[MIR] A pass to type-check MIR

src/librustc/middle/expr_use_visitor.rs

@@ -721,10 +721,11 @@ impl<'d,'t,'a,'tcx> ExprUseVisitor<'d,'t,'a,'tcx> {
         if let Some(adjustment) = adj {
             match adjustment {
                 adjustment::AdjustReifyFnPointer |
-                adjustment::AdjustUnsafeFnPointer => {
+                adjustment::AdjustUnsafeFnPointer |
+                adjustment::AdjustMutToConstPointer => {
                     // Creating a closure/fn-pointer or unsizing consumes
                     // the input and stores it into the resulting rvalue.
-                    debug!("walk_adjustment(AdjustReifyFnPointer|AdjustUnsafeFnPointer)");
+                    debug!("walk_adjustment: trivial adjustment");
                     let cmt_unadjusted =
                         return_if_err!(self.mc.cat_expr_unadjusted(expr));
                     self.delegate_consume(expr.id, expr.span, cmt_unadjusted);

src/librustc/middle/mem_categorization.rs

@@ -430,6 +430,7 @@ impl<'t, 'a,'tcx> MemCategorizationContext<'t, 'a, 'tcx> {
 
                     adjustment::AdjustReifyFnPointer |
                     adjustment::AdjustUnsafeFnPointer |
+                    adjustment::AdjustMutToConstPointer |
                     adjustment::AdjustDerefRef(_) => {
                         debug!("cat_expr({:?}): {:?}",
                                adjustment,

src/librustc/middle/ty/adjustment.rs

@@ -21,8 +21,9 @@ use rustc_front::hir;
 
 #[derive(Copy, Clone)]
 pub enum AutoAdjustment<'tcx> {
-    AdjustReifyFnPointer,   // go from a fn-item type to a fn-pointer type
-    AdjustUnsafeFnPointer,  // go from a safe fn pointer to an unsafe fn pointer
+    AdjustReifyFnPointer,    // go from a fn-item type to a fn-pointer type
+    AdjustUnsafeFnPointer,   // go from a safe fn pointer to an unsafe fn pointer
+    AdjustMutToConstPointer, // go from a mut raw pointer to a const raw pointer
     AdjustDerefRef(AutoDerefRef<'tcx>),
 }
 
@@ -106,7 +107,8 @@ impl<'tcx> AutoAdjustment<'tcx> {
     pub fn is_identity(&self) -> bool {
         match *self {
             AdjustReifyFnPointer |
-            AdjustUnsafeFnPointer => false,
+            AdjustUnsafeFnPointer |
+            AdjustMutToConstPointer => false,
             AdjustDerefRef(ref r) => r.is_identity(),
         }
     }
@@ -151,7 +153,7 @@ impl<'tcx> ty::TyS<'tcx> {
         return match adjustment {
             Some(adjustment) => {
                 match *adjustment {
-                   AdjustReifyFnPointer => {
+                    AdjustReifyFnPointer => {
                         match self.sty {
                             ty::TyBareFn(Some(_), b) => {
                                 cx.mk_fn(None, b)
@@ -164,17 +166,32 @@ impl<'tcx> ty::TyS<'tcx> {
                         }
                     }
 
-                   AdjustUnsafeFnPointer => {
+                    AdjustUnsafeFnPointer => {
                         match self.sty {
                             ty::TyBareFn(None, b) => cx.safe_to_unsafe_fn_ty(b),
                             ref b => {
                                 cx.sess.bug(
-                                    &format!("AdjustReifyFnPointer adjustment on non-fn-item: \
+                                    &format!("AdjustUnsafeFnPointer adjustment on non-fn-ptr: \
                                              {:?}",
                                             b));
                             }
                         }
-                   }
+                    }
+
+                    AdjustMutToConstPointer => {
+                        match self.sty {
+                            ty::TyRawPtr(mt) => cx.mk_ptr(ty::TypeAndMut {
+                                ty: mt.ty,
+                                mutbl: hir::MutImmutable
+                            }),
+                            ref b => {
+                                cx.sess.bug(
+                                    &format!("AdjustMutToConstPointer on non-raw-ptr: \
+                                             {:?}",
+                                            b));
+                            }
+                        }
+                    }
 
