fix: address CodeRabbit findings — []string keepAlive + needsKeepAlive analysis

- Add reflect.Slice to needsKeepAlive check ([]string args need keepAlive)
- Keep individual CString allocations in keepAlive (prevent GC during C call)
- Fix variadic detection: use loop var v instead of args[i]

commit: a02394b1b2afe4553a50f6ed58d590b413491b3a
author: brice · 7mo ago · 2026-03-23 09:51 UTC
parent: d2ade5c
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

1 file · +9 -6

M func.go +9 -6


@@ -224,11 +224,12 @@ func RegisterFunc(fptr any, cfn uintptr) {
224	224		// and variadic []any args (unknown types at registration time).
225	225		needsKeepAlive := false
226	226		for i := 0; i < ty.NumIn(); i++ {
227		-	switch ty.In(i).Kind() {
228		-	case reflect.String, reflect.Struct, reflect.Array:
	227	+	inKind := ty.In(i).Kind()
	228	+	switch inKind {
	229	+	case reflect.String, reflect.Struct, reflect.Array, reflect.Slice:
	230	+	// Slice covers []string (CString allocs) and variadic ...any ([]any)
229	231		needsKeepAlive = true
230	232		case reflect.Interface:
231		-	// variadic []any — could contain anything
232	233		needsKeepAlive = true
233	234		}
234	235		}

@@ -312,7 +313,7 @@ func RegisterFunc(fptr any, cfn uintptr) {
312	313		}
313	314		}
314	315		for i, v := range args {
315		-	if variadic, ok := xreflect.TypeAssert[[]any](args[i]); ok {
	316	+	if variadic, ok := xreflect.TypeAssert[[]any](v); ok {
316	317		if i != len(args)-1 {
317	318		panic("purego: can only expand last parameter")
318	319		}

@@ -342,7 +343,7 @@ func RegisterFunc(fptr any, cfn uintptr) {
342	343		defer runtime.KeepAlive(args)
343	344
344	345		for i, v := range args {
345		-	if variadic, ok := xreflect.TypeAssert[[]any](args[i]); ok {
	346	+	if variadic, ok := xreflect.TypeAssert[[]any](v); ok {
346	347		if i != len(args)-1 {
347	348		panic("purego: can only expand last parameter")
348	349		}

@@ -516,7 +517,9 @@ func addValue(v reflect.Value, keepAlive []any, addInt func(x uintptr), addFloat
516	517		} else {
517	518		res := make([]*byte, len(ss)+1)
518	519		for i, s := range ss {
519		-	res[i] = strings.CString(s)
	520	+	ptr := strings.CString(s)
	521	+	keepAlive = append(keepAlive, ptr)
	522	+	res[i] = ptr
520	523		}
521	524		// NULL-terminated for C
522	525		res[len(ss)] = nil

 	// and variadic []any args (unknown types at registration time).
 	needsKeepAlive := false
 	for i := 0; i < ty.NumIn(); i++ {
-		switch ty.In(i).Kind() {
+		inKind := ty.In(i).Kind()
-		case reflect.String, reflect.Struct, reflect.Array:
+		switch inKind {
+		case reflect.String, reflect.Struct, reflect.Array, reflect.Slice:
+			// Slice covers []string (CString allocs) and variadic ...any ([]any)
 			needsKeepAlive = true
 		case reflect.Interface:
-			// variadic []any — could contain anything
 			needsKeepAlive = true
 		}
 	}
 				}
 			}
 			for i, v := range args {
-				if variadic, ok := xreflect.TypeAssert[[]any](args[i]); ok {
+				if variadic, ok := xreflect.TypeAssert[[]any](v); ok {
 					if i != len(args)-1 {
 						panic("purego: can only expand last parameter")
 					}
 		defer runtime.KeepAlive(args)
 		for i, v := range args {
-			if variadic, ok := xreflect.TypeAssert[[]any](args[i]); ok {
+			if variadic, ok := xreflect.TypeAssert[[]any](v); ok {
 				if i != len(args)-1 {
 					panic("purego: can only expand last parameter")
 				}
 			} else {
 				res := make([]*byte, len(ss)+1)
 				for i, s := range ss {
-					res[i] = strings.CString(s)
+					ptr := strings.CString(s)
+					keepAlive = append(keepAlive, ptr)
+					res[i] = ptr
 				}
 				// NULL-terminated for C
 				res[len(ss)] = nil