rust/src/librustc/infer/error_reporting/note.rs
2018-01-26 16:38:07 -08:00

455 lines
24 KiB
Rust

// Copyright 2017 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use infer::{self, InferCtxt, SubregionOrigin};
use middle::region;
use ty::{self, Region};
use ty::error::TypeError;
use errors::DiagnosticBuilder;
impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
pub(super) fn note_region_origin(&self,
err: &mut DiagnosticBuilder,
origin: &SubregionOrigin<'tcx>) {
match *origin {
infer::Subtype(ref trace) => {
if let Some((expected, found)) = self.values_str(&trace.values) {
let expected = expected.content();
let found = found.content();
err.note(&format!("...so that the {}:\nexpected {}\n found {}",
trace.cause.as_requirement_str(),
expected,
found));
} else {
// FIXME: this really should be handled at some earlier stage. Our
// handling of region checking when type errors are present is
// *terrible*.
err.span_note(trace.cause.span,
&format!("...so that {}", trace.cause.as_requirement_str()));
}
}
infer::Reborrow(span) => {
err.span_note(span,
"...so that reference does not outlive borrowed content");
}
infer::ReborrowUpvar(span, ref upvar_id) => {
let var_node_id = self.tcx.hir.hir_to_node_id(upvar_id.var_id);
let var_name = self.tcx.hir.name(var_node_id);
err.span_note(span,
&format!("...so that closure can access `{}`", var_name));
}
infer::InfStackClosure(span) => {
err.span_note(span, "...so that closure does not outlive its stack frame");
}
infer::InvokeClosure(span) => {
err.span_note(span,
"...so that closure is not invoked outside its lifetime");
}
infer::DerefPointer(span) => {
err.span_note(span,
"...so that pointer is not dereferenced outside its lifetime");
}
infer::FreeVariable(span, id) => {
err.span_note(span,
&format!("...so that captured variable `{}` does not outlive the \
enclosing closure",
self.tcx.hir.name(id)));
}
infer::IndexSlice(span) => {
err.span_note(span, "...so that slice is not indexed outside the lifetime");
}
infer::RelateObjectBound(span) => {
err.span_note(span, "...so that it can be closed over into an object");
}
infer::CallRcvr(span) => {
err.span_note(span,
"...so that method receiver is valid for the method call");
}
infer::CallArg(span) => {
err.span_note(span, "...so that argument is valid for the call");
}
infer::CallReturn(span) => {
err.span_note(span, "...so that return value is valid for the call");
}
infer::Operand(span) => {
err.span_note(span, "...so that operand is valid for operation");
}
infer::AddrOf(span) => {
err.span_note(span, "...so that reference is valid at the time of borrow");
}
infer::AutoBorrow(span) => {
err.span_note(span,
"...so that auto-reference is valid at the time of borrow");
}
infer::ExprTypeIsNotInScope(t, span) => {
err.span_note(span,
&format!("...so type `{}` of expression is valid during the \
expression",
self.ty_to_string(t)));
}
infer::BindingTypeIsNotValidAtDecl(span) => {
err.span_note(span,
"...so that variable is valid at time of its declaration");
}
infer::ParameterInScope(_, span) => {
err.span_note(span,
"...so that a type/lifetime parameter is in scope here");
}
infer::DataBorrowed(ty, span) => {
err.span_note(span,
&format!("...so that the type `{}` is not borrowed for too long",
self.ty_to_string(ty)));
}
infer::ReferenceOutlivesReferent(ty, span) => {
err.span_note(span,
&format!("...so that the reference type `{}` does not outlive the \
data it points at",
self.ty_to_string(ty)));
}
infer::RelateParamBound(span, t) => {
err.span_note(span,
&format!("...so that the type `{}` will meet its required \
lifetime bounds",
self.ty_to_string(t)));
}
infer::RelateDefaultParamBound(span, t) => {
err.span_note(span,
&format!("...so that type parameter instantiated with `{}`, will \
meet its declared lifetime bounds",
self.ty_to_string(t)));
}
infer::RelateRegionParamBound(span) => {
err.span_note(span,
"...so that the declared lifetime parameter bounds are satisfied");
}
infer::SafeDestructor(span) => {
err.span_note(span,
"...so that references are valid when the destructor runs");
}
infer::CompareImplMethodObligation { span, .. } => {
err.span_note(span,
"...so that the definition in impl matches the definition from the \
trait");
}
}
}
pub(super) fn report_concrete_failure(&self,
region_scope_tree: &region::ScopeTree,
origin: SubregionOrigin<'tcx>,
sub: Region<'tcx>,
sup: Region<'tcx>)
-> DiagnosticBuilder<'tcx> {
match origin {
infer::Subtype(trace) => {
let terr = TypeError::RegionsDoesNotOutlive(sup, sub);
let mut err = self.report_and_explain_type_error(trace, &terr);
self.tcx.note_and_explain_region(region_scope_tree, &mut err, "", sup, "...");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"...does not necessarily outlive ", sub, "");
err
}
infer::Reborrow(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0312,
"lifetime of reference outlives lifetime of \
borrowed content...");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"...the reference is valid for ",
sub,
"...");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"...but the borrowed content is only valid for ",
sup,
"");
err
}
infer::ReborrowUpvar(span, ref upvar_id) => {
let var_node_id = self.tcx.hir.hir_to_node_id(upvar_id.var_id);
let var_name = self.tcx.hir.name(var_node_id);
let mut err = struct_span_err!(self.tcx.sess,
span,
E0313,
"lifetime of borrowed pointer outlives lifetime \
of captured variable `{}`...",
var_name);
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"...the borrowed pointer is valid for ",
sub,
"...");
self.tcx.note_and_explain_region(
region_scope_tree,
&mut err,
&format!("...but `{}` is only valid for ", var_name),
sup,
"");
err
}
infer::InfStackClosure(span) => {
let mut err =
struct_span_err!(self.tcx.sess, span, E0314, "closure outlives stack frame");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"...the closure must be valid for ",
sub,
"...");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"...but the closure's stack frame is only valid \
for ",
sup,
"");
err
}
infer::InvokeClosure(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0315,
