mathieu/granite-rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Improve debug output from coherence.

Browse source
This commit is contained in:
Niko Matsakis 2015-02-23 13:02:31 -05:00
parent eb841fc44a
commit 206c2546c0
1 changed files with 20 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

23
src/librustc/middle/traits/coherence.rs
View file

@ -52,9 +52,16 @@ fn overlap(selcx: &mut SelectionContext,
b_def_id: ast::DefId)
-> bool
{
debug!("overlap(a_def_id={}, b_def_id={})",
a_def_id.repr(selcx.tcx()),
b_def_id.repr(selcx.tcx()));
let (a_trait_ref, a_obligations) = impl_trait_ref_and_oblig(selcx, a_def_id);
let (b_trait_ref, b_obligations) = impl_trait_ref_and_oblig(selcx, b_def_id);
debug!("overlap: a_trait_ref={}", a_trait_ref.repr(selcx.tcx()));
debug!("overlap: b_trait_ref={}", b_trait_ref.repr(selcx.tcx()));
// Does `a <: b` hold? If not, no overlap.
if let Err(_) = infer::mk_sub_poly_trait_refs(selcx.infcx(),
true,
@ -64,10 +71,20 @@ fn overlap(selcx: &mut SelectionContext,
return false;
}
debug!("overlap: subtraitref check succeeded");
// Are any of the obligations unsatisfiable? If so, no overlap.
a_obligations.iter()
.chain(b_obligations.iter())
.all(|o| selcx.evaluate_obligation(o))
let opt_failing_obligation =
a_obligations.iter()
.chain(b_obligations.iter())
.find(|o| !selcx.evaluate_obligation(o));
if let Some(failing_obligation) = opt_failing_obligation {
debug!("overlap: obligation unsatisfiable {}", failing_obligation.repr(selcx.tcx()));
return false;
}
true
}
/// Instantiate fresh variables for all bound parameters of the impl