Rollup merge of #78545 - jackh726:anonymous, r=oli-obk

Make anonymous binders start at 0 A few changes to some test outputs, but these actually look *more* correct to me.
2024-11-22 14:55:26 +00:00 · 2020-10-30 18:00:56 +09:00 · 2020-10-30 18:00:56 +09:00 · 05f80f03a9
commit 05f80f03a9
parent f8539221d0 41ce397990
12 changed files with 24 additions and 32 deletions
--- a/compiler/rustc_middle/src/ty/fold.rs
+++ b/compiler/rustc_middle/src/ty/fold.rs
@ -684,7 +684,7 @@ impl<'tcx> TyCtxt<'tcx> {
    }

    /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
-    /// assigned starting at 1 and increasing monotonically in the order traversed
+    /// assigned starting at 0 and increasing monotonically in the order traversed
    /// by the fold operation.
    ///
    /// The chief purpose of this function is to canonicalize regions so that two
@ -698,8 +698,9 @@ impl<'tcx> TyCtxt<'tcx> {
        let mut counter = 0;
        Binder::bind(
            self.replace_late_bound_regions(sig, |_| {
+                let r = self.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BrAnon(counter)));
                counter += 1;
-                self.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BrAnon(counter)))
+                r
            })
            .0,
        )
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@ -200,15 +200,9 @@ impl SymbolMangler<'tcx> {

        let lifetimes = regions
            .into_iter()
-            .map(|br| {
-                match br {
-                    ty::BrAnon(i) => {
-                        // FIXME(eddyb) for some reason, `anonymize_late_bound_regions` starts at `1`.
-                        assert_ne!(i, 0);
-                        i - 1
-                    }
-                    _ => bug!("symbol_names: non-anonymized region `{:?}` in `{:?}`", br, value),
-                }
+            .map(|br| match br {
+                ty::BrAnon(i) => i,
+                _ => bug!("symbol_names: non-anonymized region `{:?}` in `{:?}`", br, value),
            })
            .max()
            .map_or(0, |max| max + 1);
@ -327,10 +321,6 @@ impl Printer<'tcx> for SymbolMangler<'tcx> {
            // Late-bound lifetimes use indices starting at 1,
            // see `BinderLevel` for more details.
            ty::ReLateBound(debruijn, ty::BrAnon(i)) => {
-                // FIXME(eddyb) for some reason, `anonymize_late_bound_regions` starts at `1`.
-                assert_ne!(i, 0);
-                let i = i - 1;
-
                let binder = &self.binders[self.binders.len() - 1 - debruijn.index()];
                let depth = binder.lifetime_depths.start + i;

--- a/compiler/rustc_typeck/src/check/generator_interior.rs
+++ b/compiler/rustc_typeck/src/check/generator_interior.rs
@ -186,8 +186,9 @@ pub fn resolve_interior<'a, 'tcx>(
                // which means that none of the regions inside relate to any other, even if
                // typeck had previously found constraints that would cause them to be related.
                let folded = fcx.tcx.fold_regions(&erased, &mut false, |_, current_depth| {
+                    let r = fcx.tcx.mk_region(ty::ReLateBound(current_depth, ty::BrAnon(counter)));
                    counter += 1;
-                    fcx.tcx.mk_region(ty::ReLateBound(current_depth, ty::BrAnon(counter)))
+                    r
                });

