gopy/bind/gengo.go

405 lines
7.6 KiB
Go

// Copyright 2015 The go-python Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bind
import (
"fmt"
"go/token"
"path/filepath"
"strings"
"golang.org/x/tools/go/types"
)
const (
goPreamble = `// Package main is an autogenerated binder stub for package %[1]s.
// gopy gen -lang=go %[1]s
//
// File is generated by gopy gen. Do not edit.
package main
//#cgo pkg-config: python2 --cflags --libs
//#include <stdlib.h>
//#include <string.h>
import "C"
import (
"unsafe"
%[2]q
)
var _ = unsafe.Pointer(nil)
// --- begin cgo helpers ---
//export CGoPy_GoString
func CGoPy_GoString(str *C.char) string {
return C.GoString(str)
}
//export CGoPy_CString
func CGoPy_CString(s string) *C.char {
return C.CString(s)
}
//export CGoPy_ErrorIsNil
func CGoPy_ErrorIsNil(err error) bool {
return err == nil
}
//export CGoPy_ErrorString
func CGoPy_ErrorString(err error) *C.char {
return C.CString(err.Error())
}
// --- end cgo helpers ---
`
)
type goGen struct {
*printer
fset *token.FileSet
pkg *Package
err ErrorList
}
func (g *goGen) gen() error {
g.genPreamble()
for _, s := range g.pkg.structs {
g.genStruct(s)
}
// expose ctors at module level
// FIXME(sbinet): attach them to structs?
// -> problem is if one has 2 or more ctors with exactly the same signature.
for _, s := range g.pkg.structs {
for _, ctor := range s.ctors {
g.genFunc(ctor)
}
}
for _, f := range g.pkg.funcs {
g.genFunc(f)
}
for _, c := range g.pkg.consts {
g.genConst(c)
}
g.Printf("// buildmode=c-shared needs a 'main'\nfunc main() {}\n\n")
g.Printf("func init() {\n")
g.Indent()
g.Printf("// make sure cgo is used and cgo hooks are run\n")
g.Printf("str := C.CString(%q)\n", g.pkg.Name())
g.Printf("C.free(unsafe.Pointer(str))\n")
g.Outdent()
g.Printf("}\n")
if len(g.err) > 0 {
return g.err
}
return nil
}
func (g *goGen) genFunc(f Func) {
sig := f.Signature()
params := "(" + g.tupleString(sig.Params()) + ")"
ret := g.tupleString(sig.Results())
if len(sig.Results()) > 1 {
ret = "(" + ret + ") "
} else {
ret += " "
}
//funcName := o.Name()
g.Printf(`
//export GoPy_%[1]s
// GoPy_%[1]s wraps %[2]s.%[3]s
func GoPy_%[1]s%[4]v%[5]v{
`,
f.ID(),
f.Package().Name(),
f.GoName(),
params,
ret,
)
g.Indent()
g.genFuncBody(f)
g.Outdent()
g.Printf("}\n\n")
}
func (g *goGen) genFuncBody(f Func) {
sig := f.Signature()
results := sig.Results()
for i := range results {
if i > 0 {
g.Printf(", ")
}
g.Printf("_gopy_%03d", i)
}
if len(results) > 0 {
g.Printf(" := ")
}
g.Printf("%s.%s(", g.pkg.Name(), f.GoName())
args := sig.Params()
for i, arg := range args {
tail := ""
if i+1 < len(args) {
tail = ", "
}
g.Printf("%s%s", arg.Name(), tail)
}
g.Printf(")\n")
if len(results) <= 0 {
return
}
g.Printf("return ")
for i, res := range results {
if i > 0 {
g.Printf(", ")
}
// if needWrap(res.GoType()) {
// g.Printf("")
// }
if res.needWrap() {
g.Printf("%s(unsafe.Pointer(&", res.dtype.cgotype)
}
g.Printf("_gopy_%03d /* %#v %v */", i, res, res.GoType().Underlying())
if res.needWrap() {
g.Printf("))")
}
}
g.Printf("\n")
}
func (g *goGen) genStruct(s Struct) {
//fmt.Printf("obj: %#v\ntyp: %#v\n", obj, typ)
typ := s.Struct()
pkgname := s.Package().Name()
g.Printf("//export GoPy_%[1]s\n", s.ID())
g.Printf("type GoPy_%[1]s unsafe.Pointer\n\n", s.ID())
for i := 0; i < typ.NumFields(); i++ {
f := typ.Field(i)
if !f.Exported() {
continue
}
ft := f.Type()
ftname := g.qualifiedType(ft)
if needWrapType(ft) {
ftname = fmt.Sprintf("GoPy_%[1]s_field_%d", s.ID(), i+1)
g.Printf("//export %s\n", ftname)
g.Printf("type %s unsafe.Pointer\n\n", ftname)
}
// -- getter --
g.Printf("//export GoPy_%[1]s_getter_%[2]d\n", s.ID(), i+1)
