Rollup merge of rust-lang#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 rust-lang#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 (rust-lang#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 rust-lang#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
-/// where we should dump a MIR representation output files.
-fn dump_file_basename<'tcx>(
+/// 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>(
     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:?}"),
@@ -186,32 +188,31 @@ 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,
+/// 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
+/// other things, and hence takes the extension as an argument.
+pub fn create_dump_file<'tcx>(
+    tcx: TyCtxt<'tcx>,
     extension: &str,
+    pass_num: bool,
+    pass_name: &str,
+    disambiguator: &dyn Display,
+    body: &Body<'tcx>,
 ) -> io::Result<io::BufWriter<fs::File>> {
-    let file_path = dump_path(tcx, file_basename, extension);
+    let file_path = dump_path(tcx, extension, pass_num, pass_name, disambiguator, body);
     if let Some(parent) = file_path.parent() {
         fs::create_dir_all(parent).map_err(|e| {
             io::Error::new(
@@ -225,25 +226,6 @@ fn create_dump_file_with_basename(
     })?))
 }
 
-/// 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
-/// other things, and hence takes the extension as an argument.
-pub fn create_dump_file<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    extension: &str,
-    pass_num: bool,
-    pass_name: &str,
-    disambiguator: &dyn Display,
-    body: &Body<'tcx>,
-) -> io::Result<io::BufWriter<fs::File>> {
-    create_dump_file_with_basename(
-        tcx,
-        &dump_file_basename(tcx, pass_num, pass_name, disambiguator, body),
-        extension,
-    )
-}
-
 ///////////////////////////////////////////////////////////////////////////
 // Whole MIR bodies