Allow building for wasm32-wasi target. (#42)

Signed-off-by: Piotr Sikora <piotrsikora@google.com>

Author: PiotrSikora

.github/workflows/rust.yml

@@ -89,17 +89,28 @@ jobs:
       run: |
         rustup toolchain install stable --component clippy --component rustfmt
         rustup target add wasm32-unknown-unknown
+        rustup target add wasm32-wasi
 
-    - name: Build
+    - name: Build (wasm32-unknown-unknown)
       env:
         RUSTFLAGS: -D warnings -C link-args=-S
       run: cargo build --release --all-targets --target=wasm32-unknown-unknown
 
-    - name: Format (clippy)
+    - name: Clippy (wasm32-unknown-unknown)
       env:
         RUSTFLAGS: -D warnings -C link-args=-S
       run: cargo clippy --release --all-targets --target=wasm32-unknown-unknown
 
+    - name: Build (wasm32-wasi)
+      env:
+        RUSTFLAGS: -D warnings -C link-args=-S
+      run: cargo build --release --all-targets --target=wasm32-wasi
+
+    - name: Clippy (wasm32-wasi)
+      env:
+        RUSTFLAGS: -D warnings -C link-args=-S
+      run: cargo clippy --release --all-targets --target=wasm32-wasi
+
     - name: Format (rustfmt)
       run: cargo fmt -- --check
 
@@ -122,18 +133,29 @@ jobs:
       run: |
         rustup toolchain install nightly --component clippy --component rustfmt
         rustup +nightly target add wasm32-unknown-unknown
+        rustup +nightly target add wasm32-wasi
         rustup default nightly
 
-    - name: Build
+    - name: Build (wasm32-unknown-unknown)
       env:
         RUSTFLAGS: -D warnings -C link-args=-S
       run: cargo build --release --all-targets --target=wasm32-unknown-unknown
 
-    - name: Format (clippy)
+    - name: Clippy (wasm32-unknown-unknown)
       env:
         RUSTFLAGS: -D warnings -C link-args=-S
       run: cargo clippy --release --all-targets --target=wasm32-unknown-unknown
 
+    - name: Build (wasm32-wasi)
+      env:
+        RUSTFLAGS: -D warnings -C link-args=-S
+      run: cargo build --release --all-targets --target=wasm32-wasi
+
+    - name: Clippy (wasm32-wasi)
+      env:
+        RUSTFLAGS: -D warnings -C link-args=-S
+      run: cargo clippy --release --all-targets --target=wasm32-wasi
+
     - name: Format (rustfmt)
       run: cargo fmt -- --check
 

src/allocator.rs

@@ -15,8 +15,12 @@
 #[global_allocator]
 static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
+#[cfg_attr(
+    all(target_arch = "wasm32", target_os = "unknown"),
+    export_name = "malloc"
+)]
 #[no_mangle]
-pub extern "C" fn malloc(size: usize) -> *mut u8 {
+pub extern "C" fn proxy_on_memory_allocate(size: usize) -> *mut u8 {
     let mut vec: Vec<u8> = Vec::with_capacity(size);
     unsafe {
         vec.set_len(size);