rust: macros: enable use of hyphens in module names

Some modules might need naming that contains hyphens "-" to match the
auto-probing by name in the platform devices that comes from the device
tree.

But Rust identifier cannot contain hyphens, so replace them with
underscores.

Signed-off-by: Anisse Astier <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
[ Viresh: Replace "-" with '-', minor commit log fix, rename variable and
  fix line length checkpatch warnings ]
Reviewed-by: Benno Lossin <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>

Author: anisse

rust/macros/module.rs

@@ -185,7 +185,9 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
 
     let info = ModuleInfo::parse(&mut it);
 
-    let mut modinfo = ModInfoBuilder::new(info.name.as_ref());
+    // Rust does not allow hyphens in identifiers, use underscore instead.
+    let ident = info.name.replace('-', "_");
+    let mut modinfo = ModInfoBuilder::new(ident.as_ref());
     if let Some(author) = info.author {
         modinfo.emit("author", &author);
     }
@@ -310,22 +312,23 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
                     #[doc(hidden)]
                     #[link_section = \"{initcall_section}\"]
                     #[used]
-                    pub static __{name}_initcall: extern \"C\" fn() -> kernel::ffi::c_int = __{name}_init;
+                    pub static __{ident}_initcall: extern \"C\" fn() ->
+                        kernel::ffi::c_int = __{ident}_init;
 
                     #[cfg(not(MODULE))]
                     #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
                     core::arch::global_asm!(
                         r#\".section \"{initcall_section}\", \"a\"
-                        __{name}_initcall:
-                            .long   __{name}_init - .
+                        __{ident}_initcall:
+                            .long   __{ident}_init - .
                             .previous
                         \"#
                     );
 
                     #[cfg(not(MODULE))]
                     #[doc(hidden)]
                     #[no_mangle]
-                    pub extern \"C\" fn __{name}_init() -> kernel::ffi::c_int {{
+                    pub extern \"C\" fn __{ident}_init() -> kernel::ffi::c_int {{
                         // SAFETY: This function is inaccessible to the outside due to the double
                         // module wrapping it. It is called exactly once by the C side via its
                         // placement above in the initcall section.
@@ -335,13 +338,13 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
                     #[cfg(not(MODULE))]
                     #[doc(hidden)]
                     #[no_mangle]
-                    pub extern \"C\" fn __{name}_exit() {{
+                    pub extern \"C\" fn __{ident}_exit() {{
                         // SAFETY:
                         // - This function is inaccessible to the outside due to the double
                         //   module wrapping it. It is called exactly once by the C side via its
                         //   unique name,
-                        // - furthermore it is only called after `__{name}_init` has returned `0`
-                        //   (which delegates to `__init`).
+                        // - furthermore it is only called after `__{ident}_init` has
+                        //   returned `0` (which delegates to `__init`).
                         unsafe {{ __exit() }}
                     }}
 
@@ -381,6 +384,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
         ",
         type_ = info.type_,
         name = info.name,
+        ident = ident,
         modinfo = modinfo.buffer,
         initcall_section = ".initcall6.init"
     )