Handle statics in MIR typeck with user type annotations

rpjohnst · rpjohnst · commit d6b6488e20c8 · 2020-04-19T13:25:20.000-07:00
diff --git a/src/librustc_mir/borrow_check/type_check/mod.rs b/src/librustc_mir/borrow_check/type_check/mod.rs
@@ -366,20 +366,6 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
                         );
                     }
                 }
-            } else if let Some(static_def_id) = constant.check_static_ptr(tcx) {
-                let unnormalized_ty = tcx.type_of(static_def_id);
-                let locations = location.to_locations();
-                let normalized_ty = self.cx.normalize(unnormalized_ty, locations);
-                let literal_ty = constant.literal.ty.builtin_deref(true).unwrap().ty;
-
-                if let Err(terr) = self.cx.eq_types(
-                    normalized_ty,
-                    literal_ty,
-                    locations,
-                    ConstraintCategory::Boring,
-                ) {
-                    span_mirbug!(self, constant, "bad static type {:?} ({:?})", constant, terr);
-                }
             }
 
             if let ty::FnDef(def_id, substs) = constant.literal.ty.kind {
diff --git a/src/librustc_mir_build/build/expr/as_constant.rs b/src/librustc_mir_build/build/expr/as_constant.rs
@@ -21,7 +21,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         let Expr { ty, temp_lifetime: _, span, kind } = expr;
         match kind {
             ExprKind::Scope { region_scope: _, lint_level: _, value } => this.as_constant(value),
-            ExprKind::Literal { literal, user_ty } => {
+            ExprKind::Literal { literal, user_ty } |
+            ExprKind::StaticRef { literal, user_ty, .. } => {
                 let user_ty = user_ty.map(|user_ty| {
                     this.canonical_user_type_annotations.push(CanonicalUserTypeAnnotation {
                         span,
@@ -32,7 +33,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 assert_eq!(literal.ty, ty);
                 Constant { span, user_ty, literal }
             }
-            ExprKind::StaticRef { literal, .. } => Constant { span, user_ty: None, literal },
             _ => span_bug!(span, "expression is not a valid constant {:?}", kind),
         }
     }
diff --git a/src/librustc_mir_build/hair/cx/expr.rs b/src/librustc_mir_build/hair/cx/expr.rs
@@ -6,6 +6,7 @@ use crate::hair::*;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_index::vec::Idx;
+use rustc_infer::infer::RegionVariableOrigin;
 use rustc_middle::mir::interpret::Scalar;
 use rustc_middle::mir::BorrowKind;
 use rustc_middle::ty::adjustment::{
@@ -742,13 +743,26 @@ fn convert_path_expr<'a, 'tcx>(
             let ty = cx.tcx.static_ptr_ty(id);
             let ptr = cx.tcx.alloc_map.lock().create_static_alloc(id);
             let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
+
+            // Keep regions around in a user type annotation for MIR typeck:
+            let static_ty = cx.tcx.type_of(id);
+            let static_ptr_ty = if cx.tcx.is_mutable_static(id) {
+                cx.tcx.mk_mut_ptr(static_ty)
+            } else {
+                let origin = RegionVariableOrigin::AddrOfRegion(expr.span);
+                let region = cx.infcx.next_region_var(origin);
+                cx.tcx.mk_imm_ref(region, static_ty)
+            };
+            let user_ty = cx.infcx.canonicalize_user_type_annotation(&UserType::Ty(static_ptr_ty));
+
             ExprKind::Deref {
                 arg: Expr {
                     ty,
                     temp_lifetime,
                     span: expr.span,
                     kind: ExprKind::StaticRef {
                         literal: ty::Const::from_scalar(cx.tcx, Scalar::Ptr(ptr.into()), ty),
+                        user_ty: Some(user_ty),
                         def_id: id,
                     },
                 }
diff --git a/src/librustc_mir_build/hair/mod.rs b/src/librustc_mir_build/hair/mod.rs
@@ -275,6 +275,7 @@ crate enum ExprKind<'tcx> {
     /// info for diagnostics.
     StaticRef {
         literal: &'tcx Const<'tcx>,
+        user_ty: Option<Canonical<'tcx, UserType<'tcx>>>,
         def_id: DefId,
     },
     LlvmInlineAsm {
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.BAR-promoted[0].ConstProp.after.mir b/src/test/mir-opt/const-promotion-extern-static/rustc.BAR-promoted[0].ConstProp.after.mir
@@ -13,6 +13,7 @@ promoted[0] in BAR: &[&i32; 1] = {
                                          // + val: Value(Scalar(alloc0+0))
                                          // mir::Constant
                                          // + span: $DIR/const-promotion-extern-static.rs:9:33: 9:34
+                                         // + user_ty: UserType(0)
                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc0+0)) }
         _2 = _3;                         // bb0[1]: scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
         _1 = [move _2];                  // bb0[2]: scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.BAR.PromoteTemps.diff b/src/test/mir-opt/const-promotion-extern-static/rustc.BAR.PromoteTemps.diff
@@ -1,6 +1,9 @@
 - // MIR for `BAR` before PromoteTemps
 + // MIR for `BAR` after PromoteTemps
   
