refactor(buildinfo): use a macro instead of a build script

Use one of our own macros to read the board name from a shell
environment variable we provide from the build system.
This was previously done using a build script, leveraging the fact that
cargo exposed `--cfg` flags as environment variables, but using a macro
is simpler, faster, and safer.

.github/workflows/main.yml

@@ -136,7 +136,7 @@ jobs:
       - name: clippy
         uses: clechasseur/rs-clippy-check@v3
         with:
-          args: --verbose --locked --features no-boards -p riot-rs -p riot-rs-boards -p riot-rs-buildinfo -p riot-rs-chips -p riot-rs-debug -p riot-rs-embassy -p riot-rs-macros -p riot-rs-random -p riot-rs-rt -p riot-rs-utils
+          args: --verbose --locked --features no-boards -p riot-rs -p riot-rs-boards -p riot-rs-chips -p riot-rs-debug -p riot-rs-embassy -p riot-rs-macros -p riot-rs-random -p riot-rs-rt -p riot-rs-utils
 
       - name: rustdoc
         run: RUSTDOCFLAGS='-D warnings' cargo doc -p riot-rs --features no-boards,bench,threading,random,csprng,hwrng

Cargo.toml

@@ -58,6 +58,7 @@ riot-rs-boards = { path = "src/riot-rs-boards", default-features = false }
 riot-rs-debug = { path = "src/riot-rs-debug", default-features = false }
 riot-rs-rt = { path = "src/riot-rs-rt" }
 riot-rs-runqueue = { path = "src/riot-rs-runqueue" }
+riot-rs-utils = { path = "src/riot-rs-utils", default-features = false }
 
 const_panic = { version = "0.2.8", default_features = false }
 document-features = "0.2.8"

laze-project.yml

@@ -25,6 +25,7 @@ contexts:
         - >-
           OPENOCD_ARGS="${OPENOCD_ARGS}"
           SCRIPTS=${SCRIPTS}
+          CONFIG_BOARD=${builder}
           CARGO_BUILD_TARGET=${RUSTC_TARGET}
           ${CARGO_TARGET_PREFIX}_RUNNER=${CARGO_RUNNER}
           ${CARGO_TARGET_PREFIX}_RUSTFLAGS="${RUSTFLAGS}"

src/riot-rs-embassy/Cargo.toml

@@ -26,8 +26,8 @@ embassy-usb = { workspace = true, optional = true }
 riot-rs-threads = { path = "../riot-rs-threads", optional = true }
 riot-rs-debug = { workspace = true }
 riot-rs-rt = { path = "../riot-rs-rt" }
-riot-rs-utils = { path = "../riot-rs-utils" }
 riot-rs-random = { path = "../riot-rs-random", optional = true }
+riot-rs-utils = { workspace = true }
 
 heapless = "0.8.0"
 once_cell = { version = "1.19.0", default-features = false, features = [

src/riot-rs-rt/Cargo.toml

@@ -12,7 +12,7 @@ cfg-if.workspace = true
 linkme.workspace = true
 riot-rs-debug.workspace = true
 riot-rs-threads = { path = "../riot-rs-threads", optional = true }
-riot-rs-utils = { path = "../riot-rs-utils" }
+riot-rs-utils = { workspace = true }
 rtt-target = { version = "0.4.0", optional = true }
 
 [target.'cfg(context = "cortex-m")'.dependencies]

src/riot-rs/Cargo.toml

@@ -12,13 +12,13 @@ document-features = { workspace = true }
 linkme = { workspace = true }
 riot-rs-bench = { workspace = true, optional = true }
 riot-rs-boards = { path = "../riot-rs-boards" }
-riot-rs-buildinfo = { path = "../riot-rs-buildinfo" }
 riot-rs-debug = { workspace = true }
 riot-rs-embassy = { path = "../riot-rs-embassy" }
 riot-rs-macros = { path = "../riot-rs-macros" }
 riot-rs-random = { path = "../riot-rs-random", optional = true }
 riot-rs-rt = { path = "../riot-rs-rt" }
 riot-rs-threads = { path = "../riot-rs-threads", optional = true }
+riot-rs-utils = { workspace = true }
 static_cell = { workspace = true }
 
 [target.'cfg(context = "cortex-m")'.dependencies]

src/riot-rs/src/buildinfo.rs

@@ -0,0 +1,11 @@
+//! Exposes information about the build.
+
+/// The board name.
+///
+/// The board name is read from the `CONFIG_BOARD` environment variable, which is expected to be
+/// provided by the build system.
+pub const BOARD: &str = riot_rs_utils::str_from_env_or!(
+    "CONFIG_BOARD",
+    "unknown",
+    "board name provided by the build system"
+);

src/riot-rs/src/lib.rs

@@ -7,12 +7,12 @@
 #![no_std]
 #![feature(doc_auto_cfg)]
 
+pub mod buildinfo;
+
 #[cfg(feature = "bench")]
 #[doc(inline)]
 pub use riot_rs_bench as bench;
 #[doc(inline)]
-pub use riot_rs_buildinfo as buildinfo;
-#[doc(inline)]
 pub use riot_rs_debug as debug;
 #[doc(inline)]
 pub use riot_rs_embassy as embassy;