simplify the MirPass traits and passes dramatically

Overall goal: reduce the amount of context a mir pass needs so that it
resembles a query.

- The hooks are no longer "threaded down" to the pass, but rather run
  automatically from the top-level (we also thread down the current pass
  number, so that the files are sorted better).
  - The hook now receives a *single* callback, rather than a callback per-MIR.
- The traits are no longer lifetime parameters, which moved to the
  methods -- given that we required
  `for<'tcx>` objecs, there wasn't much point to that.
- Several passes now store a `String` instead of a `&'l str` (again, no
  point).

23 files changed, 251 insertions, 266 deletions

diff --git a/src/librustc/dep_graph/safe.rs b/src/librustc/dep_graph/safe.rs
index f85f0338ed9..59dce6f6bb0 100644
--- a/src/librustc/dep_graph/safe.rs
+++ b/src/librustc/dep_graph/safe.rs
@@ -50,6 +50,12 @@ impl<A, B> DepGraphSafe for (A, B)
 {
 }
 
+/// Shared ref to dep-graph-safe stuff should still be dep-graph-safe.
+impl<'a, A> DepGraphSafe for &'a A
+    where A: DepGraphSafe,
+{
+}
+
 /// No data here! :)
 impl DepGraphSafe for () {
 }
diff --git a/src/librustc/mir/transform.rs b/src/librustc/mir/transform.rs
index 37113cee4a5..89f2fb59d51 100644
--- a/src/librustc/mir/transform.rs
+++ b/src/librustc/mir/transform.rs
@@ -18,7 +18,6 @@ use syntax::ast::NodeId;
 use util::common::time;
 
 use std::borrow::Cow;
-use std::fmt;
 
 /// Where a specific Mir comes from.
 #[derive(Debug, Copy, Clone)]
@@ -73,59 +72,61 @@ impl<'a, 'tcx> MirSource {
 
 /// Various information about pass.
 pub trait Pass {
-    // fn should_run(Session) to check if pass should run?
-    fn name<'a>(&self) -> Cow<'static, str> {
-        let name = unsafe { ::std::intrinsics::type_name::<Self>() };
-        if let Some(tail) = name.rfind(":") {
-            Cow::from(&name[tail+1..])
-        } else {
-            Cow::from(name)
-        }
+    fn name<'a>(&'a self) -> Cow<'a, str> {
+        default_name::<Self>()
     }
-    fn disambiguator<'a>(&'a self) -> Option<Box<fmt::Display+'a>> { None }
+
+    fn run_pass<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>);
 }
 
-/// A pass which inspects the whole Mir map.
-pub trait MirMapPass<'tcx>: Pass {
-    fn run_pass<'a>(
-        &self,
-        tcx: TyCtxt<'a, 'tcx, 'tcx>,
-        hooks: &mut [Box<for<'s> MirPassHook<'s>>]);
+/// Generates a default name for the pass based on the name of the
+/// type `T`.
+pub fn default_name<T: ?Sized>() -> Cow<'static, str> {
+    let name = unsafe { ::std::intrinsics::type_name::<T>() };
+    if let Some(tail) = name.rfind(":") {
+        Cow::from(&name[tail+1..])
+    } else {
+        Cow::from(name)
+    }
 }
 
-pub trait MirPassHook<'tcx>: Pass {
-    fn on_mir_pass<'a>(
-        &self,
-        tcx: TyCtxt<'a, 'tcx, 'tcx>,
-        src: MirSource,
-        mir: &Mir<'tcx>,
-        pass: &Pass,
-        is_after: bool
-    );
+pub trait PassHook {
+    fn on_mir_pass<'a, 'tcx>(&self,
+                             tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                             pass: &Pass,
+                             pass_num: usize,
+                             is_after: bool);
 }
 
-/// A pass which inspects Mir of functions in isolation.
-pub trait MirPass<'tcx>: Pass {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    src: MirSource, mir: &mut Mir<'tcx>);
+/// A streamlined trait that you can implement to create a pass; the
+/// pass will be named after the type, and it will consist of a main
+/// loop that goes over each available MIR and applies `run_pass`.
+pub trait MirPass {
+    fn name<'a>(&'a self) -> Cow<'a, str> {
+        default_name::<Self>()
+    }
+
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          src: MirSource,
+                          mir: &mut Mir<'tcx>);
 }
 
-impl<'tcx, T: MirPass<'tcx>> MirMapPass<'tcx> for T {
-    fn run_pass<'a>(&self,
-                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    hooks: &mut [Box<for<'s> MirPassHook<'s>>])
-    {
+impl<T: MirPass> Pass for T {
+    fn name<'a>(&'a self) -> Cow<'a, str> {
+        MirPass::name(self)
+    }
+
+    fn run_pass<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) {
         for &def_id in tcx.mir_keys(LOCAL_CRATE).iter() {
-            run_hooks(tcx, hooks, self, false);
             run_map_pass_task(tcx, self, def_id);
-            run_hooks(tcx, hooks, self, false);
         }
     }
 }
 
-fn run_map_pass_task<'a, 'tcx, T: MirPass<'tcx>>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                                 pass: &T,
-                                                 def_id: DefId) {
+fn run_map_pass_task<'a, 'tcx, T: MirPass>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                           pass: &T,
+                                           def_id: DefId) {
     let _task = tcx.dep_graph.in_task(DepNode::Mir(def_id));
     let mir = &mut tcx.mir(def_id).borrow_mut();
     let id = tcx.hir.as_local_node_id(def_id).expect("mir source requires local def-id");
@@ -138,36 +139,11 @@ fn run_map_pass_task<'a, 'tcx, T: MirPass<'tcx>>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     }
 }
 