+  | User Type Annotations
+  | 0: Canonical { max_universe: U0, variables: [CanonicalVarInfo { kind: Region(U0) }], value: Ty(&i32) } at $DIR/const-promotion-extern-static.rs:9:33: 9:34
+  |
   static mut BAR: *const &i32 = {
       let mut _0: *const &i32;             // return place in scope 0 at $DIR/const-promotion-extern-static.rs:9:17: 9:28
       let mut _1: &[&i32];                 // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
@@ -25,6 +28,7 @@
 +                                          // + val: Unevaluated(DefId(0:6 ~ const_promotion_extern_static[317d]::BAR[0]), [], Some(promoted[0]))
                                            // mir::Constant
 -                                          // + span: $DIR/const-promotion-extern-static.rs:9:33: 9:34
+-                                          // + user_ty: UserType(0)
 -                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc0+0)) }
 -         _4 = &(*_5);                     // bb0[6]: scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
 -         _3 = [move _4];                  // bb0[7]: scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.FOO-promoted[0].ConstProp.after.mir b/src/test/mir-opt/const-promotion-extern-static/rustc.FOO-promoted[0].ConstProp.after.mir
@@ -15,6 +15,7 @@ promoted[0] in FOO: &[&i32; 1] = {
                                          // + val: Value(Scalar(alloc2+0))
                                          // mir::Constant
                                          // + span: $DIR/const-promotion-extern-static.rs:13:42: 13:43
+                                         // + user_ty: UserType(0)
                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc2+0)) }
         _2 = _3;                         // bb0[1]: scope 0 at $DIR/const-promotion-extern-static.rs:13:41: 13:43
         _1 = [move _2];                  // bb0[2]: scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
diff --git a/src/test/mir-opt/const-promotion-extern-static/rustc.FOO.PromoteTemps.diff b/src/test/mir-opt/const-promotion-extern-static/rustc.FOO.PromoteTemps.diff
@@ -1,6 +1,9 @@
 - // MIR for `FOO` before PromoteTemps
 + // MIR for `FOO` after PromoteTemps
   
