rust: module: introduce `authors` key

In the `module!` macro, the `author` field is currently of type `String`.

Since modules can have multiple authors, this limitation prevents
specifying more than one.

Add an `authors` field as `Option<Vec<String>>` to allow creating
modules with multiple authors, and change the documentation and all
current users to use it. Eventually, the single `author` field may
be removed.

[ The `modinfo` key needs to still be `author`; otherwise, tooling
  may not work properly, e.g.:

      $ modinfo --author samples/rust/rust_print.ko
      Rust for Linux Contributors

  I have also kept the original `author` field (undocumented), so
  that we can drop it more easily in a kernel cycle or two.

    - Miguel ]

Suggested-by: Miguel Ojeda <[email protected]>
Link: https://github.com/Rust-for-Linux/linux/issues/244
Reviewed-by: Charalampos Mitrodimas <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Signed-off-by: Guilherme Giacomo Simoes <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Fixed `modinfo` key. Kept `author` field. Reworded message
  accordingly. Updated my email. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index cdf94f4982df..42ed16c48b37 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -95,6 +95,7 @@ struct ModuleInfo {
     license: String,
     name: String,
     author: Option<String>,
+    authors: Option<Vec<String>>,
     description: Option<String>,
     alias: Option<Vec<String>>,
     firmware: Option<Vec<String>>,
@@ -108,6 +109,7 @@ impl ModuleInfo {
             "type",
             "name",
             "author",
+            "authors",
             "description",
             "license",
             "alias",
@@ -136,6 +138,7 @@ impl ModuleInfo {
                 "type" => info.type_ = expect_ident(it),
                 "name" => info.name = expect_string_ascii(it),
                 "author" => info.author = Some(expect_string(it)),
+                "authors" => info.authors = Some(expect_string_array(it)),
                 "description" => info.description = Some(expect_string(it)),
                 "license" => info.license = expect_string_ascii(it),
                 "alias" => info.alias = Some(expect_string_array(it)),
@@ -186,6 +189,11 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
     if let Some(author) = info.author {
         modinfo.emit("author", &author);
     }
+    if let Some(authors) = info.authors {
+        for author in authors {
+            modinfo.emit("author", &author);
+        }
+    }
     if let Some(description) = info.description {
         modinfo.emit("description", &description);
     }