-/// Invokes `hooks` on all the MIR that exists. This is read-only, so
-/// new new tasks need to be created.
-pub fn run_hooks<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                           hooks: &mut [Box<for<'s> MirPassHook<'s>>],
-                           pass: &Pass,
-                           is_after: bool)
-{
-    for &def_id in tcx.mir_keys(LOCAL_CRATE).iter() {
-        let mir = tcx.item_mir(def_id);
-        let id = tcx.hir.as_local_node_id(def_id).expect("mir source requires local def-id");
-
-        let source = MirSource::from_node(tcx, id);
-        for hook in &mut *hooks {
-            hook.on_mir_pass(tcx, source, &mir, pass, is_after);
-        }
-
-        for (i, mir) in mir.promoted.iter_enumerated() {
-            let source = MirSource::Promoted(id, i);
-            for hook in &mut *hooks {
-                hook.on_mir_pass(tcx, source, &mir, pass, false);
-            }
-        }
-    }
-}
-
 /// A manager for MIR passes.
 pub struct Passes {
-    passes: Vec<Box<for<'tcx> MirMapPass<'tcx>>>,
-    pass_hooks: Vec<Box<for<'tcx> MirPassHook<'tcx>>>,
-    plugin_passes: Vec<Box<for<'tcx> MirMapPass<'tcx>>>
+    passes: Vec<Box<Pass>>,
+    pass_hooks: Vec<Box<PassHook>>,
+    plugin_passes: Vec<Box<Pass>>
 }
 
 impl<'a, 'tcx> Passes {
@@ -181,27 +157,34 @@ impl<'a, 'tcx> Passes {
     }
 
     pub fn run_passes(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>) {
-        let Passes { ref mut passes, ref mut plugin_passes, ref mut pass_hooks } = *self;
-        for pass in plugin_passes.iter_mut().chain(passes.iter_mut()) {
-            time(tcx.sess.time_passes(), &*pass.name(),
-                 || pass.run_pass(tcx, pass_hooks));
+        // NB: passes are numbered from 1, since "construction" is zero.
+        for (pass, pass_num) in self.plugin_passes.iter().chain(&self.passes).zip(1..) {
+            for hook in &self.pass_hooks {
+                hook.on_mir_pass(tcx, &**pass, pass_num, false);
+            }
+
+            time(tcx.sess.time_passes(), &*pass.name(), || pass.run_pass(tcx));
+
+            for hook in &self.pass_hooks {
+                hook.on_mir_pass(tcx, &**pass, pass_num, true);
+            }
         }
     }
 
     /// Pushes a built-in pass.
-    pub fn push_pass(&mut self, pass: Box<for<'b> MirMapPass<'b>>) {
+    pub fn push_pass(&mut self, pass: Box<Pass>) {
         self.passes.push(pass);
     }
 
     /// Pushes a pass hook.
-    pub fn push_hook(&mut self, hook: Box<for<'b> MirPassHook<'b>>) {
+    pub fn push_hook(&mut self, hook: Box<PassHook>) {
         self.pass_hooks.push(hook);
     }
 }
 
 /// Copies the plugin passes.
-impl ::std::iter::Extend<Box<for<'a> MirMapPass<'a>>> for Passes {
-    fn extend<I: IntoIterator<Item=Box<for <'a> MirMapPass<'a>>>>(&mut self, it: I) {
+impl ::std::iter::Extend<Box<Pass>> for Passes {
+    fn extend<I: IntoIterator<Item=Box<Pass>>>(&mut self, it: I) {
         self.plugin_passes.extend(it);
     }
 }
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index d107e9a8485..fdfcd83d5b4 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -1003,6 +1003,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "dump MIR state at various points in translation"),
     dump_mir_dir: Option<String> = (None, parse_opt_string, [UNTRACKED],
           "the directory the MIR is dumped into"),
+    dump_mir_exclude_pass_number: bool = (false, parse_bool, [UNTRACKED],
+          "if set, exclude the pass number when dumping MIR (used in tests)"),
     perf_stats: bool = (false, parse_bool, [UNTRACKED],
           "print some performance-related statistics"),
     hir_stats: bool = (false, parse_bool, [UNTRACKED],
diff --git a/src/librustc_borrowck/borrowck/mir/elaborate_drops.rs b/src/librustc_borrowck/borrowck/mir/elaborate_drops.rs
index 106d8fe952d..4ae8bdc284b 100644
--- a/src/librustc_borrowck/borrowck/mir/elaborate_drops.rs
+++ b/src/librustc_borrowck/borrowck/mir/elaborate_drops.rs
@@ -16,7 +16,7 @@ use super::{drop_flag_effects_for_location, on_lookup_result_bits};
 use super::MoveDataParamEnv;
 use rustc::ty::{self, TyCtxt};
 use rustc::mir::*;
-use rustc::mir::transform::{Pass, MirPass, MirSource};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc::middle::const_val::ConstVal;
 use rustc::util::nodemap::FxHashMap;
 use rustc_data_structures::indexed_set::IdxSetBuf;
@@ -32,9 +32,11 @@ use std::u32;
 
 pub struct ElaborateDrops;
 
