From eb2aca307fc14dbcf0325f0dc06bb2f15faddc85 Mon Sep 17 00:00:00 2001 From: Ariel Ben-Yehuda Date: Thu, 24 Sep 2015 19:58:00 +0300 Subject: [PATCH] deduplicate trait errors before they are displayed Because of type inference, duplicate obligations exist and cause duplicate errors. To avoid this, only display the first error for each (predicate,span). The inclusion of the span is somewhat bikesheddy, but *is* the more conservative option (it does not remove some instability, as duplicate obligations are ignored by `duplicate_set` under some inference conditions). Fixes #28098 cc #21528 (is it a dupe?) --- src/librustc/middle/infer/mod.rs | 7 +++- src/librustc/middle/traits/error_reporting.rs | 27 ++++++++++++++ src/librustc/middle/traits/fulfill.rs | 6 ++++ src/librustc/middle/traits/mod.rs | 2 ++ ...ed-types-ICE-when-projecting-out-of-err.rs | 1 - .../compile-fail/associated-types-path-2.rs | 1 - .../compile-fail/coerce-unsafe-to-closure.rs | 1 - .../compile-fail/const-eval-overflow-4b.rs | 2 -- src/test/compile-fail/fn-variance-1.rs | 2 -- src/test/compile-fail/for-loop-bogosity.rs | 3 -- .../compile-fail/indexing-requires-a-uint.rs | 1 - src/test/compile-fail/integral-indexing.rs | 8 ----- src/test/compile-fail/issue-11771.rs | 2 -- src/test/compile-fail/issue-13352.rs | 1 - src/test/compile-fail/issue-14084.rs | 1 - src/test/compile-fail/issue-20605.rs | 3 -- src/test/compile-fail/issue-2149.rs | 1 - src/test/compile-fail/issue-22645.rs | 4 +-- src/test/compile-fail/issue-24352.rs | 1 - src/test/compile-fail/issue-28098.rs | 35 +++++++++++++++++++ .../compile-fail/shift-various-bad-types.rs | 3 -- src/test/compile-fail/str-idx.rs | 1 - src/test/compile-fail/str-mut-idx.rs | 1 - .../unboxed-closures-unsafe-extern-fn.rs | 1 - .../unboxed-closures-wrong-abi.rs | 1 - ...boxed-closures-wrong-arg-type-extern-fn.rs | 1 - 26 files changed, 77 insertions(+), 40 deletions(-) create mode 100644 src/test/compile-fail/issue-28098.rs diff --git a/src/librustc/middle/infer/mod.rs b/src/librustc/middle/infer/mod.rs index 917727907ba8..3def56f94a18 100644 --- a/src/librustc/middle/infer/mod.rs +++ b/src/librustc/middle/infer/mod.rs @@ -43,7 +43,7 @@ use std::rc::Rc; use syntax::ast; use syntax::codemap; use syntax::codemap::{Span, DUMMY_SP}; -use util::nodemap::{FnvHashMap, NodeMap}; +use util::nodemap::{FnvHashMap, FnvHashSet, NodeMap}; use self::combine::CombineFields; use self::region_inference::{RegionVarBindings, RegionSnapshot}; @@ -92,6 +92,10 @@ pub struct InferCtxt<'a, 'tcx: 'a> { pub fulfillment_cx: RefCell>, + // the set of predicates on which errors have been reported, to + // avoid reporting the same error twice. + pub reported_trait_errors: RefCell>>, + // This is a temporary field used for toggling on normalization in the inference context, // as we move towards the approach described here: // https://internals.rust-lang.org/t/flattening-the-contexts-for-fun-and-profit/2293 @@ -374,6 +378,7 @@ pub fn new_infer_ctxt<'a, 'tcx>(tcx: &'a ty::ctxt<'tcx>, region_vars: RegionVarBindings::new(tcx), parameter_environment: param_env.unwrap_or(tcx.empty_parameter_environment()), fulfillment_cx: RefCell::new(traits::FulfillmentContext::new(errors_will_be_reported)), + reported_trait_errors: RefCell::new(FnvHashSet()), normalize: false, err_count_on_creation: tcx.sess.err_count() } diff --git a/src/librustc/middle/traits/error_reporting.rs b/src/librustc/middle/traits/error_reporting.rs index 