// 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:
fn := &Function{
name: name,
object: obj,
Signature: obj.Type().(*types.Signature),
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 fn.Signature.Recv() == nil {
pkg.Members[name] = fn // package-level function
}
default: // (incl. *types.Package)
panic("unexpected Object type: " + obj.String())
}
}