// testMainSlice emits to fn code to construct a slice of type slice
// (one of []testing.Internal{Test,Benchmark,Example}) for all
// functions in testfuncs. It returns the slice value.
//
func testMainSlice(fn *Function, testfuncs []*Function, slice types.Type) Value {
if testfuncs == nil {
return nilConst(slice)
}
tElem := slice.(*types.Slice).Elem()
tPtrString := types.NewPointer(tString)
tPtrElem := types.NewPointer(tElem)
tPtrFunc := types.NewPointer(funcField(slice))
// TODO(adonovan): fix: populate the
// testing.InternalExample.Output field correctly so that tests
// work correctly under the interpreter. This requires that we
// do this step using ASTs, not *ssa.Functions---quite a
// redesign. See also the fake runExample in go/ssa/interp.
// Emit: array = new [n]testing.InternalTest
tArray := types.NewArray(tElem, int64(len(testfuncs)))
array := emitNew(fn, tArray, token.NoPos)
array.Comment = "test main"
for i, testfunc := range testfuncs {
// Emit: pitem = &array[i]
ia := &IndexAddr{X: array, Index: intConst(int64(i))}
ia.setType(tPtrElem)
pitem := fn.emit(ia)
// Emit: pname = &pitem.Name
fa := &FieldAddr{X: pitem, Field: 0} // .Name
fa.setType(tPtrString)
pname := fn.emit(fa)
// Emit: *pname = "testfunc"
emitStore(fn, pname, stringConst(testfunc.Name()), token.NoPos)
// Emit: pfunc = &pitem.F
fa = &FieldAddr{X: pitem, Field: 1} // .F
fa.setType(tPtrFunc)
pfunc := fn.emit(fa)
// Emit: *pfunc = testfunc
emitStore(fn, pfunc, testfunc, token.NoPos)
}
// Emit: slice array[:]
sl := &Slice{X: array}
sl.setType(slice)
return fn.emit(sl)
}
// IntuitiveMethodSet returns the intuitive method set of a type T,
// which is the set of methods you can call on an addressable value of
// that type.
//
// The result always contains MethodSet(T), and is exactly MethodSet(T)
// for interface types and for pointer-to-concrete types.
// For all other concrete types T, the result additionally
// contains each method belonging to *T if there is no identically
// named method on T itself.
//
// This corresponds to user intuition about method sets;
// this function is intended only for user interfaces.
//
// The order of the result is as for types.MethodSet(T).
//
func IntuitiveMethodSet(T types.Type, msets *MethodSetCache) []*types.Selection {
isPointerToConcrete := func(T types.Type) bool {
ptr, ok := T.(*types.Pointer)
return ok && !types.IsInterface(ptr.Elem())
}
var result []*types.Selection
mset := msets.MethodSet(T)
if types.IsInterface(T) || isPointerToConcrete(T) {
for i, n := 0, mset.Len(); i < n; i++ {
result = append(result, mset.At(i))
}
} else {
// T is some other concrete type.
// Report methods of T and *T, preferring those of T.
pmset := msets.MethodSet(types.NewPointer(T))
for i, n := 0, pmset.Len(); i < n; i++ {
meth := pmset.At(i)
if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil {
meth = m
}
result = append(result, meth)
}
}
return result
}
func (c *funcContext) makeReceiver(x ast.Expr, sel *types.Selection) *expression {
if !sel.Obj().Exported() {
c.p.dependencies[sel.Obj()] = true
}
recvType := sel.Recv()
for _, index := range sel.Index()[:len(sel.Index())-1] {
if ptr, isPtr := recvType.(*types.Pointer); isPtr {
recvType = ptr.Elem()
}
s := recvType.Underlying().(*types.Struct)
recvType = s.Field(index).Type()
x = c.newIdent(c.formatExpr("%e.%s", x, fieldName(s, index)).String(), recvType)
}
_, isPointer := recvType.Underlying().(*types.Pointer)
methodsRecvType := sel.Obj().Type().(*types.Signature).Recv().Type()
_, pointerExpected := methodsRecvType.(*types.Pointer)
if !isPointer && pointerExpected {
recvType = types.NewPointer(recvType)
x = c.setType(&ast.UnaryExpr{Op: token.AND, X: x}, recvType)
}
recv := c.translateExpr(x)
if isWrapped(recvType) {
recv = c.formatExpr("new %s(%s)", c.typeName(methodsRecvType), recv)
}
return recv
}
func (g *objcGen) genStructH(obj *types.TypeName, t *types.Struct) {
g.Printf("@interface %s%s : NSObject {\n", g.namePrefix, obj.Name())
g.Printf("}\n")
g.Printf("@property(strong, readonly) id _ref;\n")
g.Printf("\n")
g.Printf("- (id)initWithRef:(id)ref;\n")
// accessors to exported fields.
