Rollup merge of #120038 - Zalathar:dump-path, r=WaffleLapkin

Don't create a separate "basename" when naming and opening a MIR dump file

These functions were split up by #77080, in order to support passing the dump file's “basename” (filename without extension) to the implementation of `-Zdump-mir-spanview`, so that it could be used as a page title.

That flag has since been removed (#119566), so now there's no particular reason for this code to handle the basename separately from the filename or full path.

This PR therefore restores things to (roughly) how they were before #77080.

compiler/rustc_middle/src/mir/pretty.rs

@@ -142,15 +142,17 @@ fn dump_matched_mir_node<'tcx, F>(
     }
 }
 
-/// Returns the file basename portion (without extension) of a filename path
+/// Returns the path to the filename where we should dump a given MIR.
-/// where we should dump a MIR representation output files.
+/// Also used by other bits of code (e.g., NLL inference) that dump
-fn dump_file_basename<'tcx>(
+/// graphviz data or other things.
+fn dump_path<'tcx>(
     tcx: TyCtxt<'tcx>,
+    extension: &str,
     pass_num: bool,
     pass_name: &str,
     disambiguator: &dyn Display,
     body: &Body<'tcx>,
-) -> String {
+) -> PathBuf {
     let source = body.source;
     let promotion_id = match source.promoted {
         Some(id) => format!("-{id:?}"),
@@ -186,45 +188,18 @@ fn dump_file_basename<'tcx>(
         _ => String::new(),
     };
 
-    format!(
-        "{crate_name}.{item_name}{shim_disambiguator}{promotion_id}{pass_num}.{pass_name}.{disambiguator}",
-    )
-}
-
-/// Returns the path to the filename where we should dump a given MIR.
-/// Also used by other bits of code (e.g., NLL inference) that dump
-/// graphviz data or other things.
-fn dump_path(tcx: TyCtxt<'_>, basename: &str, extension: &str) -> PathBuf {
     let mut file_path = PathBuf::new();
     file_path.push(Path::new(&tcx.sess.opts.unstable_opts.dump_mir_dir));
 
-    let file_name = format!("{basename}.{extension}",);
+    let file_name = format!(
+        "{crate_name}.{item_name}{shim_disambiguator}{promotion_id}{pass_num}.{pass_name}.{disambiguator}.{extension}",
+    );
 
     file_path.push(&file_name);
 
     file_path
 }
 
-/// Attempts to open the MIR dump file with the given name and extension.
-fn create_dump_file_with_basename(
-    tcx: TyCtxt<'_>,
-    file_basename: &str,
-    extension: &str,
-) -> io::Result<io::BufWriter<fs::File>> {
-    let file_path = dump_path(tcx, file_basename, extension);
-    if let Some(parent) = file_path.parent() {
-        fs::create_dir_all(parent).map_err(|e| {
-            io::Error::new(
-                e.kind(),
-                format!("IO error creating MIR dump directory: {parent:?}; {e}"),
-            )
-        })?;
-    }
-    Ok(io::BufWriter::new(fs::File::create(&file_path).map_err(|e| {
-        io::Error::new(e.kind(), format!("IO error creating MIR dump file: {file_path:?}; {e}"))
-    })?))
-}
-
 /// Attempts to open a file where we should dump a given MIR or other
 /// bit of MIR-related data. Used by `mir-dump`, but also by other
 /// bits of code (e.g., NLL inference) that dump graphviz data or
@@ -237,11 +212,18 @@ pub fn create_dump_file<'tcx>(
     disambiguator: &dyn Display,
     body: &Body<'tcx>,
 ) -> io::Result<io::BufWriter<fs::File>> {
-    create_dump_file_with_basename(
+    let file_path = dump_path(tcx, extension, pass_num, pass_name, disambiguator, body);
-        tcx,
+    if let Some(parent) = file_path.parent() {
-        &dump_file_basename(tcx, pass_num, pass_name, disambiguator, body),
+        fs::create_dir_all(parent).map_err(|e| {
-        extension,
+            io::Error::new(
-    )
+                e.kind(),
+                format!("IO error creating MIR dump directory: {parent:?}; {e}"),
+            )
+        })?;
+    }
+    Ok(io::BufWriter::new(fs::File::create(&file_path).map_err(|e| {
+        io::Error::new(e.kind(), format!("IO error creating MIR dump file: {file_path:?}; {e}"))
+    })?))
 }
 
 ///////////////////////////////////////////////////////////////////////////