ci: ensure build works with GOARCH=wasm

.github/workflows/ci.yml

@@ -67,6 +67,14 @@ jobs:
           go build -v ./...
           go test -c -o /dev/null ./... >/dev/null
 
+      - name: Cross build wasm
+        env:
+          GOOS: js
+          GOARCH: wasm
+        run: |
+          go build -v ./...
+          go test -c -o /dev/null ./... >/dev/null
+
   build-docs:
     name: Build Documentation
     runs-on: ubuntu-22.04

cmd/bpf2go/gen/target.go

@@ -14,19 +14,20 @@ import (
 var ErrInvalidTarget = errors.New("unsupported target")
 
 var targetsByGoArch = map[GoArch]Target{
-	"386":      {"bpfel", "x86"},
-	"amd64":    {"bpfel", "x86"},
-	"arm":      {"bpfel", "arm"},
-	"arm64":    {"bpfel", "arm64"},
-	"loong64":  {"bpfel", "loongarch"},
-	"mips":     {"bpfeb", "mips"},
-	"mipsle":   {"bpfel", ""},
-	"mips64":   {"bpfeb", ""},
-	"mips64le": {"bpfel", ""},
-	"ppc64":    {"bpfeb", "powerpc"},
-	"ppc64le":  {"bpfel", "powerpc"},
-	"riscv64":  {"bpfel", "riscv"},
-	"s390x":    {"bpfeb", "s390"},
+	"386":      {"bpfel", "x86", ""},
+	"amd64":    {"bpfel", "x86", ""},
+	"arm":      {"bpfel", "arm", ""},
+	"arm64":    {"bpfel", "arm64", ""},
+	"loong64":  {"bpfel", "loongarch", ""},
+	"mips":     {"bpfeb", "mips", ""},
+	"mipsle":   {"bpfel", "", ""},
+	"mips64":   {"bpfeb", "", ""},
+	"mips64le": {"bpfel", "", ""},
+	"ppc64":    {"bpfeb", "powerpc", ""},
+	"ppc64le":  {"bpfel", "powerpc", ""},
+	"riscv64":  {"bpfel", "riscv", ""},
+	"s390x":    {"bpfeb", "s390", ""},
+	"wasm":     {"bpfel", "", "js"},
 }
 
 type Target struct {
@@ -36,6 +37,8 @@ type Target struct {
 	// Linux arch string, used to define __TARGET_ARCH_xzy macros used by
 	// https://github.com/libbpf/libbpf/blob/master/src/bpf_tracing.h
 	linux string
+	// GOOS override for use during tests.
+	goos string
 }
 
 // TargetsByGoArch returns all supported targets.
@@ -118,7 +121,7 @@ func FindTarget(id string) (Target, GoArches, error) {
 			}
 		}
 		slices.Sort(goarches)
-		return Target{id, ""}, goarches, nil
+		return Target{id, "", ""}, goarches, nil
 
 	case "native":
 		id = runtime.GOARCH

cmd/bpf2go/gen/target_test.go

@@ -43,32 +43,32 @@ func TestCollectTargets(t *testing.T) {
 	}{
 		{
 			"bpf",
-			Target{"bpf", ""},
+			Target{"bpf", "", ""},
 			nil,
 		},
 		{
 			"bpfel",
-			Target{"bpfel", ""},
+			Target{"bpfel", "", ""},
 			clangArches["bpfel"],
 		},
 		{
 			"bpfeb",
-			Target{"bpfeb", ""},
+			Target{"bpfeb", "", ""},
 			clangArches["bpfeb"],
 		},
 		{
 			"amd64",
-			Target{"bpfel", "x86"},
+			Target{"bpfel", "x86", ""},
 			linuxArchesLE["x86"],
 		},
 		{
 			"386",
-			Target{"bpfel", "x86"},
+			Target{"bpfel", "x86", ""},
 			linuxArchesLE["x86"],
 		},
 		{
 			"ppc64",
-			Target{"bpfeb", "powerpc"},
+			Target{"bpfeb", "powerpc", ""},
 			linuxArchesBE["powerpc"],
 		},
 		{
@@ -111,10 +111,14 @@ func TestCollectTargetsErrors(t *testing.T) {
 func TestGoarches(t *testing.T) {
 	exe := goBin(t)
 
-	for GoArch := range targetsByGoArch {
+	for GoArch, tgt := range targetsByGoArch {
 		t.Run(string(GoArch), func(t *testing.T) {
+			goOS := "linux"
+			if tgt.goos != "" {
+				goOS = tgt.goos
+			}
 			goEnv := exec.Command(exe, "env")
-			goEnv.Env = []string{"GOROOT=/", "GOOS=linux", "GOARCH=" + string(GoArch)}
+			goEnv.Env = []string{"GOROOT=/", "GOOS=" + string(goOS), "GOARCH=" + string(GoArch)}
 			output, err := goEnv.CombinedOutput()
 			qt.Assert(t, qt.IsNil(err), qt.Commentf("go output is:\n%s", string(output)))
 		})

internal/endian_le.go

@@ -1,4 +1,4 @@
-//go:build 386 || amd64 || amd64p32 || arm || arm64 || loong64 || mipsle || mips64le || mips64p32le || ppc64le || riscv64
+//go:build 386 || amd64 || amd64p32 || arm || arm64 || loong64 || mipsle || mips64le || mips64p32le || ppc64le || riscv64 || wasm
 
 package internal