| // Copyright 2014 The Go 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" |
| "go/types" |
| "strings" |
| ) |
| |
| type goGen struct { |
| *printer |
| fset *token.FileSet |
| pkg *types.Package |
| err ErrorList |
| } |
| |
| func (g *goGen) errorf(format string, args ...interface{}) { |
| g.err = append(g.err, fmt.Errorf(format, args...)) |
| } |
| |
| const goPreamble = `// Package go_%s is an autogenerated binder stub for package %s. |
| // gobind -lang=go %s |
| // |
| // File is generated by gobind. Do not edit. |
| package go_%s |
| |
| import ( |
| "golang.org/x/mobile/bind/seq" |
| %q |
| ) |
| |
| ` |
| |
| func (g *goGen) genPreamble() { |
| n := g.pkg.Name() |
| g.Printf(goPreamble, n, n, g.pkg.Path(), n, g.pkg.Path()) |
| } |
| |
| func (g *goGen) genFuncBody(o *types.Func, selectorLHS string) { |
| sig := o.Type().(*types.Signature) |
| params := sig.Params() |
| for i := 0; i < params.Len(); i++ { |
| p := params.At(i) |
| g.genRead("param_"+paramName(params, i), "in", p.Type()) |
| } |
| |
| res := sig.Results() |
| if res.Len() > 2 || res.Len() == 2 && !isErrorType(res.At(1).Type()) { |
| g.errorf("functions and methods must return either zero or one values, and optionally an error") |
| return |
| } |
| returnsValue := false |
| returnsError := false |
| if res.Len() == 1 { |
| if isErrorType(res.At(0).Type()) { |
| returnsError = true |
| g.Printf("err := ") |
| } else { |
| returnsValue = true |
| g.Printf("res := ") |
| } |
| } else if res.Len() == 2 { |
| returnsValue = true |
| returnsError = true |
| g.Printf("res, err := ") |
| } |
| |
| g.Printf("%s.%s(", selectorLHS, o.Name()) |
| for i := 0; i < params.Len(); i++ { |
| if i > 0 { |
| g.Printf(", ") |
| } |
| g.Printf("param_%s", paramName(params, i)) |
| } |
| g.Printf(")\n") |
| |
| if returnsValue { |
| g.genWrite("res", "out", res.At(0).Type()) |
| } |
| if returnsError { |
| g.genWrite("err", "out", res.At(res.Len()-1).Type()) |
| } |
| } |
| |
| func (g *goGen) genWrite(valName, seqName string, T types.Type) { |
| if isErrorType(T) { |
| g.Printf("if %s == nil {\n", valName) |
| g.Printf(" %s.WriteString(\"\");\n", seqName) |
| g.Printf("} else {\n") |
| g.Printf(" %s.WriteString(%s.Error());\n", seqName, valName) |
| g.Printf("}\n") |
| return |
| } |
| switch T := T.(type) { |
| case *types.Pointer: |
| // TODO(crawshaw): test *int |
| // TODO(crawshaw): test **Generator |
| switch T := T.Elem().(type) { |
| case *types.Named: |
| obj := T.Obj() |
| if obj.Pkg() != g.pkg { |
| g.errorf("type %s not defined in package %s", T, g.pkg) |
| return |
| } |
| g.Printf("%s.WriteGoRef(%s)\n", seqName, valName) |
| default: |
| g.errorf("unsupported type %s", T) |
| } |
| case *types.Named: |
| switch u := T.Underlying().(type) { |
| case *types.Interface, *types.Pointer: |
| g.Printf("%s.WriteGoRef(%s)\n", seqName, valName) |
| default: |
| g.errorf("unsupported, direct named type %s: %s", T, u) |
| } |
| default: |
| g.Printf("%s.Write%s(%s);\n", seqName, seqType(T), valName) |
| } |
| } |
| |
