Merge pull request #7 from max-niederman/wasm-no-std

remove `std` dependency for WASM builds

.cargo/config.toml

@@ -4,5 +4,11 @@ target = "./armv7a-vexos-eabi.json"
 [target.armv7a-vexos]
 runner = "python runner.py"
 
+[target.wasm32-unknown-unknown]
+rustflags = [
+    "-Ctarget-feature=+atomics,+bulk-memory,+mutable-globals",
+    "-Clink-arg=--shared-memory",
+]
+
 [unstable]
 build-std = ["core", "compiler_builtins", "alloc"]

pros/Cargo.toml

@@ -20,5 +20,8 @@ snafu = { version = "0.7.5", default-features = false, features = [
 ] }
 no_std_io = { version = "0.6.0", features = ["alloc"] }
 
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+dlmalloc = { version = "0.2.4", features = ["global"] }
+
 [features]
 lvgl = ["pros-sys/xapi"]

pros/src/lib.rs

@@ -1,5 +1,5 @@
 #![feature(error_in_core, stdsimd)]
-#![cfg_attr(not(target_arch = "wasm32"), no_std)]
+#![no_std]
 
 extern crate alloc;
 

pros/src/wasm_env.rs

@@ -2,14 +2,34 @@
 
 extern crate alloc;
 
+use core::panic::PanicInfo;
+
 use alloc::{
-    alloc::{alloc, dealloc, handle_alloc_error, Layout},
+    alloc::{alloc, dealloc, handle_alloc_error, GlobalAlloc, Layout},
     collections::BTreeMap,
+    ffi::CString,
+    format,
 };
 
+use dlmalloc::GlobalDlmalloc;
+
 // no multithreading in wasm
 static mut LAYOUTS: BTreeMap<*mut u8, Layout> = BTreeMap::new();
 
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    extern "C" {
+        fn sim_abort(msg: *const core::ffi::c_char) -> !;
+    }
+
+    let msg_str = format!("{info}");
+    let msg_c_str = CString::new(msg_str).unwrap();
+
+    unsafe {
+        sim_abort(msg_c_str.as_ptr());
+    }
+}
+
 #[no_mangle]
 extern "C" fn wasm_memalign(alignment: usize, size: usize) -> *mut u8 {
     if size == 0 {
@@ -38,3 +58,6 @@ extern "C" fn wasm_free(ptr: *mut u8) {
         unsafe { dealloc(ptr, layout) };
     }
 }
+
+#[global_allocator]
+static ALLOCATOR: GlobalDlmalloc = GlobalDlmalloc;