-impl<'tcx> MirPass<'tcx> for ElaborateDrops {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    src: MirSource, mir: &mut Mir<'tcx>)
+impl MirPass for ElaborateDrops {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          src: MirSource,
+                          mir: &mut Mir<'tcx>)
     {
         debug!("elaborate_drops({:?} @ {:?})", src, mir.span);
         match src {
@@ -74,8 +76,6 @@ impl<'tcx> MirPass<'tcx> for ElaborateDrops {
     }
 }
 
-impl Pass for ElaborateDrops {}
-
 /// Return the set of basic blocks whose unwind edges are known
 /// to not be reachable, because they are `drop` terminators
 /// that can't drop anything.
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 5d6bc235761..64fb2168ca1 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -979,8 +979,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
             passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("initial"));
             passes.push_pass(box mir::transform::type_check::TypeckMir);
             passes.push_pass(box mir::transform::qualify_consts::QualifyAndPromoteConstants);
-            passes.push_pass(
-                box mir::transform::simplify_branches::SimplifyBranches::new("initial"));
+            passes.push_pass(box mir::transform::simplify_branches::SimplifyBranches::new("initial"));
             passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("qualify-consts"));
             // And run everything.
             passes.run_passes(tcx);
diff --git a/src/librustc_mir/mir_map.rs b/src/librustc_mir/mir_map.rs
index 353ca3bbd09..6aa7089e7a9 100644
--- a/src/librustc_mir/mir_map.rs
+++ b/src/librustc_mir/mir_map.rs
@@ -192,7 +192,7 @@ fn build_mir<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId)
             mem::transmute::<Mir, Mir<'tcx>>(mir)
         };
 
-        mir_util::dump_mir(tcx, "mir_map", &0, src, &mir);
+        mir_util::dump_mir(tcx, 0, "mir_map", &0, src, &mir);
 
         tcx.alloc_mir(mir)
     })
@@ -251,7 +251,7 @@ fn create_constructor_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                 mem::transmute::<Mir, Mir<'tcx>>(mir)
             };
 
-            mir_util::dump_mir(tcx, "mir_map", &0, src, &mir);
+            mir_util::dump_mir(tcx, 0, "mir_map", &0, src, &mir);
 
             tcx.alloc_mir(mir)
         })
diff --git a/src/librustc_mir/transform/add_call_guards.rs b/src/librustc_mir/transform/add_call_guards.rs
index 9e67beb86e6..b7c7a1774dd 100644
--- a/src/librustc_mir/transform/add_call_guards.rs
+++ b/src/librustc_mir/transform/add_call_guards.rs
@@ -10,7 +10,7 @@
 
 use rustc::ty::TyCtxt;
 use rustc::mir::*;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
 
 pub struct AddCallGuards;
@@ -35,8 +35,11 @@ pub struct AddCallGuards;
  *
  */
 
-impl<'tcx> MirPass<'tcx> for AddCallGuards {
-    fn run_pass<'a>(&self, _tcx: TyCtxt<'a, 'tcx, 'tcx>, _src: MirSource, mir: &mut Mir<'tcx>) {
+impl MirPass for AddCallGuards {
+    fn run_pass<'a, 'tcx>(&self,
+                          _tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          _src: MirSource,
+                          mir: &mut Mir<'tcx>) {
         add_call_guards(mir);
     }
 }
@@ -82,5 +85,3 @@ pub fn add_call_guards(mir: &mut Mir) {
 
     mir.basic_blocks_mut().extend(new_blocks);
 }
-
-impl Pass for AddCallGuards {}
diff --git a/src/librustc_mir/transform/copy_prop.rs b/src/librustc_mir/transform/copy_prop.rs
index b7cacfe1296..fbb67161bac 100644
--- a/src/librustc_mir/transform/copy_prop.rs
+++ b/src/librustc_mir/transform/copy_prop.rs
@@ -30,7 +30,7 @@
 //! future.
 
 use rustc::mir::{Constant, Local, LocalKind, Location, Lvalue, Mir, Operand, Rvalue, StatementKind};
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc::mir::visit::MutVisitor;
 use rustc::ty::TyCtxt;
 use util::def_use::DefUseAnalysis;
@@ -38,13 +38,11 @@ use transform::qualify_consts;
 
 pub struct CopyPropagation;
 
-impl Pass for CopyPropagation {}
-
-impl<'tcx> MirPass<'tcx> for CopyPropagation {
-    fn run_pass<'a>(&self,
-                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    source: MirSource,
-                    mir: &mut Mir<'tcx>) {
+impl MirPass for CopyPropagation {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          source: MirSource,
+                          mir: &mut Mir<'tcx>) {
         match source {
             MirSource::Const(_) => {
                 // Don't run on constants, because constant qualification might reject the
diff --git a/src/librustc_mir/transform/deaggregator.rs b/src/librustc_mir/transform/deaggregator.rs
index 6d91e6fa55b..4309f91c635 100644
--- a/src/librustc_mir/transform/deaggregator.rs
+++ b/src/librustc_mir/transform/deaggregator.rs
@@ -10,16 +10,16 @@
 
 use rustc::ty::TyCtxt;
 use rustc::mir::*;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc_data_structures::indexed_vec::Idx;
 
 pub struct Deaggregator;
 
-impl Pass for Deaggregator {}
-
-impl<'tcx> MirPass<'tcx> for Deaggregator {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    source: MirSource, mir: &mut Mir<'tcx>) {
+impl MirPass for Deaggregator {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          source: MirSource,
+                          mir: &mut Mir<'tcx>) {
         let node_id = source.item_id();
         let node_path = tcx.item_path_str(tcx.hir.local_def_id(node_id));
         debug!("running on: {:?}", node_path);
diff --git a/src/librustc_mir/transform/dump_mir.rs b/src/librustc_mir/transform/dump_mir.rs
index 4c6754b88b6..528afd184c6 100644
--- a/src/librustc_mir/transform/dump_mir.rs
+++ b/src/librustc_mir/transform/dump_mir.rs
@@ -10,70 +10,71 @@
 
 //! This pass just dumps MIR at a specified point.
 