| func (g *goGen) genFunc(o *types.Func) { |
| g.Printf("func proxy_%s(out, in *seq.Buffer) {\n", o.Name()) |
| g.Indent() |
| g.genFuncBody(o, g.pkg.Name()) |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| |
| func (g *goGen) genStruct(obj *types.TypeName, T *types.Struct) { |
| fields := exportedFields(T) |
| methods := exportedMethodSet(types.NewPointer(obj.Type())) |
| |
| g.Printf("const (\n") |
| g.Indent() |
| g.Printf("proxy%s_Descriptor = \"go.%s.%s\"\n", obj.Name(), g.pkg.Name(), obj.Name()) |
| for i, f := range fields { |
| g.Printf("proxy%s_%s_Get_Code = 0x%x0f\n", obj.Name(), f.Name(), i) |
| g.Printf("proxy%s_%s_Set_Code = 0x%x1f\n", obj.Name(), f.Name(), i) |
| } |
| for i, m := range methods { |
| g.Printf("proxy%s_%s_Code = 0x%x0c\n", obj.Name(), m.Name(), i) |
| } |
| g.Outdent() |
| g.Printf(")\n\n") |
| |
| g.Printf("type proxy%s seq.Ref\n\n", obj.Name()) |
| |
| for _, f := range fields { |
| g.Printf("func proxy%s_%s_Set(out, in *seq.Buffer) {\n", obj.Name(), f.Name()) |
| g.Indent() |
| g.Printf("ref := in.ReadRef()\n") |
| g.genRead("v", "in", f.Type()) |
| g.Printf("ref.Get().(*%s.%s).%s = v\n", g.pkg.Name(), obj.Name(), f.Name()) |
| g.Outdent() |
| g.Printf("}\n\n") |
| |
| g.Printf("func proxy%s_%s_Get(out, in *seq.Buffer) {\n", obj.Name(), f.Name()) |
| g.Indent() |
| g.Printf("ref := in.ReadRef()\n") |
| g.Printf("v := ref.Get().(*%s.%s).%s\n", g.pkg.Name(), obj.Name(), f.Name()) |
| g.genWrite("v", "out", f.Type()) |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| |
| for _, m := range methods { |
| g.Printf("func proxy%s_%s(out, in *seq.Buffer) {\n", obj.Name(), m.Name()) |
| g.Indent() |
| g.Printf("ref := in.ReadRef()\n") |
| g.Printf("v := ref.Get().(*%s.%s)\n", g.pkg.Name(), obj.Name()) |
| g.genFuncBody(m, "v") |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| |
| g.Printf("func init() {\n") |
| g.Indent() |
| for _, f := range fields { |
| n := f.Name() |
| g.Printf("seq.Register(proxy%s_Descriptor, proxy%s_%s_Set_Code, proxy%s_%s_Set)\n", obj.Name(), obj.Name(), n, obj.Name(), n) |
| g.Printf("seq.Register(proxy%s_Descriptor, proxy%s_%s_Get_Code, proxy%s_%s_Get)\n", obj.Name(), obj.Name(), n, obj.Name(), n) |
| } |
| for _, m := range methods { |
| n := m.Name() |
| g.Printf("seq.Register(proxy%s_Descriptor, proxy%s_%s_Code, proxy%s_%s)\n", obj.Name(), obj.Name(), n, obj.Name(), n) |
| } |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| |
| func (g *goGen) genInterface(obj *types.TypeName) { |
| iface := obj.Type().(*types.Named).Underlying().(*types.Interface) |
| ifaceDesc := fmt.Sprintf("go.%s.%s", g.pkg.Name(), obj.Name()) |
| |
| summary := makeIfaceSummary(iface) |
| |
| // Descriptor and code for interface methods. |
| g.Printf("const (\n") |
| g.Indent() |
| g.Printf("proxy%s_Descriptor = %q\n", obj.Name(), ifaceDesc) |
| for i, m := range summary.callable { |
| g.Printf("proxy%s_%s_Code = 0x%x0a\n", obj.Name(), m.Name(), i+1) |
| } |
| g.Outdent() |
| g.Printf(")\n\n") |
| |
| // Define the entry points. |
| for _, m := range summary.callable { |
