c#: Update to use latest packages incorporating WasmImportLinkage (#791)

* Update to use latest packages incorporating WasmImportLinkage Remove WasmImport from csproj Move cabi-realloc to c * update to 9.0.0 redo import name * move the cabi_realloc compilation to csproj * update emscripten to 3.1.47 (LLVM 17) * Use BeforeTargets instead of BeforeBuild, append cabi_realloc to file names.
bytecodealliance · Dec 19, 2023 · 04b715a · 04b715a
1 parent 1c5d94f
commit 04b715a
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Showing 4 changed files with 76 additions and 82 deletions.
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
@@ -57,8 +57,8 @@ jobs:
         curl.exe -OL https://github.com/emscripten-core/emsdk/archive/refs/heads/main.zip
         unzip main.zip
         cd emsdk-main
-        ./emsdk.bat install 3.1.23
-        ./emsdk.bat activate 3.1.23
+        ./emsdk.bat install 3.1.47
+        ./emsdk.bat activate 3.1.47
       if : matrix.os == 'windows-latest'
 
     - run: ci/download-teavm.sh

diff --git a/crates/csharp/src/csproj.rs b/crates/csharp/src/csproj.rs
@@ -9,7 +9,6 @@ pub struct CSProject {
     aot: bool,
     clean_targets: bool,
     world_name: String,
-    wasm_imports: Vec<(String, String)>,
 }
 
 impl CSProject {
@@ -20,14 +19,14 @@ impl CSProject {
             aot: false,
             clean_targets: false,
             world_name: world_name.to_string(),
-            wasm_imports: Vec::new(),
         }
     }
 
     pub fn generate(&self) -> Result<()> {
         let name = &self.name;
         let world = &self.world_name.replace("-", "_");
         let snake_world = world.to_upper_camel_case();
+        let camel = snake_world.to_upper_camel_case();
 
         fs::write(
             self.dir.join("rd.xml"),
@@ -57,8 +56,9 @@ impl CSProject {
             <PublishTrimmed>true</PublishTrimmed>
             <AssemblyName>{name}</AssemblyName>
         </PropertyGroup>
-            <ItemGroup>
+        <ItemGroup>
           <NativeLibrary Include=\"{world}_component_type.o\" />
+          <NativeLibrary Include=\"$(MSBuildProjectDirectory)/{camel}_cabi_realloc.o\" />
    
         </ItemGroup>
 
@@ -79,12 +79,27 @@ impl CSProject {
                 </ItemGroup>
    
                 <ItemGroup>
-                    <PackageReference Include="Microsoft.DotNet.ILCompiler.LLVM" Version="8.0.0-*" />
-                    <PackageReference Include="runtime.win-x64.Microsoft.DotNet.ILCompiler.LLVM" Version="8.0.0-*" />
+                    <PackageReference Include="Microsoft.DotNet.ILCompiler.LLVM" Version="9.0.0-*" />
+                    <PackageReference Include="runtime.win-x64.Microsoft.DotNet.ILCompiler.LLVM" Version="9.0.0-*" />
                 </ItemGroup>
+
+                <Target Name="CheckWasmSdks">
+                    <Error Text="Emscripten not found, not compiling to WebAssembly. To enable WebAssembly compilation, install Emscripten and ensure the EMSDK environment variable points to the directory containing upstream/emscripten/emcc.bat"
+                        Condition="'$(EMSDK)' == ''" />
+                </Target>
                 "#,
             );
 
+            csproj.push_str(&format!("
+              <Target Name=\"CompileCabiRealloc\" BeforeTargets=\"IlcCompile\" DependsOnTargets=\"CheckWasmSdks\" 
+                Inputs=\"$(MSBuildProjectDirectory)/{camel}_cabi_realloc.c\"
+                Outputs=\"$(MSBuildProjectDirectory)/{camel}_cabi_realloc.o\"
+                >
+                <Exec Command=\"emcc.bat &quot;$(MSBuildProjectDirectory)/{camel}_cabi_realloc.c&quot; -c -o &quot;$(MSBuildProjectDirectory)/{camel}_cabi_realloc.o&quot;\"/>
+              </Target>
+            "
+            ));
+
             fs::write(
                 self.dir.join("nuget.config"),
                 r#"<?xml version="1.0" encoding="utf-8"?>
@@ -103,19 +118,6 @@ impl CSProject {
             )?;
         }
 