                     AdjustDerefRef(ref adj) => {
                         let mut adjusted_ty = self;

src/librustc/middle/ty/context.rs

@@ -131,6 +131,12 @@ pub struct Tables<'tcx> {
     /// equivalents. This table is not used in trans (since regions
     /// are erased there) and hence is not serialized to metadata.
     pub liberated_fn_sigs: NodeMap<ty::FnSig<'tcx>>,
+
+    /// For each FRU expression, record the normalized types of the fields
+    /// of the struct - this is needed because it is non-trivial to
+    /// normalize while preserving regions. This table is used only in
+    /// MIR construction and hence is not serialized to metadata.
+    pub fru_field_types: NodeMap<Vec<Ty<'tcx>>>
 }
 
 impl<'tcx> Tables<'tcx> {
@@ -144,6 +150,7 @@ impl<'tcx> Tables<'tcx> {
             closure_tys: DefIdMap(),
             closure_kinds: DefIdMap(),
             liberated_fn_sigs: NodeMap(),
+            fru_field_types: NodeMap()
         }
     }
 

src/librustc/mir/mir_map.rs

@@ -8,20 +8,30 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use dep_graph::DepNode;
 use util::nodemap::NodeMap;
 use mir::repr::Mir;
 use mir::transform::MirPass;
 use middle::ty;
+use middle::infer;
 
 pub struct MirMap<'tcx> {
     pub map: NodeMap<Mir<'tcx>>,
 }
 
 impl<'tcx> MirMap<'tcx> {
     pub fn run_passes(&mut self, passes: &mut [Box<MirPass>], tcx: &ty::ctxt<'tcx>) {
-        for (_, ref mut mir) in &mut self.map {
+        if passes.is_empty() { return; }
+
+        for (&id, mir) in &mut self.map {
+            let did = tcx.map.local_def_id(id);
+            let _task = tcx.dep_graph.in_task(DepNode::MirMapConstruction(did));
+
+            let param_env = ty::ParameterEnvironment::for_item(tcx, id);
+            let infcx = infer::new_infer_ctxt(tcx, &tcx.tables, Some(param_env));
+
             for pass in &mut *passes {
-                pass.run_on_mir(mir, tcx)
+                pass.run_on_mir(mir, &infcx)
             }
         }
     }

src/librustc/mir/repr.rs

@@ -45,6 +45,9 @@ pub struct Mir<'tcx> {
     /// values in that it is possible to borrow them and mutate them
     /// through the resulting reference.
     pub temp_decls: Vec<TempDecl<'tcx>>,
+
+    /// A span representing this MIR, for error reporting
+    pub span: Span,
 }
 
 /// where execution begins
@@ -145,7 +148,7 @@ pub enum BorrowKind {
 
 /// A "variable" is a binding declared by the user as part of the fn
 /// decl, a let, etc.
-#[derive(Clone, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
 pub struct VarDecl<'tcx> {
     pub mutability: Mutability,
     pub name: Name,
@@ -154,7 +157,7 @@ pub struct VarDecl<'tcx> {
 
 /// A "temp" is a temporary that we place on the stack. They are
 /// anonymous, always mutable, and have only a type.
-#[derive(Clone, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
 pub struct TempDecl<'tcx> {
     pub ty: Ty<'tcx>,
 }
@@ -170,7 +173,7 @@ pub struct TempDecl<'tcx> {
 ///
 /// there is only one argument, of type `(i32, u32)`, but two bindings
 /// (`x` and `y`).
-#[derive(Clone, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
 pub struct ArgDecl<'tcx> {
     pub ty: Ty<'tcx>,
 }
@@ -499,7 +502,7 @@ pub struct Projection<'tcx, B, V> {
 #[derive(Clone, Debug, PartialEq, RustcEncodable, RustcDecodable)]
 pub enum ProjectionElem<'tcx, V> {
     Deref,
-    Field(Field),
+    Field(Field, Ty<'tcx>),
     Index(V),
 