| g.Printf("func proxy%s_%s(out, in *seq.Buffer) {\n", obj.Name(), m.Name()) |
| g.Indent() |
| g.Printf("ref := in.ReadRef()\n") |
| g.Printf("v := ref.Get().(%s.%s)\n", g.pkg.Name(), obj.Name()) |
| g.genFuncBody(m, "v") |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| |
| // Register the method entry points. |
| if len(summary.callable) > 0 { |
| g.Printf("func init() {\n") |
| g.Indent() |
| for _, m := range summary.callable { |
| g.Printf("seq.Register(proxy%s_Descriptor, proxy%s_%s_Code, proxy%s_%s)\n", |
| obj.Name(), obj.Name(), m.Name(), obj.Name(), m.Name()) |
| } |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| |
| // Define a proxy interface. |
| if !summary.implementable { |
| // The interface defines an unexported method or a method that |
| // uses an unexported type. We cannot generate a proxy object |
| // for such a type. |
| return |
| } |
| g.Printf("type proxy%s seq.Ref\n\n", obj.Name()) |
| |
| for i := 0; i < iface.NumMethods(); i++ { |
| m := iface.Method(i) |
| sig := m.Type().(*types.Signature) |
| params := sig.Params() |
| res := sig.Results() |
| |
| if res.Len() > 2 || |
| (res.Len() == 2 && !isErrorType(res.At(1).Type())) { |
| g.errorf("functions and methods must return either zero or one value, and optionally an error: %s.%s", obj.Name(), m.Name()) |
| continue |
| } |
| |
| g.Printf("func (p *proxy%s) %s(", obj.Name(), m.Name()) |
| for i := 0; i < params.Len(); i++ { |
| if i > 0 { |
| g.Printf(", ") |
| } |
| g.Printf("%s %s", paramName(params, i), g.typeString(params.At(i).Type())) |
| } |
| g.Printf(") ") |
| |
| if res.Len() == 1 { |
| g.Printf(g.typeString(res.At(0).Type())) |
| } else if res.Len() == 2 { |
| g.Printf("(%s, error)", g.typeString(res.At(0).Type())) |
| } |
| g.Printf(" {\n") |
| g.Indent() |
| |
| g.Printf("in := new(seq.Buffer)\n") |
| for i := 0; i < params.Len(); i++ { |
| g.genWrite(paramName(params, i), "in", params.At(i).Type()) |
| } |
| |
| if res.Len() == 0 { |
| g.Printf("seq.Transact((*seq.Ref)(p), %q, proxy%s_%s_Code, in)\n", ifaceDesc, obj.Name(), m.Name()) |
| } else { |
| g.Printf("out := seq.Transact((*seq.Ref)(p), %q, proxy%s_%s_Code, in)\n", ifaceDesc, obj.Name(), m.Name()) |
| var rvs []string |
| for i := 0; i < res.Len(); i++ { |
| rv := fmt.Sprintf("res_%d", i) |
| g.genRead(rv, "out", res.At(i).Type()) |
| rvs = append(rvs, rv) |
| } |
| g.Printf("return %s\n", strings.Join(rvs, ",")) |
| } |
| |
| g.Outdent() |
| g.Printf("}\n\n") |
| } |
| } |
| |
| func (g *goGen) genRead(valName, seqName string, typ types.Type) { |
| if isErrorType(typ) { |
| g.Printf("%s := %s.ReadError()\n", valName, seqName) |
| return |
| } |
| switch t := typ.(type) { |
| case *types.Pointer: |
| switch u := t.Elem().(type) { |
| case *types.Named: |
| o := u.Obj() |
| if o.Pkg() != g.pkg { |
| g.errorf("type %s not defined in package %s", u, g.pkg) |
| return |
| } |
| g.Printf("// Must be a Go object\n") |
| g.Printf("%s_ref := %s.ReadRef()\n", valName, seqName) |
| g.Printf("%s := %s_ref.Get().(*%s.%s)\n", valName, valName, g.pkg.Name(), o.Name()) |