                cause.ty = folded;
--- a/src/test/ui/closure-expected-type/expect-fn-supply-fn.stderr
+++ b/src/test/ui/closure-expected-type/expect-fn-supply-fn.stderr
@ -6,7 +6,7 @@ LL |     with_closure_expecting_fn_with_free_region(|x: fn(&'x u32), y| {});
   |
   = note: expected fn pointer `fn(&u32)`
              found fn pointer `fn(&'x u32)`
-note: the anonymous lifetime #2 defined on the body at 16:48...
+note: the anonymous lifetime #1 defined on the body at 16:48...
  --> $DIR/expect-fn-supply-fn.rs:16:48
   |
 LL |     with_closure_expecting_fn_with_free_region(|x: fn(&'x u32), y| {});
@ -30,7 +30,7 @@ note: the lifetime `'x` as defined on the function body at 13:36...
   |
 LL | fn expect_free_supply_free_from_fn<'x>(x: &'x u32) {
   |                                    ^^
-note: ...does not necessarily outlive the anonymous lifetime #2 defined on the body at 16:48
+note: ...does not necessarily outlive the anonymous lifetime #1 defined on the body at 16:48
  --> $DIR/expect-fn-supply-fn.rs:16:48
   |
 LL |     with_closure_expecting_fn_with_free_region(|x: fn(&'x u32), y| {});
--- a/src/test/ui/closures/closure-expected-type/expect-region-supply-region-2.stderr
+++ b/src/test/ui/closures/closure-expected-type/expect-region-supply-region-2.stderr
@ -6,7 +6,7 @@ LL |     closure_expecting_bound(|x: &'x u32| {
   |
   = note: expected reference `&u32`
              found reference `&'x u32`
-note: the anonymous lifetime #2 defined on the body at 14:29...
+note: the anonymous lifetime #1 defined on the body at 14:29...
  --> $DIR/expect-region-supply-region-2.rs:14:29
   |
 LL |       closure_expecting_bound(|x: &'x u32| {
@ -37,7 +37,7 @@ note: the lifetime `'x` as defined on the function body at 9:30...
   |
 LL | fn expect_bound_supply_named<'x>() {
   |                              ^^
-note: ...does not necessarily outlive the anonymous lifetime #2 defined on the body at 14:29
+note: ...does not necessarily outlive the anonymous lifetime #1 defined on the body at 14:29
  --> $DIR/expect-region-supply-region-2.rs:14:29
   |
 LL |       closure_expecting_bound(|x: &'x u32| {
--- a/src/test/ui/issues/issue-10291.stderr
+++ b/src/test/ui/issues/issue-10291.stderr
@ -4,7 +4,7 @@ error[E0312]: lifetime of reference outlives lifetime of borrowed content...
 LL |         x
   |         ^
   |
-note: ...the reference is valid for the anonymous lifetime #2 defined on the body at 2:69...
+note: ...the reference is valid for the anonymous lifetime #1 defined on the body at 2:69...
  --> $DIR/issue-10291.rs:2:69
   |
 LL |       drop::<Box<dyn for<'z> FnMut(&'z isize) -> &'z isize>>(Box::new(|z| {
--- a/src/test/ui/issues/issue-52533-1.stderr
+++ b/src/test/ui/issues/issue-52533-1.stderr
@ -6,12 +6,12 @@ LL |     gimme(|x, y| y)
   |
   = note: expected reference `&Foo<'_, '_, u32>`
              found reference `&Foo<'_, '_, u32>`
-note: the anonymous lifetime #4 defined on the body at 9:11...
+note: the anonymous lifetime #3 defined on the body at 9:11...
  --> $DIR/issue-52533-1.rs:9:11
   |
 LL |     gimme(|x, y| y)
   |           ^^^^^^^^
-note: ...does not necessarily outlive the anonymous lifetime #3 defined on the body at 9:11
+note: ...does not necessarily outlive the anonymous lifetime #2 defined on the body at 9:11
  --> $DIR/issue-52533-1.rs:9:11
   |
 LL |     gimme(|x, y| y)
--- a/src/test/ui/issues/issue-52533.stderr
+++ b/src/test/ui/issues/issue-52533.stderr
@ -4,12 +4,12 @@ error[E0312]: lifetime of reference outlives lifetime of borrowed content...
 LL |     foo(|a, b| b)
   |                ^
   |
-note: ...the reference is valid for the anonymous lifetime #2 defined on the body at 5:9...
+note: ...the reference is valid for the anonymous lifetime #1 defined on the body at 5:9...
  --> $DIR/issue-52533.rs:5:9
   |
 LL |     foo(|a, b| b)
