Move rustc_mir::transform to rustc_mir_transform.

compiler/rustc_mir_transform/src/dump_mir.rs

@@ -0,0 +1,59 @@
+//! This pass just dumps MIR at a specified point.
+
+use std::borrow::Cow;
+use std::fmt;
+use std::fs::File;
+use std::io;
+
+use crate::util as mir_util;
+use crate::MirPass;
+use rustc_middle::mir::Body;
+use rustc_middle::ty::TyCtxt;
+use rustc_session::config::{OutputFilenames, OutputType};
+
+pub struct Marker(pub &'static str);
+
+impl<'tcx> MirPass<'tcx> for Marker {
+    fn name(&self) -> Cow<'_, str> {
+        Cow::Borrowed(self.0)
+    }
+
+    fn run_pass(&self, _tcx: TyCtxt<'tcx>, _body: &mut Body<'tcx>) {}
+}
+
+pub struct Disambiguator {
+    is_after: bool,
+}
+
+impl fmt::Display for Disambiguator {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let title = if self.is_after { "after" } else { "before" };
+        write!(formatter, "{}", title)
+    }
+}
+
+pub fn on_mir_pass<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    pass_num: &dyn fmt::Display,
+    pass_name: &str,
+    body: &Body<'tcx>,
+    is_after: bool,
+) {
+    if mir_util::dump_enabled(tcx, pass_name, body.source.def_id()) {
+        mir_util::dump_mir(
+            tcx,
+            Some(pass_num),
+            pass_name,
+            &Disambiguator { is_after },
+            body,
+            |_, _| Ok(()),
+        );
+    }
+}
+
+pub fn emit_mir(tcx: TyCtxt<'_>, outputs: &OutputFilenames) -> io::Result<()> {
+    let path = outputs.path(OutputType::Mir);
+    let mut f = io::BufWriter::new(File::create(&path)?);
+    mir_util::write_mir_pretty(tcx, None, &mut f)?;
+    Ok(())
+}