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")
}
// interfaceMethod returns a function and receiver pointer for the specified
// interface and method pair.
func (fr *frame) interfaceMethod(lliface llvm.Value, ifacety types.Type, method *types.Func) (fn, recv *govalue) {
llitab := fr.builder.CreateExtractValue(lliface, 0, "")
recv = newValue(fr.builder.CreateExtractValue(lliface, 1, ""), types.Typ[types.UnsafePointer])
methodset := fr.types.MethodSet(ifacety)
// TODO(axw) cache ordered method index
index := -1
for i, m := range orderedMethodSet(methodset) {
if m.Obj() == method {
index = i
break
}
}
if index == -1 {
panic("could not find method index")
}
llitab = fr.builder.CreateBitCast(llitab, llvm.PointerType(llvm.PointerType(llvm.Int8Type(), 0), 0), "")
// Skip runtime type pointer.
llifnptr := fr.builder.CreateGEP(llitab, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), uint64(index+1), false),
}, "")
llifn := fr.builder.CreateLoad(llifnptr, "")
// Replace receiver type with unsafe.Pointer.
recvparam := types.NewParam(0, nil, "", types.Typ[types.UnsafePointer])
sig := method.Type().(*types.Signature)
sig = types.NewSignature(nil, recvparam, sig.Params(), sig.Results(), sig.Variadic())
fn = newValue(llifn, sig)
return
}
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)
t := seqType(p.Type())
if t == "Ref" {
name := p.Type().(*types.Named).Obj().Name()
g.Printf("var param_%s %s.%s\n", p.Name(), g.pkg.Name(), name)
g.Printf("param_%s_ref := in.ReadRef()\n", p.Name())
g.Printf("if param_%s_ref.Num < 0 {\n", p.Name())
g.Printf(" param_%s = param_%s_ref.Get().(%s.%s)\n", p.Name(), p.Name(), g.pkg.Name(), name)
g.Printf("} else {\n")
g.Printf(" param_%s = (*proxy%s)(param_%s_ref)\n", p.Name(), name, p.Name())
g.Printf("}\n")
} else {
g.Printf("param_%s := in.Read%s()\n", p.Name(), t)
}
}
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", params.At(i).Name())
}
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 (p *printer) printFunc(recvType types.Type, obj *types.Func) {
p.print("func ")
sig := obj.Type().(*types.Signature)
if recvType != nil {
p.print("(")
p.writeType(p.pkg, recvType)
p.print(") ")
}
p.print(obj.Name())
p.writeSignature(p.pkg, sig)
}
func (g *javaGen) genFunc(o *types.Func, method bool) {
if err := g.funcSignature(o, !method); err != nil {
g.errorf("%v", err)
return
}
sig := o.Type().(*types.Signature)
res := sig.Results()
g.Printf(" {\n")
g.Indent()
g.Printf("go.Seq _in = new go.Seq();\n")
g.Printf("go.Seq _out = new go.Seq();\n")
returnsError := false
var resultType types.Type
if res.Len() > 0 {
if !isErrorType(res.At(0).Type()) {
resultType = res.At(0).Type()
}
if res.Len() > 1 || isErrorType(res.At(0).Type()) {
returnsError = true
}
}
if resultType != nil {
t := g.javaType(resultType)
g.Printf("%s _result;\n", t)
}
if method {
g.Printf("_in.writeRef(ref);\n")
}
params := sig.Params()
for i := 0; i < params.Len(); i++ {
p := params.At(i)
g.Printf("_in.write%s;\n", seqWrite(p.Type(), paramName(params, i)))
}
g.Printf("Seq.send(DESCRIPTOR, CALL_%s, _in, _out);\n", o.Name())
if resultType != nil {
g.genRead("_result", "_out", resultType)
}
if returnsError {
g.Printf(`String _err = _out.readString();
if (_err != null) {
throw new Exception(_err);
}
`)
}
if resultType != nil {
g.Printf("return _result;\n")
}
g.Outdent()
g.Printf("}\n\n")
}
// check if function is a test function for the testing package
// we don't unexport those
func (e *Export) checkFunction(from *types.Func, to string) {
if !strings.HasPrefix(from.Name(), "Test") {
return
}
sig := from.Type().(*types.Signature)
if sig.Params().Len() != 1 {
return
}
if sig.Params().At(0).Type().String() == "*testing.T" {
e.Conflicting = true
return
}
}
func (g *goGen) genFuncBody(o *types.Func) {
sig := o.Type().(*types.Signature)
results := newVars(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(), o.Name())
args := sig.Params()
for i := 0; i < args.Len(); i++ {
arg := args.At(i)
tail := ""
if i+1 < args.Len() {
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 *cpyGen) genFunc(o *types.Func) {
g.impl.Printf(`
/* pythonization of: %[2]s.%[1]s */
static PyObject*
gopy_%[1]s(PyObject *self, PyObject *args) {
`,
o.Name(), g.pkg.pkg.Name(),
)
g.impl.Indent()
g.genFuncBody(o)
g.impl.Outdent()
g.impl.Printf("}\n\n")
}
// lookupMethod returns the method set for type typ, which may be one
// of the interpreter's fake types.
