resolve: Attempt to resolve unresolved paths in macro namespace

Author: petrochenkov

src/librustc_resolve/diagnostics.rs

@@ -414,7 +414,7 @@ impl<'a> Resolver<'a> {
  };
 
  match (res, source) {
- (Res::Def(DefKind::Macro(..), _), _) => {
+ (Res::Def(DefKind::Macro(MacroKind::Bang), _), _) => {
  err.span_suggestion(
  span,
  "use `!` to invoke the macro",
@@ -574,7 +574,7 @@ impl<'a> Resolver<'a> {
  for derive in &parent_scope.derives {
  let parent_scope = ParentScope { derives: Vec::new(), ..*parent_scope };
  if let Ok((Some(ext), _)) = this.resolve_macro_path(
- derive, MacroKind::Derive, &parent_scope, true, true
+ derive, MacroKind::Derive, &parent_scope, false, false
  ) {
  suggestions.extend(ext.helper_attrs.iter().map(|name| {
  TypoSuggestion::from_res(*name, res)

src/librustc_resolve/lib.rs

@@ -3664,9 +3664,7 @@ impl<'a> Resolver<'a> {
  crate_lint: CrateLint,
  ) -> Option<PartialRes> {
  let mut fin_res = None;
- // FIXME: can't resolve paths in macro namespace yet, macros are
- // processed by the little special hack below.
- for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
+ for (i, ns) in [primary_ns, TypeNS, ValueNS].iter().cloned().enumerate() {
  if i == 0 || ns != primary_ns {
  match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
  // If defer_to_typeck, then resolution > no resolution,
@@ -3675,21 +3673,25 @@ impl<'a> Resolver<'a> {
  defer_to_typeck =>
  return Some(partial_res),
  partial_res => if fin_res.is_none() { fin_res = partial_res },
- };
+ }
  }
  }
- if primary_ns != MacroNS &&
- (self.macro_names.contains(&path[0].ident.modern()) ||
- self.builtin_macros.get(&path[0].ident.name).cloned()
- .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang) ||
- self.macro_use_prelude.get(&path[0].ident.name).cloned()
- .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang)) {
- // Return some dummy definition, it's enough for error reporting.
- return Some(PartialRes::new(Res::Def(
- DefKind::Macro(MacroKind::Bang),
- DefId::local(CRATE_DEF_INDEX),
- )));
+
+ // `MacroNS`
+ assert!(primary_ns != MacroNS);
+ if qself.is_none() {
+ let path_seg = |seg: &Segment| ast::PathSegment::from_ident(seg.ident);
+ let path = Path { segments: path.iter().map(path_seg).collect(), span };
+ let parent_scope =
+ ParentScope { module: self.current_module, ..self.dummy_parent_scope() };
+ for macro_kind in &[MacroKind::Bang, MacroKind::Attr, MacroKind::Derive] {
+ if let Ok((_, res)) = self.resolve_macro_path(&path, *macro_kind,
+ &parent_scope, false, false) {
+ return Some(PartialRes::new(res));
+ }
+ }
  }
+
  fin_res
  }
 

src/test/ui/hygiene/rustc-macro-transparency.rs

@@ -26,6 +26,6 @@ fn main() {
  Opaque; //~ ERROR cannot find value `Opaque` in this scope
 
  transparent; // OK
- semitransparent; //~ ERROR cannot find value `semitransparent` in this scope
- opaque; //~ ERROR cannot find value `opaque` in this scope
+ semitransparent; //~ ERROR expected value, found macro `semitransparent`
+ opaque; //~ ERROR expected value, found macro `opaque`
 }

src/test/ui/hygiene/rustc-macro-transparency.stderr

@@ -4,18 +4,19 @@ error[E0425]: cannot find value `Opaque` in this scope
 LL | Opaque;
  | ^^^^^^ help: a local variable with a similar name exists: `opaque`
 
