x/ffi: wrap c/ffi

x/ffi/ffi.go

@@ -0,0 +1,93 @@
+package ffi
+
+import (
+	"fmt"
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/ffi"
+)
+
+type Type = ffi.Type
+
+type Signature = ffi.Cif
+
+type Error int
+
+func (s Error) Error() string {
+	switch s {
+	case ffi.OK:
+		return "ok"
+	case ffi.BAD_TYPEDEF:
+		return "bad type def"
+	case ffi.BAD_ABI:
+		return "bad ABI"
+	case ffi.BAD_ARGTYPE:
+		return "bad argument type"
+	}
+	return fmt.Sprintf("invalid status: %v", int(s))
+}
+
+func NewSignature(ret *Type, args ...*Type) (*Signature, error) {
+	var cif Signature
+	var atype **Type
+	if len(args) > 0 {
+		atype = &args[0]
+	}
+	status := ffi.PrepCif(&cif, ffi.DefaultAbi, c.Uint(len(args)), ret, atype)
+	if status == 0 {
+		return &cif, nil
+	}
+	return nil, Error(status)
+}
+
+func NewSignatureVar(ret *Type, fixed int, args ...*Type) (*Signature, error) {
+	var cif Signature
+	var atype **Type
+	if len(args) > 0 {
+		atype = &args[0]
+	}
+	status := ffi.PrepCifVar(&cif, ffi.DefaultAbi, c.Uint(fixed), c.Uint(len(args)), ret, atype)
+	if status == ffi.OK {
+		return &cif, nil
+	}
+	return nil, Error(status)
+}
+
+func Call(cif *Signature, fn unsafe.Pointer, ret unsafe.Pointer, args ...unsafe.Pointer) {
+	var avalues *unsafe.Pointer
+	if len(args) > 0 {
+		avalues = &args[0]
+	}
+	ffi.Call(cif, fn, ret, avalues)
+}
+
+type Closure struct {
+	ptr unsafe.Pointer
+	Fn  unsafe.Pointer
+}
+
+func NewClosure() *Closure {
+	c := &Closure{}
+	c.ptr = ffi.ClosureAlloc(&c.Fn)
+	return c
+}
+
+func (c *Closure) Free() {
+	if c != nil && c.ptr != nil {
+		ffi.ClosureFree(c.ptr)
+		c.ptr = nil
+	}
+}
+
+func (c *Closure) Bind(cif *Signature, fn ffi.ClosureFunc, userdata unsafe.Pointer) error {
+	status := ffi.PreClosureLoc(c.ptr, cif, fn, userdata, c.Fn)
+	if status == ffi.OK {
+		return nil
+	}
+	return Error(status)
+}
+
+func Index(args *unsafe.Pointer, i uintptr) unsafe.Pointer {
+	return ffi.Index(args, i)
+}