   |         ^^^^^^^^
-note: ...but the borrowed content is only valid for the anonymous lifetime #3 defined on the body at 5:9
+note: ...but the borrowed content is only valid for the anonymous lifetime #2 defined on the body at 5:9
  --> $DIR/issue-52533.rs:5:9
   |
 LL |     foo(|a, b| b)
--- a/src/test/ui/regions/regions-nested-fns.stderr
+++ b/src/test/ui/regions/regions-nested-fns.stderr
@ -4,7 +4,7 @@ error[E0495]: cannot infer an appropriate lifetime due to conflicting requiremen
 LL |     let mut ay = &y;
   |                  ^^
   |
-note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 7:58...
+note: first, the lifetime cannot outlive the anonymous lifetime #1 defined on the body at 7:58...
  --> $DIR/regions-nested-fns.rs:7:58
   |
 LL |       ignore::<Box<dyn for<'z> FnMut(&'z isize)>>(Box::new(|z| {
@ -19,7 +19,7 @@ note: ...so that reference does not outlive borrowed content
   |
 LL |         ay = z;
   |              ^
-note: but, the lifetime must be valid for the anonymous lifetime #2 defined on the body at 13:72...
+note: but, the lifetime must be valid for the anonymous lifetime #1 defined on the body at 13:72...
  --> $DIR/regions-nested-fns.rs:13:72
   |
 LL |       ignore::< Box<dyn for<'z> FnMut(&'z isize) -> &'z isize>>(Box::new(|z| {
@ -48,7 +48,7 @@ error[E0312]: lifetime of reference outlives lifetime of borrowed content...
 LL |         if false { return x; }
   |                           ^
   |
-note: ...the reference is valid for the anonymous lifetime #2 defined on the body at 13:72...
+note: ...the reference is valid for the anonymous lifetime #1 defined on the body at 13:72...
  --> $DIR/regions-nested-fns.rs:13:72
   |
 LL |       ignore::< Box<dyn for<'z> FnMut(&'z isize) -> &'z isize>>(Box::new(|z| {
--- a/src/test/ui/regions/regions-ret-borrowed-1.stderr
+++ b/src/test/ui/regions/regions-ret-borrowed-1.stderr
@ -4,7 +4,7 @@ error[E0495]: cannot infer an appropriate lifetime due to conflicting requiremen
 LL |     with(|o| o)
   |              ^
   |
-note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 10:10...
+note: first, the lifetime cannot outlive the anonymous lifetime #1 defined on the body at 10:10...
  --> $DIR/regions-ret-borrowed-1.rs:10:10
   |
 LL |     with(|o| o)
--- a/src/test/ui/regions/regions-ret-borrowed.stderr
+++ b/src/test/ui/regions/regions-ret-borrowed.stderr
@ -4,7 +4,7 @@ error[E0495]: cannot infer an appropriate lifetime due to conflicting requiremen
 LL |     with(|o| o)
   |              ^
   |
-note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the body at 13:10...
+note: first, the lifetime cannot outlive the anonymous lifetime #1 defined on the body at 13:10...
  --> $DIR/regions-ret-borrowed.rs:13:10
   |
 LL |     with(|o| o)
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-argument-types-two-region-pointers.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-argument-types-two-region-pointers.stderr
@ -4,7 +4,7 @@ error[E0312]: lifetime of reference outlives lifetime of borrowed content...
 LL |         x.set(y);
   |               ^
   |
-note: ...the reference is valid for the anonymous lifetime #3 defined on the body at 16:14...
+note: ...the reference is valid for the anonymous lifetime #2 defined on the body at 16:14...
  --> $DIR/unboxed-closures-infer-argument-types-two-region-pointers.rs:16:14
   |
 LL |       doit(0, &|x, y| {
@ -12,7 +12,7 @@ LL |       doit(0, &|x, y| {
 LL | |         x.set(y);
 LL | |     });
   | |_____^
-note: ...but the borrowed content is only valid for the anonymous lifetime #4 defined on the body at 16:14
+note: ...but the borrowed content is only valid for the anonymous lifetime #3 defined on the body at 16:14
  --> $DIR/unboxed-closures-infer-argument-types-two-region-pointers.rs:16:14
   |
 LL |       doit(0, &|x, y| {