for _, f := range exportedFields(t) {
if t := f.Type(); !g.isSupported(t) {
g.Printf("// skipped field %s.%s with unsupported type: %T\n\n", obj.Name(), f.Name(), t)
continue
}
name, typ := f.Name(), g.objcFieldType(f.Type())
g.Printf("- (%s)%s;\n", typ, lowerFirst(name))
g.Printf("- (void)set%s:(%s)v;\n", name, typ)
}
// exported methods
for _, m := range exportedMethodSet(types.NewPointer(obj.Type())) {
if !g.isSigSupported(m.Type()) {
g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
continue
}
s := g.funcSummary(m)
g.Printf("- %s;\n", lowerFirst(s.asMethod(g)))
}
g.Printf("@end\n")
}
// emitImplicitSelections emits to f code to apply the sequence of
// implicit field selections specified by indices to base value v, and
// returns the selected value.
//
// If v is the address of a struct, the result will be the address of
// a field; if it is the value of a struct, the result will be the
// value of a field.
//
func emitImplicitSelections(f *Function, v Value, indices []int) Value {
for _, index := range indices {
fld := deref(v.Type()).Underlying().(*types.Struct).Field(index)
if isPointer(v.Type()) {
instr := &FieldAddr{
X: v,
Field: index,
}
instr.setType(types.NewPointer(fld.Type()))
v = f.emit(instr)
// Load the field's value iff indirectly embedded.
if isPointer(fld.Type()) {
v = emitLoad(f, v)
}
} else {
instr := &Field{
X: v,
Field: index,
}
instr.setType(fld.Type())
v = f.emit(instr)
}
}
return v
}
// emitFieldSelection emits to f code to select the index'th field of v.
//
// If wantAddr, the input must be a pointer-to-struct and the result
// will be the field's address; otherwise the result will be the
// field's value.
// Ident id is used for position and debug info.
//
func emitFieldSelection(f *Function, v Value, index int, wantAddr bool, id *ast.Ident) Value {
fld := deref(v.Type()).Underlying().(*types.Struct).Field(index)
if isPointer(v.Type()) {
instr := &FieldAddr{
X: v,
Field: index,
}
instr.setPos(id.Pos())
instr.setType(types.NewPointer(fld.Type()))
v = f.emit(instr)
// Load the field's value iff we don't want its address.
if !wantAddr {
v = emitLoad(f, v)
}
} else {
instr := &Field{
X: v,
Field: index,
}
instr.setPos(id.Pos())
instr.setType(fld.Type())
v = f.emit(instr)
}
emitDebugRef(f, id, v, wantAddr)
return v
}
// lockPath returns a typePath describing the location of a lock value
// contained in typ. If there is no contained lock, it returns nil.
func lockPath(tpkg *types.Package, typ types.Type) typePath {
if typ == nil {
return nil
}
// We're only interested in the case in which the underlying
// type is a struct. (Interfaces and pointers are safe to copy.)
styp, ok := typ.Underlying().(*types.Struct)
if !ok {
return nil
}
// We're looking for cases in which a reference to this type
// can be locked, but a value cannot. This differentiates
// embedded interfaces from embedded values.
if plock := types.NewMethodSet(types.NewPointer(typ)).Lookup(tpkg, "Lock"); plock != nil {
if lock := types.NewMethodSet(typ).Lookup(tpkg, "Lock"); lock == nil {
return []types.Type{typ}
}
}
nfields := styp.NumFields()
for i := 0; i < nfields; i++ {
ftyp := styp.Field(i).Type()
subpath := lockPath(tpkg, ftyp)
if subpath != nil {
return append(subpath, typ)
}
}
return nil
}
// emitNew emits to f a new (heap Alloc) instruction allocating an
// object of type typ. pos is the optional source location.
