From 0b11eec45a467749055376c482cfdba7dce7b49f Mon Sep 17 00:00:00 2001
From: Anuraag Agrawal <anuraaga@gmail.com>
Date: Fri, 16 Jun 2023 11:54:47 +0900
Subject: [PATCH] Export malloc/free by default to match TinyGo 0.28 behavior
 (#16)

---
 bench/bench_test.go   | 29 +++++++++++++++++++++++++++++
 init.go               |  4 +++-
 magefiles/magefile.go | 22 ++++++++++++++++------
 3 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/bench/bench_test.go b/bench/bench_test.go
index 372e090..c9579a8 100644
--- a/bench/bench_test.go
+++ b/bench/bench_test.go
@@ -13,6 +13,35 @@ import (
 	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
 )
 
+// TestExportsMalloc is in the bench package since it already provides a fully packaged binary.
+// This could be cleaned up by using a different package, but for now we'll stick with being a little
+// lazy.
+func TestExportsMalloc(t *testing.T) {
+	wasm, err := os.ReadFile(filepath.Join("..", "build", "bench.wasm"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ctx := context.Background()
+	r := wazero.NewRuntime(ctx)
+	wasi_snapshot_preview1.MustInstantiate(ctx, r)
+
+	mod, err := r.InstantiateModuleFromBinary(ctx, wasm)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	malloc := mod.ExportedFunction("malloc")
+	free := mod.ExportedFunction("free")
+
+	if malloc == nil {
+		t.Error("malloc is not exported")
+	}
+	if free == nil {
+		t.Error("free is not exported")
+	}
+}
+
 func BenchmarkGC(b *testing.B) {
 	tests := []string{"bench.wasm", "benchref.wasm"}
 	for _, tc := range tests {
diff --git a/init.go b/init.go
index ef006cc..efce564 100644
--- a/init.go
+++ b/init.go
@@ -1,9 +1,11 @@
 // Copyright wasilibs authors
 // SPDX-License-Identifier: MIT
 
+//go:build tinygo
+
 package nottinygc
 
 /*
-#cgo LDFLAGS: -Lwasm -lgc -lmimalloc -lclang_rt.builtins-wasm32
+#cgo LDFLAGS: -Lwasm -lgc -lmimalloc -lclang_rt.builtins-wasm32 --export=malloc --export=free
 */
 import "C"
diff --git a/magefiles/magefile.go b/magefiles/magefile.go
index 15ca06f..67435a0 100644
--- a/magefiles/magefile.go
+++ b/magefiles/magefile.go
@@ -40,6 +40,14 @@ func Test() error {
 		return fmt.Errorf("unexpected error message: %s", s)
 	}
 
+	if err := buildBenchExecutable(); err != nil {
+		return err
+	}
+
+	if err := sh.RunV("go", "test", "./bench"); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -69,8 +77,6 @@ func Format() error {
 	return nil
 }
 
-var errMissingCopyrightHeaders = errors.New("missing copyright headers, use go run mage.go format")
-
 func Lint() error {
 	if _, err := sh.Exec(map[string]string{}, io.Discard, io.Discard, "go", "run", fmt.Sprintf("github.com/google/addlicense@%s", verAddLicense),
 		"-check",
@@ -81,7 +87,7 @@ func Lint() error {
 		"-ignore", "**/*.yml",
 		"-ignore", "**/*.yaml",
 		"."); err != nil {
-		return errMissingCopyrightHeaders
+		return fmt.Errorf("missing copyright headers, use go run mage.go format: %w", err)
 	}
 
 	return sh.RunV("go", "run", fmt.Sprintf("github.com/golangci/golangci-lint/cmd/golangci-lint@%s", verGolancCILint), "run")
@@ -112,7 +118,7 @@ func UpdateLibs() error {
 
 // Bench runs benchmarks.
 func Bench() error {
-	if err := os.MkdirAll("build", 0o755); err != nil {
+	if err := buildBenchExecutable(); err != nil {
 		return err
 	}
 
@@ -120,11 +126,15 @@ func Bench() error {
 		return err
 	}
 
-	if err := sh.RunV("tinygo", "build", "-gc=custom", "-tags=custommalloc", "-scheduler=none", "-target=wasi", "-o", "build/bench.wasm", "./bench"); err != nil {
+	return sh.RunV("go", "test", "-bench=.", "-benchtime=10s", "./bench")
+}
+
+func buildBenchExecutable() error {
+	if err := os.MkdirAll("build", 0o755); err != nil {
 		return err
 	}
 
-	return sh.RunV("go", "test", "-bench=.", "-benchtime=10s", "./bench")
+	return sh.RunV("tinygo", "build", "-gc=custom", "-tags=custommalloc", "-scheduler=none", "-target=wasi", "-o", "build/bench.wasm", "./bench")
 }
 
 var Default = Test