func (p *exporter) signature(sig *types.Signature) {
// We need the receiver information (T vs *T)
// for methods associated with named types.
// We do not record interface receiver types in the
// export data because 1) the importer can derive them
// from the interface type and 2) they create cycles
// in the type graph.
if recv := sig.Recv(); recv != nil {
if _, ok := recv.Type().Underlying().(*types.Interface); !ok {
// 1-element tuple
p.int(1)
p.param(recv)
} else {
// 0-element tuple
p.int(0)
}
} else {
// 0-element tuple
p.int(0)
}
p.tuple(sig.Params())
p.tuple(sig.Results())
if sig.Variadic() {
p.int(1)
} else {
p.int(0)
}
}
func hasError(sig *types.Signature) bool {
res := sig.Results()
if res == nil || res.Len() <= 0 {
return false
}
nerr := 0
for i := 0; i < res.Len(); i++ {
ret := res.At(i)
if isErrorType(ret.Type()) {
nerr++
}
}
switch {
case nerr == 0:
return false
case nerr == 1:
return true
default:
panic(fmt.Errorf(
"gopy: invalid number of comma-errors (%d)",
nerr,
))
}
return false
}
func newSignatureFrom(pkg *Package, sig *types.Signature) *Signature {
var recv *Var
if sig.Recv() != nil {
recv = newVarFrom(pkg, sig.Recv())
}
return &Signature{
ret: newVarsFrom(pkg, sig.Results()),
args: newVarsFrom(pkg, sig.Params()),
recv: recv,
}
}
func (w *Walker) writeSignature(buf *bytes.Buffer, sig *types.Signature) {
w.writeParams(buf, sig.Params(), sig.Variadic())
switch res := sig.Results(); res.Len() {
case 0:
// nothing to do
case 1:
buf.WriteByte(' ')
w.writeType(buf, res.At(0).Type())
default:
buf.WriteByte(' ')
w.writeParams(buf, res, false)
}
}
func (b *Builder) convertSignature(u types.Universe, t *tc.Signature) *types.Signature {
signature := &types.Signature{}
for i := 0; i < t.Params().Len(); i++ {
signature.Parameters = append(signature.Parameters, b.walkType(u, nil, t.Params().At(i).Type()))
}
for i := 0; i < t.Results().Len(); i++ {
signature.Results = append(signature.Results, b.walkType(u, nil, t.Results().At(i).Type()))
}
if r := t.Recv(); r != nil {
signature.Receiver = b.walkType(u, nil, r.Type())
}
signature.Variadic = t.Variadic()
return signature
}
func isImplementable(sig *types.Signature) bool {
params := sig.Params()
for i := 0; i < params.Len(); i++ {
if !isExported(params.At(i).Type()) {
return false
}
}
res := sig.Results()
for i := 0; i < res.Len(); i++ {
if !isExported(res.At(i).Type()) {
return false
}
}
return true
}
func (c *converter) convertSignature(v *gotypes.Signature) *types.Signature {
if v == nil {
return nil
}
if v, ok := c.converted[v]; ok {
return v.(*types.Signature)
}
ret := types.NewSignature(
c.convertParamVar(v.Recv()),
c.convertTuple(v.Params(), c.convertParamVar),
c.convertTuple(v.Results(), c.convertParamVar),
v.Variadic(),
)
c.converted[v] = ret
return ret
}
func (c *funcContext) translateCall(e *ast.CallExpr, sig *types.Signature, fun *expression) *expression {
args := c.translateArgs(sig, e.Args, e.Ellipsis.IsValid(), false)
if c.Blocking[e] {
resumeCase := c.caseCounter
c.caseCounter++
returnVar := "$r"
if sig.Results().Len() != 0 {
returnVar = c.newVariable("_r")
}
c.Printf("%[1]s = %[2]s(%[3]s); /* */ $s = %[4]d; case %[4]d: if($c) { $c = false; %[1]s = %[1]s.$blk(); } if (%[1]s && %[1]s.$blk !== undefined) { break s; }", returnVar, fun, strings.Join(args, ", "), resumeCase)
if sig.Results().Len() != 0 {
return c.formatExpr("%s", returnVar)
}
return c.formatExpr("")
}
return c.formatExpr("%s(%s)", fun, strings.Join(args, ", "))
}
func newFuncFrom(p *Package, parent string, obj types.Object, sig *types.Signature) (Func, error) {
haserr := false
res := sig.Results()
var ret types.Type
switch res.Len() {
case 2:
if !isErrorType(res.At(1).Type()) {
return Func{}, fmt.Errorf(
"bind: second result value must be of type error: %s",