+use std::borrow::Cow;
 use std::fmt;
 use std::fs::File;
 use std::io;
 
+use rustc::hir::def_id::LOCAL_CRATE;
 use rustc::session::config::{OutputFilenames, OutputType};
 use rustc::ty::TyCtxt;
-use rustc::mir::*;
-use rustc::mir::transform::{Pass, MirPass, MirPassHook, MirSource};
+use rustc::mir::transform::{Pass, PassHook, MirSource};
 use util as mir_util;
 
-pub struct Marker<'a>(pub &'a str);
+pub struct Marker(pub &'static str);
 
-impl<'b, 'tcx> MirPass<'tcx> for Marker<'b> {
-    fn run_pass<'a>(&self, _tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    _src: MirSource, _mir: &mut Mir<'tcx>)
-    {}
-}
+impl Pass for Marker {
+    fn name<'a>(&'a self) -> Cow<'a, str> {
+        Cow::Borrowed(self.0)
+    }
 
-impl<'b> Pass for Marker<'b> {
-    fn name(&self) -> ::std::borrow::Cow<'static, str> { String::from(self.0).into() }
+    fn run_pass<'a, 'tcx>(&self, _tcx: TyCtxt<'a, 'tcx, 'tcx>) {
+        // no-op
+    }
 }
 
-pub struct Disambiguator<'a> {
-    pass: &'a Pass,
+pub struct Disambiguator {
     is_after: bool
 }
 
-impl<'a> fmt::Display for Disambiguator<'a> {
+impl fmt::Display for Disambiguator {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         let title = if self.is_after { "after" } else { "before" };
-        if let Some(fmt) = self.pass.disambiguator() {
-            write!(formatter, "{}-{}", fmt, title)
-        } else {
-            write!(formatter, "{}", title)
-        }
+        write!(formatter, "{}", title)
     }
 }
 
 pub struct DumpMir;
 
-impl<'tcx> MirPassHook<'tcx> for DumpMir {
-    fn on_mir_pass<'a>(
+impl PassHook for DumpMir {
+    fn on_mir_pass<'a, 'tcx>(
         &self,
         tcx: TyCtxt<'a, 'tcx, 'tcx>,
-        src: MirSource,
-        mir: &Mir<'tcx>,
         pass: &Pass,
+        pass_num: usize,
         is_after: bool)
     {
-        mir_util::dump_mir(
-            tcx,
-            &*pass.name(),
-            &Disambiguator {
-                pass: pass,
-                is_after: is_after
-            },
-            src,
-            mir
-        );
+        // No dump filters enabled.
+        if tcx.sess.opts.debugging_opts.dump_mir.is_none() {
+            return;
+        }
+
+        for &def_id in tcx.mir_keys(LOCAL_CRATE).iter() {
+            let id = tcx.hir.as_local_node_id(def_id).unwrap();
+            let source = MirSource::from_node(tcx, id);
+            let mir = tcx.item_mir(def_id);
+            mir_util::dump_mir(
+                tcx,
+                pass_num,
+                &*pass.name(),
+                &Disambiguator { is_after },
+                source,
+                &mir
+            );
+        }
     }
 }
 
-impl<'b> Pass for DumpMir {}
-
 pub fn emit_mir<'a, 'tcx>(
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     outputs: &OutputFilenames)
diff --git a/src/librustc_mir/transform/erase_regions.rs b/src/librustc_mir/transform/erase_regions.rs
index 05e056ed0be..19714849b09 100644
--- a/src/librustc_mir/transform/erase_regions.rs
+++ b/src/librustc_mir/transform/erase_regions.rs
@@ -16,7 +16,7 @@ use rustc::ty::subst::Substs;
 use rustc::ty::{Ty, TyCtxt, ClosureSubsts};
 use rustc::mir::*;
 use rustc::mir::visit::MutVisitor;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 
 struct EraseRegionsVisitor<'a, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
@@ -69,11 +69,11 @@ impl<'a, 'tcx> MutVisitor<'tcx> for EraseRegionsVisitor<'a, 'tcx> {
 
 pub struct EraseRegions;
 
-impl Pass for EraseRegions {}
-
-impl<'tcx> MirPass<'tcx> for EraseRegions {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    _: MirSource, mir: &mut Mir<'tcx>) {
+impl MirPass for EraseRegions {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          _: MirSource,
+                          mir: &mut Mir<'tcx>) {
         EraseRegionsVisitor::new(tcx).visit_mir(mir);
     }
 }
diff --git a/src/librustc_mir/transform/inline.rs b/src/librustc_mir/transform/inline.rs
index b11a3c805f9..b0a067063dd 100644
--- a/src/librustc_mir/transform/inline.rs
+++ b/src/librustc_mir/transform/inline.rs
@@ -10,7 +10,7 @@
 
