buffer_test.go

@@ -1,6 +1,9 @@
 package cgo
 
-import "testing"
+import (
+	"testing"
+	"unsafe"
+)
 
 func TestBufferLifecycleAndCopy(t *testing.T) {
 	t.Parallel()
@@ -68,6 +71,39 @@ func TestBufferUseAfterFreePanics(t *testing.T) {
 	})
 }
 
+func TestCStringRoundTrip(t *testing.T) {
+	t.Parallel()
+
+	source := "hello"
+	cString := CString(source)
+	defer Free(unsafe.Pointer(cString))
+
+	converted := GoString(cString)
+	if converted != source {
+		t.Fatalf("expected %q, got %q", source, converted)
+	}
+}
+
+func TestGoStringNilIsEmpty(t *testing.T) {
+	t.Parallel()
+
+	got := GoString(nil)
+	if got != "" {
+		t.Fatalf("expected empty string, got %q", got)
+	}
+}
+
+func TestFreeNilDoesNotPanic(t *testing.T) {
+	t.Parallel()
+
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("Free(nil) panicked: %v", r)
+		}
+	}()
+	Free(nil)
+}
+
 func assertPanics(t *testing.T, want string, fn func()) {
 	t.Helper()
 

string_conversion.go

@@ -0,0 +1,39 @@
+package cgo
+
+/*
+#include <stdlib.h>
+*/
+import "C"
+
+import "unsafe"
+
+// GoString converts a null-terminated C string to a Go string.
+//
+//	cStr := C.CString("example")
+//	result := cgo.GoString(cStr)
+//	cgo.Free(unsafe.Pointer(cStr))
+func GoString(cs *C.char) string {
+	if cs == nil {
+		return ""
+	}
+	return C.GoString(cs)
+}
+
+// CString converts a Go string to a C string.
+//
+//	cStr := cgo.CString("hello")
+//	defer cgo.Free(unsafe.Pointer(cStr))
+func CString(value string) *C.char {
+	return C.CString(value)
+}
+
+// Free releases memory previously returned by CString.
+//
+//	cStr := cgo.CString("hello")
+//	cgo.Free(unsafe.Pointer(cStr))
+func Free(ptr unsafe.Pointer) {
+	if ptr == nil {
+		return
+	}
+	C.free(ptr)
+}