Gate extra formatting behind a feature flag in arm-app

YuhanLiin · Jul 16, 2024 · c352ba1 · c352ba1
1 parent 5946783
commit c352ba1
Show file tree

Hide file tree

Showing 3 changed files with 20 additions and 19 deletions.
diff --git a/examples/arm-app/Cargo.toml b/examples/arm-app/Cargo.toml
@@ -8,10 +8,14 @@ version = "0.0.0"
 [dependencies]
 cortex-m = "0.6.0"
 cortex-m-rt = "0.6.10"
-cortex-m-semihosting = "0.3.3"
+cortex-m-semihosting = { version = "0.3.3", optional = true }
 panic-halt = "0.2.0"
 
 micropb = { path = "../../micropb", features = ["container-heapless"] }
 
 [build-dependencies]
 micropb-gen = { path = "../../micropb-gen" }
+
+[features]
+default = ["formatting"]
+formatting = ["dep:cortex-m-semihosting"]
diff --git a/examples/arm-app/README.md b/examples/arm-app/README.md
@@ -4,6 +4,6 @@ To build, run `cargo build --profile release-lto`. This will build for the `thum
 
 To run the code, run `qemu-system-arm -cpu cortex-m4 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel <executable-file>` after building.
 
-To check the size of the binary, run `cargo size --profile release-lto`. The current size is about 12.5 kB.
+To check the size of the binary without including formatting/printing code, run `cargo size --profile release-lto --no-default-features 00 -- -A`. The current size of the `.text` section is 8.7 kB.
 
-To disassemble the binary, run `cargo objdump --profile release-lto -- -disassemble`.
+To disassemble the binary without formatting/printing code, run `cargo objdump --profile release-lto --no-default-features -- --disassemble`.
diff --git a/examples/arm-app/src/main.rs b/examples/arm-app/src/main.rs
@@ -1,8 +1,9 @@
 #![no_std]
 #![no_main]
 
-use core::{mem::size_of, str::FromStr};
+use core::{hint::black_box, mem::size_of, str::FromStr};
 
+#[cfg(feature = "formatting")]
 use cortex_m_semihosting::{debug, hprintln};
 use micropb::{
     heapless::{String, Vec},
@@ -26,6 +27,7 @@ use proto::raw_::*;
 
 #[entry]
 fn main() -> ! {
+    #[cfg(feature = "formatting")]
     hprintln!(
         "size of Packet = {}, Packet_::Msg = {}, LogBundle = {}, Log = {}",
         size_of::<Packet>(),
@@ -102,23 +104,18 @@ fn main() -> ! {
     let mut logs_pkt_out = Packet::default();
     logs_pkt_out.decode_len_delimited(&mut decoder).unwrap();
 
-    // Don't use assert to check message equality, because debug printing logic bloats code size
-    if init_pkt != init_pkt_out {
-        // Uncomment to debug panic
-        //hprintln!("init_pkt = {init_pkt:?}\ninit_pkt_out = {init_pkt_out:?}").unwrap();
-        panic!("init package fails roundtrip test");
-    }
-    if logs_pkt != logs_pkt_out {
-        // Uncomment to debug panic
-        //hprintln!("logs_pkt = {logs_pkt:?}\nlogs_pkt_out = {logs_pkt_out:?}").unwrap();
-        panic!("log package fails roundtrip test");
-    }
+    #[cfg(feature = "formatting")]
+    {
+        assert_eq!(init_pkt, init_pkt_out);
+        assert_eq!(logs_pkt, logs_pkt_out);
+        hprintln!("Example complete").unwrap();
 
-    hprintln!("Example complete").unwrap();
+        // exit QEMU
+        // NOTE do not run this on hardware; it can corrupt OpenOCD state
+        debug::exit(debug::EXIT_SUCCESS);
+    }
 
-    // exit QEMU
-    // NOTE do not run this on hardware; it can corrupt OpenOCD state
-    debug::exit(debug::EXIT_SUCCESS);
+    black_box((init_pkt, init_pkt_out, logs_pkt, logs_pkt_out));
 
     loop {}
 }