func lookupMethod(i *interpreter, typ types.Type, meth *types.Func) *ssa.Function {
switch typ {
case rtypeType:
return i.rtypeMethods[meth.Id()]
case errorType:
return i.errorMethods[meth.Id()]
}
return i.prog.LookupMethod(typ, meth.Pkg(), meth.Name())
}
func (g *javaGen) funcSignature(o *types.Func, static bool) error {
sig := o.Type().(*types.Signature)
res := sig.Results()
var returnsError bool
var ret string
switch res.Len() {
case 2:
if !isErrorType(res.At(1).Type()) {
return fmt.Errorf("second result value must be of type error: %s", o)
}
returnsError = true
ret = g.javaType(res.At(0).Type())
case 1:
if isErrorType(res.At(0).Type()) {
returnsError = true
ret = "void"
} else {
ret = g.javaType(res.At(0).Type())
}
case 0:
ret = "void"
default:
return fmt.Errorf("too many result values: %s", o)
}
g.Printf("public ")
if static {
g.Printf("static ")
}
g.Printf("%s %s(", ret, o.Name())
params := sig.Params()
for i := 0; i < params.Len(); i++ {
if i > 0 {
g.Printf(", ")
}
v := sig.Params().At(i)
name := paramName(params, i)
jt := g.javaType(v.Type())
g.Printf("%s %s", jt, name)
}
g.Printf(")")
if returnsError {
g.Printf(" throws Exception")
}
return nil
}
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 checkFuncValue(t *testing.T, prog *ssa.Program, obj *types.Func) {
fn := prog.FuncValue(obj)
// fmt.Printf("FuncValue(%s) = %s\n", obj, fn) // debugging
if fn == nil {
if obj.Name() != "interfaceMethod" {
t.Errorf("FuncValue(%s) == nil", obj)
}
return
}
if fnobj := fn.Object(); fnobj != obj {
t.Errorf("FuncValue(%s).Object() == %s; value was %s",
obj, fnobj, fn.Name())
return
}
if !types.Identical(fn.Type(), obj.Type()) {
t.Errorf("FuncValue(%s).Type() == %s", obj, fn.Type())
return
}
}
func (g *goGen) genFunc(o *types.Func) {
sig := o.Type().(*types.Signature)
params := "(" + g.tupleString(sig.Params()) + ")"
ret := g.tupleString(sig.Results())
if sig.Results().Len() > 1 {
ret = "(" + ret + ") "
} else {
ret += " "
}
//funcName := o.Name()
g.Printf(`
//export GoPy_%[1]s
// GoPy_%[1]s wraps %[2]s
func GoPy_%[1]s%[3]v%[4]v{
`,
o.Name(), o.FullName(),
params,
ret,
)
g.Indent()
g.genFuncBody(o)
g.Outdent()
g.Printf("}\n\n")
}
func (p *Processor) tryMatchNewFunc(models []*Model, fun *types.Func) {
modelName := fun.Name()[len("new"):]
for _, m := range models {
if m.Name != modelName {
continue
}
sig := fun.Type().(*types.Signature)
if sig.Recv() != nil {
continue
}
res := sig.Results()
for i := 0; i < res.Len(); i++ {
if isTypeOrPtrTo(res.At(i).Type(), m.CheckedNode) {
m.NewFunc = fun
return
}
}
}
}
// makeBound returns a bound method wrapper (or "bound"), a synthetic
// function that delegates to a concrete or interface method denoted
// by obj. The resulting function has no receiver, but has one free
// variable which will be used as the method's receiver in the
// tail-call.
//
// Use MakeClosure with such a wrapper to construct a bound method
// closure. e.g.:
//
// type T int or: type T interface { meth() }
// func (t T) meth()
// var t T
// f := t.meth
// f() // calls t.meth()
//
// f is a closure of a synthetic wrapper defined as if by:
//
// f := func() { return t.meth() }
//
// Unlike makeWrapper, makeBound need perform no indirection or field
// selections because that can be done before the closure is
// constructed.
//
// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu)
//
func makeBound(prog *Program, obj *types.Func) *Function {
prog.methodsMu.Lock()
defer prog.methodsMu.Unlock()
fn, ok := prog.bounds[obj]
if !ok {
description := fmt.Sprintf("bound method wrapper for %s", obj)
if prog.mode&LogSource != 0 {
defer logStack("%s", description)()
}
fn = &Function{
name: obj.Name() + "$bound",
object: obj,
Signature: changeRecv(obj.Type().(*types.Signature), nil), // drop receiver
Synthetic: description,
Prog: prog,
pos: obj.Pos(),
}
fv := &FreeVar{name: "recv", typ: recvType(obj), parent: fn}
fn.FreeVars = []*FreeVar{fv}
fn.startBody()
createParams(fn, 0)
var c Call
if !isInterface(recvType(obj)) { // concrete
c.Call.Value = prog.declaredFunc(obj)
c.Call.Args = []Value{fv}
} else {
c.Call.Value = fv
c.Call.Method = obj
}
for _, arg := range fn.Params {
c.Call.Args = append(c.Call.Args, arg)
}
emitTailCall(fn, &c)
fn.finishBody()
prog.bounds[obj] = fn
}
return fn
}
// checkMethod performs safety checks for renaming a method.
// There are three hazards:
// - declaration conflicts
// - selection ambiguity/changes
// - entailed renamings of assignable concrete/interface types (for now, just reject)
func (r *renamer) checkMethod(from *types.Func) {
// e.g. error.Error
if from.Pkg() == nil {
r.errorf(from.Pos(), "you cannot rename built-in method %s", from)
return
}
// As always, having to support concrete methods with pointer
// and non-pointer receivers, and named vs unnamed types with
// methods, makes tooling fun.
