purego: support string arguments in Go callbacks from C

commit: 1e7d6d6fac76affcbf0d2f7ba9765e54c8bd76e9
author: brice · 6mo ago · 2026-04-15 03:32 UTC
committer: brice · 25d ago · 2026-09-27 05:38 UTC
parent: a44f95e
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

1 file · +27 -1

M syscall_unix.go +27 -1


@@ -11,6 +11,8 @@ import (
11	11		"runtime"
12	12		"sync"
13	13		"unsafe"
	14	+
	15	+	"github.com/bnema/purego/internal/strings"
14	16		)
15	17
16	18		var syscallXABI0 uintptr

@@ -78,7 +80,7 @@ func compileCallback(fn any) uintptr {
78	80		continue
79	81		case reflect.Interface, reflect.Func, reflect.Slice,
80	82		reflect.Chan, reflect.Complex64, reflect.Complex128,
81		-	reflect.String, reflect.Map, reflect.Invalid:
	83	+	reflect.Map, reflect.Invalid:
82	84		panic("purego: unsupported argument type: " + in.Kind().String())
83	85		}
84	86		}

@@ -230,6 +232,30 @@ func callbackWrap(a *callbackArgs) {
230	232		}
231	233		}
232	234		floatsN += slots
	235	+	case reflect.String:
	236	+	slots = 1
	237	+	var ptr uintptr
	238	+	if intsN+slots > numOfIntegerRegisters() {
	239	+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
	240	+	ptr = uintptr(callbackArgFromStack(a.args, stackSlot, &stackByteOffset, reflect.TypeOf(uintptr(0))).Uint())
	241	+	} else if stackFrame != nil {
	242	+	if runtime.GOARCH == "s390x" {
	243	+	ptr = uintptr(callbackArgFromSlotBigEndian(unsafe.Pointer(&stackFrame[stackSlot]), reflect.TypeOf(uintptr(0))).Uint())
	244	+	} else {
	245	+	ptr = (uintptr)(unsafe.Pointer(&stackFrame[stackSlot]))
	246	+	}
	247	+	stackSlot += slots
	248	+	} else {
	249	+	ptr = frame[stackSlot]
	250	+	stackSlot += slots
	251	+	}
	252	+	} else {
	253	+	pos := intsN + numOfFloatRegisters()
	254	+	ptr = frame[pos]
	255	+	}
	256	+	intsN += slots
	257	+	args[i] = reflect.ValueOf(strings.GoString(ptr))
	258	+	continue
233	259		case reflect.Struct:
234	260		if i == 0 && inType.AssignableTo(reflect.TypeFor[CDecl]()) {
235	261		args[i] = reflect.Zero(inType)


@@ -11,6 +11,8 @@ import (
11		"runtime"	11		"runtime"
12		"sync"	12		"sync"
13		"unsafe"	13		"unsafe"
			14	+
			15	+	"github.com/bnema/purego/internal/strings"
14		)	16		)
15			17
16		var syscallXABI0 uintptr	18		var syscallXABI0 uintptr

@@ -78,7 +80,7 @@ func compileCallback(fn any) uintptr {
78		continue	80		continue
79		case reflect.Interface, reflect.Func, reflect.Slice,	81		case reflect.Interface, reflect.Func, reflect.Slice,
80		reflect.Chan, reflect.Complex64, reflect.Complex128,	82		reflect.Chan, reflect.Complex64, reflect.Complex128,
81	-	reflect.String, reflect.Map, reflect.Invalid:	83	+	reflect.Map, reflect.Invalid:
82		panic("purego: unsupported argument type: " + in.Kind().String())	84		panic("purego: unsupported argument type: " + in.Kind().String())
83		}	85		}
84		}	86		}

@@ -230,6 +232,30 @@ func callbackWrap(a *callbackArgs) {
230		}	232		}
231		}	233		}
232		floatsN += slots	234		floatsN += slots
			235	+	case reflect.String:
			236	+	slots = 1
			237	+	var ptr uintptr
			238	+	if intsN+slots > numOfIntegerRegisters() {
			239	+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
			240	+	ptr = uintptr(callbackArgFromStack(a.args, stackSlot, &stackByteOffset, reflect.TypeOf(uintptr(0))).Uint())
			241	+	} else if stackFrame != nil {
			242	+	if runtime.GOARCH == "s390x" {
			243	+	ptr = uintptr(callbackArgFromSlotBigEndian(unsafe.Pointer(&stackFrame[stackSlot]), reflect.TypeOf(uintptr(0))).Uint())
			244	+	} else {
			245	+	ptr = (uintptr)(unsafe.Pointer(&stackFrame[stackSlot]))
			246	+	}
			247	+	stackSlot += slots
			248	+	} else {
			249	+	ptr = frame[stackSlot]
			250	+	stackSlot += slots
			251	+	}
			252	+	} else {
			253	+	pos := intsN + numOfFloatRegisters()
			254	+	ptr = frame[pos]
			255	+	}
			256	+	intsN += slots
			257	+	args[i] = reflect.ValueOf(strings.GoString(ptr))
			258	+	continue
233		case reflect.Struct:	259		case reflect.Struct:
234		if i == 0 && inType.AssignableTo(reflect.TypeFor[CDecl]()) {	260		if i == 0 && inType.AssignableTo(reflect.TypeFor[CDecl]()) {
235		args[i] = reflect.Zero(inType)	261		args[i] = reflect.Zero(inType)