-        if !&self.wasm_imports.is_empty() {
-            csproj.push_str("\t<ItemGroup>\n");
-            for (module_name, func_name) in &self.wasm_imports {
-                csproj.push_str(&format!(
-                    r#"
-                    <WasmImport Include="{}!{}" />
-                    "#,
-                    module_name, func_name,
-                ));
-            }
-            csproj.push_str("\t</ItemGroup>\n\n");
-        }
-
         if self.clean_targets {
             let mut wasm_filename = self.dir.join(name);
             wasm_filename.set_extension("wasm");
@@ -138,7 +140,6 @@ impl CSProject {
             "#,
         );
 
-        let camel = snake_world.to_upper_camel_case();
         fs::write(self.dir.join(format!("{camel}.csproj")), csproj)?;
 
         Ok(())
@@ -151,9 +152,4 @@ impl CSProject {
     pub fn clean(&mut self) {
         self.clean_targets = true;
     }
-
-    pub fn add_import(&mut self, module_name: &str, func_name: &str) {
-        self.wasm_imports
-            .push((module_name.to_string(), func_name.to_string()));
-    }
 }
diff --git a/crates/csharp/src/lib.rs b/crates/csharp/src/lib.rs
@@ -161,8 +161,8 @@ impl WorldGenerator for CSharp {
         let name = &format!("{}-world", resolve.worlds[world].name);
         let mut gen = self.interface(resolve, name, true);
 
-        for (_, func) in funcs {
-            gen.import(name, func);
+        for (import_module_name, func) in funcs {
+            gen.import(import_module_name, func);
         }
 
         gen.add_world_fragment();
@@ -409,41 +409,39 @@ impl WorldGenerator for CSharp {
         }
 
         src.push_str("\n");
-        src.push_str(
-            r#"
-                internal static class Intrinsics
-                {
-                    [UnmanagedCallersOnly(EntryPoint = "cabi_realloc")]
-                    internal static IntPtr cabi_realloc(IntPtr ptr, uint old_size, uint align, uint new_size)
-                    {
-                        if (new_size == 0)
-                        {
-                            if(old_size != 0)
-                            {
-                                Marshal.Release(ptr);
-                            }
-                            return new IntPtr((int)align);
-                        }
-                
-                        if (new_size > int.MaxValue)
-                        {
-                            throw new ArgumentException("Cannot allocate more that int.MaxValue", nameof(new_size));
-                        }
-                        
-                        if(old_size != 0)
-                        {
-                            return Marshal.ReAllocHGlobal(ptr, (int)new_size);
-                        }
 
-                        return Marshal.AllocHGlobal((int)new_size);
-                    }
-                }
-            "#,
-        );
         src.push_str("}\n");
 
         files.push(&format!("{name}.cs"), indent(&src).as_bytes());
 