     /// These indices are generated by slice patterns. Easiest to explain
@@ -550,8 +553,8 @@ impl Field {
 }
 
 impl<'tcx> Lvalue<'tcx> {
-    pub fn field(self, f: Field) -> Lvalue<'tcx> {
-        self.elem(ProjectionElem::Field(f))
+    pub fn field(self, f: Field, ty: Ty<'tcx>) -> Lvalue<'tcx> {
+        self.elem(ProjectionElem::Field(f, ty))
     }
 
     pub fn deref(self) -> Lvalue<'tcx> {
@@ -591,8 +594,8 @@ impl<'tcx> Debug for Lvalue<'tcx> {
                         write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].name),
                     ProjectionElem::Deref =>
                         write!(fmt, "(*{:?})", data.base),
-                    ProjectionElem::Field(field) =>
-                        write!(fmt, "{:?}.{:?}", data.base, field.index()),
+                    ProjectionElem::Field(field, ty) =>
+                        write!(fmt, "({:?}.{:?}: {:?})", data.base, field.index(), ty),
                     ProjectionElem::Index(ref index) =>
                         write!(fmt, "{:?}[{:?}]", data.base, index),
                     ProjectionElem::ConstantIndex { offset, min_length, from_end: false } =>

src/librustc/mir/tcx.rs

@@ -14,7 +14,8 @@
  */
 
 use mir::repr::*;
-use middle::subst::Substs;
+use middle::const_eval::ConstVal;
+use middle::subst::{Subst, Substs};
 use middle::ty::{self, AdtDef, Ty};
 use rustc_front::hir;
 
@@ -72,23 +73,7 @@ impl<'tcx> LvalueTy<'tcx> {
                         tcx.sess.bug(&format!("cannot downcast non-enum type: `{:?}`", self))
                     }
                 },
-            ProjectionElem::Field(field) => {
-                let field_ty = match self {
-                    LvalueTy::Ty { ty } => match ty.sty {
-                        ty::TyStruct(adt_def, substs) =>
-                            adt_def.struct_variant().fields[field.index()].ty(tcx, substs),
-                        ty::TyTuple(ref tys) =>
-                            tys[field.index()],
-                        ty::TyClosure(_, ref closure_substs) =>
-                            closure_substs.upvar_tys[field.index()],
-                        _ =>
-                            tcx.sess.bug(&format!("cannot get field of type: `{:?}`", ty)),
-                    },
-                    LvalueTy::Downcast { adt_def, substs, variant_index } =>
-                        adt_def.variants[variant_index].fields[field.index()].ty(tcx, substs),
-                };
-                LvalueTy::Ty { ty: field_ty }
-            }
+            ProjectionElem::Field(_, fty) => LvalueTy::Ty { ty: fty }
         }
     }
 }
@@ -150,6 +135,73 @@ impl<'tcx> Mir<'tcx> {
                 self.lvalue_ty(tcx, &proj.base).projection_ty(tcx, &proj.elem)
         }
     }
+
+    pub fn rvalue_ty(&self,
+                     tcx: &ty::ctxt<'tcx>,
+                     rvalue: &Rvalue<'tcx>)
+                     -> Option<Ty<'tcx>>
+    {
+        match *rvalue {
+            Rvalue::Use(ref operand) => Some(self.operand_ty(tcx, operand)),
+            Rvalue::Repeat(ref operand, ref count) => {
+                if let ConstVal::Uint(u) = count.value {
+                    let op_ty = self.operand_ty(tcx, operand);
+                    Some(tcx.mk_array(op_ty, u as usize))
+                } else {
+                    None
+                }
+            }
+            Rvalue::Ref(reg, bk, ref lv) => {
+                let lv_ty = self.lvalue_ty(tcx, lv).to_ty(tcx);
+                Some(tcx.mk_ref(
+                    tcx.mk_region(reg),
+                    ty::TypeAndMut {
+                        ty: lv_ty,
+                        mutbl: bk.to_mutbl_lossy()
+                    }
+                ))
+            }
+            Rvalue::Len(..) => Some(tcx.types.usize),
+            Rvalue::Cast(_, _, ty) => Some(ty),
+            Rvalue::BinaryOp(op, ref lhs, ref rhs) => {
+                let lhs_ty = self.operand_ty(tcx, lhs);
+                let rhs_ty = self.operand_ty(tcx, rhs);
+                Some(self.binop_ty(tcx, op, lhs_ty, rhs_ty))
+            }
+            Rvalue::UnaryOp(_, ref operand) => {
+                Some(self.operand_ty(tcx, operand))
+            }
+            Rvalue::Box(t) => {
+                Some(tcx.mk_box(t))
+            }
+            Rvalue::Aggregate(ref ak, ref ops) => {
+                match *ak {
+                    AggregateKind::Vec => {
+                        if let Some(operand) = ops.get(0) {
+                            let ty = self.operand_ty(tcx, operand);
+                            Some(tcx.mk_array(ty, ops.len()))
+                        } else {
+                            None
+                        }
+                    }
+                    AggregateKind::Tuple => {
+                        Some(tcx.mk_tup(
+                            ops.iter().map(|op| self.operand_ty(tcx, op)).collect()
+                        ))
+                    }
+                    AggregateKind::Adt(def, _, substs) => {
+                        Some(def.type_scheme(tcx).ty.subst(tcx, substs))
+                    }
+                    AggregateKind::Closure(did, substs) => {
+                        Some(tcx.mk_closure_from_closure_substs(
+                            did, Box::new(substs.clone())))
+                    }
+                }
+            }
+            Rvalue::Slice { .. } => None,
+            Rvalue::InlineAsm(..) => None
+        }
+    }
 }
 