// ASSIGNABILITY
//
// For now, if any method renaming breaks a required
// assignability to another type, we reject it.
//
// TODO(adonovan): probably we should compute the entailed
// renamings so that an interface method renaming causes
// concrete methods to change too. But which ones?
//
// There is no correct answer, only heuristics, because Go's
// "duck typing" doesn't distinguish intentional from contingent
// assignability. There are two obvious approaches:
//
// (1) Update the minimum set of types to preserve the
// assignability of types all syntactic assignments
// (incl. implicit ones in calls, returns, sends, etc).
// The satisfy.Finder enumerates these.
// This is likely to be an underapproximation.
//
// (2) Update all types that are assignable to/from the changed
// type. This requires computing the "implements" relation
// for all pairs of types (as godoc and oracle do).
// This is likely to be an overapproximation.
//
// If a concrete type is renamed, we probably do not want to
// rename corresponding interfaces; interface renamings should
// probably be initiated at the interface. (But what if a
// concrete type implements multiple interfaces with the same
// method? Then the user is stuck.)
//
// We need some experience before we decide how to implement this.
// Check for conflict at point of declaration.
// Check to ensure preservation of assignability requirements.
recv := from.Type().(*types.Signature).Recv().Type()
if isInterface(recv) {
// Abstract method
// declaration
prev, _, _ := types.LookupFieldOrMethod(recv, false, from.Pkg(), r.to)
if prev != nil {
r.errorf(from.Pos(), "renaming this interface method %q to %q",
from.Name(), r.to)
r.errorf(prev.Pos(), "\twould conflict with this method")
return
}
// Check all interfaces that embed this one for
// declaration conflicts too.
for _, info := range r.packages {
// Start with named interface types (better errors)
for _, obj := range info.Defs {
if obj, ok := obj.(*types.TypeName); ok && isInterface(obj.Type()) {
f, _, _ := types.LookupFieldOrMethod(
obj.Type(), false, from.Pkg(), from.Name())
if f == nil {
continue
}
t, _, _ := types.LookupFieldOrMethod(
obj.Type(), false, from.Pkg(), r.to)
if t == nil {
continue
}
r.errorf(from.Pos(), "renaming this interface method %q to %q",
from.Name(), r.to)
r.errorf(t.Pos(), "\twould conflict with this method")
r.errorf(obj.Pos(), "\tin named interface type %q", obj.Name())
}
}
// Now look at all literal interface types (includes named ones again).
for e, tv := range info.Types {
if e, ok := e.(*ast.InterfaceType); ok {
_ = e
_ = tv.Type.(*types.Interface)
// TODO(adonovan): implement same check as above.
}
}
}
// assignability
for T := range r.findAssignments(recv) {
if obj, _, _ := types.LookupFieldOrMethod(T, false, from.Pkg(), from.Name()); obj == nil {
continue
}
r.errorf(from.Pos(), "renaming this method %q to %q",
from.Name(), r.to)
var pos token.Pos
var other string
if named, ok := T.(*types.Named); ok {
pos = named.Obj().Pos()
other = named.Obj().Name()
} else {
pos = from.Pos()
other = T.String()
}
r.errorf(pos, "\twould make %s no longer assignable to it", other)
return
}
} else {
// Concrete method
// declaration
prev, indices, _ := types.LookupFieldOrMethod(recv, true, from.Pkg(), r.to)
if prev != nil && len(indices) == 1 {
r.errorf(from.Pos(), "renaming this method %q to %q",
from.Name(), r.to)
r.errorf(prev.Pos(), "\twould conflict with this %s",
objectKind(prev))
return
}
// assignability (of both T and *T)
recvBase := deref(recv)
for _, R := range []types.Type{recvBase, types.NewPointer(recvBase)} {
for I := range r.findAssignments(R) {
if obj, _, _ := types.LookupFieldOrMethod(I, true, from.Pkg(), from.Name()); obj == nil {
continue
}
r.errorf(from.Pos(), "renaming this method %q to %q",
from.Name(), r.to)
var pos token.Pos
var iface string
if named, ok := I.(*types.Named); ok {
pos = named.Obj().Pos()
iface = "interface " + named.Obj().Name()
} else {
pos = from.Pos()
iface = I.String()
}
r.errorf(pos, "\twould make it no longer assignable to %s", iface)
return // one is enough
}
}
}
// Check integrity of existing (field and method) selections.
// We skip this if there were errors above, to avoid redundant errors.
r.checkSelections(from)
}
func (g *objcGen) funcSummary(obj *types.Func) *funcSummary {
s := &funcSummary{name: obj.Name()}
sig := obj.Type().(*types.Signature)
params := sig.Params()
for i := 0; i < params.Len(); i++ {
p := params.At(i)
v := paramInfo{
typ: p.Type(),
name: paramName(params, i),
}
s.params = append(s.params, v)
}
res := sig.Results()
switch res.Len() {
case 0:
s.ret = "void"
case 1:
p := res.At(0)
if isErrorType(p.Type()) {
s.retParams = append(s.retParams, paramInfo{
typ: p.Type(),
name: "error",
})
s.ret = "BOOL"
} else {
name := p.Name()
if name == "" || paramRE.MatchString(name) {
name = "ret0_"
}
typ := p.Type()
s.retParams = append(s.retParams, paramInfo{typ: typ, name: name})
s.ret = g.objcType(typ)
}
case 2:
name := res.At(0).Name()
if name == "" || paramRE.MatchString(name) {
name = "ret0_"
}
s.retParams = append(s.retParams, paramInfo{
typ: res.At(0).Type(),
name: name,
})
if !isErrorType(res.At(1).Type()) {
g.errorf("second result value must be of type error: %s", obj)
return nil
}
s.retParams = append(s.retParams, paramInfo{
typ: res.At(1).Type(),
name: "error", // TODO(hyangah): name collision check.
