resolve: Block expansion of a derive container until all its derives are resolved

Also mark derive helpers as known as a part of the derive container's expansion instead of expansion of the derives themselves which may happen too late.

src/test/ui/derives/deriving-bounds.stderr

@@ -1,15 +1,3 @@
-error: cannot find derive macro `Send` in this scope
-  --> $DIR/deriving-bounds.rs:1:10
-   |
-LL | #[derive(Send)]
-   |          ^^^^
-   |
-note: unsafe traits like `Send` should be implemented explicitly
-  --> $DIR/deriving-bounds.rs:1:10
-   |
-LL | #[derive(Send)]
-   |          ^^^^
-
 error: cannot find derive macro `Sync` in this scope
   --> $DIR/deriving-bounds.rs:5:10
    |
@@ -22,5 +10,17 @@ note: unsafe traits like `Sync` should be implemented explicitly
 LL | #[derive(Sync)]
    |          ^^^^
 
+error: cannot find derive macro `Send` in this scope
+  --> $DIR/deriving-bounds.rs:1:10
+   |
+LL | #[derive(Send)]
+   |          ^^^^
+   |
+note: unsafe traits like `Send` should be implemented explicitly
+  --> $DIR/deriving-bounds.rs:1:10
+   |
+LL | #[derive(Send)]
+   |          ^^^^
+
 error: aborting due to 2 previous errors
 

src/test/ui/feature-gate/issue-43106-gating-of-derive-2.stderr

@@ -1,5 +1,5 @@
 error: cannot find derive macro `x3300` in this scope
-  --> $DIR/issue-43106-gating-of-derive-2.rs:4:14
+  --> $DIR/issue-43106-gating-of-derive-2.rs:12:14
    |
 LL |     #[derive(x3300)]
    |              ^^^^^
@@ -11,7 +11,7 @@ LL |     #[derive(x3300)]
    |              ^^^^^
 
 error: cannot find derive macro `x3300` in this scope
-  --> $DIR/issue-43106-gating-of-derive-2.rs:12:14
+  --> $DIR/issue-43106-gating-of-derive-2.rs:4:14
    |
 LL |     #[derive(x3300)]
    |              ^^^^^

src/test/ui/feature-gate/issue-43106-gating-of-derive.rs

@@ -1,9 +1,6 @@
 // `#![derive]` raises errors when it occurs at contexts other than ADT
 // definitions.
 
-#![derive(Debug)]
-//~^ ERROR `derive` may only be applied to structs, enums and unions
-
 #[derive(Debug)]
 //~^ ERROR `derive` may only be applied to structs, enums and unions
 mod derive {

src/test/ui/feature-gate/issue-43106-gating-of-derive.stderr

@@ -1,38 +1,32 @@
 error: `derive` may only be applied to structs, enums and unions
   --> $DIR/issue-43106-gating-of-derive.rs:4:1
    |
-LL | #![derive(Debug)]
-   | ^^^^^^^^^^^^^^^^^ help: try an outer attribute: `#[derive(Debug)]`
-
-error: `derive` may only be applied to structs, enums and unions
-  --> $DIR/issue-43106-gating-of-derive.rs:7:1
-   |
 LL | #[derive(Debug)]
    | ^^^^^^^^^^^^^^^^
 
 error: `derive` may only be applied to structs, enums and unions
-  --> $DIR/issue-43106-gating-of-derive.rs:10:17
+  --> $DIR/issue-43106-gating-of-derive.rs:7:17
    |
 LL |     mod inner { #![derive(Debug)] }
    |                 ^^^^^^^^^^^^^^^^^ help: try an outer attribute: `#[derive(Debug)]`
 
 error: `derive` may only be applied to structs, enums and unions
-  --> $DIR/issue-43106-gating-of-derive.rs:13:5
+  --> $DIR/issue-43106-gating-of-derive.rs:10:5
    |
 LL |     #[derive(Debug)]
    |     ^^^^^^^^^^^^^^^^
 
 error: `derive` may only be applied to structs, enums and unions
-  --> $DIR/issue-43106-gating-of-derive.rs:26:5
+  --> $DIR/issue-43106-gating-of-derive.rs:23:5
    |
 LL |     #[derive(Debug)]
    |     ^^^^^^^^^^^^^^^^
 
 error: `derive` may only be applied to structs, enums and unions
-  --> $DIR/issue-43106-gating-of-derive.rs:30:5
+  --> $DIR/issue-43106-gating-of-derive.rs:27:5
    |
 LL |     #[derive(Debug)]
    |     ^^^^^^^^^^^^^^^^
 
