Tweak to allow exit code 0 to panic to prevent executing the LLVM unr…

…eachable instruction.

Signed-off-by: Phil Kedy <[email protected]>

imports/wasi_snapshot_preview1/proc.go

@@ -28,14 +28,13 @@ var procExit = &wasm.HostFunc{
 
 func procExitFn(ctx context.Context, mod api.Module, params []uint64) {
 	exitCode := uint32(params[0])
+
 	// TinyGo 0.35.0 calls proc_exit from _start, even for exit code 0.
-	if exitCode == 0 {
-		return
+	if exitCode != 0 {
+		// Ensure other callers see the exit code.
+		_ = mod.CloseWithExitCode(ctx, exitCode)
 	}
 
-	// Ensure other callers see the exit code.
-	_ = mod.CloseWithExitCode(ctx, exitCode)
-
 	// Prevent any code from executing after this function. For example, LLVM
 	// inserts unreachable instructions after calls to exit.
 	// See: https://github.com/emscripten-core/emscripten/issues/12322

imports/wasi_snapshot_preview1/proc_test.go

@@ -19,9 +19,11 @@ func Test_procExit(t *testing.T) {
 		expectedLog string
 	}{
 		{
-			name:        "success (exitcode 0)",
-			exitCode:    0,
-			expectedLog: ``,
+			name:     "success (exitcode 0)",
+			exitCode: 0,
+			expectedLog: `
+==> wasi_snapshot_preview1.proc_exit(rval=0)
+`,
 		},
 		{
 			name:     "arbitrary non-zero exitcode",