 impl BorrowKind {

src/librustc/mir/transform.rs

@@ -9,8 +9,8 @@
 // except according to those terms.
 
 use mir::repr::Mir;
-use middle::ty::ctxt;
+use middle::infer::InferCtxt;
 
 pub trait MirPass {
-    fn run_on_mir<'tcx>(&mut self, mir: &mut Mir<'tcx>, tcx: &ctxt<'tcx>);
+    fn run_on_mir<'a, 'tcx>(&mut self, mir: &mut Mir<'tcx>, infcx: &InferCtxt<'a, 'tcx>);
 }

src/librustc/session/config.rs

@@ -138,6 +138,7 @@ pub struct Options {
     pub no_trans: bool,
     pub error_format: ErrorOutputType,
     pub treat_err_as_bug: bool,
+    pub mir_opt_level: usize,
 
     /// if true, build up the dep-graph
     pub build_dep_graph: bool,
@@ -254,6 +255,7 @@ pub fn basic_options() -> Options {
         parse_only: false,
         no_trans: false,
         treat_err_as_bug: false,
+        mir_opt_level: 1,
         build_dep_graph: false,
         dump_dep_graph: false,
         no_analysis: false,
@@ -655,6 +657,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "show spans for compiler debugging (expr|pat|ty)"),
     print_trans_items: Option<String> = (None, parse_opt_string,
           "print the result of the translation item collection pass"),
+    mir_opt_level: Option<usize> = (None, parse_opt_uint,
+          "set the MIR optimization level (0-3)"),
 }
 
 pub fn default_lib_output() -> CrateType {
@@ -988,6 +992,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
     let parse_only = debugging_opts.parse_only;
     let no_trans = debugging_opts.no_trans;
     let treat_err_as_bug = debugging_opts.treat_err_as_bug;
+    let mir_opt_level = debugging_opts.mir_opt_level.unwrap_or(1);
     let incremental_compilation = debugging_opts.incr_comp;
     let dump_dep_graph = debugging_opts.dump_dep_graph;
     let no_analysis = debugging_opts.no_analysis;
@@ -1166,6 +1171,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         parse_only: parse_only,
         no_trans: no_trans,
         treat_err_as_bug: treat_err_as_bug,
+        mir_opt_level: mir_opt_level,
         build_dep_graph: incremental_compilation || dump_dep_graph,
         dump_dep_graph: dump_dep_graph,
         no_analysis: no_analysis,

src/librustc/util/ppaux.rs

@@ -396,6 +396,9 @@ impl<'tcx> fmt::Debug for ty::adjustment::AutoAdjustment<'tcx> {
             ty::adjustment::AdjustUnsafeFnPointer => {
                 write!(f, "AdjustUnsafeFnPointer")
             }
+            ty::adjustment::AdjustMutToConstPointer => {
+                write!(f, "AdjustMutToConstPointer")
+            }
             ty::adjustment::AdjustDerefRef(ref data) => {
                 write!(f, "{:?}", data)
             }