2ed53f16afd2..ce71ba2ff2e7 100644 --- a/src/librustc/middle/traits/error_reporting.rs +++ b/src/librustc/middle/traits/error_reporting.rs @@ -33,6 +33,26 @@ use std::fmt; use syntax::codemap::Span; use rustc_front::attr::{AttributeMethods, AttrMetaMethods}; +#[derive(Debug, PartialEq, Eq, Hash)] +pub struct TraitErrorKey<'tcx> { + is_warning: bool, + span: Span, + predicate: ty::Predicate<'tcx> +} + +impl<'tcx> TraitErrorKey<'tcx> { + fn from_error<'a>(infcx: &InferCtxt<'a, 'tcx>, + e: &FulfillmentError<'tcx>) -> Self { + let predicate = + infcx.resolve_type_vars_if_possible(&e.obligation.predicate); + TraitErrorKey { + is_warning: is_warning(&e.obligation), + span: e.obligation.cause.span, + predicate: infcx.tcx.erase_regions(&predicate) + } + } +} + pub fn report_fulfillment_errors<'a, 'tcx>(infcx: &InferCtxt<'a, 'tcx>, errors: &Vec>) { for error in errors { @@ -42,6 +62,13 @@ pub fn report_fulfillment_errors<'a, 'tcx>(infcx: &InferCtxt<'a, 'tcx>, fn report_fulfillment_error<'a, 'tcx>(infcx: &InferCtxt<'a, 'tcx>, error: &FulfillmentError<'tcx>) { + let error_key = TraitErrorKey::from_error(infcx, error); + debug!("report_fulfillment_errors({:?}) - key={:?}", + error, error_key); + if !infcx.reported_trait_errors.borrow_mut().insert(error_key) { + debug!("report_fulfillment_errors: skipping duplicate"); + return; + } match error.code { FulfillmentErrorCode::CodeSelectionError(ref e) => { report_selection_error(infcx, &error.obligation, e); diff --git a/src/librustc/middle/traits/fulfill.rs b/src/librustc/middle/traits/fulfill.rs index 29032f0c4719..d4e6f693d965 100644 --- a/src/librustc/middle/traits/fulfill.rs +++ b/src/librustc/middle/traits/fulfill.rs @@ -49,6 +49,12 @@ pub struct FulfillmentContext<'tcx> { // than the `SelectionCache`: it avoids duplicate errors and // permits recursive obligations, which are often generated from // traits like `Send` et al. + // + // Note that because of type inference, a predicate can still + // occur twice in the predicates list, for example when 2 + // initially-distinct type variables are unified after being + // inserted. Deduplicating the predicate set on selection had a + // significant performance cost the last time I checked. duplicate_set: FulfilledPredicates<'tcx>, // A list of all obligations that have been registered with this diff --git a/src/librustc/middle/traits/mod.rs b/src/librustc/middle/traits/mod.rs index b0d4d92e8e1b..7f76cfaee586 100644 --- a/src/librustc/middle/traits/mod.rs +++ b/src/librustc/middle/traits/mod.rs @@ -21,10 +21,12 @@ use middle::subst; use middle::ty::{self, HasTypeFlags, Ty}; use middle::ty::fold::TypeFoldable; use middle::infer::{self, fixup_err_to_string, InferCtxt}; + use std::rc::Rc; use syntax::ast; use syntax::codemap::{Span, DUMMY_SP}; +pub use self::error_reporting::TraitErrorKey; pub use self::error_reporting::report_fulfillment_errors; pub use self::error_reporting::report_overflow_error; pub use self::error_reporting::report_selection_error; diff --git a/src/test/compile-fail/associated-types-ICE-when-projecting-out-of-err.rs b/src/test/compile-fail/associated-types-ICE-when-projecting-out-of-err.rs index 4aad828590a3..c5a47f3e5358 100644 --- a/src/test/compile-fail/associated-types-ICE-when-projecting-out-of-err.rs +++ b/src/test/compile-fail/associated-types-ICE-when-projecting-out-of-err.rs @@ -32,5 +32,4 @@ fn ice(a: A) { let r = loop {}; r = r + a; //~^ ERROR not implemented - //~| ERROR not