[PATCH v2 07/28] rust: macros: take string literals in `module!`

ojeda
2022-12-02T16:15:49Z

From: Gary Guo <gary@garyguo.net>

Instead of taking binary string literals, take string ones instead,
making it easier for users to define a module, i.e. instead of
calling `module!` like:

module! {
...
name: b"rust_minimal",
...
}

now it is called as:

module! {
...
name: "rust_minimal",
...
}

Module names, aliases and license strings are restricted to
ASCII only. However, the author and the description allows UTF-8.

For simplicity (avoid parsing), escape sequences and raw string
literals are not yet handled.

Link: https://github.com/Rust-for-Linux/linux/issues/252
Link: https://lore.kernel.org/lkml/YukvvPOOu8uZl7+n@yadro.com/
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
rust/macros/helpers.rs | 24 ++++++++++++++++++------
rust/macros/lib.rs | 12 ++++++------
rust/macros/module.rs | 10 +++++-----
samples/rust/rust_minimal.rs | 8 ++++----
samples/rust/rust_print.rs | 8 ++++----
5 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index cdc7dc6135d2..cf7ad950dc1e 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -18,10 +18,16 @@ pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
}
}

-pub(crate) fn try_byte_string(it: &mut token_stream::IntoIter) -> Option<String> {
- try_literal(it).and_then(|byte_string| {
- if byte_string.starts_with("b\"") && byte_string.ends_with('\"') {
- Some(byte_string[2..byte_string.len() - 1].to_string())
+pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option<String> {
+ try_literal(it).and_then(|string| {
+ if string.starts_with('\"') && string.ends_with('\"') {
+ let content = &string[1..string.len() - 1];
+ if content.contains('\\') {
+ panic!("Escape sequences in string literals not yet handled");
+ }
+ Some(content.to_string())
+ } else if string.starts_with("r\"") {
+ panic!("Raw string literals are not yet handled");
} else {
None
}
@@ -40,8 +46,14 @@ pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
}
}

-pub(crate) fn expect_byte_string(it: &mut token_stream::IntoIter) -> String {
- try_byte_string(it).expect("Expected byte string")
+pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String {
+ try_string(it).expect("Expected string")
+}
+
+pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String {
+ let string = try_string(it).expect("Expected string");
+ assert!(string.is_ascii(), "Expected ASCII string");
+ string
}

pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index e40caaf0a656..c1d385e345b9 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -25,20 +25,20 @@ use proc_macro::TokenStream;
///
/// module!{
/// type: MyModule,
-/// name: b"my_kernel_module",
-/// author: b"Rust for Linux Contributors",
-/// description: b"My very own kernel module!",
-/// license: b"GPL",
+/// name: "my_kernel_module",
+/// author: "Rust for Linux Contributors",
+/// description: "My very own kernel module!",
+/// license: "GPL",
/// params: {
/// my_i32: i32 {
/// default: 42,
/// permissions: 0o000,
-/// description: b"Example of i32",
+/// description: "Example of i32",
/// },
/// writeable_i32: i32 {
/// default: 42,
/// permissions: 0o644,
-/// description: b"Example of i32",
+/// description: "Example of i32",
/// },
/// },
/// }
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 186a5b8be23c..a7e363c2b044 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -108,11 +108,11 @@ impl ModuleInfo {

match key.as_str() {
"type" => info.type_ = expect_ident(it),
- "name" => info.name = expect_byte_string(it),
- "author" => info.author = Some(expect_byte_string(it)),
- "description" => info.description = Some(expect_byte_string(it)),
- "license" => info.license = expect_byte_string(it),
- "alias" => info.alias = Some(expect_byte_string(it)),
+ "name" => info.name = expect_string_ascii(it),
+ "author" => info.author = Some(expect_string(it)),
+ "description" => info.description = Some(expect_string(it)),
+ "license" => info.license = expect_string_ascii(it),
+ "alias" => info.alias = Some(expect_string_ascii(it)),
_ => panic!(
"Unknown key \"{}\". Valid keys are: {:?}.",
key, EXPECTED_KEYS
diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs
index 54ad17685742..dc05f4bbe27e 100644
--- a/samples/rust/rust_minimal.rs
+++ b/samples/rust/rust_minimal.rs
@@ -6,10 +6,10 @@ use kernel::prelude::*;

module! {
type: RustMinimal,
- name: b"rust_minimal",
- author: b"Rust for Linux Contributors",
- description: b"Rust minimal sample",
- license: b"GPL",
+ name: "rust_minimal",
+ author: "Rust for Linux Contributors",
+ description: "Rust minimal sample",
+ license: "GPL",
}

struct RustMinimal {
diff --git a/samples/rust/rust_print.rs b/samples/rust/rust_print.rs
index 09f737790f3f..8b39d9cef6d1 100644
--- a/samples/rust/rust_print.rs
+++ b/samples/rust/rust_print.rs
@@ -7,10 +7,10 @@ use kernel::prelude::*;

module! {
type: RustPrint,
- name: b"rust_print",
- author: b"Rust for Linux Contributors",
- description: b"Rust printing macros sample",
- license: b"GPL",
+ name: "rust_print",
+ author: "Rust for Linux Contributors",
+ description: "Rust printing macros sample",
+ license: "GPL",
}

struct RustPrint;
--
2.38.1