purego: support string arguments in Go callbacks from C

commit: a7a757496003828984098b524cea737794202c53
author: brice · 6mo ago · 2026-04-15 03:32 UTC
parent: 3078bf4
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 syscall15XABI0 uintptr

@@ -82,7 +84,7 @@ func compileCallback(fn any) uintptr {
82	84		continue
83	85		case reflect.Interface, reflect.Func, reflect.Slice,
84	86		reflect.Chan, reflect.Complex64, reflect.Complex128,
85		-	reflect.String, reflect.Map, reflect.Invalid:
	87	+	reflect.Map, reflect.Invalid:
86	88		panic("purego: unsupported argument type: " + in.Kind().String())
87	89		}
88	90		}

@@ -211,6 +213,30 @@ func callbackWrap(a *callbackArgs) {
211	213		}
212	214		}
213	215		floatsN += slots
	216	+	case reflect.String:
	217	+	slots = 1
	218	+	var ptr uintptr
	219	+	if intsN+slots > numOfIntegerRegisters() {
	220	+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
	221	+	ptr = uintptr(callbackArgFromStack(a.args, stackSlot, &stackByteOffset, reflect.TypeOf(uintptr(0))).Uint())
	222	+	} else if stackFrame != nil {
	223	+	if runtime.GOARCH == "s390x" {
	224	+	ptr = uintptr(callbackArgFromSlotBigEndian(unsafe.Pointer(&stackFrame[stackSlot]), reflect.TypeOf(uintptr(0))).Uint())
	225	+	} else {
	226	+	ptr = (uintptr)(unsafe.Pointer(&stackFrame[stackSlot]))
	227	+	}
	228	+	stackSlot += slots
	229	+	} else {
	230	+	ptr = frame[stackSlot]
	231	+	stackSlot += slots
	232	+	}
	233	+	} else {
	234	+	pos := intsN + numOfFloatRegisters()
	235	+	ptr = frame[pos]
	236	+	}
	237	+	intsN += slots
	238	+	args[i] = reflect.ValueOf(strings.GoString(ptr))
	239	+	continue
214	240		case reflect.Struct:
215	241		if i == 0 && inType.AssignableTo(reflect.TypeOf(CDecl{})) {
216	242		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 syscall15XABI0 uintptr	18		var syscall15XABI0 uintptr

@@ -82,7 +84,7 @@ func compileCallback(fn any) uintptr {
82		continue	84		continue
83		case reflect.Interface, reflect.Func, reflect.Slice,	85		case reflect.Interface, reflect.Func, reflect.Slice,
84		reflect.Chan, reflect.Complex64, reflect.Complex128,	86		reflect.Chan, reflect.Complex64, reflect.Complex128,
85	-	reflect.String, reflect.Map, reflect.Invalid:	87	+	reflect.Map, reflect.Invalid:
86		panic("purego: unsupported argument type: " + in.Kind().String())	88		panic("purego: unsupported argument type: " + in.Kind().String())
87		}	89		}
88		}	90		}

@@ -211,6 +213,30 @@ func callbackWrap(a *callbackArgs) {
211		}	213		}
212		}	214		}
213		floatsN += slots	215		floatsN += slots
			216	+	case reflect.String:
			217	+	slots = 1
			218	+	var ptr uintptr
			219	+	if intsN+slots > numOfIntegerRegisters() {
			220	+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
			221	+	ptr = uintptr(callbackArgFromStack(a.args, stackSlot, &stackByteOffset, reflect.TypeOf(uintptr(0))).Uint())
			222	+	} else if stackFrame != nil {
			223	+	if runtime.GOARCH == "s390x" {
			224	+	ptr = uintptr(callbackArgFromSlotBigEndian(unsafe.Pointer(&stackFrame[stackSlot]), reflect.TypeOf(uintptr(0))).Uint())
			225	+	} else {
			226	+	ptr = (uintptr)(unsafe.Pointer(&stackFrame[stackSlot]))
			227	+	}
			228	+	stackSlot += slots
			229	+	} else {
			230	+	ptr = frame[stackSlot]
			231	+	stackSlot += slots
			232	+	}
			233	+	} else {
			234	+	pos := intsN + numOfFloatRegisters()
			235	+	ptr = frame[pos]
			236	+	}
			237	+	intsN += slots
			238	+	args[i] = reflect.ValueOf(strings.GoString(ptr))
			239	+	continue
214		case reflect.Struct:	240		case reflect.Struct:
215		if i == 0 && inType.AssignableTo(reflect.TypeOf(CDecl{})) {	241		if i == 0 && inType.AssignableTo(reflect.TypeOf(CDecl{})) {
216		args[i] = reflect.Zero(inType)	242		args[i] = reflect.Zero(inType)