Add linux build support (#619)

Author: kennykerr

.github/workflows/build.yml

@@ -11,10 +11,16 @@ env:
 
 jobs:
   test:
-    runs-on: windows-latest
+    runs-on: ${{ matrix.os }}
     strategy: 
-      matrix: 
-        rust: [stable]
+      matrix:
+        include:
+        - os: windows-latest
+          rust: stable
+          other: x86_64-pc-windows-msvc
+        - os: ubuntu-latest
+          rust: stable
+          other: i686-unknown-linux-gnu
     steps:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
@@ -24,9 +30,14 @@ jobs:
         override: true
         components: rustfmt
 
-    - name: tests
+    - name: build
+      run: cargo build
+      if: matrix.os == 'ubuntu-latest'
+
+    - name: test
       run: cargo test --all
+      if: matrix.os == 'windows-latest'
 
     - name: fmt
       run: cargo fmt --all -- --check
-      if: matrix.rust == 'stable'
+      if: matrix.os == 'windows-latest'

crates/gen/src/types/function.rs

@@ -50,13 +50,21 @@ impl Function {
             link = "onecoreuap";
         }
 
-        quote! {
-            pub unsafe fn #name<#constraints>(#params) #return_type {
-                #[link(name = #link)]
-                extern "system" {
-                    pub fn #name(#(#abi_params),*) #abi_return_type;
+        if cfg!(windows) {
+            quote! {
+                pub unsafe fn #name<#constraints>(#params) #return_type {
+                    #[link(name = #link)]
+                    extern "system" {
+                        pub fn #name(#(#abi_params),*) #abi_return_type;
+                    }
+                    #name(#(#args),*)
+                }
+            }
+        } else {
+            quote! {
+                pub unsafe fn #name<#constraints>(#params) #return_type {
+                    panic!("Unsupported target OS");
                 }
-                #name(#(#args),*)
             }
         }
     }