})
s.ret = "BOOL"
default:
// TODO(hyangah): relax the constraint on multiple return params.
g.errorf("too many result values: %s", obj)
return nil
}
return s
}
// Implements displays the "implements" relation as it pertains to the
// selected type.
// If the selection is a method, 'implements' displays
// the corresponding methods of the types that would have been reported
// by an implements query on the receiver type.
//
func implements(q *Query) error {
lconf := loader.Config{Build: q.Build}
allowErrors(&lconf)
qpkg, err := importQueryPackage(q.Pos, &lconf)
if err != nil {
return err
}
// Set the packages to search.
if len(q.Scope) > 0 {
// Inspect all packages in the analysis scope, if specified.
if err := setPTAScope(&lconf, q.Scope); err != nil {
return err
}
} else {
// Otherwise inspect the forward and reverse
// transitive closure of the selected package.
// (In theory even this is incomplete.)
_, rev, _ := importgraph.Build(q.Build)
for path := range rev.Search(qpkg) {
lconf.ImportWithTests(path)
}
// TODO(adonovan): for completeness, we should also
// type-check and inspect function bodies in all
// imported packages. This would be expensive, but we
// could optimize by skipping functions that do not
// contain type declarations. This would require
// changing the loader's TypeCheckFuncBodies hook to
// provide the []*ast.File.
}
// Load/parse/type-check the program.
lprog, err := lconf.Load()
if err != nil {
return err
}
q.Fset = lprog.Fset
qpos, err := parseQueryPos(lprog, q.Pos, false)
if err != nil {
return err
}
// Find the selected type.
path, action := findInterestingNode(qpos.info, qpos.path)
var method *types.Func
var T types.Type // selected type (receiver if method != nil)
switch action {
case actionExpr:
// method?
if id, ok := path[0].(*ast.Ident); ok {
if obj, ok := qpos.info.ObjectOf(id).(*types.Func); ok {
recv := obj.Type().(*types.Signature).Recv()
if recv == nil {
return fmt.Errorf("this function is not a method")
}
method = obj
T = recv.Type()
}
}
case actionType:
T = qpos.info.TypeOf(path[0].(ast.Expr))
}
if T == nil {
return fmt.Errorf("no type or method here")
}
// Find all named types, even local types (which can have
// methods via promotion) and the built-in "error".
var allNamed []types.Type
for _, info := range lprog.AllPackages {
for _, obj := range info.Defs {
if obj, ok := obj.(*types.TypeName); ok {
allNamed = append(allNamed, obj.Type())
}
}
}
allNamed = append(allNamed, types.Universe.Lookup("error").Type())
var msets typeutil.MethodSetCache
// Test each named type.
var to, from, fromPtr []types.Type
for _, U := range allNamed {
if isInterface(T) {
if msets.MethodSet(T).Len() == 0 {
continue // empty interface
}
if isInterface(U) {
if msets.MethodSet(U).Len() == 0 {
continue // empty interface
}
// T interface, U interface
if !types.Identical(T, U) {
if types.AssignableTo(U, T) {
to = append(to, U)
}
if types.AssignableTo(T, U) {
from = append(from, U)
}
}
} else {
// T interface, U concrete
if types.AssignableTo(U, T) {
to = append(to, U)
} else if pU := types.NewPointer(U); types.AssignableTo(pU, T) {
to = append(to, pU)
}
}
} else if isInterface(U) {
if msets.MethodSet(U).Len() == 0 {
continue // empty interface
}
// T concrete, U interface
if types.AssignableTo(T, U) {
from = append(from, U)
} else if pT := types.NewPointer(T); types.AssignableTo(pT, U) {
fromPtr = append(fromPtr, U)
}
}
}
var pos interface{} = qpos
if nt, ok := deref(T).(*types.Named); ok {
pos = nt.Obj()
}
// Sort types (arbitrarily) to ensure test determinism.
sort.Sort(typesByString(to))
sort.Sort(typesByString(from))
sort.Sort(typesByString(fromPtr))
var toMethod, fromMethod, fromPtrMethod []*types.Selection // contain nils
if method != nil {
for _, t := range to {
toMethod = append(toMethod,
types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
}
for _, t := range from {
fromMethod = append(fromMethod,
types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
}
for _, t := range fromPtr {
fromPtrMethod = append(fromPtrMethod,
types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
}
}
q.result = &implementsResult{
qpos, T, pos, to, from, fromPtr, method, toMethod, fromMethod, fromPtrMethod,
}
return nil
}
// On success, findObjects returns the list of objects named
// spec.fromName matching the spec. On success, the result has exactly
// one element unless spec.searchFor!="", in which case it has at least one
// element.