obj,
)
}
haserr = true
ret = res.At(0).Type()
case 1:
if isErrorType(res.At(0).Type()) {
haserr = true
ret = nil
} else {
ret = res.At(0).Type()
}
case 0:
ret = nil
default:
return Func{}, fmt.Errorf("bind: too many results to return: %v", obj)
}
id := obj.Pkg().Name() + "_" + obj.Name()
if parent != "" {
id = obj.Pkg().Name() + "_" + parent + "_" + obj.Name()
}
return Func{
pkg: p,
sig: newSignatureFrom(p, sig),
typ: obj.Type(),
name: obj.Name(),
id: id,
doc: p.getDoc(parent, obj),
ret: ret,
err: haserr,
}, nil
}
func (p *printer) writeSignatureInternal(this *types.Package, sig *types.Signature, visited []types.Type) {
p.writeTuple(this, sig.Params(), sig.Variadic(), visited)
res := sig.Results()
n := res.Len()
if n == 0 {
// no result
return
}
p.print(" ")
if n == 1 && res.At(0).Name() == "" {
// single unnamed result
p.writeTypeInternal(this, res.At(0).Type(), visited)
return
}
// multiple or named result(s)
p.writeTuple(this, res, false, visited)
}
func sigResultsCompatible(s1, s2 *types.Signature) bool {
if s1.Results().Len() == 0 {
return true
}
extra := tuplesCompatibleExtra(s1.Results(), s2.Results(), cmpUpper)
switch {
case extra == nil:
return false
case len(extra) == 0:
return true
}
return false
}
func changeRecv(s *types.Signature, recv *types.Var) *types.Signature {
return types.NewSignature(recv, s.Params(), s.Results(), s.Variadic())
}
func (c *funcContext) translateBuiltin(name string, sig *types.Signature, args []ast.Expr, ellipsis bool) *expression {
switch name {
case "new":
t := sig.Results().At(0).Type().(*types.Pointer)
if c.p.Pkg.Path() == "syscall" && types.Identical(t.Elem().Underlying(), types.Typ[types.Uintptr]) {
return c.formatExpr("new Uint8Array(8)")
}
switch t.Elem().Underlying().(type) {
case *types.Struct, *types.Array:
return c.formatExpr("%e", c.zeroValue(t.Elem()))
default:
return c.formatExpr("$newDataPointer(%e, %s)", c.zeroValue(t.Elem()), c.typeName(t))
}
case "make":
switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
case *types.Slice:
t := c.typeName(c.p.TypeOf(args[0]))
if len(args) == 3 {
return c.formatExpr("$makeSlice(%s, %f, %f)", t, args[1], args[2])
}
return c.formatExpr("$makeSlice(%s, %f)", t, args[1])
case *types.Map:
if len(args) == 2 && c.p.Types[args[1]].Value == nil {
return c.formatExpr(`((%1f < 0 || %1f > 2147483647) ? $throwRuntimeError("makemap: size out of range") : {})`, args[1])
}
return c.formatExpr("{}")
case *types.Chan:
length := "0"
if len(args) == 2 {
length = c.formatExpr("%f", args[1]).String()
}
return c.formatExpr("new $Chan(%s, %s)", c.typeName(c.p.TypeOf(args[0]).Underlying().(*types.Chan).Elem()), length)
default:
panic(fmt.Sprintf("Unhandled make type: %T\n", argType))
}
case "len":
switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
case *types.Basic:
return c.formatExpr("%e.length", args[0])
case *types.Slice:
return c.formatExpr("%e.$length", args[0])
case *types.Pointer:
return c.formatExpr("(%e, %d)", args[0], argType.Elem().(*types.Array).Len())
case *types.Map:
return c.formatExpr("$keys(%e).length", args[0])
case *types.Chan:
return c.formatExpr("%e.$buffer.length", args[0])
// length of array is constant
default:
panic(fmt.Sprintf("Unhandled len type: %T\n", argType))
}
case "cap":
switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
case *types.Slice, *types.Chan:
return c.formatExpr("%e.$capacity", args[0])
case *types.Pointer:
return c.formatExpr("(%e, %d)", args[0], argType.Elem().(*types.Array).Len())
// capacity of array is constant
default:
panic(fmt.Sprintf("Unhandled cap type: %T\n", argType))
}
case "panic":
return c.formatExpr("$panic(%s)", c.translateImplicitConversion(args[0], types.NewInterface(nil, nil)))
case "append":
if ellipsis || len(args) == 1 {
