go/types: simplify some code and remove TODOs (cleanup)
- remove Checker.cycle in favor of using a "seen" map
- rename Checker.typeCycle -> Checker.cycle
- remove TODO in api.go since the API is frozen
Change-Id: I182a8215978dad54e9c6e79c21c5ec88ec802349
Reviewed-on: https://go-review.googlesource.com/c/go/+/198042
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
diff --git a/src/go/types/api.go b/src/go/types/api.go
index 6699231..2a21ad0 100644
--- a/src/go/types/api.go
+++ b/src/go/types/api.go
@@ -259,9 +259,6 @@
Value constant.Value
}
-// TODO(gri) Consider eliminating the IsVoid predicate. Instead, report
-// "void" values as regular values but with the empty tuple type.
-
// IsVoid reports whether the corresponding expression
// is a function call without results.
func (tv TypeAndValue) IsVoid() bool {
diff --git a/src/go/types/decl.go b/src/go/types/decl.go
index 4485ea8..d0027ae 100644
--- a/src/go/types/decl.go
+++ b/src/go/types/decl.go
@@ -125,17 +125,17 @@
// order code.
switch obj := obj.(type) {
case *Const:
- if check.typeCycle(obj) || obj.typ == nil {
+ if check.cycle(obj) || obj.typ == nil {
obj.typ = Typ[Invalid]
}
case *Var:
- if check.typeCycle(obj) || obj.typ == nil {
+ if check.cycle(obj) || obj.typ == nil {
obj.typ = Typ[Invalid]
}
case *TypeName:
- if check.typeCycle(obj) {
+ if check.cycle(obj) {
// break cycle
// (without this, calling underlying()
// below may lead to an endless loop
@@ -145,7 +145,7 @@
}
case *Func:
- if check.typeCycle(obj) {
+ if check.cycle(obj) {
// Don't set obj.typ to Typ[Invalid] here
// because plenty of code type-asserts that
// functions have a *Signature type. Grey
@@ -198,11 +198,9 @@
}
}
-// typeCycle checks if the cycle starting with obj is valid and
+// cycle checks if the cycle starting with obj is valid and
// reports an error if it is not.
-// TODO(gri) rename s/typeCycle/cycle/ once we don't need the other
-// cycle method anymore.
-func (check *Checker) typeCycle(obj Object) (isCycle bool) {
+func (check *Checker) cycle(obj Object) (isCycle bool) {
// The object map contains the package scope objects and the non-interface methods.
if debug {
info := check.objMap[obj]
diff --git a/src/go/types/resolver.go b/src/go/types/resolver.go
index 93de63b..2073034 100644
--- a/src/go/types/resolver.go
+++ b/src/go/types/resolver.go
@@ -482,7 +482,7 @@
// non-alias type name. If we encounter anything but pointer types or
// parentheses we're done. If we encounter more than one pointer type
// we're done.
- var path []*TypeName
+ var seen map[*TypeName]bool
for {
typ = unparen(typ)
@@ -496,7 +496,7 @@
typ = unparen(pexpr.X) // continue with pointer base type
}
- // typ must be the name
+ // typ must be a name
name, _ := typ.(*ast.Ident)
if name == nil {
return false, nil
@@ -516,7 +516,7 @@
}
// ... which we have not seen before
- if check.cycle(tname, path, false) {
+ if seen[tname] {
return false, nil
}
@@ -529,28 +529,11 @@
// otherwise, continue resolving
typ = tdecl.typ
- path = append(path, tname)
- }
-}
-
-// cycle reports whether obj appears in path or not.
-// If it does, and report is set, it also reports a cycle error.
-func (check *Checker) cycle(obj *TypeName, path []*TypeName, report bool) bool {
- // (it's ok to iterate forward because each named type appears at most once in path)
- for i, prev := range path {
- if prev == obj {
- if report {
- check.errorf(obj.pos, "illegal cycle in declaration of %s", obj.name)
- // print cycle
- for _, obj := range path[i:] {
- check.errorf(obj.Pos(), "\t%s refers to", obj.Name()) // secondary error, \t indented
- }
- check.errorf(obj.Pos(), "\t%s", obj.Name())
- }
- return true
+ if seen == nil {
+ seen = make(map[*TypeName]bool)
}
+ seen[tname] = true
}
- return false
}
// packageObjects typechecks all package objects, but not function bodies.