 //! Inlining pass for MIR functions
 
-use rustc::hir::def_id::{DefId, LOCAL_CRATE};
+use rustc::hir::def_id::DefId;
 
 use rustc_data_structures::bitvec::BitVector;
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
@@ -18,7 +18,7 @@ use rustc_data_structures::graph;
 
 use rustc::dep_graph::DepNode;
 use rustc::mir::*;
-use rustc::mir::transform::{self, MirMapPass, MirPassHook, MirSource, Pass};
+use rustc::mir::transform::{MirSource, Pass};
 use rustc::mir::visit::*;
 use rustc::traits;
 use rustc::ty::{self, Ty, TyCtxt};
@@ -42,12 +42,8 @@ const UNKNOWN_SIZE_COST: usize = 10;
 
 pub struct Inline;
 
-impl<'tcx> MirMapPass<'tcx> for Inline {
-    fn run_pass<'a>(
-        &self,
-        tcx: TyCtxt<'a, 'tcx, 'tcx>,
-        hooks: &mut [Box<for<'s> MirPassHook<'s>>]) {
-
+impl Pass for Inline {
+    fn run_pass<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) {
         if tcx.sess.opts.debugging_opts.mir_opt_level < 2 { return; }
 
         let _ignore = tcx.dep_graph.in_ignore();
@@ -58,18 +54,12 @@ impl<'tcx> MirMapPass<'tcx> for Inline {
             tcx: tcx,
         };
 
-        transform::run_hooks(tcx, hooks, self, false);
-
         for scc in callgraph.scc_iter() {
             inliner.inline_scc(&callgraph, &scc);
         }
-
-        transform::run_hooks(tcx, hooks, self, true);
     }
 }
 
-impl<'tcx> Pass for Inline { }
-
 struct Inliner<'a, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 }
diff --git a/src/librustc_mir/transform/instcombine.rs b/src/librustc_mir/transform/instcombine.rs
index 89ac0762fbf..88a368077d4 100644
--- a/src/librustc_mir/transform/instcombine.rs
+++ b/src/librustc_mir/transform/instcombine.rs
@@ -11,7 +11,7 @@
 //! Performs various peephole optimizations.
 
 use rustc::mir::{Location, Lvalue, Mir, Operand, ProjectionElem, Rvalue, Local};
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc::mir::visit::{MutVisitor, Visitor};
 use rustc::ty::TyCtxt;
 use rustc::util::nodemap::FxHashSet;
@@ -20,13 +20,11 @@ use std::mem;
 
 pub struct InstCombine;
 
-impl Pass for InstCombine {}
-
-impl<'tcx> MirPass<'tcx> for InstCombine {
-    fn run_pass<'a>(&self,
-                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    _: MirSource,
-                    mir: &mut Mir<'tcx>) {
+impl MirPass for InstCombine {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          _: MirSource,
+                          mir: &mut Mir<'tcx>) {
         // We only run when optimizing MIR (at any level).
         if tcx.sess.opts.debugging_opts.mir_opt_level == 0 {
             return
diff --git a/src/librustc_mir/transform/no_landing_pads.rs b/src/librustc_mir/transform/no_landing_pads.rs
index 264b2ea4bb9..8595663ba18 100644
--- a/src/librustc_mir/transform/no_landing_pads.rs
+++ b/src/librustc_mir/transform/no_landing_pads.rs
@@ -14,10 +14,25 @@
 use rustc::ty::TyCtxt;
 use rustc::mir::*;
 use rustc::mir::visit::MutVisitor;
-use rustc::mir::transform::{Pass, MirPass, MirSource};
+use rustc::mir::transform::{MirPass, MirSource};
 
 pub struct NoLandingPads;
 
+impl MirPass for NoLandingPads {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          _: MirSource,
+                          mir: &mut Mir<'tcx>) {
+        no_landing_pads(tcx, mir)
+    }
+}
+
+pub fn no_landing_pads<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, mir: &mut Mir<'tcx>) {
+    if tcx.sess.no_landing_pads() {
+        NoLandingPads.visit_mir(mir);
+    }
+}
+
 impl<'tcx> MutVisitor<'tcx> for NoLandingPads {
     fn visit_terminator(&mut self,
                         bb: BasicBlock,
@@ -41,18 +56,3 @@ impl<'tcx> MutVisitor<'tcx> for NoLandingPads {
         self.super_terminator(bb, terminator, location);
     }
 }
-
-pub fn no_landing_pads<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, mir: &mut Mir<'tcx>) {
-    if tcx.sess.no_landing_pads() {
-        NoLandingPads.visit_mir(mir);
-    }
-}
-
-impl<'tcx> MirPass<'tcx> for NoLandingPads {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    _: MirSource, mir: &mut Mir<'tcx>) {
-        no_landing_pads(tcx, mir)
-    }
-}
-
-impl Pass for NoLandingPads {}
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index e0948b75f27..7e7e85f2ec9 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -27,7 +27,7 @@ use rustc::ty::cast::CastTy;
 use rustc::ty::maps::Providers;
 use rustc::mir::*;
 use rustc::mir::traversal::ReversePostorder;
-use rustc::mir::transform::{Pass, MirMapPass, MirPassHook, MirSource};
+use rustc::mir::transform::{Pass, MirSource};
 use rustc::mir::visit::{LvalueContext, Visitor};
 use rustc::middle::lang_items;
 use syntax::abi::Abi;
@@ -939,12 +939,9 @@ fn qualify_const_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
 pub struct QualifyAndPromoteConstants;
 