g.Printf("func GoPy_%[1]s_getter_%[2]d(self GoPy_%[1]s) %[3]s {\n",
s.ID(), i+1,
ftname,
)
g.Indent()
g.Printf(
"ret := (*%[1]s)(unsafe.Pointer(self))\n",
pkgname+"."+s.GoName(),
)
if needWrapType(ft) {
g.Printf("return %s(unsafe.Pointer(&ret.%s))\n", ftname, f.Name())
} else {
g.Printf("return ret.%s\n", f.Name())
}
g.Outdent()
g.Printf("}\n\n")
// -- setter --
g.Printf("//export GoPy_%[1]s_setter_%[2]d\n", s.ID(), i+1)
g.Printf("func GoPy_%[1]s_setter_%[2]d(self GoPy_%[1]s, v %[3]s) {\n",
s.ID(), i+1, ftname,
)
g.Indent()
fset := "v"
if needWrapType(ft) {
fset = fmt.Sprintf("*(*%s.%s)(unsafe.Pointer(v))",
f.Pkg().Name(),
types.TypeString(f.Type(), types.RelativeTo(f.Pkg())),
)
}
g.Printf(
"(*%[1]s)(unsafe.Pointer(self)).%[2]s = %[3]s\n",
pkgname+"."+s.GoName(),
f.Name(),
fset,
)
g.Outdent()
g.Printf("}\n\n")
}
for _, m := range s.meths {
g.genMethod(s, m)
}
g.Printf("//export GoPy_%[1]s_new\n", s.ID())
g.Printf("func GoPy_%[1]s_new() GoPy_%[1]s {\n", s.ID())
g.Indent()
g.Printf("return (GoPy_%[1]s)(unsafe.Pointer(&%[2]s.%[3]s{}))\n",
s.ID(),
pkgname,
s.GoName(),
)
g.Outdent()
g.Printf("}\n\n")
}
func (g *goGen) genMethod(s Struct, m Func) {
sig := m.Signature()
params := "(self GoPy_" + s.ID()
if len(sig.Params()) > 0 {
params += ", " + g.tupleString(sig.Params())
}
params += ")"
ret := g.tupleString(sig.Results())
if len(sig.Results()) > 1 {
ret = "(" + ret + ")"
} else {
ret += " "
}
g.Printf("//export GoPy_%[1]s\n", m.ID())
g.Printf("func GoPy_%[1]s%[2]s%[3]s{\n",
m.ID(),
params,
ret,
)
g.Indent()
g.genMethodBody(s, m)
g.Outdent()
g.Printf("}\n\n")
}
func (g *goGen) genMethodBody(s Struct, m Func) {
sig := m.Signature()
results := sig.Results()
for i := range results {
if i > 0 {
g.Printf(", ")
}
g.Printf("_gopy_%03d", i)
}
if len(results) > 0 {
g.Printf(" := ")
}
g.Printf("(*%s.%s)(unsafe.Pointer(self)).%s(",
g.pkg.Name(), s.GoName(),
m.GoName(),
)
args := sig.Params()
for i, arg := range args {
tail := ""
if i+1 < len(args) {
tail = ", "
}
g.Printf("%s%s", arg.Name(), tail)
}
g.Printf(")\n")
if len(results) <= 0 {
return
}
g.Printf("return ")
for i, res := range results {
if i > 0 {
g.Printf(", ")
}
// if needWrap(res.GoType()) {
// g.Printf("")
// }
if res.needWrap() {
g.Printf("%s(unsafe.Pointer(&", res.dtype.cgotype)
}
g.Printf("_gopy_%03d /* %#v %v */", i, res, res.GoType().Underlying())
if res.needWrap() {
g.Printf("))")
}
}
g.Printf("\n")
}
func (g *goGen) genConst(o Const) {
pkgname := o.obj.Pkg().Name()
tname := types.TypeString(o.obj.Type(), types.RelativeTo(o.obj.Pkg()))
if strings.HasPrefix(tname, "untyped ") {
tname = string(tname[len("untyped "):])
}
g.Printf("//export GoPy_get_%s\n", o.id)
g.Printf("func GoPy_get_%[1]s() %[2]s {\n", o.id, tname)
g.Indent()
g.Printf("return %s.%s\n", pkgname, o.obj.Name())
g.Outdent()
g.Printf("}\n\n")
}
func (g *goGen) genPreamble() {
n := g.pkg.pkg.Name()
g.Printf(goPreamble, n, g.pkg.pkg.Path(), filepath.Base(n))
}
func (g *goGen) tupleString(tuple []*Var) string {
n := len(tuple)
if n <= 0 {
return ""
}
str := make([]string, 0, n)
for _, v := range tuple {
n := v.Name()
typ := v.GoType()
str = append(str, n+" "+g.qualifiedType(typ))
}
return strings.Join(str, ", ")
}
func (g *goGen) qualifiedType(typ types.Type) string {
switch typ := typ.(type) {
case *types.Basic:
return typ.Name()
case *types.Named:
obj := typ.Obj()
switch typ.Underlying().(type) {
case *types.Struct:
return "GoPy_" + obj.Pkg().Name() + "_" + obj.Name()
case *types.Interface:
if obj.Name() == "error" {
return "error"
}
return "GoPy_" + obj.Name()
default:
return "GoPy_ooops_" + obj.Name()
}
}
return fmt.Sprintf("%#T", typ)
}