//
func emitNew(f *Function, typ types.Type, pos token.Pos) *Alloc {
v := &Alloc{Heap: true}
v.setType(types.NewPointer(typ))
v.setPos(pos)
f.emit(v)
return v
}
// PointerType = "*" ("any" | Type) .
func (p *parser) parsePointerType(pkg *types.Package) types.Type {
p.expect('*')
if p.tok == scanner.Ident {
p.expectKeyword("any")
return types.Typ[types.UnsafePointer]
}
return types.NewPointer(p.parseType(pkg))
}
// addLocal creates an anonymous local variable of type typ, adds it
// to function f and returns it. pos is the optional source location.
//
func (f *Function) addLocal(typ types.Type, pos token.Pos) *Alloc {
v := &Alloc{}
v.setType(types.NewPointer(typ))
v.setPos(pos)
f.Locals = append(f.Locals, v)
f.emit(v)
return v
}
func getMethods(pkg *types.Package, typename string) map[string]*types.Func {
r := make(map[string]*types.Func)
mset := types.NewMethodSet(types.NewPointer(pkg.Scope().Lookup(typename).Type()))
for i := 0; i < mset.Len(); i++ {
fn := mset.At(i).Obj().(*types.Func)
r[fn.Name()] = fn
}
return r
}
// memberFromObject populates package pkg with a member for the
// typechecker object obj.
//
// For objects from Go source code, syntax is the associated syntax
// tree (for funcs and vars only); it will be used during the build
// phase.
//
func memberFromObject(pkg *Package, obj types.Object, syntax ast.Node) {
name := obj.Name()
switch obj := obj.(type) {
case *types.TypeName:
pkg.Members[name] = &Type{
object: obj,
pkg: pkg,
}
case *types.Const:
c := &NamedConst{
object: obj,
Value: NewConst(obj.Val(), obj.Type()),
pkg: pkg,
}
pkg.values[obj] = c.Value
pkg.Members[name] = c
case *types.Var:
g := &Global{
Pkg: pkg,
name: name,
object: obj,
typ: types.NewPointer(obj.Type()), // address
pos: obj.Pos(),
}
pkg.values[obj] = g
pkg.Members[name] = g
case *types.Func:
sig := obj.Type().(*types.Signature)
if sig.Recv() == nil && name == "init" {
pkg.ninit++
name = fmt.Sprintf("init#%d", pkg.ninit)
}
fn := &Function{
name: name,
object: obj,
Signature: sig,
syntax: syntax,
pos: obj.Pos(),
Pkg: pkg,
Prog: pkg.Prog,
}
if syntax == nil {
fn.Synthetic = "loaded from gc object file"
}
pkg.values[obj] = fn
if sig.Recv() == nil {
pkg.Members[name] = fn // package-level function
}
default: // (incl. *types.Package)
panic("unexpected Object type: " + obj.String())
}
}
// addSpilledParam declares a parameter that is pre-spilled to the
// stack; the function body will load/store the spilled location.
// Subsequent lifting will eliminate spills where possible.
//
func (f *Function) addSpilledParam(obj types.Object) {
param := f.addParamObj(obj)
spill := &Alloc{Comment: obj.Name()}
spill.setType(types.NewPointer(obj.Type()))
spill.setPos(obj.Pos())
f.objects[obj] = spill
f.Locals = append(f.Locals, spill)
f.emit(spill)
f.emit(&Store{Addr: spill, Val: param})
}
func (g *ObjcGen) genStructM(obj *types.TypeName, t *types.Struct) {
fields := exportedFields(t)
methods := exportedMethodSet(types.NewPointer(obj.Type()))
g.Printf("\n")
oinf := g.ostructs[obj]
g.Printf("@implementation %s%s {\n", g.namePrefix, obj.Name())
g.Printf("}\n\n")
g.Printf("- (id)initWithRef:(id)ref {\n")
g.Indent()
g.Printf("self = [super init];\n")
g.Printf("if (self) { __ref = ref; }\n")
g.Printf("return self;\n")
g.Outdent()
g.Printf("}\n\n")
if oinf != nil {
g.Printf("- (id)init {\n")
g.Indent()
g.Printf("self = [super init];\n")
g.Printf("if (self) {\n")
g.Indent()
g.Printf("__ref = go_seq_from_refnum(new_%s_%s());\n", g.pkgPrefix, obj.Name())
g.Outdent()
g.Printf("}\n")
g.Printf("return self;\n")
g.Outdent()
g.Printf("}\n\n")
}
for _, f := range fields {
if !g.isSupported(f.Type()) {
g.Printf("// skipped unsupported field %s with type %T\n\n", f.Name(), f)
continue
}
g.genGetter(obj.Name(), f)
g.genSetter(obj.Name(), f)
}
for _, m := range methods {
if !g.isSigSupported(m.Type()) {
g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
continue
}
s := g.funcSummary(g.ostructs[obj], m)
g.Printf("- %s {\n", s.asMethod(g))
g.Indent()
g.genFunc(s, obj.Name())
g.Outdent()
g.Printf("}\n\n")
}
g.Printf("@end\n\n")
}
func main() {
// Parse one file.
