Rollup merge of rust-lang#47987 - Zoxc:rm-recursion-checking, r=eddyb

Remove "static item recursion checking" in favor of relying on cycle checks in the query engine

Tests are changed to use the cycle check error message instead. Some duplicate tests are removed.

r? @eddyb

Author: Manishearth

src/librustc/ty/maps/plumbing.rs

@@ -84,7 +84,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             let span = self.sess.codemap().def_span(span);
             let mut err =
                 struct_span_err!(self.sess, span, E0391,
-                                 "unsupported cyclic reference between types/traits detected");
+                                 "cyclic dependency detected");
             err.span_label(span, "cyclic reference");
 
             err.span_note(self.sess.codemap().def_span(stack[0].0),

src/librustc_driver/driver.rs

@@ -36,7 +36,7 @@ use rustc_typeck as typeck;
 use rustc_privacy;
 use rustc_plugin::registry::Registry;
 use rustc_plugin as plugin;
-use rustc_passes::{self, ast_validation, loops, consts, static_recursion, hir_stats};
+use rustc_passes::{self, ast_validation, loops, consts, hir_stats};
 use rustc_const_eval::{self, check_match};
 use super::Compilation;
 
@@ -990,10 +990,6 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(trans: &TransCrate,
          "loop checking",
          || loops::check_crate(sess, &hir_map));
 
-    time(time_passes,
-              "static item recursion checking",
-              || static_recursion::check_crate(sess, &hir_map))?;
-
     let mut local_providers = ty::maps::Providers::default();
     default_provide(&mut local_providers);
     trans.provide(&mut local_providers);

src/librustc_passes/diagnostics.rs

@@ -128,22 +128,6 @@ impl !Enterprise for Foo { }
 Please note that negative impls are only allowed for auto traits.
 "##,
 
-E0265: r##"
-This error indicates that a static or constant references itself.
-All statics and constants need to resolve to a value in an acyclic manner.
-
-For example, neither of the following can be sensibly compiled:
-
-```compile_fail,E0265
-const X: u32 = X;
-```
-
-```compile_fail,E0265
-const X: u32 = Y;
-const Y: u32 = X;
-```
-"##,
-
 E0267: r##"
 This error indicates the use of a loop keyword (`break` or `continue`) inside a
 closure but outside of any loop. Erroneous code example:

src/librustc_passes/lib.rs

@@ -42,7 +42,6 @@ pub mod consts;
 pub mod hir_stats;
 pub mod loops;
 mod mir_stats;
-pub mod static_recursion;
 
 __build_diagnostic_array! { librustc_passes, DIAGNOSTICS }
 

src/librustc_passes/static_recursion.rs

@@ -17,7 +17,7 @@
 #![feature(specialization)]
 
 trait Trait<T> { type Assoc; }
-//~^ unsupported cyclic reference between types/traits detected [E0391]
+//~^ cyclic dependency detected [E0391]
 
 impl<T> Trait<T> for Vec<T> {
     type Assoc = ();

src/test/compile-fail/coherence-inherited-assoc-ty-cycle-err.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: unsupported cyclic reference between types/traits detected
+// error-pattern: cyclic dependency detected
 
 #![feature(const_fn)]
 

src/test/compile-fail/const-size_of-cycle.rs

@@ -25,7 +25,7 @@ trait Trait { type Item; }
 struct A<T>
     where T : Trait,
           T : Add<T::Item>
-    //~^ ERROR unsupported cyclic reference between types/traits detected
+    //~^ ERROR cyclic dependency detected
     //~| ERROR associated type `Item` not found for `T`
 {
     data: T

src/test/compile-fail/cycle-projection-based-on-where-clause.rs

@@ -12,7 +12,7 @@
 // again references the trait.
 
 trait Foo<X = Box<Foo>> {
-    //~^ ERROR unsupported cyclic reference
+    //~^ ERROR cyclic dependency detected
 }
 
 fn main() { }

src/test/compile-fail/cycle-trait-default-type-trait.rs

@@ -11,7 +11,7 @@
 // Test a supertrait cycle where a trait extends itself.
 
 trait Chromosome: Chromosome {
-    //~^ ERROR unsupported cyclic reference
+    //~^ ERROR cyclic dependency detected
 }
 
 fn main() { }

src/test/compile-fail/cycle-trait-supertrait-direct.rs

@@ -9,6 +9,6 @@
 // except according to those terms.
 
 type x = Vec<x>;
-//~^ ERROR unsupported cyclic reference
+//~^ ERROR cyclic dependency detected
 
 fn main() { let b: x = Vec::new(); }