From f38d42f2c4c6ad0d7cbdad5e1417cac3be2a5dcb Mon Sep 17 00:00:00 2001
From: Cherry Mui <cherryyz@google.com>
Date: Mon, 19 Aug 2024 15:17:04 -0400
Subject: [PATCH] cmd/link: support wasmexport on js/wasm
Add export functions to the wasm module on GOOS=js. (Other parts
work the same way as wasip1.)
Add a test.
Fixes #65199.
Change-Id: Ia22580859fe40631d487f70ee293c12867e0c988
Reviewed-on: https://go-review.googlesource.com/c/go/+/606855
Reviewed-by: Zxilly Chou <zxilly@outlook.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
---
misc/wasm/wasm_exec.js | 5 +++
src/cmd/link/internal/wasm/asm.go | 8 ++++-
src/syscall/js/js_test.go | 52 +++++++++++++++++++++++++++----
3 files changed, 58 insertions(+), 7 deletions(-)
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js
index 0f635d6d540..af7e28f5f48 100644
--- a/misc/wasm/wasm_exec.js
+++ b/misc/wasm/wasm_exec.js
@@ -216,10 +216,15 @@
return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len));
}
+ const testCallExport = (a, b) => {
+ return this._inst.exports.testExport(a, b);
+ }
+
const timeOrigin = Date.now() - performance.now();
this.importObject = {
_gotest: {
add: (a, b) => a + b,
+ callExport: testCallExport,
},
gojs: {
// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
diff --git a/src/cmd/link/internal/wasm/asm.go b/src/cmd/link/internal/wasm/asm.go
index 87a67754ccb..2a4c1ee7ea7 100644
--- a/src/cmd/link/internal/wasm/asm.go
+++ b/src/cmd/link/internal/wasm/asm.go
@@ -446,7 +446,7 @@ func writeExportSec(ctxt *ld.Link, ldr *loader.Loader, lenHostImports int) {
ctxt.Out.WriteByte(0x02) // mem export
writeUleb128(ctxt.Out, 0) // memidx
case "js":
- writeUleb128(ctxt.Out, 4) // number of exports
+ writeUleb128(ctxt.Out, uint64(4+len(ldr.WasmExports))) // number of exports
for _, name := range []string{"run", "resume", "getsp"} {
s := ldr.Lookup("wasm_export_"+name, 0)
if s == 0 {
@@ -457,6 +457,12 @@ func writeExportSec(ctxt *ld.Link, ldr *loader.Loader, lenHostImports int) {
ctxt.Out.WriteByte(0x00) // func export
writeUleb128(ctxt.Out, uint64(idx)) // funcidx
}
+ for _, s := range ldr.WasmExports {
+ idx := uint32(lenHostImports) + uint32(ldr.SymValue(s)>>16) - funcValueOffset
+ writeName(ctxt.Out, ldr.SymName(s))
+ ctxt.Out.WriteByte(0x00) // func export
+ writeUleb128(ctxt.Out, uint64(idx)) // funcidx
+ }
writeName(ctxt.Out, "mem") // inst.exports.mem in wasm_exec.js
ctxt.Out.WriteByte(0x02) // mem export
writeUleb128(ctxt.Out, 0) // memidx
diff --git a/src/syscall/js/js_test.go b/src/syscall/js/js_test.go
index cec5f28a082..d6bcc6370d4 100644
--- a/src/syscall/js/js_test.go
+++ b/src/syscall/js/js_test.go
@@ -56,6 +56,46 @@ func TestWasmImport(t *testing.T) {
}
}
+// testCallExport is imported from host (wasm_exec.js), which calls testExport.
+//
+//go:wasmimport _gotest callExport
+func testCallExport(a int32, b int64) int64
+
+//go:wasmexport testExport
+func testExport(a int32, b int64) int64 {
+ testExportCalled = true
+ // test stack growth
+ growStack(1000)
+ // force a goroutine switch
+ ch := make(chan int64)
+ go func() {
+ ch <- int64(a)
+ ch <- b
+ }()
+ return <-ch + <-ch
+}
+
+var testExportCalled bool
+
+func growStack(n int64) {
+ if n > 0 {
+ growStack(n - 1)
+ }
+}
+
+func TestWasmExport(t *testing.T) {
+ testExportCalled = false
+ a := int32(123)
+ b := int64(456)
+ want := int64(a) + b
+ if got := testCallExport(a, b); got != want {
+ t.Errorf("got %v, want %v", got, want)
+ }
+ if !testExportCalled {
+ t.Error("testExport not called")
+ }
+}
+
func TestBool(t *testing.T) {
want := true
o := dummys.Get("someBool")
@@ -587,13 +627,13 @@ func TestGarbageCollection(t *testing.T) {
// Note: All JavaScript functions return a JavaScript array, which will cause
// one allocation to be created to track the Value.gcPtr for the Value finalizer.
var allocTests = []struct {
- argLen int // The number of arguments to use for the syscall
+ argLen int // The number of arguments to use for the syscall
expected int // The expected number of allocations
}{
// For less than or equal to 16 arguments, we expect 1 allocation:
// - makeValue new(ref)
- {0, 1},
- {2, 1},
+ {0, 1},
+ {2, 1},
{15, 1},
{16, 1},
// For greater than 16 arguments, we expect 3 allocation:
@@ -613,7 +653,7 @@ func TestCallAllocations(t *testing.T) {
tmpArray := js.Global().Get("Array").New(0)
numAllocs := testing.AllocsPerRun(100, func() {
tmpArray.Call("concat", args...)
- });
+ })
if numAllocs != float64(test.expected) {
t.Errorf("got numAllocs %#v, want %#v", numAllocs, test.expected)
@@ -630,7 +670,7 @@ func TestInvokeAllocations(t *testing.T) {
concatFunc := tmpArray.Get("concat").Call("bind", tmpArray)
numAllocs := testing.AllocsPerRun(100, func() {
concatFunc.Invoke(args...)
- });
+ })
if numAllocs != float64(test.expected) {
t.Errorf("got numAllocs %#v, want %#v", numAllocs, test.expected)
@@ -647,7 +687,7 @@ func TestNewAllocations(t *testing.T) {
numAllocs := testing.AllocsPerRun(100, func() {
arrayConstructor.New(args...)
- });
+ })
if numAllocs != float64(test.expected) {
t.Errorf("got numAllocs %#v, want %#v", numAllocs, test.expected)
--
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