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors
 

src/test/ui/issues/issue-36617.rs

@@ -1,3 +1,4 @@
 #![derive(Copy)] //~ ERROR `derive` may only be applied to structs, enums and unions
+                 //~| ERROR cannot determine resolution for the derive macro `Copy`
 
 fn main() {}

src/test/ui/issues/issue-36617.stderr

@@ -4,5 +4,13 @@ error: `derive` may only be applied to structs, enums and unions
 LL | #![derive(Copy)]
    | ^^^^^^^^^^^^^^^^ help: try an outer attribute: `#[derive(Copy)]`
 
-error: aborting due to previous error
+error: cannot determine resolution for the derive macro `Copy`
+  --> $DIR/issue-36617.rs:1:11
+   |
+LL | #![derive(Copy)]
+   |           ^^^^
+   |
+   = note: import resolution is stuck, try simplifying macro imports
+
+error: aborting due to 2 previous errors
 

src/test/ui/proc-macro/derive-helper-configured.rs

@@ -0,0 +1,18 @@
+// Derive helpers are resolved successfully inside `cfg_attr`.
+
+// check-pass
+// compile-flats:--cfg TRUE
+// aux-build:test-macros.rs
+
+#[macro_use]
+extern crate test_macros;
+
+#[cfg_attr(TRUE, empty_helper)]
+#[derive(Empty)]
+#[cfg_attr(TRUE, empty_helper)]
+struct S {
+    #[cfg_attr(TRUE, empty_helper)]
+    field: u8,
+}
+
+fn main() {}

src/test/ui/proc-macro/derive-helper-shadowing.rs

@@ -19,7 +19,8 @@ struct S {
         struct U;
 
         mod inner {
-            #[empty_helper] //~ ERROR cannot find attribute macro `empty_helper` in this scope
+            // FIXME No ambiguity, attributes in non-macro positions are not resolved properly
+            #[empty_helper]
             struct V;
         }
 

src/test/ui/proc-macro/derive-helper-shadowing.stderr

@@ -1,9 +1,3 @@
-error: cannot find attribute macro `empty_helper` in this scope
-  --> $DIR/derive-helper-shadowing.rs:22:15
-   |
-LL |             #[empty_helper]
-   |               ^^^^^^^^^^^^
-
 error[E0659]: `empty_helper` is ambiguous (derive helper attribute vs any other name)
   --> $DIR/derive-helper-shadowing.rs:8:3
    |
@@ -22,6 +16,6 @@ LL | use test_macros::empty_attr as empty_helper;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = help: use `crate::empty_helper` to refer to this attribute macro unambiguously
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0659`.