-error[E0425]: cannot find value `semitransparent` in this scope
+error[E0423]: expected value, found macro `semitransparent`
  --> $DIR/rustc-macro-transparency.rs:29:5
  |
 LL | semitransparent;
- | ^^^^^^^^^^^^^^^ not found in this scope
+ | ^^^^^^^^^^^^^^^ help: use `!` to invoke the macro: `semitransparent!`
 
-error[E0425]: cannot find value `opaque` in this scope
+error[E0423]: expected value, found macro `opaque`
  --> $DIR/rustc-macro-transparency.rs:30:5
  |
 LL | opaque;
- | ^^^^^^ not found in this scope
+ | ^^^^^^ help: use `!` to invoke the macro: `opaque!`
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0425`.
+Some errors have detailed explanations: E0423, E0425.
+For more information about an error, try `rustc --explain E0423`.

src/test/ui/impl-trait/universal_wrong_bounds.rs

@@ -6,9 +6,8 @@ fn foo(f: impl Display + Clone) -> String {
  wants_clone(f);
 }
 
-fn wants_debug(g: impl Debug) { } //~ ERROR cannot find
-fn wants_display(g: impl Debug) { } //~ ERROR cannot find
+fn wants_debug(g: impl Debug) { } //~ ERROR expected trait, found derive macro `Debug`
+fn wants_display(g: impl Debug) { } //~ ERROR expected trait, found derive macro `Debug`
 fn wants_clone(g: impl Clone) { }
 
-fn main() {
-}
+fn main() {}

src/test/ui/impl-trait/universal_wrong_bounds.stderr

@@ -1,23 +1,23 @@
-error[E0405]: cannot find trait `Debug` in this scope
+error[E0404]: expected trait, found derive macro `Debug`
  --> $DIR/universal_wrong_bounds.rs:9:24
  |
 LL | fn wants_debug(g: impl Debug) { }
- | ^^^^^ not found in this scope
-help: possible candidate is found in another module, you can import it into scope
+ | ^^^^^ not a trait
+help: possible better candidate is found in another module, you can import it into scope
  |
 LL | use std::fmt::Debug;
  |
 
-error[E0405]: cannot find trait `Debug` in this scope
+error[E0404]: expected trait, found derive macro `Debug`
  --> $DIR/universal_wrong_bounds.rs:10:26
  |
 LL | fn wants_display(g: impl Debug) { }
- | ^^^^^ not found in this scope
-help: possible candidate is found in another module, you can import it into scope
+ | ^^^^^ not a trait
+help: possible better candidate is found in another module, you can import it into scope
  |
 LL | use std::fmt::Debug;
  |
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0405`.
+For more information about this error, try `rustc --explain E0404`.

src/test/ui/issues/issue-37534.rs

@@ -1,5 +1,5 @@
 struct Foo<T: ?Hash> { }
-//~^ ERROR cannot find trait `Hash` in this scope
+//~^ ERROR expected trait, found derive macro `Hash`
 //~^^ ERROR parameter `T` is never used
 //~^^^ WARN default bound relaxed for a type parameter, but this does nothing
 

src/test/ui/issues/issue-37534.stderr

@@ -1,9 +1,9 @@
-error[E0405]: cannot find trait `Hash` in this scope
+error[E0404]: expected trait, found derive macro `Hash`
  --> $DIR/issue-37534.rs:1:16
  |
 LL | struct Foo<T: ?Hash> { }
- | ^^^^ not found in this scope
-help: possible candidate is found in another module, you can import it into scope
+ | ^^^^ not a trait
+help: possible better candidate is found in another module, you can import it into scope
  |
 LL | use std::hash::Hash;
  |
@@ -24,5 +24,5 @@ LL | struct Foo<T: ?Hash> { }
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0392, E0405.
+Some errors have detailed explanations: E0392, E0404.
 For more information about an error, try `rustc --explain E0392`.

