use rustc_ast::Mutability;
use rustc_errors::Applicability;
use rustc_hir as hir;
-use rustc_middle::ty::Ty;
+use rustc_middle::ty::{Ref, Ty};
use rustc_session::lint::builtin::FUTURE_PRELUDE_COLLISION;
use rustc_span::symbol::kw::Underscore;
use rustc_span::symbol::{sym, Ident};
return;
}
- self.tcx.struct_span_lint_hir(
- FUTURE_PRELUDE_COLLISION,
- call_expr.hir_id,
- call_expr.span,
- |lint| {
- let sp = call_expr.span;
- let trait_name =
- self.trait_path_or_bare_name(span, call_expr.hir_id, pick.item.container.id());
-
- let mut lint = lint.build(&format!(
- "trait method `{}` will become ambiguous in Rust 2021",
- segment.ident.name
- ));
-
- if let Ok(self_expr) = self.sess().source_map().span_to_snippet(self_expr.span) {
+ if matches!(pick.kind, probe::PickKind::InherentImplPick | probe::PickKind::ObjectPick) {
+ // avoid repeatedly adding unneeded `&*`s
+ if pick.autoderefs == 1
+ && matches!(
+ pick.autoref_or_ptr_adjustment,
+ Some(probe::AutorefOrPtrAdjustment::Autoref { .. })
+ )
+ && matches!(self_ty.kind(), Ref(..))
+ {
+ return;
+ }
+
+ // if it's an inherent `self` method (not `&self` or `&mut self`), it will take
+ // precedence over the `TryInto` impl, and thus won't break in 2021 edition
+ if pick.autoderefs == 0 && pick.autoref_or_ptr_adjustment.is_none() {
+ return;
+ }
+
+ // Inherent impls only require not relying on autoref and autoderef in order to
+ // ensure that the trait implementation won't be used
+ self.tcx.struct_span_lint_hir(
+ FUTURE_PRELUDE_COLLISION,
+ self_expr.hir_id,
+ self_expr.span,
+ |lint| {
+ let sp = self_expr.span;
+
+ let mut lint = lint.build(&format!(
+ "trait method `{}` will become ambiguous in Rust 2021",
+ segment.ident.name
+ ));
+
let derefs = "*".repeat(pick.autoderefs);
let autoref = match pick.autoref_or_ptr_adjustment {
}) => "&",
Some(probe::AutorefOrPtrAdjustment::ToConstPtr) | None => "",
};
- let self_adjusted = if let Some(probe::AutorefOrPtrAdjustment::ToConstPtr) =
- pick.autoref_or_ptr_adjustment
+ if let Ok(self_expr) = self.sess().source_map().span_to_snippet(self_expr.span)
{
- format!("{}{} as *const _", derefs, self_expr)
+ let self_adjusted = if let Some(probe::AutorefOrPtrAdjustment::ToConstPtr) =
+ pick.autoref_or_ptr_adjustment
+ {
+ format!("{}{} as *const _", derefs, self_expr)
+ } else {
+ format!("{}{}{}", autoref, derefs, self_expr)
+ };
+
+ lint.span_suggestion(
+ sp,
+ "disambiguate the method call",
+ format!("({})", self_adjusted),
+ Applicability::MachineApplicable,
+ );
} else {
- format!("{}{}{}", autoref, derefs, self_expr)
- };
- let args = args
- .iter()
- .skip(1)
- .map(|arg| {
- format!(
- ", {}",
- self.sess().source_map().span_to_snippet(arg.span).unwrap()
- )
- })
- .collect::<String>();
-
- lint.span_suggestion(
- sp,
- "disambiguate the associated function",
- format!(
- "{}::{}({}{})",
- trait_name, segment.ident.name, self_adjusted, args
- ),
- Applicability::MachineApplicable,
- );
- } else {
- lint.span_help(
- sp,
- &format!(
- "disambiguate the associated function with `{}::{}(...)`",
- trait_name, segment.ident,
- ),
+ let self_adjusted = if let Some(probe::AutorefOrPtrAdjustment::ToConstPtr) =
+ pick.autoref_or_ptr_adjustment