| default: |
| g.errorf("unsupported type %s", t) |
| } |
| case *types.Named: |
| switch t.Underlying().(type) { |
| case *types.Interface, *types.Pointer: |
| hasProxy := true |
| if iface, ok := t.Underlying().(*types.Interface); ok { |
| hasProxy = makeIfaceSummary(iface).implementable |
| } |
| o := t.Obj() |
| if o.Pkg() != g.pkg { |
| g.errorf("type %s not defined in package %s", t, g.pkg) |
| return |
| } |
| g.Printf("var %s %s\n", valName, g.typeString(t)) |
| g.Printf("%s_ref := %s.ReadRef()\n", valName, seqName) |
| g.Printf("if %s_ref.Num < 0 { // go object \n", valName) |
| g.Printf(" %s = %s_ref.Get().(%s.%s)\n", valName, valName, g.pkg.Name(), o.Name()) |
| if hasProxy { |
| g.Printf("} else { // foreign object \n") |
| g.Printf(" %s = (*proxy%s)(%s_ref)\n", valName, o.Name(), valName) |
| } |
| g.Printf("}\n") |
| } |
| default: |
| g.Printf("%s := %s.Read%s()\n", valName, seqName, seqType(t)) |
| } |
| } |
| |
| func (g *goGen) typeString(typ types.Type) string { |
| pkg := g.pkg |
| |
| switch t := typ.(type) { |
| case *types.Named: |
| obj := t.Obj() |
| if obj.Pkg() == nil { // e.g. error type is *types.Named. |
| return types.TypeString(typ, types.RelativeTo(pkg)) |
| } |
| if obj.Pkg() != g.pkg { |
| g.errorf("type %s not defined in package %s", t, g.pkg) |
| } |
| |
| switch t.Underlying().(type) { |
| case *types.Interface, *types.Struct: |
| return fmt.Sprintf("%s.%s", pkg.Name(), types.TypeString(typ, types.RelativeTo(pkg))) |
| default: |
| g.errorf("unsupported named type %s / %T", t, t) |
| } |
| case *types.Pointer: |
| switch t := t.Elem().(type) { |
| case *types.Named: |
| return fmt.Sprintf("*%s", g.typeString(t)) |
| default: |
| g.errorf("not yet supported, pointer type %s / %T", t, t) |
| } |
| default: |
| return types.TypeString(typ, types.RelativeTo(pkg)) |
| } |
| return "" |
| } |
| |
| func (g *goGen) gen() error { |
| g.genPreamble() |
| |
| var funcs []string |
| |
| scope := g.pkg.Scope() |
| names := scope.Names() |
| for _, name := range names { |
| obj := scope.Lookup(name) |
| if !obj.Exported() { |
| continue |
| } |
| |
| switch obj := obj.(type) { |
| // TODO(crawshaw): case *types.Var: |
| case *types.Func: |
| // TODO(crawshaw): functions that are not implementable from |
| // another language may still be callable. |
| if isCallable(obj) { |
| g.genFunc(obj) |
| funcs = append(funcs, obj.Name()) |
| } |
| case *types.TypeName: |
| named := obj.Type().(*types.Named) |
| switch T := named.Underlying().(type) { |
| case *types.Struct: |
| g.genStruct(obj, T) |
| case *types.Interface: |
| g.genInterface(obj) |
| } |
| case *types.Const: |
| default: |
| g.errorf("not yet supported, name for %v / %T", obj, obj) |
| continue |
| } |
| } |
| |
| if len(funcs) > 0 { |
| g.Printf("func init() {\n") |
| g.Indent() |
| for i, name := range funcs { |
| g.Printf("seq.Register(%q, %d, proxy_%s)\n", g.pkg.Name(), i+1, name) |
| } |
| g.Outdent() |
| g.Printf("}\n") |
| } |
| |
| if len(g.err) > 0 { |
| return g.err |
| } |
| return nil |
| } |