src/test/ui/no-implicit-prelude-nested.rs

@@ -9,7 +9,7 @@ mod foo {
  mod baz {
  struct Test;
  impl Add for Test {} //~ ERROR cannot find trait `Add` in this scope
- impl Clone for Test {} //~ ERROR cannot find trait `Clone` in this scope
+ impl Clone for Test {} //~ ERROR expected trait, found derive macro `Clone`
  impl Iterator for Test {} //~ ERROR cannot find trait `Iterator` in this scope
  impl ToString for Test {} //~ ERROR cannot find trait `ToString` in this scope
  impl Writer for Test {} //~ ERROR cannot find trait `Writer` in this scope
@@ -21,7 +21,7 @@ mod foo {
 
  struct Test;
  impl Add for Test {} //~ ERROR cannot find trait `Add` in this scope
- impl Clone for Test {} //~ ERROR cannot find trait `Clone` in this scope
+ impl Clone for Test {} //~ ERROR expected trait, found derive macro `Clone`
  impl Iterator for Test {} //~ ERROR cannot find trait `Iterator` in this scope
  impl ToString for Test {} //~ ERROR cannot find trait `ToString` in this scope
  impl Writer for Test {} //~ ERROR cannot find trait `Writer` in this scope
@@ -36,7 +36,7 @@ fn qux() {
  mod qux_inner {
  struct Test;
  impl Add for Test {} //~ ERROR cannot find trait `Add` in this scope
- impl Clone for Test {} //~ ERROR cannot find trait `Clone` in this scope
+ impl Clone for Test {} //~ ERROR expected trait, found derive macro `Clone`
  impl Iterator for Test {} //~ ERROR cannot find trait `Iterator` in this scope
  impl ToString for Test {} //~ ERROR cannot find trait `ToString` in this scope
  impl Writer for Test {} //~ ERROR cannot find trait `Writer` in this scope

src/test/ui/no-implicit-prelude-nested.stderr

@@ -8,12 +8,12 @@ help: possible candidate is found in another module, you can import it into scop
 LL | use std::ops::Add;
  |
 
-error[E0405]: cannot find trait `Clone` in this scope
+error[E0404]: expected trait, found derive macro `Clone`
  --> $DIR/no-implicit-prelude-nested.rs:12:14
  |
 LL | impl Clone for Test {}
- | ^^^^^ not found in this scope
-help: possible candidates are found in other modules, you can import them into scope
+ | ^^^^^ not a trait
+help: possible better candidates are found in other modules, you can import them into scope
  |
 LL | use std::clone::Clone;
  |
@@ -72,12 +72,12 @@ help: possible candidate is found in another module, you can import it into scop
 LL | use std::ops::Add;
  |
 
-error[E0405]: cannot find trait `Clone` in this scope
+error[E0404]: expected trait, found derive macro `Clone`
  --> $DIR/no-implicit-prelude-nested.rs:24:10
  |
 LL | impl Clone for Test {}
- | ^^^^^ not found in this scope
-help: possible candidates are found in other modules, you can import them into scope
+ | ^^^^^ not a trait
+help: possible better candidates are found in other modules, you can import them into scope
  |
 LL | use std::clone::Clone;
  |
@@ -136,12 +136,12 @@ help: possible candidate is found in another module, you can import it into scop
 LL | use std::ops::Add;
  |
 
-error[E0405]: cannot find trait `Clone` in this scope
+error[E0404]: expected trait, found derive macro `Clone`
  --> $DIR/no-implicit-prelude-nested.rs:39:14
  |
 LL | impl Clone for Test {}
- | ^^^^^ not found in this scope
-help: possible candidates are found in other modules, you can import them into scope
+ | ^^^^^ not a trait
+help: possible better candidates are found in other modules, you can import them into scope
  |
 LL | use std::clone::Clone;
  |
@@ -192,5 +192,5 @@ LL | use std::prelude::v1::drop;
 
 error: aborting due to 18 previous errors
 
-Some errors have detailed explanations: E0405, E0425.
-For more information about an error, try `rustc --explain E0405`.
+Some errors have detailed explanations: E0404, E0405, E0425.
+For more information about an error, try `rustc --explain E0404`.