// objDecl type-checks the declaration of obj in its respective (file) environment.
// For the meaning of def, see Checker.definedType, in typexpr.go.
-func (check *Checker) objDecl(obj Object, def *Named) {
+func (check *Checker) objDecl(obj Object, def *TypeName) {
if check.conf.Trace && obj.Type() == nil {
if check.indent == 0 {
fmt.Println() // empty line between top-level objects for readability
// the syntactic information. We should consider storing
// this information explicitly in the object.
var alias bool
- if d := check.objMap[obj]; d != nil {
- alias = d.tdecl.Alias // package-level object
+ if check.conf._EnableAlias {
+ alias = obj.IsAlias()
} else {
- alias = obj.IsAlias() // function local object
+ if d := check.objMap[obj]; d != nil {
+ alias = d.tdecl.Alias // package-level object
+ } else {
+ alias = obj.IsAlias() // function local object
+ }
}
if !alias {
ndef++
func (check *Checker) cycleError(cycle []Object) {
// name returns the (possibly qualified) object name.
// This is needed because with generic types, cycles
- // may refer to imported types. See issue #50788.
+ // may refer to imported types. See go.dev/issue/50788.
// TODO(gri) This functionality is used elsewhere. Factor it out.
name := func(obj Object) string {
return packagePrefix(obj.Pkg(), check.qualifier) + obj.Name()
// If obj is a type alias, mark it as valid (not broken) in order to avoid follow-on errors.
tname, _ := obj.(*TypeName)
if tname != nil && tname.IsAlias() {
- check.validAlias(tname, Typ[Invalid])
+ // If we use Alias nodes, it is initialized with Typ[Invalid].
+ // TODO(gri) Adjust this code if we initialize with nil.
+ if !check.conf._EnableAlias {
+ check.validAlias(tname, Typ[Invalid])
+ }
}
// report a more concise error for self references
func firstInSrc(path []Object) int {
fst, pos := 0, path[0].Pos()
for i, t := range path[1:] {
- if t.Pos().Cmp(pos) < 0 {
+ if cmpPos(t.Pos(), pos) < 0 {
fst, pos = i+1, t.Pos()
}
}
t := check.typ(typ)
if !isConstType(t) {
// don't report an error if the type is an invalid C (defined) type
- // (issue #22090)
- if under(t) != Typ[Invalid] {
+ // (go.dev/issue/22090)
+ if isValid(under(t)) {
check.errorf(typ, InvalidConstType, "invalid constant type %s", t)
}
obj.typ = Typ[Invalid]
// expression and not the current constant declaration. Use
// the constant identifier position for any errors during
// init expression evaluation since that is all we have
- // (see issues #42991, #42992).
+ // (see issues go.dev/issue/42991, go.dev/issue/42992).
check.errpos = obj.pos
}
- check.expr(&x, init)
+ check.expr(nil, &x, init)
}
check.initConst(obj, &x)
}
func (check *Checker) varDecl(obj *Var, lhs []*Var, typ, init syntax.Expr) {
assert(obj.typ == nil)
- // If we have undefined variable types due to errors,
- // mark variables as used to avoid follow-on errors.
- // Matches compiler behavior.
- defer func() {
- if obj.typ == Typ[Invalid] {
- obj.used = true
- }
- for _, lhs := range lhs {
- if lhs.typ == Typ[Invalid] {
- lhs.used = true
- }
- }
- }()
-
// determine type, if any
if typ != nil {
obj.typ = check.varType(typ)
if lhs == nil || len(lhs) == 1 {
assert(lhs == nil || lhs[0] == obj)
var x operand
- check.expr(&x, init)
+ check.expr(obj.typ, &x, init)
check.initVar(obj, &x, "variable declaration")
return
}
// We have multiple variables on the lhs and one init expr.
// Make sure all variables have been given the same type if
// one was specified, otherwise they assume the type of the
- // init expression values (was issue #15755).
+ // init expression values (was go.dev/issue/15755).
if typ != nil {
for _, lhs := range lhs {
lhs.typ = obj.typ
// isImportedConstraint reports whether typ is an imported type constraint.
func (check *Checker) isImportedConstraint(typ Type) bool {
- named, _ := typ.(*Named)
+ named := asNamed(typ)
if named == nil || named.obj.pkg == check.pkg || named.obj.pkg == nil {
return false
}
return u != nil && !u.IsMethodSet()
}
-func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *Named) {
+func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *TypeName) {
assert(obj.typ == nil)
var rhs Type
check.later(func() {
- if t, _ := obj.typ.(*Named); t != nil { // type may be invalid
+ if t := asNamed(obj.typ); t != nil { // type may be invalid
check.validType(t)
}
// If typ is local, an error was already reported where typ is specified/defined.