//
func findObjects(info *loader.PackageInfo, spec *spec) ([]types.Object, error) {
if spec.pkgMember == "" {
if spec.searchFor == "" {
panic(spec)
}
objects := searchDefs(&info.Info, spec.searchFor)
if objects == nil {
return nil, fmt.Errorf("no object %q declared in package %q",
spec.searchFor, info.Pkg.Path())
}
return objects, nil
}
pkgMember := info.Pkg.Scope().Lookup(spec.pkgMember)
if pkgMember == nil {
return nil, fmt.Errorf("package %q has no member %q",
info.Pkg.Path(), spec.pkgMember)
}
var searchFunc *types.Func
if spec.typeMember == "" {
// package member
if spec.searchFor == "" {
return []types.Object{pkgMember}, nil
}
// Search within pkgMember, which must be a function.
searchFunc, _ = pkgMember.(*types.Func)
if searchFunc == nil {
return nil, fmt.Errorf("cannot search for %q within %s %q",
spec.searchFor, objectKind(pkgMember), pkgMember)
}
} else {
// field/method of type
// e.g. (encoding/json.Decoder).Decode
// or ::x within it.
tName, _ := pkgMember.(*types.TypeName)
if tName == nil {
return nil, fmt.Errorf("%s.%s is a %s, not a type",
info.Pkg.Path(), pkgMember.Name(), objectKind(pkgMember))
}
// search within named type.
obj, _, _ := types.LookupFieldOrMethod(tName.Type(), true, info.Pkg, spec.typeMember)
if obj == nil {
return nil, fmt.Errorf("cannot find field or method %q of %s %s.%s",
spec.typeMember, typeKind(tName.Type()), info.Pkg.Path(), tName.Name())
}
if spec.searchFor == "" {
return []types.Object{obj}, nil
}
searchFunc, _ = obj.(*types.Func)
if searchFunc == nil {
return nil, fmt.Errorf("cannot search for local name %q within %s (%s.%s).%s; need a function",
spec.searchFor, objectKind(obj), info.Pkg.Path(), tName.Name(),
obj.Name())
}
if isInterface(tName.Type()) {
return nil, fmt.Errorf("cannot search for local name %q within abstract method (%s.%s).%s",
spec.searchFor, info.Pkg.Path(), tName.Name(), searchFunc.Name())
}
}
// -- search within function or method --
decl := funcDecl(info, searchFunc)
if decl == nil {
return nil, fmt.Errorf("cannot find syntax for %s", searchFunc) // can't happen?
}
var objects []types.Object
for _, obj := range searchDefs(&info.Info, spec.searchFor) {
// We use positions, not scopes, to determine whether
// the obj is within searchFunc. This is clumsy, but the
// alternative, using the types.Scope tree, doesn't
// account for non-lexical objects like fields and
// interface methods.
if decl.Pos() <= obj.Pos() && obj.Pos() < decl.End() && obj != searchFunc {
objects = append(objects, obj)
}
}
if objects == nil {
return nil, fmt.Errorf("no local definition of %q within %s",
spec.searchFor, searchFunc)
}
return objects, nil
}
// recvType returns the receiver type of method obj.
func recvType(obj *types.Func) types.Type {
return obj.Type().(*types.Signature).Recv().Type()
}
// declaredFunc returns the concrete function/method denoted by obj.
// Panic ensues if there is none.
//
func (prog *Program) declaredFunc(obj *types.Func) *Function {
if v := prog.packageLevelValue(obj); v != nil {
return v.(*Function)
}
panic("no concrete method: " + obj.String())
}
// checkMethod performs safety checks for renaming a method.
// There are three hazards:
// - declaration conflicts
// - selection ambiguity/changes
// - entailed renamings of assignable concrete/interface types.
// We reject renamings initiated at concrete methods if it would
// change the assignability relation. For renamings of abstract
// methods, we rename all methods transitively coupled to it via
// assignability.
func (r *Unexporter) checkMethod(objsToUpdate map[types.Object]string, from *types.Func, to string) {
// e.g. error.Error
if from.Pkg() == nil {
r.warn(from, r.errorf(from.Pos(), "you cannot rename built-in method %s", from))
return
}
// ASSIGNABILITY: We reject renamings of concrete methods that
// would break a 'satisfy' constraint; but renamings of abstract
// methods are allowed to proceed, and we rename affected
// concrete and abstract methods as necessary. It is the
// initial method that determines the policy.
// Check for conflict at point of declaration.
// Check to ensure preservation of assignability requirements.
R := recv(from).Type()
if isInterface(R) {
// Abstract method
// declaration
prev, _, _ := types.LookupFieldOrMethod(R, false, from.Pkg(), to)
if prev != nil {
r.warn(from,
r.errorf(from.Pos(), "renaming this interface method %q to %q",
from.Name(), to),
r.errorf(prev.Pos(), "\twould conflict with this method"))
return
}
// Check all interfaces that embed this one for
// declaration conflicts too.
for _, info := range r.packages {
// Start with named interface types (better errors)
for _, obj := range info.Defs {
if obj, ok := obj.(*types.TypeName); ok && isInterface(obj.Type()) {
f, _, _ := types.LookupFieldOrMethod(
obj.Type(), false, from.Pkg(), from.Name())
if f == nil {
continue
}
t, _, _ := types.LookupFieldOrMethod(
obj.Type(), false, from.Pkg(), to)
if t == nil {
continue
}
r.warn(from,
r.errorf(from.Pos(), "renaming this interface method %q to %q",
from.Name(), to),
r.errorf(t.Pos(), "\twould conflict with this method"),
r.errorf(obj.Pos(), "\tin named interface type %q", obj.Name()))
}
}
// Now look at all literal interface types (includes named ones again).
for e, tv := range info.Types {
if e, ok := e.(*ast.InterfaceType); ok {
_ = e
_ = tv.Type.(*types.Interface)
// TODO(adonovan): implement same check as above.