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, "input.go", input, 0)
if err != nil {
log.Fatal(err) // parse error
}
conf := types.Config{Importer: importer.Default()}
pkg, err := conf.Check("hello", fset, []*ast.File{f}, nil)
if err != nil {
log.Fatal(err) // type error
}
//!+implements
// Find all named types at package level.
var allNamed []*types.Named
for _, name := range pkg.Scope().Names() {
if obj, ok := pkg.Scope().Lookup(name).(*types.TypeName); ok {
allNamed = append(allNamed, obj.Type().(*types.Named))
}
}
// Test assignability of all distinct pairs of
// named types (T, U) where U is an interface.
for _, T := range allNamed {
for _, U := range allNamed {
if T == U || !types.IsInterface(U) {
continue
}
if types.AssignableTo(T, U) {
fmt.Printf("%s satisfies %s\n", T, U)
} else if !types.IsInterface(T) &&
types.AssignableTo(types.NewPointer(T), U) {
fmt.Printf("%s satisfies %s\n", types.NewPointer(T), U)
}
}
}
//!-implements
}
func (cache *MethodSetCache) lookupNamed(named *types.Named) struct{ value, pointer *types.MethodSet } {
if cache.named == nil {
cache.named = make(map[*types.Named]struct{ value, pointer *types.MethodSet })
}
// Avoid recomputing mset(*T) for each distinct Pointer
// instance whose underlying type is a named type.
msets, ok := cache.named[named]
if !ok {
msets.value = types.NewMethodSet(named)
msets.pointer = types.NewMethodSet(types.NewPointer(named))
cache.named[named] = msets
}
return msets
}
func (g *goGen) genStruct(obj *types.TypeName, T *types.Struct) {
fields := exportedFields(T)
methods := exportedMethodSet(types.NewPointer(obj.Type()))
for _, f := range fields {
if t := f.Type(); !g.isSupported(t) {
g.Printf("// skipped field %s.%s with unsupported type: %T\n\n", obj.Name(), f.Name(), t)
continue
}
g.Printf("//export proxy%s_%s_%s_Set\n", g.pkgPrefix, obj.Name(), f.Name())
g.Printf("func proxy%s_%s_%s_Set(refnum C.int32_t, v C.%s) {\n", g.pkgPrefix, obj.Name(), f.Name(), g.cgoType(f.Type()))
g.Indent()
g.Printf("ref := _seq.FromRefNum(int32(refnum))\n")
g.genRead("_v", "v", f.Type(), modeRetained)
g.Printf("ref.Get().(*%s%s).%s = _v\n", g.pkgName(g.Pkg), obj.Name(), f.Name())
g.Outdent()
g.Printf("}\n\n")
g.Printf("//export proxy%s_%s_%s_Get\n", g.pkgPrefix, obj.Name(), f.Name())
g.Printf("func proxy%s_%s_%s_Get(refnum C.int32_t) C.%s {\n", g.pkgPrefix, obj.Name(), f.Name(), g.cgoType(f.Type()))
g.Indent()
g.Printf("ref := _seq.FromRefNum(int32(refnum))\n")
g.Printf("v := ref.Get().(*%s%s).%s\n", g.pkgName(g.Pkg), obj.Name(), f.Name())
g.genWrite("_v", "v", f.Type(), modeRetained)
g.Printf("return _v\n")
g.Outdent()
g.Printf("}\n\n")
}
for _, m := range methods {
if !g.isSigSupported(m.Type()) {
g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
continue
}
g.genFuncSignature(m, obj.Name())
g.Indent()
g.Printf("ref := _seq.FromRefNum(int32(refnum))\n")
g.Printf("v := ref.Get().(*%s%s)\n", g.pkgName(g.Pkg), obj.Name())
g.genFuncBody(m, "v.")