implemented } diff --git a/src/test/compile-fail/associated-types-path-2.rs b/src/test/compile-fail/associated-types-path-2.rs index e603cca7f384..c9374d429380 100644 --- a/src/test/compile-fail/associated-types-path-2.rs +++ b/src/test/compile-fail/associated-types-path-2.rs @@ -39,7 +39,6 @@ pub fn f1_int_uint() { pub fn f1_uint_uint() { f1(2u32, 4u32); //~^ ERROR the trait `Foo` is not implemented - //~| ERROR the trait `Foo` is not implemented } pub fn f1_uint_int() { diff --git a/src/test/compile-fail/coerce-unsafe-to-closure.rs b/src/test/compile-fail/coerce-unsafe-to-closure.rs index 27b4a04054f0..90cbbf242aad 100644 --- a/src/test/compile-fail/coerce-unsafe-to-closure.rs +++ b/src/test/compile-fail/coerce-unsafe-to-closure.rs @@ -11,5 +11,4 @@ fn main() { let x: Option<&[u8]> = Some("foo").map(std::mem::transmute); //~^ ERROR E0277 - //~| ERROR E0277 } diff --git a/src/test/compile-fail/const-eval-overflow-4b.rs b/src/test/compile-fail/const-eval-overflow-4b.rs index 6322b56a82f0..a8f47ab92e52 100644 --- a/src/test/compile-fail/const-eval-overflow-4b.rs +++ b/src/test/compile-fail/const-eval-overflow-4b.rs @@ -23,7 +23,6 @@ const A_I8_T : [u32; (i8::MAX as i8 + 1u8) as usize] //~^ ERROR mismatched types //~| the trait `core::ops::Add` is not implemented for the type `i8` - //~| the trait `core::ops::Add` is not implemented for the type `i8` = [0; (i8::MAX as usize) + 1]; fn main() { @@ -33,4 +32,3 @@ fn main() { fn foo(x: T) { println!("{:?}", x); } - diff --git a/src/test/compile-fail/fn-variance-1.rs b/src/test/compile-fail/fn-variance-1.rs index 8e1e88a92e45..e9dd1cb719db 100644 --- a/src/test/compile-fail/fn-variance-1.rs +++ b/src/test/compile-fail/fn-variance-1.rs @@ -20,10 +20,8 @@ fn main() { apply(&3, takes_imm); apply(&3, takes_mut); //~^ ERROR (values differ in mutability) - //~| ERROR (values differ in mutability) apply(&mut 3, takes_mut); apply(&mut 3, takes_imm); //~^ ERROR (values differ in mutability) - //~| ERROR (values differ in mutability) } diff --git a/src/test/compile-fail/for-loop-bogosity.rs b/src/test/compile-fail/for-loop-bogosity.rs index 6bc0e74a2eb5..c77683045170 100644 --- a/src/test/compile-fail/for-loop-bogosity.rs +++ b/src/test/compile-fail/for-loop-bogosity.rs @@ -25,9 +25,6 @@ pub fn main() { y: 2, }; for x in bogus { //~ ERROR `core::iter::Iterator` is not implemented for the type `MyStruct` - //~^ ERROR - //~^^ ERROR - // FIXME(#21528) not fulfilled obligation error should be reported once, not thrice drop(x); } } diff --git a/src/test/compile-fail/indexing-requires-a-uint.rs b/src/test/compile-fail/indexing-requires-a-uint.rs index 3ca00fcb66ac..3d3b7bc1bcb4 100644 --- a/src/test/compile-fail/indexing-requires-a-uint.rs +++ b/src/test/compile-fail/indexing-requires-a-uint.rs @@ -14,7 +14,6 @@ fn main() { fn bar(_: T) {} [0][0u8]; //~ ERROR: the trait `core::ops::Index` is not implemented - //~^ ERROR: the trait `core::ops::Index` is not implemented [0][0]; // should infer to be a usize diff --git a/src/test/compile-fail/integral-indexing.rs b/src/test/compile-fail/integral-indexing.rs index e2fb0fa4f2fa..f78d677679bc 100644 --- a/src/test/compile-fail/integral-indexing.rs +++ b/src/test/compile-fail/integral-indexing.rs @@ -14,21 +14,13 @@ pub fn main() { v[3_usize]; v[3]; v[3u8]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented v[3i8]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented v[3u32]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented