Allow ensure_no_std to run without alloc

Author: mkj

.github/workflows/main.yml

@@ -67,6 +67,7 @@ jobs:
           toolchain: nightly
           targets: thumbv7em-none-eabihf
       - run: cd ensure_no_std && cargo build --release --target thumbv7em-none-eabihf
+      - run: cd ensure_no_std && cargo build --release --target thumbv7em-none-eabihf --no-default-features
 
   ensure_wasm:
     name: Ensure wasm

ensure_no_std/Cargo.toml

@@ -22,11 +22,11 @@ name = "ensure_no_std"
 path = "src/main.rs"
 
 [features]
-default = ["alloc"]
+default = ["alloc", "deku/alloc", "deku/bits" ]
 alloc = []
 
 [dependencies]
 cortex-m-rt = "0.7.3"
-deku = { path = "../", default-features = false, features = ["alloc", "bits"] }
+deku = { path = "../", default-features = false }
 embedded-alloc = "0.6.0"
 

ensure_no_std/src/lib.rs

@@ -1,6 +1,8 @@
 #![no_std]
 
+#[cfg(feature = "alloc")]
 extern crate alloc;
 
 pub mod no_alloc_imports;
+#[cfg(feature = "alloc")]
 pub mod with_alloc_imports;

ensure_no_std/src/main.rs

@@ -2,23 +2,22 @@
 #![no_std]
 #![no_main]
 
-extern crate alloc;
-
 use no_std_lib::*;
 
 use core::panic::PanicInfo;
 
 use cortex_m_rt::entry;
-use embedded_alloc::LlffHeap as Heap;
-
-#[global_allocator]
-static HEAP: Heap = Heap::empty();
 
 #[entry]
 fn main() -> ! {
     // Initialize the allocator BEFORE you use it
+    #[cfg(feature = "alloc")]
     {
+        use embedded_alloc::LlffHeap as Heap;
         use core::mem::MaybeUninit;
+
+        #[global_allocator]
+        static HEAP: Heap = Heap::empty();
         const HEAP_SIZE: usize = 1024;
         static HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
         unsafe { HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
@@ -27,6 +26,7 @@ fn main() -> ! {
     // now the allocator is ready types like Box, Vec can be used.
 
     no_alloc_imports::rw();
+    #[cfg(feature = "alloc")]
     with_alloc_imports::rw();
 
     loop { /* .. */ }

ensure_no_std/src/no_alloc_imports.rs

@@ -2,29 +2,27 @@ use deku::prelude::*;
 
 #[derive(Debug, PartialEq, DekuRead, DekuWrite)]
 struct DekuTest {
-    #[deku(bits = 5)]
     field_a: u8,
-    #[deku(bits = 3)]
     field_b: u8,
     count: u8,
 }
 
 pub fn rw() {
     #[allow(clippy::unusual_byte_groupings)]
-    let test_data: &[u8] = &[0b10101_101, 0x02];
-    let mut cursor = deku::no_std_io::Cursor::new(test_data);
+    let test_data: &[u8] = &[0xaa, 0xb0, 0x02];
 
     // Test reading
-    let (_rest, val) = DekuTest::from_reader((&mut cursor, 0)).unwrap();
+    let (_rest, val) = DekuTest::from_bytes((test_data, 0)).unwrap();
     assert_eq!(
         DekuTest {
-            field_a: 0b10101,
-            field_b: 0b101,
+            field_a: 0xaa,
+            field_b: 0xb0,
             count: 0x02,
         },
         val
     );
 
     // Test writing
-    let _val = val.to_bytes().unwrap();
+    let mut buf = [0; 20];
+    let _val = val.to_slice(&mut buf).unwrap();
 }