g.Outdent()
g.Printf("}\n\n")
}
// Export constructor for ObjC and Java default no-arg constructors
g.Printf("//export new_%s_%s\n", g.Pkg.Name(), obj.Name())
g.Printf("func new_%s_%s() C.int32_t {\n", g.Pkg.Name(), obj.Name())
g.Indent()
g.Printf("return C.int32_t(_seq.ToRefNum(new(%s%s)))\n", g.pkgName(g.Pkg), obj.Name())
g.Outdent()
g.Printf("}\n")
}
func (g *ObjcGen) genStructH(obj *types.TypeName, t *types.Struct) {
g.Printf("@interface %s%s : ", g.namePrefix, obj.Name())
oinf := g.ostructs[obj]
if oinf != nil {
var prots []string
for _, sup := range oinf.supers {
if !sup.Protocol {
g.Printf(sup.Name)
} else {
prots = append(prots, sup.Name)
}
}
if len(prots) > 0 {
g.Printf(" <%s>", strings.Join(prots, ", "))
}
} else {
g.Printf("NSObject <goSeqRefInterface>")
}
g.Printf(" {\n")
g.Printf("}\n")
g.Printf("@property(strong, readonly) id _ref;\n")
g.Printf("\n")
g.Printf("- (id)initWithRef:(id)ref;\n")
if oinf != nil {
g.Printf("- (id)init;\n")
}
// accessors to exported fields.
for _, f := range exportedFields(t) {
if t := f.Type(); !g.isSupported(t) {
g.Printf("// skipped field %s.%s with unsupported type: %T\n\n", obj.Name(), f.Name(), t)
continue
}
name, typ := f.Name(), g.objcFieldType(f.Type())
g.Printf("- (%s)%s;\n", typ, objcNameReplacer(lowerFirst(name)))
g.Printf("- (void)set%s:(%s)v;\n", name, typ)
}
// exported methods
for _, m := range exportedMethodSet(types.NewPointer(obj.Type())) {
if !g.isSigSupported(m.Type()) {
g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
continue
}
s := g.funcSummary(g.ostructs[obj], m)
g.Printf("- %s;\n", objcNameReplacer(lowerFirst(s.asMethod(g))))
}
g.Printf("@end\n")
}
// Type =
// BasicType | TypeName | ArrayType | SliceType | StructType |
// PointerType | FuncType | InterfaceType | MapType | ChanType |
// "(" Type ")" .
//
// BasicType = ident .
// TypeName = ExportedName .
// SliceType = "[" "]" Type .
// PointerType = "*" Type .
// FuncType = "func" Signature .
//
func (p *parser) parseType(parent *types.Package) types.Type {
switch p.tok {
case scanner.Ident:
switch p.lit {
default:
return p.parseBasicType()
case "struct":
return p.parseStructType(parent)
case "func":
// FuncType
p.next()
return p.parseSignature(nil)
case "interface":
return p.parseInterfaceType(parent)
case "map":
return p.parseMapType(parent)
case "chan":
return p.parseChanType(parent)
}
case '@':
// TypeName
pkg, name := p.parseExportedName()
return declTypeName(pkg, name).Type()
case '[':
p.next() // look ahead
if p.tok == ']' {
// SliceType
p.next()
return types.NewSlice(p.parseType(parent))
}
return p.parseArrayType(parent)
case '*':
// PointerType
p.next()
return types.NewPointer(p.parseType(parent))
case '<':
return p.parseChanType(parent)
case '(':
// "(" Type ")"
p.next()
typ := p.parseType(parent)
p.expect(')')
return typ
}
p.errorf("expected type, got %s (%q)", scanner.TokenString(p.tok), p.lit)
return nil
}
func (g *objcGen) genRead(toName, fromName string, t types.Type, mode varMode) {
if isErrorType(t) {
g.genRead(toName, fromName, types.Typ[types.String], mode)
return
}
switch t := t.(type) {
case *types.Basic:
switch t.Kind() {
case types.String:
g.Printf("NSString *%s = go_seq_to_objc_string(%s);\n", toName, fromName)
case types.Bool:
g.Printf("BOOL %s = %s ? YES : NO;\n", toName, fromName)
default:
g.Printf("%s %s = (%s)%s;\n", g.objcType(t), toName, g.objcType(t), fromName)
}
case *types.Slice:
switch e := t.Elem().(type) {
case *types.Basic:
switch e.Kind() {
case types.Uint8: // Byte.