-impl Pass for QualifyAndPromoteConstants {}
-
-impl<'tcx> MirMapPass<'tcx> for QualifyAndPromoteConstants {
-    fn run_pass<'a>(&self,
-                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    hooks: &mut [Box<for<'s> MirPassHook<'s>>])
+impl Pass for QualifyAndPromoteConstants {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>)
     {
         for &def_id in tcx.mir_keys(LOCAL_CRATE).iter() {
             let _task = tcx.dep_graph.in_task(DepNode::Mir(def_id));
@@ -959,20 +956,15 @@ impl<'tcx> MirMapPass<'tcx> for QualifyAndPromoteConstants {
             let mir = &mut tcx.mir(def_id).borrow_mut();
             tcx.dep_graph.write(DepNode::Mir(def_id));
 
-            for hook in &mut *hooks {
-                hook.on_mir_pass(tcx, src, mir, self, false);
-            }
             self.run_pass(tcx, src, mir);
-            for hook in &mut *hooks {
-                hook.on_mir_pass(tcx, src, mir, self, true);
-            }
         }
     }
 }
 
-impl<'tcx> QualifyAndPromoteConstants {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    src: MirSource, mir: &mut Mir<'tcx>) {
+impl<'a, 'tcx> QualifyAndPromoteConstants {
+    fn run_pass(&self,
+                tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                src: MirSource, mir: &mut Mir<'tcx>) {
         let id = src.item_id();
         let def_id = tcx.hir.local_def_id(id);
         let mode = match src {
diff --git a/src/librustc_mir/transform/simplify.rs b/src/librustc_mir/transform/simplify.rs
index 0881585ddfe..d5b79c0d1c3 100644
--- a/src/librustc_mir/transform/simplify.rs
+++ b/src/librustc_mir/transform/simplify.rs
@@ -41,15 +41,15 @@ use rustc_data_structures::bitvec::BitVector;
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
 use rustc::ty::TyCtxt;
 use rustc::mir::*;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc::mir::visit::{MutVisitor, Visitor, LvalueContext};
-use std::fmt;
+use std::borrow::Cow;
 
-pub struct SimplifyCfg<'a> { label: &'a str }
+pub struct SimplifyCfg { label: String }
 
-impl<'a> SimplifyCfg<'a> {
-    pub fn new(label: &'a str) -> Self {
-        SimplifyCfg { label: label }
+impl SimplifyCfg {
+    pub fn new(label: &str) -> Self {
+        SimplifyCfg { label: format!("SimplifyCfg-{}", label) }
     }
 }
 
@@ -61,20 +61,18 @@ pub fn simplify_cfg(mir: &mut Mir) {
     mir.basic_blocks_mut().raw.shrink_to_fit();
 }
 
-impl<'l, 'tcx> MirPass<'tcx> for SimplifyCfg<'l> {
-    fn run_pass<'a>(&self, _tcx: TyCtxt<'a, 'tcx, 'tcx>, _src: MirSource, mir: &mut Mir<'tcx>) {
-        debug!("SimplifyCfg({:?}) - simplifying {:?}", self.label, mir);
-        simplify_cfg(mir);
+impl MirPass for SimplifyCfg {
+    fn name<'a>(&'a self) -> Cow<'a, str> {
+        Cow::Borrowed(&self.label)
     }
-}
 
-impl<'l> Pass for SimplifyCfg<'l> {
-    fn disambiguator<'a>(&'a self) -> Option<Box<fmt::Display+'a>> {
-        Some(Box::new(self.label))
+    fn run_pass<'a, 'tcx>(&self,
+                          _tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          _src: MirSource,
+                          mir: &mut Mir<'tcx>) {
+        debug!("SimplifyCfg({:?}) - simplifying {:?}", self.label, mir);
+        simplify_cfg(mir);
     }
-
-    // avoid calling `type_name` - it contains `<'static>`
-    fn name(&self) -> ::std::borrow::Cow<'static, str> { "SimplifyCfg".into() }
 }
 
 pub struct CfgSimplifier<'a, 'tcx: 'a> {
@@ -315,12 +313,11 @@ pub fn remove_dead_blocks(mir: &mut Mir) {
 
 pub struct SimplifyLocals;
 
-impl Pass for SimplifyLocals {
-    fn name(&self) -> ::std::borrow::Cow<'static, str> { "SimplifyLocals".into() }
-}
-
-impl<'tcx> MirPass<'tcx> for SimplifyLocals {
-    fn run_pass<'a>(&self, _: TyCtxt<'a, 'tcx, 'tcx>, _: MirSource, mir: &mut Mir<'tcx>) {
+impl MirPass for SimplifyLocals {
+    fn run_pass<'a, 'tcx>(&self,
+                          _: TyCtxt<'a, 'tcx, 'tcx>,
+                          _: MirSource,
+                          mir: &mut Mir<'tcx>) {
         let mut marker = DeclMarker { locals: BitVector::new(mir.local_decls.len()) };
         marker.visit_mir(mir);
         // Return pointer and arguments are always live
diff --git a/src/librustc_mir/transform/simplify_branches.rs b/src/librustc_mir/transform/simplify_branches.rs
index b16ee65e918..d21a6ddfdfb 100644
--- a/src/librustc_mir/transform/simplify_branches.rs
+++ b/src/librustc_mir/transform/simplify_branches.rs
@@ -12,21 +12,28 @@
 
 use rustc::ty::TyCtxt;
 use rustc::middle::const_val::ConstVal;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc::mir::*;
 