+  | User Type Annotations
+  | 0: Canonical { max_universe: U0, variables: [CanonicalVarInfo { kind: Region(U0) }], value: Ty(&i32) } at $DIR/const-promotion-extern-static.rs:13:42: 13:43
+  |
   static mut FOO: *const &i32 = {
       let mut _0: *const &i32;             // return place in scope 0 at $DIR/const-promotion-extern-static.rs:13:17: 13:28
       let mut _1: &[&i32];                 // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
@@ -27,6 +30,7 @@
 +                                          // + val: Unevaluated(DefId(0:7 ~ const_promotion_extern_static[317d]::FOO[0]), [], Some(promoted[0]))
                                            // mir::Constant
 -                                          // + span: $DIR/const-promotion-extern-static.rs:13:42: 13:43
+-                                          // + user_ty: UserType(0)
 -                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc2+0)) }
 -         _4 = &(*_5);                     // bb0[6]: scope 1 at $DIR/const-promotion-extern-static.rs:13:41: 13:43
 -         _3 = [move _4];                  // bb0[7]: scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
diff --git a/src/test/mir-opt/const_allocation/32bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation/32bit/rustc.main.ConstProp.after.mir
@@ -14,6 +14,7 @@ fn main() -> () {
                                          // + val: Value(Scalar(alloc0+0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation.rs:8:5: 8:8
+                                         // + user_ty: UserType(0)
                                          // + literal: Const { ty: &&[(std::option::Option<i32>, &[&str])], val: Value(Scalar(alloc0+0)) }
         _1 = (*_2);                      // bb0[3]: scope 0 at $DIR/const_allocation.rs:8:5: 8:8
         StorageDead(_2);                 // bb0[4]: scope 0 at $DIR/const_allocation.rs:8:8: 8:9
diff --git a/src/test/mir-opt/const_allocation/64bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation/64bit/rustc.main.ConstProp.after.mir
@@ -14,6 +14,7 @@ fn main() -> () {
                                          // + val: Value(Scalar(alloc0+0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation.rs:8:5: 8:8
+                                         // + user_ty: UserType(0)
                                          // + literal: Const { ty: &&[(std::option::Option<i32>, &[&str])], val: Value(Scalar(alloc0+0)) }
         _1 = (*_2);                      // bb0[3]: scope 0 at $DIR/const_allocation.rs:8:5: 8:8
         StorageDead(_2);                 // bb0[4]: scope 0 at $DIR/const_allocation.rs:8:8: 8:9
diff --git a/src/test/mir-opt/const_allocation2/64bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation2/64bit/rustc.main.ConstProp.after.mir
@@ -14,6 +14,7 @@ fn main() -> () {
                                          // + val: Value(Scalar(alloc0+0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation2.rs:5:5: 5:8
+                                         // + user_ty: UserType(0)
                                          // + literal: Const { ty: &&[(std::option::Option<i32>, &[&u8])], val: Value(Scalar(alloc0+0)) }
         _1 = (*_2);                      // bb0[3]: scope 0 at $DIR/const_allocation2.rs:5:5: 5:8
         StorageDead(_2);                 // bb0[4]: scope 0 at $DIR/const_allocation2.rs:5:8: 5:9
diff --git a/src/test/mir-opt/const_allocation3/64bit/rustc.main.ConstProp.after.mir b/src/test/mir-opt/const_allocation3/64bit/rustc.main.ConstProp.after.mir
@@ -14,6 +14,7 @@ fn main() -> () {
                                          // + val: Value(Scalar(alloc0+0))
                                          // mir::Constant
                                          // + span: $DIR/const_allocation3.rs:5:5: 5:8
+                                         // + user_ty: UserType(0)
                                          // + literal: Const { ty: &&Packed, val: Value(Scalar(alloc0+0)) }
         _1 = (*_2);                      // bb0[3]: scope 0 at $DIR/const_allocation3.rs:5:5: 5:8
         StorageDead(_2);                 // bb0[4]: scope 0 at $DIR/const_allocation3.rs:5:8: 5:9
diff --git a/src/test/mir-opt/const_prop/read_immutable_static/rustc.main.ConstProp.diff b/src/test/mir-opt/const_prop/read_immutable_static/rustc.main.ConstProp.diff
@@ -22,6 +22,7 @@
                                            // + val: Value(Scalar(alloc0+0))
                                            // mir::Constant
                                            // + span: $DIR/read_immutable_static.rs:7:13: 7:16
+                                           // + user_ty: UserType(0)
                                            // + literal: Const { ty: &u8, val: Value(Scalar(alloc0+0)) }
 -         _2 = (*_3);                      // bb0[4]: scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
 +         _2 = const 2u8;                  // bb0[4]: scope 0 at $DIR/read_immutable_static.rs:7:13: 7:16
@@ -39,6 +40,7 @@
                                            // + val: Value(Scalar(alloc0+0))
                                            // mir::Constant
                                            // + span: $DIR/read_immutable_static.rs:7:19: 7:22
+                                           // + user_ty: UserType(1)
                                            // + literal: Const { ty: &u8, val: Value(Scalar(alloc0+0)) }
 -         _4 = (*_5);                      // bb0[8]: scope 0 at $DIR/read_immutable_static.rs:7:19: 7:22
 -         _1 = Add(move _2, move _4);      // bb0[9]: scope 0 at $DIR/read_immutable_static.rs:7:13: 7:22

Original file line number	Diff line number	Diff line change
`@@ -21,7 +21,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {`
`21`	`21`	`let Expr { ty, temp_lifetime: _, span, kind } = expr;`
`22`	`22`	`match kind {`
`23`	`23`	`ExprKind::Scope { region_scope: _, lint_level: _, value } => this.as_constant(value),`
`24`		`- ExprKind::Literal { literal, user_ty } => {`
	`24`	`+ ExprKind::Literal { literal, user_ty } \|`
	`25`	`+ ExprKind::StaticRef { literal, user_ty, .. } => {`
`25`	`26`	`let user_ty = user_ty.map(\|user_ty\| {`
`26`	`27`	`this.canonical_user_type_annotations.push(CanonicalUserTypeAnnotation {`
`27`	`28`	`span,`
`@@ -32,7 +33,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {`
`32`	`33`	`assert_eq!(literal.ty, ty);`
`33`	`34`	`Constant { span, user_ty, literal }`
`34`	`35`	`}`
`35`		`- ExprKind::StaticRef { literal, .. } => Constant { span, user_ty: None, literal },`
`36`	`36`	`_ => span_bug!(span, "expression is not a valid constant {:?}", kind),`
`37`	`37`	`}`
`38`	`38`	`}`