g.Printf("NSData *%s = go_seq_to_objc_bytearray(%s, %d);\n", toName, fromName, g.toCFlag(mode == modeRetained))
default:
g.errorf("unsupported type: %s", t)
}
default:
g.errorf("unsupported type: %s", t)
}
case *types.Pointer:
switch t := t.Elem().(type) {
case *types.Named:
g.genRefRead(toName, fromName, types.NewPointer(t))
default:
g.errorf("unsupported type %s", t)
}
case *types.Named:
switch t.Underlying().(type) {
case *types.Interface, *types.Pointer:
g.genRefRead(toName, fromName, t)
default:
g.errorf("unsupported, direct named type %s", t)
}
default:
g.Printf("%s %s = (%s)%s;\n", g.objcType(t), toName, g.objcType(t), fromName)
}
}
// IntuitiveMethodSet returns the intuitive method set of a type, T.
//
// The result contains MethodSet(T) and additionally, if T is a
// concrete type, methods belonging to *T if there is no identically
// named method on T itself. This corresponds to user intuition about
// method sets; this function is intended only for user interfaces.
//
// The order of the result is as for types.MethodSet(T).
//
func IntuitiveMethodSet(T types.Type, msets *MethodSetCache) []*types.Selection {
var result []*types.Selection
mset := msets.MethodSet(T)
if _, ok := T.Underlying().(*types.Interface); ok {
for i, n := 0, mset.Len(); i < n; i++ {
result = append(result, mset.At(i))
}
} else {
pmset := msets.MethodSet(types.NewPointer(T))
for i, n := 0, pmset.Len(); i < n; i++ {
meth := pmset.At(i)
if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil {
meth = m
}
result = append(result, meth)
}
}
return result
}
func methodDocComment(prog *loader.Program, tname *types.TypeName, methodName string) (string, error) {
t := tname.Type()
if !types.IsInterface(t) {
// Use the pointer type to get as many methods as possible.
t = types.NewPointer(t)
}
mset := types.NewMethodSet(t)
sel := mset.Lookup(nil, methodName)
if sel == nil {
return "", errgo.Newf("cannot find method %v on %v", methodName, t)
}
obj := sel.Obj()
decl, err := findDecl(prog, obj.Pos())
if err != nil {
return "", errgo.Mask(err)
}
switch decl := decl.(type) {
case *ast.GenDecl:
if decl.Tok != token.TYPE {
return "", errgo.Newf("found non-type decl %#v", decl)
}
for _, spec := range decl.Specs {
tspec := spec.(*ast.TypeSpec)
it := tspec.Type.(*ast.InterfaceType)
for _, m := range it.Methods.List {
for _, id := range m.Names {
if id.Pos() == obj.Pos() {
return m.Doc.Text(), nil
}
}
}
}
return "", errgo.Newf("method definition not found in type")
case *ast.FuncDecl:
if decl.Name.Pos() != obj.Pos() {
return "", errgo.Newf("method definition not found (at %#v)", prog.Fset.Position(obj.Pos()))
}
return decl.Doc.Text(), nil
default:
return "", errgo.Newf("unexpected declaration %T found", decl)
}
}
// ExampleMethodSet prints the method sets of various types.
func ExampleMethodSet() {
// Parse a single source file.
const input = `
package temperature
import "fmt"
type Celsius float64
func (c Celsius) String() string { return fmt.Sprintf("%g°C", c) }
func (c *Celsius) SetF(f float64) { *c = Celsius(f - 32 / 9 * 5) }
`
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, "celsius.go", input, 0)
if err != nil {
log.Fatal(err)
}
// Type-check a package consisting of this file.
// Type information for the imported packages
// comes from $GOROOT/pkg/$GOOS_$GOOARCH/fmt.a.
conf := types.Config{Importer: importer.Default()}
pkg, err := conf.Check("temperature", fset, []*ast.File{f}, nil)
if err != nil {
log.Fatal(err)
}
// Print the method sets of Celsius and *Celsius.
celsius := pkg.Scope().Lookup("Celsius").Type()
for _, t := range []types.Type{celsius, types.NewPointer(celsius)} {
fmt.Printf("Method set of %s:\n", t)
mset := types.NewMethodSet(t)
for i := 0; i < mset.Len(); i++ {
fmt.Println(mset.At(i))
}
fmt.Println()
}
// Output:
// Method set of temperature.Celsius:
// method (temperature.Celsius) String() string
//
// Method set of *temperature.Celsius:
// method (*temperature.Celsius) SetF(f float64)
// method (*temperature.Celsius) String() string
}
// combinedMethodSet returns the method set for a named type T
// merged with all the methods of *T that have different names than
// the methods of T.