+ {
+ format!("{}(...) as *const _", derefs)
+ } else {
+ format!("{}{}...", autoref, derefs)
+ };
+ lint.span_help(
+ sp,
+ &format!("disambiguate the method call with `({})`", self_adjusted,),
+ );
+ }
+
+ lint.emit();
+ },
+ );
+ } else {
+ // trait implementations require full disambiguation to not clash with the new prelude
+ // additions (i.e. convert from dot-call to fully-qualified call)
+ self.tcx.struct_span_lint_hir(
+ FUTURE_PRELUDE_COLLISION,
+ call_expr.hir_id,
+ call_expr.span,
+ |lint| {
+ let sp = call_expr.span;
+ let trait_name = self.trait_path_or_bare_name(
+ span,
+ call_expr.hir_id,
+ pick.item.container.id(),
);
- }
- lint.emit();
- },
- );
+ let mut lint = lint.build(&format!(
+ "trait method `{}` will become ambiguous in Rust 2021",
+ segment.ident.name
+ ));
+
+ let (self_adjusted, precise) = self.adjust_expr(pick, self_expr);
+ if precise {
+ let args = args
+ .iter()
+ .skip(1)
+ .map(|arg| {
+ format!(
+ ", {}",
+ self.sess().source_map().span_to_snippet(arg.span).unwrap()
+ )
+ })
+ .collect::<String>();
+
+ lint.span_suggestion(
+ sp,
+ "disambiguate the associated function",
+ format!(
+ "{}::{}({}{})",
+ trait_name, segment.ident.name, self_adjusted, args
+ ),
+ Applicability::MachineApplicable,
+ );
+ } else {
+ lint.span_help(
+ sp,
+ &format!(
+ "disambiguate the associated function with `{}::{}(...)`",
+ trait_name, segment.ident,
+ ),
+ );
+ }
+
+ lint.emit();
+ },
+ );
+ }
}
pub(super) fn lint_fully_qualified_call_from_2018(
// All that is left is `_`! We need to use the full path. It doesn't matter which one we pick,
// so just take the first one.
match import_items[0].kind {
- ItemKind::Use(path, _) => {
- // FIXME: serialize path into something readable like a::b, there must be a fn for this
- debug!("no name for trait, found import of path: {:?}", path);
- return None;
- }
+ ItemKind::Use(path, _) => Some(
+ path.segments
+ .iter()
+ .map(|segment| segment.ident.to_string())
+ .collect::<Vec<_>>()
+ .join("::"),
+ ),
_ => {
span_bug!(span, "unexpected item kind, expected a use: {:?}", import_items[0].kind);
}
}
}
+
+ /// Creates a string version of the `expr` that includes explicit adjustments.
+ /// Returns the string and also a bool indicating whther this is a *precise*
+ /// suggestion.
+ fn adjust_expr(&self, pick: &Pick<'tcx>, expr: &hir::Expr<'tcx>) -> (String, bool) {
+ let derefs = "*".repeat(pick.autoderefs);
+
+ let autoref = match pick.autoref_or_ptr_adjustment {
+ Some(probe::AutorefOrPtrAdjustment::Autoref { mutbl: Mutability::Mut, .. }) => "&mut ",
+ Some(probe::AutorefOrPtrAdjustment::Autoref { mutbl: Mutability::Not, .. }) => "&",
+ Some(probe::AutorefOrPtrAdjustment::ToConstPtr) | None => "",
+ };
+
+ let (expr_text, precise) =
+ if let Ok(expr_text) = self.sess().source_map().span_to_snippet(expr.span) {
+ (expr_text, true)
+ } else {
+ (format!("(..)"), false)
+ };
+
+ let adjusted_text = if let Some(probe::AutorefOrPtrAdjustment::ToConstPtr) =
+ pick.autoref_or_ptr_adjustment
+ {
+ format!("{}{} as *const _", derefs, expr_text)
+ } else {
+ format!("{}{}{}", autoref, derefs, expr_text)
+ };
+
+ (adjusted_text, precise)
+ }
}
projects / rust.git / blobdiff