}
}
}
// assignability
//
// Find the set of concrete or abstract methods directly
// coupled to abstract method 'from' by some
// satisfy.Constraint, and rename them too.
for key := range r.satisfy() {
// key = (lhs, rhs) where lhs is always an interface.
lsel := r.msets.MethodSet(key.LHS).Lookup(from.Pkg(), from.Name())
if lsel == nil {
continue
}
rmethods := r.msets.MethodSet(key.RHS)
rsel := rmethods.Lookup(from.Pkg(), from.Name())
if rsel == nil {
continue
}
// If both sides have a method of this name,
// and one of them is m, the other must be coupled.
var coupled *types.Func
switch from {
case lsel.Obj():
coupled = rsel.Obj().(*types.Func)
case rsel.Obj():
coupled = lsel.Obj().(*types.Func)
default:
continue
}
// We must treat concrete-to-interface
// constraints like an implicit selection C.f of
// each interface method I.f, and check that the
// renaming leaves the selection unchanged and
// unambiguous.
//
// Fun fact: the implicit selection of C.f
// type I interface{f()}
// type C struct{I}
// func (C) g()
// var _ I = C{} // here
// yields abstract method I.f. This can make error
// messages less than obvious.
//
if !isInterface(key.RHS) {
// The logic below was derived from checkSelections.
rtosel := rmethods.Lookup(from.Pkg(), to)
if rtosel != nil {
rto := rtosel.Obj().(*types.Func)
delta := len(rsel.Index()) - len(rtosel.Index())
if delta < 0 {
continue // no ambiguity
}
// TODO(adonovan): record the constraint's position.
keyPos := token.NoPos
rename := r.errorf(from.Pos(), "renaming this method %q to %q",
from.Name(), to)
if delta == 0 {
// analogous to same-block conflict
r.warn(from, rename,
r.errorf(keyPos, "\twould make the %s method of %s invoked via interface %s ambiguous",
to, key.RHS, key.LHS),
r.errorf(rto.Pos(), "\twith (%s).%s",
recv(rto).Type(), to))
} else {
// analogous to super-block conflict
r.warn(from, rename,
r.errorf(keyPos, "\twould change the %s method of %s invoked via interface %s",
to, key.RHS, key.LHS),
r.errorf(coupled.Pos(), "\tfrom (%s).%s",
recv(coupled).Type(), to),
r.errorf(rto.Pos(), "\tto (%s).%s",
recv(rto).Type(), to))
}
return // one error is enough
}
}
if !r.changeMethods {
// This should be unreachable.
r.warn(from,
r.errorf(from.Pos(), "internal error: during renaming of abstract method %s", from),
r.errorf(coupled.Pos(), "\tchangedMethods=false, coupled method=%s", coupled),
r.errorf(from.Pos(), "\tPlease file a bug report"))
return
}
// Rename the coupled method to preserve assignability.
r.check(objsToUpdate, coupled, to)
}
} else {
// Concrete method
// declaration
prev, indices, _ := types.LookupFieldOrMethod(R, true, from.Pkg(), to)
if prev != nil && len(indices) == 1 {
r.warn(from,
r.errorf(from.Pos(), "renaming this method %q to %q",
from.Name(), to),
r.errorf(prev.Pos(), "\twould conflict with this %s",
objectKind(prev)))
return
}
// assignability
//
// Find the set of abstract methods coupled to concrete
// method 'from' by some satisfy.Constraint, and rename
// them too.
//
// Coupling may be indirect, e.g. I.f <-> C.f via type D.
//
// type I interface {f()}
// type C int
// type (C) f()
// type D struct{C}
// var _ I = D{}
//
for key := range r.satisfy() {
// key = (lhs, rhs) where lhs is always an interface.
if isInterface(key.RHS) {
continue
}
rsel := r.msets.MethodSet(key.RHS).Lookup(from.Pkg(), from.Name())
if rsel == nil || rsel.Obj() != from {
continue // rhs does not have the method
}
lsel := r.msets.MethodSet(key.LHS).Lookup(from.Pkg(), from.Name())
if lsel == nil {
continue
}
imeth := lsel.Obj().(*types.Func)
// imeth is the abstract method (e.g. I.f)
// and key.RHS is the concrete coupling type (e.g. D).
if !r.changeMethods {
rename := r.errorf(from.Pos(), "renaming this method %q to %q",
from.Name(), to)
var pos token.Pos
var iface string
i := recv(imeth).Type()
if named, ok := i.(*types.Named); ok {
pos = named.Obj().Pos()
iface = "interface " + named.Obj().Name()
} else {
pos = from.Pos()
iface = i.String()
}
r.warn(from, rename,
r.errorf(pos, "\twould make %s no longer assignable to %s",
key.RHS, iface),
r.errorf(imeth.Pos(), "\t(rename %s.%s if you intend to change both types)",
i, from.Name()))
return // one error is enough
}
// Rename the coupled interface method to preserve assignability.
r.check(objsToUpdate, imeth, to)
}
}
// Check integrity of existing (field and method) selections.