//
// combinedMethodSet is analogous to types/typeutil.IntuitiveMethodSet
// but doesn't require a MethodSetCache.
// TODO(gri) If this functionality doesn't change over time, consider
// just calling IntuitiveMethodSet eventually.
func combinedMethodSet(T *types.Named) []*types.Selection {
// method set for T
mset := types.NewMethodSet(T)
var res []*types.Selection
for i, n := 0, mset.Len(); i < n; i++ {
res = append(res, mset.At(i))
}
// add all *T methods with names different from T methods
pmset := types.NewMethodSet(types.NewPointer(T))
for i, n := 0, pmset.Len(); i < n; i++ {
pm := pmset.At(i)
if obj := pm.Obj(); mset.Lookup(obj.Pkg(), obj.Name()) == nil {
res = append(res, pm)
}
}
return res
}
func (c *funcContext) makeReceiver(e *ast.SelectorExpr) *expression {
sel, _ := c.p.SelectionOf(e)
if !sel.Obj().Exported() {
c.p.dependencies[sel.Obj()] = true
}
x := e.X
recvType := sel.Recv()
if len(sel.Index()) > 1 {
for _, index := range sel.Index()[:len(sel.Index())-1] {
if ptr, isPtr := recvType.(*types.Pointer); isPtr {
recvType = ptr.Elem()
}
s := recvType.Underlying().(*types.Struct)
recvType = s.Field(index).Type()
}
fakeSel := &ast.SelectorExpr{X: x, Sel: ast.NewIdent("o")}
c.p.additionalSelections[fakeSel] = &fakeSelection{
kind: types.FieldVal,
recv: sel.Recv(),
index: sel.Index()[:len(sel.Index())-1],
typ: recvType,
}
x = c.setType(fakeSel, recvType)
}
_, isPointer := recvType.Underlying().(*types.Pointer)
methodsRecvType := sel.Obj().Type().(*types.Signature).Recv().Type()
_, pointerExpected := methodsRecvType.(*types.Pointer)
if !isPointer && pointerExpected {
recvType = types.NewPointer(recvType)
x = c.setType(&ast.UnaryExpr{Op: token.AND, X: x}, recvType)
}
recv := c.translateExpr(x)
if isWrapped(recvType) {
recv = c.formatExpr("new %s(%s)", c.typeName(methodsRecvType), recv)
}
return recv
}
func (g *objcGen) genStructH(obj *types.TypeName, t *types.Struct) {
g.Printf("@interface %s%s : NSObject {\n", g.namePrefix, obj.Name())
g.Printf("}\n")
g.Printf("@property(strong, readonly) id _ref;\n")
g.Printf("\n")
g.Printf("- (id)initWithRef:(id)ref;\n")
// accessors to exported fields.
for _, f := range exportedFields(t) {
name, typ := f.Name(), g.objcFieldType(f.Type())
g.Printf("- (%s)%s;\n", typ, lowerFirst(name))
g.Printf("- (void)set%s:(%s)v;\n", name, typ)
}
// exported methods
for _, m := range exportedMethodSet(types.NewPointer(obj.Type())) {
s := g.funcSummary(m)
g.Printf("- %s;\n", lowerFirst(s.asMethod(g)))
}
g.Printf("@end\n")
}
func (g *objcGen) genStructM(obj *types.TypeName, t *types.Struct) {
fields := exportedFields(t)
methods := exportedMethodSet(types.NewPointer(obj.Type()))
desc := fmt.Sprintf("_GO_%s_%s", g.pkgName, obj.Name())
g.Printf("#define %s_DESCRIPTOR_ \"go.%s.%s\"\n", desc, g.pkgName, obj.Name())
for i, f := range fields {
g.Printf("#define %s_FIELD_%s_GET_ (0x%x0f)\n", desc, f.Name(), i)
g.Printf("#define %s_FIELD_%s_SET_ (0x%x1f)\n", desc, f.Name(), i)
}
for i, m := range methods {
g.Printf("#define %s_%s_ (0x%x0c)\n", desc, m.Name(), i)
}
g.Printf("\n")
g.Printf("@implementation %s%s {\n", g.namePrefix, obj.Name())
g.Printf("}\n\n")
g.Printf("- (id)initWithRef:(id)ref {\n")
g.Indent()
g.Printf("self = [super init];\n")
g.Printf("if (self) { __ref = ref; }\n")
g.Printf("return self;\n")
g.Outdent()
g.Printf("}\n\n")
for _, f := range fields {
g.genGetter(desc, f)
g.genSetter(desc, f)
}
for _, m := range methods {
s := g.funcSummary(m)
g.Printf("- %s {\n", s.asMethod(g))
g.Indent()
g.genFunc(desc+"_DESCRIPTOR_", desc+"_"+m.Name()+"_", s, true)
g.Outdent()
g.Printf("}\n\n")
}
g.Printf("@end\n")
}
// findNamedFunc returns the named function whose FuncDecl.Ident is at
// position pos.