"cannot invoke closure outside of its lifetime");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the closure is only valid for ", sup, "");
err
}
infer::DerefPointer(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0473,
"dereference of reference outside its lifetime");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the reference is only valid for ", sup, "");
err
}
infer::FreeVariable(span, id) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0474,
"captured variable `{}` does not outlive the \
enclosing closure",
self.tcx.hir.name(id));
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"captured variable is valid for ", sup, "");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"closure is valid for ", sub, "");
err
}
infer::IndexSlice(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0475,
"index of slice outside its lifetime");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the slice is only valid for ", sup, "");
err
}
infer::RelateObjectBound(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0476,
"lifetime of the source pointer does not outlive \
lifetime bound of the object type");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"object type is valid for ", sub, "");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"source pointer is only valid for ",
sup,
"");
err
}
infer::RelateParamBound(span, ty) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0477,
"the type `{}` does not fulfill the required \
lifetime",
self.ty_to_string(ty));
match *sub {
ty::ReStatic => {
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"type must satisfy ", sub, "")
}
_ => {
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"type must outlive ", sub, "")
}
}
err
}
infer::RelateRegionParamBound(span) => {
let mut err =
struct_span_err!(self.tcx.sess, span, E0478, "lifetime bound not satisfied");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"lifetime parameter instantiated with ",
sup,
"");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"but lifetime parameter must outlive ",
sub,
"");
err
}
infer::RelateDefaultParamBound(span, ty) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0479,
"the type `{}` (provided as the value of a type \
parameter) is not valid at this point",
self.ty_to_string(ty));
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"type must outlive ", sub, "");
err
}
infer::CallRcvr(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0480,
"lifetime of method receiver does not outlive the \
method call");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the receiver is only valid for ", sup, "");
err
}
infer::CallArg(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0481,
"lifetime of function argument does not outlive \
the function call");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the function argument is only valid for ",
sup,
"");
err
}
infer::CallReturn(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0482,
"lifetime of return value does not outlive the \
function call");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the return value is only valid for ",
sup,
"");
err
}
infer::Operand(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0483,
"lifetime of operand does not outlive the \
operation");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the operand is only valid for ", sup, "");
err
}
infer::AddrOf(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0484,
"reference is not valid at the time of borrow");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the borrow is only valid for ", sup, "");
err
}
infer::AutoBorrow(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0485,
"automatically reference is not valid at the time \
of borrow");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the automatic borrow is only valid for ",
sup,
"");
err
}
infer::ExprTypeIsNotInScope(t, span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0486,
"type of expression contains references that are \
not valid during the expression: `{}`",
self.ty_to_string(t));
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"type is only valid for ", sup, "");
err
}
infer::SafeDestructor(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0487,
"unsafe use of destructor: destructor might be \
called while references are dead");
// FIXME (22171): terms "super/subregion" are suboptimal
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"superregion: ", sup, "");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"subregion: ", sub, "");
err
}
infer::BindingTypeIsNotValidAtDecl(span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0488,
"lifetime of variable does not enclose its \
declaration");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the variable is only valid for ", sup, "");
err
}
infer::ParameterInScope(_, span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0489,
"type/lifetime parameter not in scope here");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the parameter is only valid for ", sub, "");
err
}
infer::DataBorrowed(ty, span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0490,
"a value of type `{}` is borrowed for too long",
self.ty_to_string(ty));
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the type is valid for ", sub, "");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"but the borrow lasts for ", sup, "");
err
}
infer::ReferenceOutlivesReferent(ty, span) => {
let mut err = struct_span_err!(self.tcx.sess,
span,
E0491,
"in type `{}`, reference has a longer lifetime \
than the data it references",
self.ty_to_string(ty));
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"the pointer is valid for ", sub, "");
self.tcx.note_and_explain_region(region_scope_tree, &mut err,
"but the referenced data is only valid for ",
sup,
"");
err
}
infer::CompareImplMethodObligation { span,
item_name,
impl_item_def_id,
trait_item_def_id } => {
self.report_extra_impl_obligation(span,
item_name,
impl_item_def_id,
trait_item_def_id,
&format!("`{}: {}`", sup, sub))
}
}
}
}