// We skip this if there were errors above, to avoid redundant errors.
r.checkSelections(objsToUpdate, from, to)
}
// recv returns the method's receiver.
func recv(meth *types.Func) *types.Var {
return meth.Type().(*types.Signature).Recv()
}
// Implements displays the "implements" relation as it pertains to the
// selected type. If the selection is a method, 'implements' displays
// the corresponding methods of the types that would have been reported
// by an implements query on the receiver type.
//
func implements(o *Oracle, qpos *QueryPos) (queryResult, error) {
// Find the selected type.
path, action := findInterestingNode(qpos.info, qpos.path)
var method *types.Func
var T types.Type // selected type (receiver if method != nil)
switch action {
case actionExpr:
// method?
if id, ok := path[0].(*ast.Ident); ok {
if obj, ok := qpos.info.ObjectOf(id).(*types.Func); ok {
recv := obj.Type().(*types.Signature).Recv()
if recv == nil {
return nil, fmt.Errorf("this function is not a method")
}
method = obj
T = recv.Type()
}
}
case actionType:
T = qpos.info.TypeOf(path[0].(ast.Expr))
}
if T == nil {
return nil, fmt.Errorf("no type or method here")
}
// Find all named types, even local types (which can have
// methods via promotion) and the built-in "error".
//
// TODO(adonovan): include all packages in PTA scope too?
// i.e. don't reduceScope?
//
var allNamed []types.Type
for _, info := range o.typeInfo {
for _, obj := range info.Defs {
if obj, ok := obj.(*types.TypeName); ok {
allNamed = append(allNamed, obj.Type())
}
}
}
allNamed = append(allNamed, types.Universe.Lookup("error").Type())
var msets types.MethodSetCache
// Test each named type.
var to, from, fromPtr []types.Type
for _, U := range allNamed {
if isInterface(T) {
if msets.MethodSet(T).Len() == 0 {
continue // empty interface
}
if isInterface(U) {
if msets.MethodSet(U).Len() == 0 {
continue // empty interface
}
// T interface, U interface
if !types.Identical(T, U) {
if types.AssignableTo(U, T) {
to = append(to, U)
}
if types.AssignableTo(T, U) {
from = append(from, U)
}
}
} else {
// T interface, U concrete
if types.AssignableTo(U, T) {
to = append(to, U)
} else if pU := types.NewPointer(U); types.AssignableTo(pU, T) {
to = append(to, pU)
}
}
} else if isInterface(U) {
if msets.MethodSet(U).Len() == 0 {
continue // empty interface
}
// T concrete, U interface
if types.AssignableTo(T, U) {
from = append(from, U)
} else if pT := types.NewPointer(T); types.AssignableTo(pT, U) {
fromPtr = append(fromPtr, U)
}
}
}
var pos interface{} = qpos
if nt, ok := deref(T).(*types.Named); ok {
pos = nt.Obj()
}
// Sort types (arbitrarily) to ensure test determinism.
sort.Sort(typesByString(to))
sort.Sort(typesByString(from))
sort.Sort(typesByString(fromPtr))
var toMethod, fromMethod, fromPtrMethod []*types.Selection // contain nils
if method != nil {
for _, t := range to {
toMethod = append(toMethod,
types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
}
for _, t := range from {
fromMethod = append(fromMethod,
types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
}
for _, t := range fromPtr {
fromPtrMethod = append(fromPtrMethod,
types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
}
}
return &implementsResult{qpos, T, pos, to, from, fromPtr, method, toMethod, fromMethod, fromPtrMethod}, nil
}
func (e *Export) checkMethod(from *types.Func, to string) {
// e.g. error.Error
if from.Pkg() == nil {
e.Conflicting = true
return
}
// ASSIGNABILITY: We reject renamings of concrete methods that
// would break a 'satisfy' constraint; but renamings of abstract
// methods are allowed to proceed, and we rename affected
// concrete and abstract methods as necessary. It is the
// initial method that determines the policy.
// Check for conflict at point of declaration.
// Check to ensure preservation of assignability requirements.
R := recv(from).Type()
if isInterface(R) {
// Abstract method
// declaration
prev, _, _ := types.LookupFieldOrMethod(R, false, from.Pkg(), to)
if prev != nil {
e.Conflicting = true
return
}
// Check all interfaces that embed this one for
// declaration conflicts too.
for _, info := range e.u.prog.AllPackages {
// Start with named interface types (better errors)
for _, obj := range info.Defs {
if obj, ok := obj.(*types.TypeName); ok && isInterface(obj.Type()) {
f, _, _ := types.LookupFieldOrMethod(
obj.Type(), false, from.Pkg(), from.Name())
if f == nil {
continue
}
t, _, _ := types.LookupFieldOrMethod(obj.Type(), false, from.Pkg(), to)
if t == nil {
continue
}
e.Conflicting = true
return
}
}
}
// assignability
//
// Find the set of concrete or abstract methods directly
// coupled to abstract method 'from' by some
// satisfy.Constraint, and rename them too.
