// lookup returns the address of the named variable identified by obj
// that is local to function f or one of its enclosing functions.
// If escaping, the reference comes from a potentially escaping pointer
// expression and the referent must be heap-allocated.
//
func (f *Function) lookup(obj types.Object, escaping bool) Value {
if v, ok := f.objects[obj]; ok {
if alloc, ok := v.(*Alloc); ok && escaping {
alloc.Heap = true
}
return v // function-local var (address)
}
// Definition must be in an enclosing function;
// plumb it through intervening closures.
if f.parent == nil {
panic("no ssa.Value for " + obj.String())
}
outer := f.parent.lookup(obj, true) // escaping
v := &FreeVar{
name: obj.Name(),
typ: outer.Type(),
pos: outer.Pos(),
outer: outer,
parent: f,
}
f.objects[obj] = v
f.FreeVars = append(f.FreeVars, v)
return v
}
// 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())
}
}
func (w *Walker) emitObj(obj types.Object) {
switch obj := obj.(type) {
case *types.Const:
w.emitf("const %s %s", obj.Name(), w.typeString(obj.Type()))
w.emitf("const %s = %s", obj.Name(), obj.Val())
case *types.Var:
w.emitf("var %s %s", obj.Name(), w.typeString(obj.Type()))
case *types.TypeName:
w.emitType(obj)
case *types.Func:
w.emitFunc(obj)
default:
panic("unknown object: " + obj.String())
}
}
func (w *Walker) emitObj(obj types.Object) {
switch obj := obj.(type) {
case *types.Const:
w.emitf("const %s %s", obj.Name(), w.typeString(obj.Type()))
x := obj.Val()
short := x.String()
exact := x.ExactString()
if short == exact {
w.emitf("const %s = %s", obj.Name(), short)
} else {
w.emitf("const %s = %s // %s", obj.Name(), short, exact)
}
case *types.Var:
w.emitf("var %s %s", obj.Name(), w.typeString(obj.Type()))
case *types.TypeName:
w.emitType(obj)
case *types.Func:
w.emitFunc(obj)
default:
panic("unknown object: " + obj.String())
}
}
func formatNode(n ast.Node, obj types.Object, prog *loader.Program) string {
var nc ast.Node
// Render a copy of the node with no documentation.
// We emit the documentation ourself.
switch n := n.(type) {
case *ast.FuncDecl:
cp := *n
cp.Doc = nil
// Don't print the whole function body
cp.Body = nil
nc = &cp
case *ast.GenDecl:
cp := *n
cp.Doc = nil
if len(n.Specs) > 0 {
// Only print this one type, not all the types in the
// gendecl
switch n.Specs[0].(type) {
case *ast.TypeSpec:
spec := findTypeSpec(n, obj.Pos())
if spec != nil {
specCp := *spec
if *showUnexportedFields == false {
trimUnexportedElems(&specCp)
}
specCp.Doc = nil
cp.Specs = []ast.Spec{&specCp}
}
cp.Lparen = 0
cp.Rparen = 0
case *ast.ValueSpec:
spec := findVarSpec(n, obj.Pos())
if spec != nil {
specCp := *spec
specCp.Doc = nil
cp.Specs = []ast.Spec{&specCp}
}
cp.Lparen = 0
cp.Rparen = 0
}
}
nc = &cp
case *ast.Field:
// Not supported by go/printer
// TODO(dominikh): Methods in interfaces are syntactically
// represented as fields. Using types.Object.String for those
// causes them to look different from real functions.
// go/printer doesn't include the import paths in names, while
// Object.String does. Fix that.
return obj.String()
default:
return obj.String()
}
buf := &bytes.Buffer{}
cfg := printer.Config{Mode: printer.UseSpaces | printer.TabIndent, Tabwidth: 8}
err := cfg.Fprint(buf, prog.Fset, nc)
if err != nil {
return obj.String()
}
return buf.String()
}