chore(flipperzero-rs#92): use cstr crate

crates/Cargo.toml

@@ -23,6 +23,7 @@ flipperzero-sys = { path = "sys", version = "0.10.0" }
 flipperzero-rt = { path = "rt", version = "0.10.0" }
 flipperzero-alloc = { path = "alloc", version = "0.10.0" }
 flipperzero-test = { path = "test", version = "0.10.0" }
+cstr = "0.2.11"
 ufmt = "0.2.0"
 document-features = "0.2.0"
 

crates/flipperzero/examples/storage.rs

@@ -18,7 +18,7 @@ use flipperzero::io::*;
 use flipperzero::println;
 use flipperzero::storage::*;
 use flipperzero_rt::{entry, manifest};
-use flipperzero_sys::c_str;
+use flipperzero_sys::cstr;
 
 manifest!(name = "Rust storage example");
 entry!(main);
@@ -43,7 +43,7 @@ fn main(_args: *mut u8) -> i32 {
     // Next, we'll open a file browser dialog and let the user select the file.
     let mut dialogs_app = DialogsApp::open();
 
-    static EXTENSION: &CStr = c_str!("*");
+    static EXTENSION: &CStr = cstr!("*");
     let file_browser_options = DialogFileBrowserOptions::new(EXTENSION).set_hide_ext(false);
     let mut start_path = FuriString::from(path);
     let result_path =

crates/sys/Cargo.toml

@@ -22,4 +22,5 @@ bench = false
 test = false
 
 [dependencies]
+cstr.workspace = true
 ufmt.workspace = true

crates/sys/src/lib.rs

@@ -31,24 +31,17 @@ mod bindings;
 
 /// Create a static C string of type [`*const c_char`][core::ffi::c_char].
 /// Will automatically add a NUL terminator.
+// TODO: don't produce intermediate `CStr` whose `length` part we don't use
 #[macro_export]
 macro_rules! c_string {
     ($str:expr $(,)?) => {{
-        ::core::concat!($str, "\0").as_ptr() as *const ::core::ffi::c_char
+        $crate::cstr!($str).as_ptr()
     }};
 }
 
 /// Create a static C string of type [`&CStr`][`core::ffi::CStr`].
 /// Will automatically add a NUL terminator.
-#[macro_export]
-macro_rules! c_str {
-    ($str:expr $(,)?) => {{
-        match ::core::ffi::CStr::from_bytes_with_nul(::core::concat!($str, "\0").as_bytes()) {
-            Ok(c_str) => c_str,
-            Err(error) => panic!("invalid C-string literal"),
-        }
-    }};
-}
+pub use cstr::cstr;
 
 /// Crash the system.
 #[macro_export]