+        let mut cabi_relloc_src = String::new();
+
+        cabi_relloc_src.push_str(
+            r#"
+                #include <stdlib.h>
+
+                /* Done in C so we can avoid initializing the dotnet runtime and hence WASI libc */
+                /* It would be preferable to do this in C# but the constrainst of cabi_realloc and the demands */
+                /* of WASI libc prevent us doing so. */
+                /* See https://github.com/bytecodealliance/wit-bindgen/issues/777  */
+                /* and https://github.com/WebAssembly/wasi-libc/issues/452 */
+                /* The component model `start` function might be an alternative to this depending on whether it 
+                /* has the same constraints as `cabi_realloc` */
+                __attribute__((__weak__, __export_name__("cabi_realloc")))
+                void *cabi_realloc(void *ptr, size_t old_size, size_t align, size_t new_size) {
+                    (void) old_size;
+                    if (new_size == 0) return (void*) align;
+                    void *ret = realloc(ptr, new_size);
+                    if (!ret) abort();
+                    return ret;
+                }
+            "#,
+        );
+        files.push(
+            &format!("{name}_cabi_realloc.c"),
+            indent(&cabi_relloc_src).as_bytes(),
+        );
+
         let generate_stub = |name: String, files: &mut Files, stubs: Stubs| {
             let stub_file_name = format!("{name}Impl");
             let interface_name = CSharp::get_class_name_from_qualified_name(name.clone());
@@ -496,6 +494,23 @@ impl WorldGenerator for CSharp {
                 .as_slice(),
         );
 
+        // TODO: remove when we switch to dotnet 9
+        let mut wasm_import_linakge_src = String::new();
+
+        wasm_import_linakge_src.push_str(
+            r#"
+            // temporarily add this attribute until it is available in dotnet 9
+            namespace System.Runtime.InteropServices
+            {
+                public class WasmImportLinkageAttribute : Attribute {}
+            }
+            "#,
+        );
+        files.push(
+            &format!("{snake}_wasm_import_linkage_attribute.cs"),
+            indent(&wasm_import_linakge_src).as_bytes(),
+        );
+
         for (name, interface_type_and_fragments) in &self.interface_fragments {
             let fragments = &interface_type_and_fragments.interface_fragments;
 
@@ -535,10 +550,11 @@ impl WorldGenerator for CSharp {
                 "// Generated by `wit-bindgen` {version}. DO NOT EDIT!
                 {CSHARP_IMPORTS}
 
-                namespace {namespace}.{name};
-
-                public static class {interface_name}Interop {{
-                    {body}
+                namespace {namespace}.{name}
+                {{
+                  public static class {interface_name}Interop {{
+                      {body}
+                  }}
                 }}
                 "
             );
@@ -694,7 +710,7 @@ impl InterfaceGenerator<'_> {
         });
     }
 
-    fn import(&mut self, _module: &String, func: &Function) {
+    fn import(&mut self, import_module_name: &str, func: &Function) {
         if func.kind != FunctionKind::Freestanding {
             todo!("resources");
         }
@@ -766,7 +782,7 @@ impl InterfaceGenerator<'_> {
             r#"
             internal static class {camel_name}WasmInterop
             {{
-                [DllImport("*", EntryPoint = "{import_name}")]
+                [DllImport("{import_module_name}", EntryPoint = "{import_name}"), WasmImportLinkage]
                 internal static extern {wasm_result_type} wasmImport{camel_name}({wasm_params});
             }}
             "#

diff --git a/tests/runtime/main.rs b/tests/runtime/main.rs
@@ -541,24 +541,6 @@ fn tests(name: &str, dir_name: &str) -> Result<Vec<PathBuf>> {
                 wit_bindgen_csharp::CSProject::new(out_dir.clone(), &assembly_name, world_name);
             csproj.aot();
 
-            // Write the WasmImports for NativeAOT-LLVM.
-            // See https://github.com/dotnet/runtimelab/issues/2383
-
-            for world in &resolve.worlds {
-                for import in &world.1.imports {
-                    let module_name = resolve.name_world_key(import.0);
-                    match import.1 {
-                        WorldItem::Function(f) => csproj.add_import(&module_name, &f.name),
-                        WorldItem::Interface(id) => {
-                            for (_, f) in resolve.interfaces[*id].functions.iter() {
-                                csproj.add_import(&module_name, &f.name)
-                            }
-                        }
-                        WorldItem::Type(_) => {}
-                    }
-                }
-            }
-
             // Copy test file to target location to be included in compilation
             let file_name = path.file_name().unwrap();
             fs::copy(path, out_dir.join(file_name.to_str().unwrap()))?;