v[3i32]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented s.as_bytes()[3_usize]; s.as_bytes()[3]; s.as_bytes()[3u8]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented s.as_bytes()[3i8]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented s.as_bytes()[3u32]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented s.as_bytes()[3i32]; //~ERROR the trait `core::ops::Index` is not implemented - //~^ ERROR the trait `core::ops::Index` is not implemented } diff --git a/src/test/compile-fail/issue-11771.rs b/src/test/compile-fail/issue-11771.rs index 40fc6b1ed6aa..69899105bc31 100644 --- a/src/test/compile-fail/issue-11771.rs +++ b/src/test/compile-fail/issue-11771.rs @@ -12,12 +12,10 @@ fn main() { let x = (); 1 + x //~^ ERROR E0277 - //~| ERROR E0277 ; let x: () = (); 1 + x //~^ ERROR E0277 - //~| ERROR E0277 ; } diff --git a/src/test/compile-fail/issue-13352.rs b/src/test/compile-fail/issue-13352.rs index 14128a0e6f7e..13e677d72bc1 100644 --- a/src/test/compile-fail/issue-13352.rs +++ b/src/test/compile-fail/issue-13352.rs @@ -18,5 +18,4 @@ fn main() { }); 2_usize + (loop {}); //~^ ERROR E0277 - //~| ERROR E0277 } diff --git a/src/test/compile-fail/issue-14084.rs b/src/test/compile-fail/issue-14084.rs index b33a6767274e..26ed9d8c26ad 100644 --- a/src/test/compile-fail/issue-14084.rs +++ b/src/test/compile-fail/issue-14084.rs @@ -14,6 +14,5 @@ fn main() { box ( () ) 0; //~^ ERROR: the trait `core::ops::Placer<_>` is not implemented - //~| ERROR: the trait `core::ops::Placer<_>` is not implemented //~| WARN deprecated syntax } diff --git a/src/test/compile-fail/issue-20605.rs b/src/test/compile-fail/issue-20605.rs index 87b7616db8ed..f2d65af9cdfc 100644 --- a/src/test/compile-fail/issue-20605.rs +++ b/src/test/compile-fail/issue-20605.rs @@ -11,9 +11,6 @@ fn changer<'a>(mut things: Box>) { for item in *things { *item = 0 } //~^ ERROR the trait `core::marker::Sized` is not implemented for the type `core::iter::Iterator -//~^^ ERROR -//~^^^ ERROR -// FIXME(#21528) error should be reported once, not thrice } fn main() {} diff --git a/src/test/compile-fail/issue-2149.rs b/src/test/compile-fail/issue-2149.rs index bb170ef7d003..256c5d8e6f72 100644 --- a/src/test/compile-fail/issue-2149.rs +++ b/src/test/compile-fail/issue-2149.rs @@ -17,7 +17,6 @@ impl vec_monad for Vec { let mut r = panic!(); for elt in self { r = r + f(*elt); } //~^ ERROR E0277 - //~| ERROR E0277 } } fn main() { diff --git a/src/test/compile-fail/issue-22645.rs b/src/test/compile-fail/issue-22645.rs index 8677934fd646..aa7fa82fa29b 100644 --- a/src/test/compile-fail/issue-22645.rs +++ b/src/test/compile-fail/issue-22645.rs @@ -23,7 +23,5 @@ impl Add for Bob { fn main() { let b = Bob + 3.5; b + 3 //~ ERROR: is not implemented - //~^ ERROR: is not implemented - //~^^ ERROR: is not implemented - //~^^^ ERROR: mismatched types + //~^ ERROR: mismatched types } diff --git a/src/test/compile-fail/issue-24352.rs b/src/test/compile-fail/issue-24352.rs index 0fbc634826bc..9936f67b3af3 100644 --- a/src/test/compile-fail/issue-24352.rs +++ b/src/test/compile-fail/issue-24352.rs @@ -11,5 +11,4 @@ fn main() { 1.0f64 - 1.0; 1.0f64 - 1 //~ ERROR: is not implemented - //~^ ERROR: is not implemented } diff --git a/src/test/compile-fail/issue-28098.rs b/src/test/compile-fail/issue-28098.rs new file mode 100644 index 000000000000..f565d24e1fd0 --- /dev/null +++ b/src/test/compile-fail/issue-28098.rs @@ -0,0 +1,35 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +fn main() { + let _ = Iterator::next(&mut ()); + //~^ ERROR the trait `core::iter::Iterator` is not implemented + + for _ in false {} + //~^ ERROR the trait `core::iter::Iterator` is not implemented + + let _ = Iterator::next(&mut ()); + //~^ ERROR the trait `core::iter::Iterator` is not implemented + + other() +} + +pub fn other() { + // check errors are still reported globally + + let _ = Iterator::next(&mut ()); + //~^ ERROR the trait `core::iter::Iterator` is not implemented + + let _ = Iterator::next(&mut ()); + //~^ ERROR the trait `core::iter::Iterator` is not implemented + + for _ in false {} + //~^ ERROR the trait `core::iter::Iterator` is not implemented +} diff --git a/src/test/compile-fail/shift-various-bad-types.rs b/src/test/compile-fail/shift-various-bad-types.rs index 24b66213b39b..c980572fa152 100644 --- a/src/test/compile-fail/shift-various-bad-types.rs +++ b/src/test/compile-fail/shift-various-bad-types.rs @@ -18,15 +18,12 @@ struct Panolpy { fn foo(p: &Panolpy) { 22 >> p.char; //~^ ERROR E0277 - //~| ERROR E0277 22 >> p.str; //~^ ERROR E0277 - //~| ERROR E0277 22 >> p; //~^ ERROR E0277 - //~| ERROR E0277 let x; 22 >> x; // ambiguity error winds up being suppressed diff --git a/src/test/compile-fail/str-idx.rs b/src/test/compile-fail/str-idx.rs index ddd2a4eeedf7..6e48ae20d09f 100644 --- a/src/test/compile-fail/str-idx.rs +++ b/src/test/compile-fail/str-idx.rs @@ -11,5 +11,4 @@ pub fn main() { let s: &str = "hello"; let c: u8 = s[4]; //~ ERROR the trait `core::ops::Index<_>` is not implemented - //~^ ERROR the trait `core::ops::Index<_>` is not implemented } diff --git a/src/test/compile-fail/str-mut-idx.rs b/src/test/compile-fail/str-mut-idx.rs index 73abe6cb59db..ec6a14778a46 100644 --- a/src/test/compile-fail/str-mut-idx.rs +++ b/src/test/compile-fail/str-mut-idx.rs @@ -17,7 +17,6 @@ fn mutate(s: &mut str) { s[1usize] = bot(); //~^ ERROR `core::ops::Index` is not implemented for the type `str` //~| ERROR `core::ops::IndexMut` is not implemented for the type `str` - //~| ERROR `core::ops::Index` is not implemented for the type `str` } pub fn main() {} diff --git a/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs b/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs index dc7c70ba649d..361df93a7166 100644 --- a/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs +++ b/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs @@ -35,7 +35,6 @@ fn b() { fn c() { let z = call_it_once(square, 22); //~^ ERROR not implemented - //~| ERROR not implemented } fn main() { } diff --git a/src/test/compile-fail/unboxed-closures-wrong-abi.rs b/src/test/compile-fail/unboxed-closures-wrong-abi.rs index cdcb435b65a6..ca15d1bb5eef 100644 --- a/src/test/compile-fail/unboxed-closures-wrong-abi.rs +++ b/src/test/compile-fail/unboxed-closures-wrong-abi.rs @@ -35,7 +35,6 @@ fn b() { fn c() { let z = call_it_once(square, 22); //~^ ERROR not implemented - //~| ERROR not implemented } fn main() { } diff --git a/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs b/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs index 150bf36dcc28..b960362aad7c 100644 --- a/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs +++ b/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs @@ -36,7 +36,6 @@ fn b() { fn c() { let z = call_it_once(square, 22); //~^ ERROR not implemented - //~| ERROR not implemented } fn main() { }