Auto merge of #62684 - petrochenkov:scopevisit, r=davidtwco

resolve: Improve candidate search for unresolved macro suggestions

Use same scope visiting machinery for both collecting suggestion candidates and actually resolving the names.

The PR is better read in per-commit fashion with whitespace changes ignored (the first commit in particular moves some code around).

This should be the last pre-requisite for https://github.com/rust-lang/rust/pull/62086.
r? @davidtwco

4 files changed, 43 insertions, 91 deletions

diff --git a/src/test/ui/feature-gates/feature-gate-custom_attribute.rs b/src/test/ui/feature-gates/feature-gate-custom_attribute.rs
index f31c9d5afc4..d34936b42a6 100644
--- a/src/test/ui/feature-gates/feature-gate-custom_attribute.rs
+++ b/src/test/ui/feature-gates/feature-gate-custom_attribute.rs
@@ -1,23 +1,18 @@
 // Check that literals in attributes parse just fine.
 
+#[fake_attr] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(100)] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(1, 2, 3)] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr("hello")] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(name = "hello")] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(1, "hi", key = 12, true, false)] //~ ERROR cannot find attribute macro `fake_attr` in th
+#[fake_attr(key = "hello", val = 10)] //~ ERROR cannot find attribute macro `fake_attr` in this scop
+#[fake_attr(key("hello"), val(10))] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(enabled = true, disabled = false)] //~ ERROR cannot find attribute macro `fake_attr` in
+#[fake_attr(true)] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(pi = 3.14159)] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_attr(b"hi")] //~ ERROR cannot find attribute macro `fake_attr` in this scope
+#[fake_doc(r"doc")] //~ ERROR cannot find attribute macro `fake_doc` in this scope
+struct Q {}
 
-#![allow(dead_code)]
-#![allow(unused_variables)]
-
-#[fake_attr] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(100)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(1, 2, 3)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr("hello")] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(name = "hello")] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(1, "hi", key = 12, true, false)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(key = "hello", val = 10)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(key("hello"), val(10))] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(enabled = true, disabled = false)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(true)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(pi = 3.14159)] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_attr(b"hi")] //~ ERROR attribute `fake_attr` is currently unknown
-#[fake_doc(r"doc")] //~ ERROR attribute `fake_doc` is currently unknown
-struct Q {  }
-
-
-fn main() { }
+fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-custom_attribute.stderr b/src/test/ui/feature-gates/feature-gate-custom_attribute.stderr
index 12175feadd6..efdc2d1cd31 100644
--- a/src/test/ui/feature-gates/feature-gate-custom_attribute.stderr
+++ b/src/test/ui/feature-gates/feature-gate-custom_attribute.stderr
@@ -1,120 +1,80 @@
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:7:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:3:3
    |
 LL | #[fake_attr]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:8:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:4:3
    |
 LL | #[fake_attr(100)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:9:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:5:3
    |
 LL | #[fake_attr(1, 2, 3)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:10:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:6:3
    |
 LL | #[fake_attr("hello")]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:11:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:7:3
    |
 LL | #[fake_attr(name = "hello")]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:12:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:8:3
    |
 LL | #[fake_attr(1, "hi", key = 12, true, false)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:13:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:9:3
    |
 LL | #[fake_attr(key = "hello", val = 10)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:14:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:10:3
    |
 LL | #[fake_attr(key("hello"), val(10))]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:15:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:11:3
    |
 LL | #[fake_attr(enabled = true, disabled = false)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:16:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:12:3
    |
 LL | #[fake_attr(true)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:17:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:13:3
    |
 LL | #[fake_attr(pi = 3.14159)]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_attr` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:18:3
+error: cannot find attribute macro `fake_attr` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:14:3
    |
 LL | #[fake_attr(b"hi")]
    |   ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: The attribute `fake_doc` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute.rs:19:3
+error: cannot find attribute macro `fake_doc` in this scope
+  --> $DIR/feature-gate-custom_attribute.rs:15:3
    |
 LL | #[fake_doc(r"doc")]
    |   ^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
 error: aborting due to 13 previous errors
 
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/feature-gates/feature-gate-rustc-attrs.rs b/src/test/ui/feature-gates/feature-gate-rustc-attrs.rs
index 9ce2fb58ab0..13983726c78 100644
--- a/src/test/ui/feature-gates/feature-gate-rustc-attrs.rs
+++ b/src/test/ui/feature-gates/feature-gate-rustc-attrs.rs
@@ -19,5 +19,5 @@ fn g() {}
 //~^ ERROR used by the test suite
 #[rustc_unknown]
 //~^ ERROR attributes starting with `rustc` are reserved for use by the `rustc` compiler
-//~| ERROR attribute `rustc_unknown` is currently unknown
+//~| ERROR cannot find attribute macro `rustc_unknown` in this scope
 fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-rustc-attrs.stderr b/src/test/ui/feature-gates/feature-gate-rustc-attrs.stderr
index 7c5aa5381e8..23cf936ee83 100644
--- a/src/test/ui/feature-gates/feature-gate-rustc-attrs.stderr
+++ b/src/test/ui/feature-gates/feature-gate-rustc-attrs.stderr
@@ -37,14 +37,11 @@ LL | #[rustc_unknown]
    = note: for more information, see https://github.com/rust-lang/rust/issues/29642
    = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
 
-error[E0658]: The attribute `rustc_unknown` is currently unknown to the compiler and may have meaning added to it in the future
+error: cannot find attribute macro `rustc_unknown` in this scope
   --> $DIR/feature-gate-rustc-attrs.rs:20:3
    |
 LL | #[rustc_unknown]
    |   ^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
 error[E0658]: used by the test suite
   --> $DIR/feature-gate-rustc-attrs.rs:18:1