Auto merge of #134841 - estebank:serde-attr-4, r=wesleywiser

Look at proc-macro attributes when encountering unknown attribute

```
error: cannot find attribute `sede` in this scope
  --> $DIR/missing-derive-2.rs:22:7
   |
LL |     #[sede(untagged)]
   |       ^^^^
   |
help: the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
   |
LL |     #[serde(untagged)]
   |         +

error: cannot find attribute `serde` in this scope
  --> $DIR/missing-derive-2.rs:16:7
   |
LL |     #[serde(untagged)]
   |       ^^^^^
   |
note: `serde` is imported here, but it is a crate, not an attribute
  --> $DIR/missing-derive-2.rs:5:1
   |
LL | extern crate serde;
   | ^^^^^^^^^^^^^^^^^^^
help: `serde` is an attribute that can be used by the derive macros `Serialize` and `Deserialize`, you might be missing a `derive` attribute
   |
LL + #[derive(Serialize, Deserialize)]
LL | enum B {
   |
```

Partially address #47608. This PR doesn't find [macros that haven't yet been imported by name](https://github.com/rust-lang/rust/pull/109278/commits/af945cb86e03b44a4b6dc4d54ec1424b00a2349e).

7 files changed, 228 insertions, 0 deletions

diff --git a/tests/ui/macros/auxiliary/serde.rs b/tests/ui/macros/auxiliary/serde.rs
new file mode 100644
index 00000000000..355b650bcf3
--- /dev/null
+++ b/tests/ui/macros/auxiliary/serde.rs
@@ -0,0 +1,19 @@
+//@ force-host
+//@ no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+#![feature(proc_macro_quote)]
+
+extern crate proc_macro;
+
+use proc_macro::*;
+
+#[proc_macro_derive(Serialize, attributes(serde))]
+pub fn serialize(ts: TokenStream) -> TokenStream {
+    quote!{}
+}
+
+#[proc_macro_derive(Deserialize, attributes(serde))]
+pub fn deserialize(ts: TokenStream) -> TokenStream {
+    quote!{}
+}
diff --git a/tests/ui/macros/missing-derive-1.rs b/tests/ui/macros/missing-derive-1.rs
new file mode 100644
index 00000000000..e23ef7bf07b
--- /dev/null
+++ b/tests/ui/macros/missing-derive-1.rs
@@ -0,0 +1,33 @@
+//@aux-build:serde.rs
+
+// derive macros imported and used
+
+extern crate serde;
+use serde::{Serialize, Deserialize};
+
+#[serde(untagged)] //~ ERROR cannot find attribute `serde`
+enum A { //~ HELP `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`
+    A,
+    B,
+}
+
+enum B { //~ HELP `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`
+    A,
+    #[serde(untagged)] //~ ERROR cannot find attribute `serde`
+    B,
+}
+
+enum C {
+    A,
+    #[sede(untagged)] //~ ERROR cannot find attribute `sede`
+    B, //~^ HELP the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
+}
+
+#[derive(Serialize, Deserialize)]
+#[serde(untagged)]
+enum D {
+    A,
+    B,
+}
+
+fn main() {}
diff --git a/tests/ui/macros/missing-derive-1.stderr b/tests/ui/macros/missing-derive-1.stderr
new file mode 100644
index 00000000000..15584100ffa
--- /dev/null
+++ b/tests/ui/macros/missing-derive-1.stderr
@@ -0,0 +1,47 @@
+error: cannot find attribute `serde` in this scope
+  --> $DIR/missing-derive-1.rs:8:3
+   |
+LL | #[serde(untagged)]
+   |   ^^^^^
+   |
+note: `serde` is imported here, but it is a crate, not an attribute
+  --> $DIR/missing-derive-1.rs:5:1
+   |
+LL | extern crate serde;
+   | ^^^^^^^^^^^^^^^^^^^
+help: `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`, you might be missing a `derive` attribute
+   |
+LL + #[derive(Deserialize, Serialize)]
+LL | enum A {
+   |
+
+error: cannot find attribute `serde` in this scope
+  --> $DIR/missing-derive-1.rs:16:7
+   |
+LL |     #[serde(untagged)]
+   |       ^^^^^
+   |
+note: `serde` is imported here, but it is a crate, not an attribute
+  --> $DIR/missing-derive-1.rs:5:1
+   |
+LL | extern crate serde;
+   | ^^^^^^^^^^^^^^^^^^^
+help: `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`, you might be missing a `derive` attribute
+   |
+LL + #[derive(Deserialize, Serialize)]
+LL | enum B {
+   |
+
+error: cannot find attribute `sede` in this scope
+  --> $DIR/missing-derive-1.rs:22:7
+   |
+LL |     #[sede(untagged)]
+   |       ^^^^
+   |
+help: the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