//
func findNamedFunc(pkg *Package, pos token.Pos) *Function {
// Look at all package members and method sets of named types.
// Not very efficient.
for _, mem := range pkg.Members {
switch mem := mem.(type) {
case *Function:
if mem.Pos() == pos {
return mem
}
case *Type:
mset := pkg.Prog.MethodSets.MethodSet(types.NewPointer(mem.Type()))
for i, n := 0, mset.Len(); i < n; i++ {
// Don't call Program.Method: avoid creating wrappers.
obj := mset.At(i).Obj().(*types.Func)
if obj.Pos() == pos {
return pkg.values[obj].(*Function)
}
}
}
}
return nil
}
func checkVarValue(t *testing.T, prog *ssa.Program, pkg *ssa.Package, ref []ast.Node, obj *types.Var, expKind string, wantAddr bool) {
// The prefix of all assertions messages.
prefix := fmt.Sprintf("VarValue(%s @ L%d)",
obj, prog.Fset.Position(ref[0].Pos()).Line)
v, gotAddr := prog.VarValue(obj, pkg, ref)
// Kind is the concrete type of the ssa Value.
gotKind := "nil"
if v != nil {
gotKind = fmt.Sprintf("%T", v)[len("*ssa."):]
}
// fmt.Printf("%s = %v (kind %q; expect %q) wantAddr=%t gotAddr=%t\n", prefix, v, gotKind, expKind, wantAddr, gotAddr) // debugging
// Check the kinds match.
// "nil" indicates expected failure (e.g. optimized away).
if expKind != gotKind {
t.Errorf("%s concrete type == %s, want %s", prefix, gotKind, expKind)
}
// Check the types match.
// If wantAddr, the expected type is the object's address.
if v != nil {
expType := obj.Type()
if wantAddr {
expType = types.NewPointer(expType)
if !gotAddr {
t.Errorf("%s: got value, want address", prefix)
}
} else if gotAddr {
t.Errorf("%s: got address, want value", prefix)
}
if !types.Identical(v.Type(), expType) {
t.Errorf("%s.Type() == %s, want %s", prefix, v.Type(), expType)
}
}
}
func (w *Walker) emitType(obj *types.TypeName) {
name := obj.Name()
typ := obj.Type()
switch typ := typ.Underlying().(type) {
case *types.Struct:
w.emitStructType(name, typ)
case *types.Interface:
w.emitIfaceType(name, typ)
return // methods are handled by emitIfaceType
default:
w.emitf("type %s %s", name, w.typeString(typ.Underlying()))
}
// emit methods with value receiver
var methodNames map[string]bool
vset := types.NewMethodSet(typ)
for i, n := 0, vset.Len(); i < n; i++ {
m := vset.At(i)
if m.Obj().Exported() {
w.emitMethod(m)
if methodNames == nil {
methodNames = make(map[string]bool)
}
methodNames[m.Obj().Name()] = true
}
}
// emit methods with pointer receiver; exclude
// methods that we have emitted already
// (the method set of *T includes the methods of T)
pset := types.NewMethodSet(types.NewPointer(typ))
for i, n := 0, pset.Len(); i < n; i++ {
m := pset.At(i)
if m.Obj().Exported() && !methodNames[m.Obj().Name()] {
w.emitMethod(m)
}
}
}