SemverQuery(
id: "macro_no_longer_exported",
human_readable_name: "macro is no longer exported",
description: "A macro_rules macro that was previously exported is no longer exported.",
required_update: Major,
lint_level: Deny,
reference_link: Some("https://doc.rust-lang.org/reference/macros-by-example.html#path-based-scope"),
query: r#"
{
CrateDiff {
baseline {
item {
... on Macro {
name @output @tag
importable_path {
path @output @tag
public_api @filter(op: "=", value: ["$true"])
}
span_: span @optional {
filename @output
begin_line @output
}
}
}
}
current {
# There's no exported macro under the name we wanted.
item @fold @transform(op: "count") @filter(op: "=", value: ["$zero"]) {
... on Macro {
name @filter(op: "=", value: ["%name"])
importable_path {
path @filter(op: "=", value: ["%path"])
}
}
}
# There is at least one macro under the same name that is *not* exported.
# Perhaps the macro is not deleted, just no longer exported.
item @fold @transform(op: "count") @filter(op: ">", value: ["$zero"]) {
... on Macro {
name @filter(op: "=", value: ["%name"])
# Check the macro still exists but is no longer public API
# and isn't doc(hidden) (which would be caught by another lint)
public_api_eligible @filter(op: "!=", value: ["$true"])
doc_hidden @filter(op: "!=", value: ["$true"])
non_exported_span_: span @optional {
filename @output
begin_line @output
end_line @output
}
}
}
}
}
}"#,
arguments: {
"true": true,
"zero": 0,
},
error_message: "A `macro_rules!` declarative macro that was previously exported with `#[macro_export]` is no longer exported. This breaks downstream code that used the macro.",
per_result_error_template: Some("macro {{name}} in {{span_filename}}:{{span_begin_line}}"),
witness: Some((
hint_template: r#"{{name}}!(...);"#,
)),
)