-use std::fmt;
+use std::borrow::Cow;
 
-pub struct SimplifyBranches<'a> { label: &'a str }
+pub struct SimplifyBranches { label: String }
 
-impl<'a> SimplifyBranches<'a> {
-    pub fn new(label: &'a str) -> Self {
-        SimplifyBranches { label: label }
+impl SimplifyBranches {
+    pub fn new(label: &str) -> Self {
+        SimplifyBranches { label: format!("SimplifyBranches-{}", label) }
     }
 }
 
-impl<'l, 'tcx> MirPass<'tcx> for SimplifyBranches<'l> {
-    fn run_pass<'a>(&self, _tcx: TyCtxt<'a, 'tcx, 'tcx>, _src: MirSource, mir: &mut Mir<'tcx>) {
+impl MirPass for SimplifyBranches {
+    fn name<'a>(&'a self) -> Cow<'a, str> {
+        Cow::Borrowed(&self.label)
+    }
+
+    fn run_pass<'a, 'tcx>(&self,
+                          _tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          _src: MirSource,
+                          mir: &mut Mir<'tcx>) {
         for block in mir.basic_blocks_mut() {
             let terminator = block.terminator_mut();
             terminator.kind = match terminator.kind {
@@ -60,11 +67,3 @@ impl<'l, 'tcx> MirPass<'tcx> for SimplifyBranches<'l> {
     }
 }
 
-impl<'l> Pass for SimplifyBranches<'l> {
-    fn disambiguator<'a>(&'a self) -> Option<Box<fmt::Display+'a>> {
-        Some(Box::new(self.label))
-    }
-
-    // avoid calling `type_name` - it contains `<'static>`
-    fn name(&self) -> ::std::borrow::Cow<'static, str> { "SimplifyBranches".into() }
-}
diff --git a/src/librustc_mir/transform/type_check.rs b/src/librustc_mir/transform/type_check.rs
index 02e34fd7998..b325470ec81 100644
--- a/src/librustc_mir/transform/type_check.rs
+++ b/src/librustc_mir/transform/type_check.rs
@@ -18,7 +18,7 @@ use rustc::ty::{self, Ty, TyCtxt, TypeVariants};
 use rustc::middle::const_val::ConstVal;
 use rustc::mir::*;
 use rustc::mir::tcx::LvalueTy;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::transform::{MirPass, MirSource};
 use rustc::mir::visit::Visitor;
 use std::fmt;
 use syntax::ast;
@@ -737,9 +737,11 @@ impl TypeckMir {
     }
 }
 
-impl<'tcx> MirPass<'tcx> for TypeckMir {
-    fn run_pass<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    src: MirSource, mir: &mut Mir<'tcx>) {
+impl MirPass for TypeckMir {
+    fn run_pass<'a, 'tcx>(&self,
+                          tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          src: MirSource,
+                          mir: &mut Mir<'tcx>) {
         let item_id = src.item_id();
         let def_id = tcx.hir.local_def_id(item_id);
         debug!("run_pass: {}", tcx.item_path_str(def_id));
@@ -765,6 +767,3 @@ impl<'tcx> MirPass<'tcx> for TypeckMir {
         });
     }
 }
-
-impl Pass for TypeckMir {
-}
diff --git a/src/librustc_mir/util/pretty.rs b/src/librustc_mir/util/pretty.rs
index c03c9c907a3..6c637f2b2a9 100644
--- a/src/librustc_mir/util/pretty.rs
+++ b/src/librustc_mir/util/pretty.rs
@@ -28,7 +28,7 @@ const ALIGN: usize = 40;
 /// representation of the mir into:
 ///
 /// ```text
-/// rustc.node<node_id>.<pass_name>.<disambiguator>
+/// rustc.node<node_id>.<pass_num>.<pass_name>.<disambiguator>
 /// ```
 ///
 /// Output from this function is controlled by passing `-Z dump-mir=<filter>`,
@@ -39,15 +39,16 @@ const ALIGN: usize = 40;
 ///   that can appear in the pass-name or the `item_path_str` for the given
 ///   node-id. If any one of the substrings match, the data is dumped out.
 pub fn dump_mir<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                          pass_num: usize,
                           pass_name: &str,
                           disambiguator: &Display,
-                          src: MirSource,
+                          source: MirSource,
                           mir: &Mir<'tcx>) {
     let filters = match tcx.sess.opts.debugging_opts.dump_mir {
         None => return,
         Some(ref filters) => filters,
     };
-    let node_id = src.item_id();
+    let node_id = source.item_id();
     let node_path = tcx.item_path_str(tcx.hir.local_def_id(node_id));
     let is_matched =
         filters.split("&")
@@ -60,26 +61,47 @@ pub fn dump_mir<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         return;
     }
 
-    let promotion_id = match src {
+    dump_matched_mir_node(tcx, pass_num, pass_name, &node_path, disambiguator, source, mir);
+    for (index, promoted_mir) in mir.promoted.iter_enumerated() {
+        let promoted_source = MirSource::Promoted(source.item_id(), index);
+        dump_matched_mir_node(tcx, pass_num, pass_name, &node_path, disambiguator,
+                              promoted_source, promoted_mir);
+    }
+}
+
+fn dump_matched_mir_node<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                   pass_num: usize,
+                                   pass_name: &str,
+                                   node_path: &str,
+                                   disambiguator: &Display,
+                                   source: MirSource,
+                                   mir: &Mir<'tcx>) {
+    let promotion_id = match source {
         MirSource::Promoted(_, id) => format!("-{:?}", id),
         _ => String::new()
     };
 