- if check.isImportedConstraint(rhs) && !check.allowVersion(check.pkg, 1, 18) {
- check.versionErrorf(tdecl.Type, "go1.18", "using type constraint %s", rhs)
- }
+ _ = check.isImportedConstraint(rhs) && check.verifyVersionf(tdecl.Type, go1_18, "using type constraint %s", rhs)
}).describef(obj, "validType(%s)", obj.Name())
- alias := tdecl.Alias
- if alias && tdecl.TParamList != nil {
+ aliasDecl := tdecl.Alias
+ if aliasDecl && tdecl.TParamList != nil {
// The parser will ensure this but we may still get an invalid AST.
// Complain and continue as regular type definition.
check.error(tdecl, BadDecl, "generic type cannot be alias")
- alias = false
+ aliasDecl = false
}
// alias declaration
- if alias {
- if !check.allowVersion(check.pkg, 1, 9) {
- check.versionErrorf(tdecl, "go1.9", "type aliases")
+ if aliasDecl {
+ check.verifyVersionf(tdecl, go1_9, "type aliases")
+ if check.conf._EnableAlias {
+ // TODO(gri) Should be able to use nil instead of Typ[Invalid] to mark
+ // the alias as incomplete. Currently this causes problems
+ // with certain cycles. Investigate.
+ alias := check.newAlias(obj, Typ[Invalid])
+ setDefType(def, alias)
+ rhs = check.definedType(tdecl.Type, obj)
+ assert(rhs != nil)
+ alias.fromRHS = rhs
+ _Unalias(alias) // resolve alias.actual
+ } else {
+ check.brokenAlias(obj)
+ rhs = check.typ(tdecl.Type)
+ check.validAlias(obj, rhs)
}
-
- check.brokenAlias(obj)
- rhs = check.typ(tdecl.Type)
- check.validAlias(obj, rhs)
return
}
// type definition or generic type declaration
named := check.newNamed(obj, nil, nil)
- def.setUnderlying(named)
+ setDefType(def, named)
if tdecl.TParamList != nil {
check.openScope(tdecl, "type parameters")
}
// determine underlying type of named
- rhs = check.definedType(tdecl.Type, named)
+ rhs = check.definedType(tdecl.Type, obj)
assert(rhs != nil)
named.fromRHS = rhs
named.underlying = Typ[Invalid]
}
- // Disallow a lone type parameter as the RHS of a type declaration (issue #45639).
+ // Disallow a lone type parameter as the RHS of a type declaration (go.dev/issue/45639).
// We don't need this restriction anymore if we make the underlying type of a type
// parameter its constraint interface: if the RHS is a lone type parameter, we will
// use its underlying type (like we do for any RHS in a type declaration), and its
}
// Set the type parameters before collecting the type constraints because
- // the parameterized type may be used by the constraints (issue #47887).
+ // the parameterized type may be used by the constraints (go.dev/issue/47887).
// Example: type T[P T[P]] interface{}
*dst = bindTParams(tparams)
// spec: "If the base type is a struct type, the non-blank method
// and field names must be distinct."
- base, _ := obj.typ.(*Named) // shouldn't fail but be conservative
+ base := asNamed(obj.typ) // shouldn't fail but be conservative
if base != nil {
assert(base.TypeArgs().Len() == 0) // collectMethods should not be called on an instantiated type
- // See issue #52529: we must delay the expansion of underlying here, as
+ // See go.dev/issue/52529: we must delay the expansion of underlying here, as
// base may not be fully set-up.
check.later(func() {
check.checkFieldUniqueness(base)
// declare all constants
lhs := make([]*Const, len(s.NameList))
- values := unpackExpr(last.Values)
+ values := syntax.UnpackListExpr(last.Values)
for i, name := range s.NameList {
obj := NewConst(name.Pos(), pkg, name.Value, nil, iota)
lhs[i] = obj
}
// initialize all variables
- values := unpackExpr(s.Values)
+ values := syntax.UnpackListExpr(s.Values)
for i, obj := range lhs0 {
var lhs []*Var
var init syntax.Expr