+   |
+LL |     #[serde(untagged)]
+   |         +
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/macros/missing-derive-2.rs b/tests/ui/macros/missing-derive-2.rs
new file mode 100644
index 00000000000..027d465d8b3
--- /dev/null
+++ b/tests/ui/macros/missing-derive-2.rs
@@ -0,0 +1,26 @@
+//@aux-build:serde.rs
+
+// derive macros imported but unused
+
+extern crate serde;
+use serde::{Serialize, Deserialize};
+
+#[serde(untagged)] //~ ERROR cannot find attribute `serde`
+enum A { //~ HELP `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`
+    A,
+    B,
+}
+
+enum B { //~ HELP `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`
+    A,
+    #[serde(untagged)] //~ ERROR cannot find attribute `serde`
+    B,
+}
+
+enum C {
+    A,
+    #[sede(untagged)] //~ ERROR cannot find attribute `sede`
+    B, //~^ HELP the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
+}
+
+fn main() {}
diff --git a/tests/ui/macros/missing-derive-2.stderr b/tests/ui/macros/missing-derive-2.stderr
new file mode 100644
index 00000000000..6c8e9e12019
--- /dev/null
+++ b/tests/ui/macros/missing-derive-2.stderr
@@ -0,0 +1,47 @@
+error: cannot find attribute `sede` in this scope
+  --> $DIR/missing-derive-2.rs:22:7
+   |
+LL |     #[sede(untagged)]
+   |       ^^^^
+   |
+help: the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
+   |
+LL |     #[serde(untagged)]
+   |         +
+
+error: cannot find attribute `serde` in this scope
+  --> $DIR/missing-derive-2.rs:16:7
+   |
+LL |     #[serde(untagged)]
+   |       ^^^^^
+   |
+note: `serde` is imported here, but it is a crate, not an attribute
+  --> $DIR/missing-derive-2.rs:5:1
+   |
+LL | extern crate serde;
+   | ^^^^^^^^^^^^^^^^^^^
+help: `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`, you might be missing a `derive` attribute
+   |
+LL + #[derive(Deserialize, Serialize)]
+LL | enum B {
+   |
+
+error: cannot find attribute `serde` in this scope
+  --> $DIR/missing-derive-2.rs:8:3
+   |
+LL | #[serde(untagged)]
+   |   ^^^^^
+   |
+note: `serde` is imported here, but it is a crate, not an attribute
+  --> $DIR/missing-derive-2.rs:5:1
+   |
+LL | extern crate serde;
+   | ^^^^^^^^^^^^^^^^^^^
+help: `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`, you might be missing a `derive` attribute
+   |
+LL + #[derive(Deserialize, Serialize)]
+LL | enum A {
+   |
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/macros/missing-derive-3.rs b/tests/ui/macros/missing-derive-3.rs
new file mode 100644
index 00000000000..8add8198890
--- /dev/null
+++ b/tests/ui/macros/missing-derive-3.rs
@@ -0,0 +1,24 @@
+//@aux-build:serde.rs
+
+// derive macros not imported, but namespace imported. Not yet handled.
+extern crate serde;
+
+#[serde(untagged)] //~ ERROR cannot find attribute `serde`
+enum A {
+    A,
+    B,
+}
+
+enum B {
+    A,
+    #[serde(untagged)] //~ ERROR cannot find attribute `serde`
+    B,
+}
+
+enum C {
+    A,
+    #[sede(untagged)] //~ ERROR cannot find attribute `sede`
+    B,
+}
+
+fn main() {}
diff --git a/tests/ui/macros/missing-derive-3.stderr b/tests/ui/macros/missing-derive-3.stderr
new file mode 100644
index 00000000000..0a7ed8d0876
--- /dev/null
+++ b/tests/ui/macros/missing-derive-3.stderr
@@ -0,0 +1,32 @@
+error: cannot find attribute `sede` in this scope
+  --> $DIR/missing-derive-3.rs:20:7
+   |
+LL |     #[sede(untagged)]
+   |       ^^^^
+
+error: cannot find attribute `serde` in this scope
+  --> $DIR/missing-derive-3.rs:14:7
+   |
+LL |     #[serde(untagged)]
+   |       ^^^^^
+   |
+note: `serde` is imported here, but it is a crate, not an attribute
+  --> $DIR/missing-derive-3.rs:4:1
+   |
+LL | extern crate serde;
+   | ^^^^^^^^^^^^^^^^^^^
+
+error: cannot find attribute `serde` in this scope
+  --> $DIR/missing-derive-3.rs:6:3
+   |
+LL | #[serde(untagged)]
+   |   ^^^^^
+   |
+note: `serde` is imported here, but it is a crate, not an attribute
+  --> $DIR/missing-derive-3.rs:4:1
+   |
+LL | extern crate serde;
+   | ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+