src/test/ui/proc-macro/resolve-error.stderr

@@ -1,50 +1,8 @@
-error: cannot find derive macro `FooWithLongNan` in this scope
-  --> $DIR/resolve-error.rs:22:10
+error: cannot find macro `bang_proc_macrp!` in this scope
+  --> $DIR/resolve-error.rs:56:5
    |
-LL | #[derive(FooWithLongNan)]
-   |          ^^^^^^^^^^^^^^ help: a derive macro with a similar name exists: `FooWithLongName`
-
-error: cannot find attribute macro `attr_proc_macra` in this scope
-  --> $DIR/resolve-error.rs:27:3
-   |
-LL | #[attr_proc_macra]
-   |   ^^^^^^^^^^^^^^^ help: an attribute macro with a similar name exists: `attr_proc_macro`
-
-error: cannot find attribute macro `FooWithLongNan` in this scope
-  --> $DIR/resolve-error.rs:31:3
-   |
-LL | #[FooWithLongNan]
-   |   ^^^^^^^^^^^^^^
-
-error: cannot find derive macro `Dlone` in this scope
-  --> $DIR/resolve-error.rs:34:10
-   |
-LL | #[derive(Dlone)]
-   |          ^^^^^ help: a derive macro with a similar name exists: `Clone`
-
-error: cannot find derive macro `Dlona` in this scope
-  --> $DIR/resolve-error.rs:38:10
-   |
-LL | #[derive(Dlona)]
-   |          ^^^^^ help: a derive macro with a similar name exists: `Clona`
-
-error: cannot find derive macro `attr_proc_macra` in this scope
-  --> $DIR/resolve-error.rs:42:10
-   |
-LL | #[derive(attr_proc_macra)]
-   |          ^^^^^^^^^^^^^^^
-
-error: cannot find macro `FooWithLongNama!` in this scope
-  --> $DIR/resolve-error.rs:47:5
-   |
-LL |     FooWithLongNama!();
-   |     ^^^^^^^^^^^^^^^ help: a macro with a similar name exists: `FooWithLongNam`
-
-error: cannot find macro `attr_proc_macra!` in this scope
-  --> $DIR/resolve-error.rs:50:5
-   |
-LL |     attr_proc_macra!();
-   |     ^^^^^^^^^^^^^^^ help: a macro with a similar name exists: `attr_proc_mac`
+LL |     bang_proc_macrp!();
+   |     ^^^^^^^^^^^^^^^ help: a macro with a similar name exists: `bang_proc_macro`
 
 error: cannot find macro `Dlona!` in this scope
   --> $DIR/resolve-error.rs:53:5
@@ -52,11 +10,53 @@ error: cannot find macro `Dlona!` in this scope
 LL |     Dlona!();
    |     ^^^^^
 
-error: cannot find macro `bang_proc_macrp!` in this scope
-  --> $DIR/resolve-error.rs:56:5
+error: cannot find macro `attr_proc_macra!` in this scope
+  --> $DIR/resolve-error.rs:50:5
    |
-LL |     bang_proc_macrp!();
-   |     ^^^^^^^^^^^^^^^ help: a macro with a similar name exists: `bang_proc_macro`
+LL |     attr_proc_macra!();
+   |     ^^^^^^^^^^^^^^^ help: a macro with a similar name exists: `attr_proc_mac`
+
+error: cannot find macro `FooWithLongNama!` in this scope
+  --> $DIR/resolve-error.rs:47:5
+   |
+LL |     FooWithLongNama!();
+   |     ^^^^^^^^^^^^^^^ help: a macro with a similar name exists: `FooWithLongNam`
+
+error: cannot find derive macro `attr_proc_macra` in this scope
+  --> $DIR/resolve-error.rs:42:10
+   |
+LL | #[derive(attr_proc_macra)]
+   |          ^^^^^^^^^^^^^^^
+
+error: cannot find derive macro `Dlona` in this scope
+  --> $DIR/resolve-error.rs:38:10
+   |
+LL | #[derive(Dlona)]
+   |          ^^^^^ help: a derive macro with a similar name exists: `Clona`
+
+error: cannot find derive macro `Dlone` in this scope
+  --> $DIR/resolve-error.rs:34:10
+   |
+LL | #[derive(Dlone)]
+   |          ^^^^^ help: a derive macro with a similar name exists: `Clone`
+
+error: cannot find attribute macro `FooWithLongNan` in this scope
+  --> $DIR/resolve-error.rs:31:3
+   |
+LL | #[FooWithLongNan]
+   |   ^^^^^^^^^^^^^^
+
+error: cannot find attribute macro `attr_proc_macra` in this scope
+  --> $DIR/resolve-error.rs:27:3
+   |
+LL | #[attr_proc_macra]
+   |   ^^^^^^^^^^^^^^^ help: an attribute macro with a similar name exists: `attr_proc_macro`
+
+error: cannot find derive macro `FooWithLongNan` in this scope
+  --> $DIR/resolve-error.rs:22:10
+   |
+LL | #[derive(FooWithLongNan)]
+   |          ^^^^^^^^^^^^^^ help: a derive macro with a similar name exists: `FooWithLongName`
 
 error: aborting due to 10 previous errors