// 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.NewPointer(typ).MethodSet().Lookup(tpkg, "Lock"); plock != nil {
if lock := typ.MethodSet().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
}
func (visit *visitor) methodSet(typ types.Type) {
mset := typ.MethodSet()
for i, n := 0, mset.Len(); i < n; i++ {
// Side-effect: creates all wrapper methods.
visit.function(visit.prog.Method(mset.At(i)))
}
}
// 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.Method(typ.MethodSet().Lookup(meth.Pkg(), meth.Name()))
}
// hasMethod reports whether the type contains a method with the given name.
// It is part of the workaround for Formatters and should be deleted when
// that workaround is no longer necessary. TODO: delete when fixed.
func hasMethod(typ types.Type, name string) bool {
set := typ.MethodSet()
for i := 0; i < set.Len(); i++ {
if set.At(i).Obj().Name() == name {
return true
}
}
return false
}
// 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 similarly
// 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).
//
// TODO(gri): move this to go/types?
//
func IntuitiveMethodSet(T types.Type) []*types.Selection {
var result []*types.Selection
mset := T.MethodSet()
if _, ok := T.Underlying().(*types.Interface); ok {
for i, n := 0, mset.Len(); i < n; i++ {
result = append(result, mset.At(i))
}
} else {
pmset := types.NewPointer(T).MethodSet()
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
}
// makeMethods ensures that all wrappers in the complete method set of
// T are generated. It is equivalent to calling prog.Method() on all
// members of T.methodSet(), but acquires fewer locks.
//
// It reports whether the type's method set is non-empty.
//
// Thread-safe.
//
// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu)
//
func (prog *Program) makeMethods(T types.Type) bool {
tmset := T.MethodSet()
n := tmset.Len()
if n == 0 {
return false // empty (common case)
}
if prog.mode&LogSource != 0 {
defer logStack("makeMethods %s", T)()
}
prog.methodsMu.Lock()
defer prog.methodsMu.Unlock()
mset := prog.createMethodSet(T)
if !mset.complete {
mset.complete = true
for i := 0; i < n; i++ {
prog.addMethod(mset, tmset.At(i))
}
}
return true
}
// genMethodsOf generates nodes and constraints for all methods of type T.
func (a *analysis) genMethodsOf(T types.Type) {
mset := T.MethodSet()
for i, n := 0, mset.Len(); i < n; i++ {
a.valueNode(a.prog.Method(mset.At(i)))
}
}