for key := range e.u.satisfy() {
// key = (lhs, rhs) where lhs is always an interface.
lsel := e.u.msets.MethodSet(key.LHS).Lookup(from.Pkg(), from.Name())
if lsel == nil {
continue
}
rmethods := e.u.msets.MethodSet(key.RHS)
rsel := rmethods.Lookup(from.Pkg(), from.Name())
if rsel == nil {
continue
}
// If both sides have a method of this name,
// and one of them is m, the other must be coupled.
var coupled *types.Func
switch from {
case lsel.Obj():
coupled = rsel.Obj().(*types.Func)
case rsel.Obj():
coupled = lsel.Obj().(*types.Func)
default:
continue
}
// We must treat concrete-to-interface
// constraints like an implicit selection C.f of
// each interface method I.f, and check that the
// renaming leaves the selection unchanged and
// unambiguous.
//
// Fun fact: the implicit selection of C.f
// type I interface{f()}
// type C struct{I}
// func (C) g()
// var _ I = C{} // here
// yields abstract method I.f. This can make error
// messages less than obvious.
//
if !isInterface(key.RHS) {
// The logic below was derived from checkSelections.
rtosel := rmethods.Lookup(from.Pkg(), to)
if rtosel != nil {
delta := len(rsel.Index()) - len(rtosel.Index())
if delta < 0 {
continue // no ambiguity
}
e.Conflicting = true
return
}
}
// Rename the coupled method to preserve assignability.
e.check(coupled, to)
}
}
// Concrete method
// declaration
prev, indices, _ := types.LookupFieldOrMethod(R, true, from.Pkg(), to)
if prev != nil && len(indices) == 1 {
e.Conflicting = true
return
}
// assignability
//
// Find the set of abstract methods coupled to concrete
// method 'from' by some satisfy.Constraint, and rename
// them too.
//
// Coupling may be indirect, e.g. I.f <-> C.f via type D.
//
// type I interface {f()}
// type C int
// type (C) f()
// type D struct{C}
// var _ I = D{}
//
for key := range e.u.satisfy() {
// key = (lhs, rhs) where lhs is always an interface.
if isInterface(key.RHS) {
continue
}
rsel := e.u.msets.MethodSet(key.RHS).Lookup(from.Pkg(), from.Name())
if rsel == nil || rsel.Obj() != from {
continue // rhs does not have the method
}
lsel := e.u.msets.MethodSet(key.LHS).Lookup(from.Pkg(), from.Name())
if lsel == nil {
continue
}
imeth := lsel.Obj().(*types.Func)
e.check(imeth, to)
}
// Check integrity of existing (field and method) selections.
// We skip this if there were errors above, to avoid redundant errors.
e.checkSelections(from, to)
}
func (g *cpyGen) genFuncBody(o *types.Func) {
funcArgs := []string{}
sig := o.Type().(*types.Signature)
res := newVars(sig.Results())
args := newVars(sig.Params())
for _, arg := range args {
arg.genDecl(g.impl)
funcArgs = append(funcArgs, arg.getFuncArg())
}
// FIXME(sbinet) pythonize (turn errors into python exceptions)
if len(res) > 0 {
switch len(res) {
case 1:
ret := res[0]
ret.genRetDecl(g.impl)
default:
g.impl.Printf("struct %[1]s_return c_gopy_ret;\n", o.Name())
/*
for i := 0; i < res.Len(); i++ {
ret := res.At(i)
n := ret.Name()
if n == "" {
n = "gopy_" + strconv.Itoa(i)
}
g.impl.Printf("%[1]s c_%[2]s;\n", ctypeName(ret.Type()), n)
}
*/
}
}
g.impl.Printf("\n")
if len(args) > 0 {
g.impl.Printf("if (!PyArg_ParseTuple(args, ")
format := []string{}
pyaddrs := []string{}
for _, arg := range args {
pyfmt, addr := arg.getArgParse()
format = append(format, pyfmt)
pyaddrs = append(pyaddrs, addr)
}
g.impl.Printf("%q, %s)) {\n", strings.Join(format, ""), strings.Join(pyaddrs, ", "))
g.impl.Indent()
g.impl.Printf("return NULL;\n")
g.impl.Outdent()
g.impl.Printf("}\n\n")
}
if len(args) > 0 {
for _, arg := range args {
arg.genFuncPreamble(g.impl)
}
g.impl.Printf("\n")
}
if len(res) > 0 {
g.impl.Printf("c_gopy_ret = ")
}
g.impl.Printf("GoPy_%[1]s(%[2]s);\n", o.Name(), strings.Join(funcArgs, ", "))
g.impl.Printf("\n")
if len(res) <= 0 {
g.impl.Printf("Py_INCREF(Py_None);\nreturn Py_None;\n")
return
}
format := []string{}
funcArgs = []string{}
switch len(res) {
case 1:
ret := res[0]
pyfmt, _ := ret.getArgParse()
format = append(format, pyfmt)
funcArgs = append(funcArgs, "c_gopy_ret")
default:
for _, ret := range res {
pyfmt, _ := ret.getArgParse()
format = append(format, pyfmt)
funcArgs = append(funcArgs, ret.getFuncArg())
}
}
g.impl.Printf("return Py_BuildValue(%q, %s);\n",
strings.Join(format, ""),
strings.Join(funcArgs, ", "),
)
//g.impl.Printf("return NULL;\n")
}