fix wasm linked module with imported function instantiation (#606)

* fix wasm linked module with imported function instantiation

* update linked module imports test to have imported fn in env namespace

.gitignore

@@ -27,6 +27,7 @@ priv/native/libwasmex.so
 test/wasm_source/target/*
 test/wasm_link_test/target/*
 test/wasm_link_dep_test/target/*
+test/wasm_link_import_test/target/*
 
 .mix_tasks
 **/.DS_Store

native/wasmex/src/instance.rs

@@ -75,8 +75,8 @@ fn link_and_create_instance(
         wasmtime_wasi::add_to_linker(&mut linker, |s: &mut StoreData| s.wasi.as_mut().unwrap())
             .map_err(|err| Error::Term(Box::new(err.to_string())))?;
     }
-    link_modules(&mut linker, store_or_caller, linked_modules)?;
     link_imports(&mut linker, imports)?;
+    link_modules(&mut linker, store_or_caller, linked_modules)?;
     linker
         .instantiate(store_or_caller, module)
         .map_err(|err| Error::Term(Box::new(err.to_string())))

test/test_helper.exs

@@ -2,6 +2,7 @@ defmodule TestHelper do
   @wasm_test_source_dir "#{Path.dirname(__ENV__.file)}/wasm_test"
   @wasm_link_test_source_dir "#{Path.dirname(__ENV__.file)}/wasm_link_test"
   @wasm_link_dep_test_source_dir "#{Path.dirname(__ENV__.file)}/wasm_link_dep_test"
+  @wasm_link_import_test_source_dir "#{Path.dirname(__ENV__.file)}/wasm_link_import_test"
   @wasm_import_test_source_dir "#{Path.dirname(__ENV__.file)}/wasm_import_test"
   @wasi_test_source_dir "#{Path.dirname(__ENV__.file)}/wasi_test"
 
@@ -15,6 +16,10 @@ defmodule TestHelper do
     do:
       "#{@wasm_link_dep_test_source_dir}/target/wasm32-unknown-unknown/debug/wasmex_link_dep_test.wasm"
 
+  def wasm_link_import_test_file_path,
+    do:
+      "#{@wasm_link_import_test_source_dir}/target/wasm32-unknown-unknown/debug/wasmex_link_import_test.wasm"
+
   def wasm_import_test_file_path,
     do: "#{@wasm_import_test_source_dir}/target/wasm32-unknown-unknown/debug/wasmex_test.wasm"
 
@@ -24,6 +29,7 @@ defmodule TestHelper do
   def precompile_wasm_files do
     {"", 0} = System.cmd("cargo", ["build"], cd: @wasm_test_source_dir)
     {"", 0} = System.cmd("cargo", ["build"], cd: @wasm_import_test_source_dir)
+    {"", 0} = System.cmd("cargo", ["build"], cd: @wasm_link_import_test_source_dir)
     {"", 0} = System.cmd("cargo", ["build"], cd: @wasi_test_source_dir)
 
     {"", 0} =
@@ -80,6 +86,15 @@ defmodule TestHelper do
     %{store: store, module: wasm_module}
   end
 
+  def wasm_link_import_module do
+    {:ok, store} = Wasmex.Store.new()
+
+    {:ok, wasm_module} =
+      Wasmex.Module.compile(store, File.read!(TestHelper.wasm_link_import_test_file_path()))
+
+    %{store: store, module: wasm_module}
+  end
+
   def wasm_import_module do
     {:ok, store} = Wasmex.Store.new()
 

test/wasm_link_import_test/.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+target = "wasm32-unknown-unknown"

test/wasm_link_import_test/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "wasmex_link_import_test"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+[lib]
+crate-type =["cdylib"]

test/wasm_link_import_test/src/lib.rs

@@ -0,0 +1,9 @@
+extern "C" {
+    fn imported_sum(a: i32, b: i32) -> i32;
+}
+
+#[no_mangle]
+pub extern "C" fn sum(from: i32, to: i32) -> i32 {
+    let result = unsafe { imported_sum(from, to) };
+    result
+}

test/wasm_link_test.exs

@@ -68,4 +68,20 @@ defmodule WasmLinkTest do
 
     assert Wasmex.call_function(pid, "calc_seq", [1, 5]) == {:ok, [15]}
   end
+
+  test "linking wasm modules with imports" do
+    calculator_wasm = File.read!(TestHelper.wasm_link_test_file_path())
+    utils_wasm = File.read!(TestHelper.wasm_link_import_test_file_path())
+
+    imports = %{
+      env: %{
+        imported_sum: {:fn, [:i32, :i32], [:i32], fn _context, a, b -> a + b end}
+      }
+    }
+
+    links = %{utils: %{bytes: utils_wasm}}
+    {:ok, pid} = Wasmex.start_link(%{bytes: calculator_wasm, links: links, imports: imports})
+
+    assert Wasmex.call_function(pid, "sum_range", [1, 5]) == {:ok, [15]}
+  end
 end