argStr := c.translateArgs(sig, args, ellipsis, false)
return c.formatExpr("$appendSlice(%s, %s)", argStr[0], argStr[1])
}
sliceType := sig.Results().At(0).Type().Underlying().(*types.Slice)
return c.formatExpr("$append(%e, %s)", args[0], strings.Join(c.translateExprSlice(args[1:], sliceType.Elem()), ", "))
case "delete":
keyType := c.p.TypeOf(args[0]).Underlying().(*types.Map).Key()
return c.formatExpr(`delete %e[%s.keyFor(%s)]`, args[0], c.typeName(keyType), c.translateImplicitConversion(args[1], keyType))
case "copy":
if basic, isBasic := c.p.TypeOf(args[1]).Underlying().(*types.Basic); isBasic && isString(basic) {
return c.formatExpr("$copyString(%e, %e)", args[0], args[1])
}
return c.formatExpr("$copySlice(%e, %e)", args[0], args[1])
case "print", "println":
return c.formatExpr("console.log(%s)", strings.Join(c.translateExprSlice(args, nil), ", "))
case "complex":
argStr := c.translateArgs(sig, args, ellipsis, false)
return c.formatExpr("new %s(%s, %s)", c.typeName(sig.Results().At(0).Type()), argStr[0], argStr[1])
case "real":
return c.formatExpr("%e.$real", args[0])
case "imag":
return c.formatExpr("%e.$imag", args[0])
case "recover":
return c.formatExpr("$recover()")
case "close":
return c.formatExpr(`$close(%e)`, args[0])
default:
panic(fmt.Sprintf("Unhandled builtin: %s\n", name))
}
}
// lostCancelPath finds a path through the CFG, from stmt (which defines
// the 'cancel' variable v) to a return statement, that doesn't "use" v.
// If it finds one, it returns the return statement (which may be synthetic).
// sig is the function's type, if known.
func lostCancelPath(f *File, g *cfg.CFG, v *types.Var, stmt ast.Node, sig *types.Signature) *ast.ReturnStmt {
vIsNamedResult := sig != nil && tupleContains(sig.Results(), v)
// uses reports whether stmts contain a "use" of variable v.
uses := func(f *File, v *types.Var, stmts []ast.Node) bool {
found := false
for _, stmt := range stmts {
ast.Inspect(stmt, func(n ast.Node) bool {
switch n := n.(type) {
case *ast.Ident:
if f.pkg.uses[n] == v {
found = true
}
case *ast.ReturnStmt:
// A naked return statement counts as a use
// of the named result variables.
if n.Results == nil && vIsNamedResult {
found = true
}
}
return !found
})
}
return found
}
// blockUses computes "uses" for each block, caching the result.
memo := make(map[*cfg.Block]bool)
blockUses := func(f *File, v *types.Var, b *cfg.Block) bool {
res, ok := memo[b]
if !ok {
res = uses(f, v, b.Nodes)
memo[b] = res
}
return res
}
// Find the var's defining block in the CFG,
// plus the rest of the statements of that block.
var defblock *cfg.Block
var rest []ast.Node
outer:
for _, b := range g.Blocks {
for i, n := range b.Nodes {
if n == stmt {
defblock = b
rest = b.Nodes[i+1:]
break outer
}
}
}
if defblock == nil {
panic("internal error: can't find defining block for cancel var")
}
// Is v "used" in the remainder of its defining block?
if uses(f, v, rest) {
return nil
}
// Does the defining block return without using v?
if ret := defblock.Return(); ret != nil {
return ret
}
// Search the CFG depth-first for a path, from defblock to a
// return block, in which v is never "used".
seen := make(map[*cfg.Block]bool)
var search func(blocks []*cfg.Block) *ast.ReturnStmt
search = func(blocks []*cfg.Block) *ast.ReturnStmt {
for _, b := range blocks {
if !seen[b] {
seen[b] = true
// Prune the search if the block uses v.
if blockUses(f, v, b) {
continue
}
// Found path to return statement?
if ret := b.Return(); ret != nil {
if debugLostCancel {
fmt.Printf("found path to return in block %s\n", b)
}
return ret // found
}
// Recur
if ret := search(b.Succs); ret != nil {
if debugLostCancel {
fmt.Printf(" from block %s\n", b)
}
return ret
}
}
}
return nil
}
return search(defblock.Succs)
}