+    let pass_num = if tcx.sess.opts.debugging_opts.dump_mir_exclude_pass_number {
+        format!("")
+    } else {
+        format!(".{:03}", pass_num)
+    };
+
     let mut file_path = PathBuf::new();
     if let Some(ref file_dir) = tcx.sess.opts.debugging_opts.dump_mir_dir {
         let p = Path::new(file_dir);
         file_path.push(p);
     };
-    let file_name = format!("rustc.node{}{}.{}.{}.mir",
-                            node_id, promotion_id, pass_name, disambiguator);
+    let file_name = format!("rustc.node{}{}{}.{}.{}.mir",
+                            source.item_id(), promotion_id, pass_num, pass_name, disambiguator);
     file_path.push(&file_name);
     let _ = fs::File::create(&file_path).and_then(|mut file| {
         writeln!(file, "// MIR for `{}`", node_path)?;
-        writeln!(file, "// node_id = {}", node_id)?;
+        writeln!(file, "// source = {:?}", source)?;
         writeln!(file, "// pass_name = {}", pass_name)?;
         writeln!(file, "// disambiguator = {}", disambiguator)?;
         writeln!(file, "")?;
-        write_mir_fn(tcx, src, mir, &mut file)?;
+        write_mir_fn(tcx, source, mir, &mut file)?;
         Ok(())
     });
 }
diff --git a/src/test/mir-opt/basic_assignment.rs b/src/test/mir-opt/basic_assignment.rs
index 9c924a23903..e4eb1aeaf9b 100644
--- a/src/test/mir-opt/basic_assignment.rs
+++ b/src/test/mir-opt/basic_assignment.rs
@@ -36,7 +36,7 @@ fn main() {
 }
 
 // END RUST SOURCE
-// START rustc.node4.SimplifyCfg.initial-after.mir
+// START rustc.node4.SimplifyCfg-initial.after.mir
 //     bb0: {
 //         StorageLive(_1);
 //         _1 = const false;
@@ -82,4 +82,4 @@ fn main() {
 //         StorageDead(_1);
 //         return;
 //     }
-// END rustc.node4.SimplifyCfg.initial-after.mir
+// END rustc.node4.SimplifyCfg-initial.after.mir
diff --git a/src/test/mir-opt/issue-38669.rs b/src/test/mir-opt/issue-38669.rs
index fbbffe8953b..5a9336e9659 100644
--- a/src/test/mir-opt/issue-38669.rs
+++ b/src/test/mir-opt/issue-38669.rs
@@ -21,7 +21,7 @@ fn main() {
 }
 
 // END RUST SOURCE
-// START rustc.node4.SimplifyCfg.initial-after.mir
+// START rustc.node4.SimplifyCfg-initial.after.mir
 //     bb0: {
 //         StorageLive(_1);
 //         _1 = const false;
@@ -48,4 +48,4 @@ fn main() {
 //         _2 = ();
 //         goto -> bb1;
 //     }
-// END rustc.node4.SimplifyCfg.initial-after.mir
+// END rustc.node4.SimplifyCfg-initial.after.mir
diff --git a/src/test/mir-opt/simplify_if.rs b/src/test/mir-opt/simplify_if.rs
index 6e80a917467..cff108246a5 100644
--- a/src/test/mir-opt/simplify_if.rs
+++ b/src/test/mir-opt/simplify_if.rs
@@ -15,13 +15,13 @@ fn main() {
 }
 
 // END RUST SOURCE
-// START rustc.node4.SimplifyBranches.initial-before.mir
+// START rustc.node4.SimplifyBranches-initial.before.mir
 // bb0: {
 //     switchInt(const false) -> [0u8: bb2, otherwise: bb1];
 // }
-// END rustc.node4.SimplifyBranches.initial-before.mir
-// START rustc.node4.SimplifyBranches.initial-after.mir
+// END rustc.node4.SimplifyBranches-initial.before.mir
+// START rustc.node4.SimplifyBranches-initial.after.mir
 // bb0: {
 //     goto -> bb2;
 // }
-// END rustc.node4.SimplifyBranches.initial-after.mir
+// END rustc.node4.SimplifyBranches-initial.after.mir
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 731665ce034..a044282666d 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -1402,18 +1402,16 @@ actual:\n\
                 }
             }
             MirOpt => {
-                args.extend(["-Z",
-                             "dump-mir=all",
-                             "-Z",
-                             "mir-opt-level=3",
-                             "-Z"]
+                args.extend(["-Zdump-mir=all",
+                             "-Zmir-opt-level=3",
+                             "-Zdump-mir-exclude-pass-number"]
                             .iter()
                             .map(|s| s.to_string()));
 
 
                 let mir_dump_dir = self.get_mir_dump_dir();
                 create_dir_all(mir_dump_dir.as_path()).unwrap();
-                let mut dir_opt = "dump-mir-dir=".to_string();
+                let mut dir_opt = "-Zdump-mir-dir=".to_string();
                 dir_opt.push_str(mir_dump_dir.to_str().unwrap());
                 debug!("dir_opt: {:?}", dir_opt);