rust/src/librustc/infer/error_reporting/note.rs

705 lines
25 KiB
Rust

use crate::infer::error_reporting::note_and_explain_region;
use crate::infer::{self, InferCtxt, SubregionOrigin};
use crate::middle::region;
use crate::ty::error::TypeError;
use crate::ty::{self, Region};
use errors::{struct_span_err, DiagnosticBuilder};
use rustc_error_codes::*;
impl<'a, 'tcx> InferCtxt<'a, '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) {
err.span_note(
trace.cause.span,
&format!("...so that the {}", trace.cause.as_requirement_str()),
);
err.note_expected_found(&"", 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_name = self.tcx.hir().name(upvar_id.var_path.hir_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::ClosureCapture(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(box trace) => {
let terr = TypeError::RegionsDoesNotOutlive(sup, sub);
let mut err = self.report_and_explain_type_error(trace, &terr);
note_and_explain_region(self.tcx, region_scope_tree, &mut err, "", sup, "...");
note_and_explain_region(
self.tcx,
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..."
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"...the reference is valid for ",
sub,
"...",
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"...but the borrowed content is only valid for ",
sup,
"",
);
err
}
infer::ReborrowUpvar(span, ref upvar_id) => {
let var_name = self.tcx.hir().name(upvar_id.var_path.hir_id);
let mut err = struct_span_err!(
self.tcx.sess,
span,
E0313,
"lifetime of borrowed pointer outlives lifetime \
of captured variable `{}`...",
var_name
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"...the borrowed pointer is valid for ",
sub,
"...",
);
note_and_explain_region(
self.tcx,
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");
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"...the closure must be valid for ",
sub,
"...",
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"the reference is only valid for ",
sup,
"",
);
err
}
infer::ClosureCapture(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)
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"captured variable is valid for ",
sup,
"",
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"object type is valid for ",
sub,
"",
);
note_and_explain_region(
self.tcx,
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 => note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"type must satisfy ",
sub,
"",
),
_ => note_and_explain_region(
self.tcx,
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");
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"lifetime parameter instantiated with ",
sup,
"",
);
note_and_explain_region(
self.tcx,
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)
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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)
);
note_and_explain_region(
self.tcx,
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
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"superregion: ",
sup,
"",
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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"
);
note_and_explain_region(
self.tcx,
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)
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"the type is valid for ",
sub,
"",
);
note_and_explain_region(
self.tcx,
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)
);
note_and_explain_region(
self.tcx,
region_scope_tree,
&mut err,
"the pointer is valid for ",
sub,
"",
);
note_and_explain_region(
self.tcx,
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),
),
}
}
pub(super) fn report_placeholder_failure(
&self,
region_scope_tree: &region::ScopeTree,
placeholder_origin: SubregionOrigin<'tcx>,
sub: Region<'tcx>,
sup: Region<'tcx>,
) -> DiagnosticBuilder<'tcx> {
// I can't think how to do better than this right now. -nikomatsakis
match placeholder_origin {
infer::Subtype(box trace) => {
let terr = TypeError::RegionsPlaceholderMismatch;
self.report_and_explain_type_error(trace, &terr)
}
_ => self.report_concrete_failure(region_scope_tree, placeholder_origin, sub, sup),
}
}
}