From 5ffa31dd90db201e305c3fe0baabab3e7977f624 Mon Sep 17 00:00:00 2001
From: Malena Gruevski <45406876+malenaohl@users.noreply.github.com>
Date: Sat, 7 Dec 2024 18:26:52 -0500
Subject: [PATCH] Add lint derive_proc_macro_missing (#1027)

Addresses a checkbox in
https://github.com/obi1kenobi/cargo-semver-checks/issues/946
---
 src/lints/derive_proc_macro_missing.ron       | 41 +++++++++++++++++++
 src/query.rs                                  |  1 +
 .../derive_proc_macro_missing/new/Cargo.toml  | 10 +++++
 .../derive_proc_macro_missing/new/src/lib.rs  | 16 ++++++++
 .../derive_proc_macro_missing/old/Cargo.toml  | 10 +++++
 .../derive_proc_macro_missing/old/src/lib.rs  | 21 ++++++++++
 .../derive_proc_macro_missing.snap            | 14 +++++++
 7 files changed, 113 insertions(+)
 create mode 100644 src/lints/derive_proc_macro_missing.ron
 create mode 100644 test_crates/derive_proc_macro_missing/new/Cargo.toml
 create mode 100644 test_crates/derive_proc_macro_missing/new/src/lib.rs
 create mode 100644 test_crates/derive_proc_macro_missing/old/Cargo.toml
 create mode 100644 test_crates/derive_proc_macro_missing/old/src/lib.rs
 create mode 100644 test_outputs/query_execution/derive_proc_macro_missing.snap

diff --git a/src/lints/derive_proc_macro_missing.ron b/src/lints/derive_proc_macro_missing.ron
new file mode 100644
index 00000000..b8dcbb53
--- /dev/null
+++ b/src/lints/derive_proc_macro_missing.ron
@@ -0,0 +1,41 @@
+SemverQuery(
+    id: "derive_proc_macro_missing",
+    human_readable_name: "derive macro removed",
+    description: "A derive macro that was previously available can no longer be used.",
+    required_update: Major,
+    lint_level: Deny,
+    reference_link: Some("https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros"),
+    query: r#"
+    {
+        CrateDiff {
+            baseline {
+                item {
+                    ... on DeriveProcMacro {
+                        macro_name: name @output @tag
+                        visibility_limit @filter(op: "=", value: ["$public"])
+
+                        span_: span @optional {
+                            filename @output
+                            begin_line @output
+                        }
+                    }
+                }
+            }
+            current @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
+                item {
+                    ... on DeriveProcMacro {
+                        visibility_limit @filter(op: "=", value: ["$public"])
+                        name @filter(op: "=", value: ["%macro_name"])
+                    }
+                }
+            }
+        }
+    }"#,
+    arguments: {
+        "public": "public",
+        "zero": 0,
+    },
+    error_message: "A derive macro has been removed. Type definitions using #[derive(...)] with this macro will fail to compile.",
+    per_result_error_template: Some("macro {{macro_name}} in {{span_filename}}:{{span_begin_line}}"),
+    witness: None,
+)
diff --git a/src/query.rs b/src/query.rs
index 81be133f..a519896d 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -1054,6 +1054,7 @@ add_lints!(
     constructible_struct_adds_private_field,
     constructible_struct_changed_type,
     declarative_macro_missing,
+    derive_proc_macro_missing,
     derive_trait_impl_removed,
     enum_marked_non_exhaustive,
     enum_missing,
diff --git a/test_crates/derive_proc_macro_missing/new/Cargo.toml b/test_crates/derive_proc_macro_missing/new/Cargo.toml
new file mode 100644
index 00000000..9ede3067
--- /dev/null
+++ b/test_crates/derive_proc_macro_missing/new/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+publish = false
+name = "derive_proc_macro_missing"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+proc-macro = true
+
+[dependencies]
diff --git a/test_crates/derive_proc_macro_missing/new/src/lib.rs b/test_crates/derive_proc_macro_missing/new/src/lib.rs
new file mode 100644
index 00000000..45ea3612
--- /dev/null
+++ b/test_crates/derive_proc_macro_missing/new/src/lib.rs
@@ -0,0 +1,16 @@
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(StaysPresent)]
+pub fn stays_present(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
+
+#[proc_macro_attribute]
+pub fn my_attribute(_attr: TokenStream, _item: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
+
+#[proc_macro]
+pub fn my_macro(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
diff --git a/test_crates/derive_proc_macro_missing/old/Cargo.toml b/test_crates/derive_proc_macro_missing/old/Cargo.toml
new file mode 100644
index 00000000..9ede3067
--- /dev/null
+++ b/test_crates/derive_proc_macro_missing/old/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+publish = false
+name = "derive_proc_macro_missing"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+proc-macro = true
+
+[dependencies]
diff --git a/test_crates/derive_proc_macro_missing/old/src/lib.rs b/test_crates/derive_proc_macro_missing/old/src/lib.rs
new file mode 100644
index 00000000..4674ced3
--- /dev/null
+++ b/test_crates/derive_proc_macro_missing/old/src/lib.rs
@@ -0,0 +1,21 @@
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(MyDerive)]
+pub fn my_derive(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
+
+#[proc_macro_derive(StaysPresent)]
+pub fn stays_present(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
+
+#[proc_macro_attribute]
+pub fn my_attribute(_attr: TokenStream, _item: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
+
+#[proc_macro]
+pub fn my_macro(_input: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
diff --git a/test_outputs/query_execution/derive_proc_macro_missing.snap b/test_outputs/query_execution/derive_proc_macro_missing.snap
new file mode 100644
index 00000000..388ec32b
--- /dev/null
+++ b/test_outputs/query_execution/derive_proc_macro_missing.snap
@@ -0,0 +1,14 @@
+---
+source: src/query.rs
+expression: "&query_execution_results"
+snapshot_kind: text
+---
+{
+  "./test_crates/derive_proc_macro_missing/": [
+    {
+      "macro_name": String("MyDerive"),
+      "span_begin_line": Uint64(4),
+      "span_filename": String("src/lib.rs"),
+    },
+  ],
+}