
 
-    maybe_write_to_file(&output_path, output, tcfg.overwrite_existing)
+    Some(path)
 }
 
 /// If we translate variadic functions, the output will only compile

c2rust-transpile/src/lib.rs

@@ -620,6 +620,8 @@ fn transpile_single(
         ),
     };
 
+    rustfmt(&output_path, build_dir);
+
     Ok((output_path, pragmas, crates))
 }
 
@@ -667,3 +669,17 @@ fn get_output_path(
         input_path
     }
 }
+
+fn rustfmt(output_path: &Path, build_dir: &Path) {
+    let edition = "2021";
+
+    let status = Command::new("rustfmt")
+        .args(["--edition", edition])
+        .arg(output_path)
+        .current_dir(build_dir)
+        .status();
+
+    if !status.map_or(false, |status| status.success()) {
+        warn!("rustfmt failed, code may not be well-formatted");
+    }
+}

c2rust-transpile/tests/snapshots.rs

@@ -90,12 +90,6 @@ fn transpile(platform: Option<&str>, c_path: &Path) {
 
     let edition = "2021";
 
-    let status = Command::new("rustfmt")
-        .args(["--edition", edition])
-        .arg(&rs_path)
-        .status();
-    assert!(status.unwrap().success());
-
     let rs = fs::read_to_string(&rs_path).unwrap();
     let debug_expr = format!("cat {}", rs_path.display());