Add support for functions with shared implementations (#1)

Package.resolved

@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/shareup/cwasm3.git",
         "state": {
           "branch": null,
-          "revision": "ba06c95a9dac8837ceaae3ace06d2149feb04e27",
-          "version": "0.4.7"
+          "revision": "93bee1c35cee166098cf290fe7b745d44730afce",
+          "version": "0.4.8"
         }
       },
       {

Tests/WasmInterpreterTests/Resources/constant.wat

@@ -0,0 +1,6 @@
+(module
+  (type (;0;) (func (result i32)))
+  (func (;0;) (type 0) (result i32)
+    i32.const 65536)
+  (export "constant_1" (func 0))
+  (export "constant_2" (func 0)))

Tests/WasmInterpreterTests/Wasm Modules/ConstantModule.swift

@@ -0,0 +1,24 @@
+import Foundation
+import WasmInterpreter
+
+public struct ConstantModule {
+    private let _vm: WasmInterpreter
+
+    init() throws {
+        _vm = try WasmInterpreter(module: ConstantModule.wasm)
+    }
+
+    func constant1() throws -> Int {
+        return Int(try _vm.call("constant_1") as Int32)
+    }
+
+    func constant2() throws -> Int {
+        return Int(try _vm.call("constant_2") as Int32)
+    }
+
+    // `wat2wasm -o >(base64) Tests/WasmInterpreterTests/Resources/constant.wat | pbcopy`
+    private static var wasm: [UInt8] {
+        let base64 = "AGFzbQEAAAABBQFgAAF/AwIBAAcbAgpjb25zdGFudF8xAAAKY29uc3RhbnRfMgAACggBBgBBgIAECw=="
+        return Array<UInt8>(Data(base64Encoded: base64)!)
+    }
+}

Tests/WasmInterpreterTests/WasmInterpreterTests.swift

@@ -2,6 +2,12 @@ import XCTest
 @testable import WasmInterpreter
 
 final class WasmInterpreterTests: XCTestCase {
+    func testCallingTwoFunctionsWithSameImplementation() throws {
+        let mod = try ConstantModule()
+        XCTAssertEqual(65536, try mod.constant1())
+        XCTAssertEqual(65536, try mod.constant2())
+    }
+
     func testPassingAndReturning32BitValues() throws {
         let mod = try AddModule()
         XCTAssertEqual(0, try mod.add(-1, 1))
@@ -31,6 +37,7 @@ final class WasmInterpreterTests: XCTestCase {
     }
 
     static var allTests = [
+        ("testCallingTwoFunctionsWithSameImplementation", testCallingTwoFunctionsWithSameImplementation),
         ("testPassingAndReturning32BitValues", testPassingAndReturning32BitValues),
         ("testPassingAndReturning64BitValues", testPassingAndReturning64BitValues),
         ("testUsingImportedFunction", testUsingImportedFunction),