go/types, types2: rename definedType to declaredType and clarify docs

declaredType seems a better name for this function because it is reached
when processing a (Named or Alias) type declaration. In both cases, the
fromRHS field (rather than the underlying field) will be set.

Change-Id: Ibb1cc338e3b0632dc63f9cf2fd9d64cef6f1aaa5
Reviewed-on: https://go-review.googlesource.com/c/go/+/695955
Auto-Submit: Mark Freeman <markfreeman@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Griesemer <gri@google.com>

2 files changed, 12 insertions, 12 deletions

diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go
index 91d2492a53..8f196ece61 100644
--- a/src/cmd/compile/internal/types2/decl.go
+++ b/src/cmd/compile/internal/types2/decl.go
@@ -532,7 +532,7 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *TypeN
 				check.collectTypeParams(&alias.tparams, tdecl.TParamList)
 			}
 
-			rhs = check.definedType(tdecl.Type, obj)
+			rhs = check.declaredType(tdecl.Type, obj)
 			assert(rhs != nil)
 
 			alias.fromRHS = rhs
@@ -576,7 +576,7 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *TypeN
 		check.collectTypeParams(&named.tparams, tdecl.TParamList)
 	}
 
-	rhs = check.definedType(tdecl.Type, obj)
+	rhs = check.declaredType(tdecl.Type, obj)
 	assert(rhs != nil)
 	named.fromRHS = rhs
 
diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go
index 8601ce6277..303f782ac4 100644
--- a/src/cmd/compile/internal/types2/typexpr.go
+++ b/src/cmd/compile/internal/types2/typexpr.go
@@ -16,7 +16,7 @@ import (
 
 // ident type-checks identifier e and initializes x with the value or type of e.
 // If an error occurred, x.mode is set to invalid.
-// For the meaning of def, see Checker.definedType, below.
+// For the meaning of def, see Checker.declaredType, below.
 // If wantType is set, the identifier e is expected to denote a type.
 func (check *Checker) ident(x *operand, e *syntax.Name, def *TypeName, wantType bool) {
 	x.mode = invalid
@@ -149,14 +149,14 @@ func (check *Checker) ident(x *operand, e *syntax.Name, def *TypeName, wantType
 // typ type-checks the type expression e and returns its type, or Typ[Invalid].
 // The type must not be an (uninstantiated) generic type.
 func (check *Checker) typ(e syntax.Expr) Type {
-	return check.definedType(e, nil)
+	return check.declaredType(e, nil)
 }
 
 // varType type-checks the type expression e and returns its type, or Typ[Invalid].
 // The type must not be an (uninstantiated) generic type and it must not be a
 // constraint interface.
 func (check *Checker) varType(e syntax.Expr) Type {
-	typ := check.definedType(e, nil)
+	typ := check.declaredType(e, nil)
 	check.validVarType(e, typ)
 	return typ
 }
@@ -187,11 +187,11 @@ func (check *Checker) validVarType(e syntax.Expr, typ Type) {
 	}).describef(e, "check var type %s", typ)
 }
 
-// definedType is like typ but also accepts a type name def.
-// If def != nil, e is the type specification for the type named def, declared
-// in a type declaration, and def.typ.underlying will be set to the type of e
-// before any components of e are type-checked.
-func (check *Checker) definedType(e syntax.Expr, def *TypeName) Type {
+// declaredType is like typ but also accepts a type name def.
+// If def != nil, e is the type specification for the [Alias] or [Named] type
+// named def, and def.typ.fromRHS will be set to the [Type] of e immediately
+// after its creation.
+func (check *Checker) declaredType(e syntax.Expr, def *TypeName) Type {
 	typ := check.typInternal(e, def)
 	assert(isTyped(typ))
 	if isGeneric(typ) {
@@ -230,7 +230,7 @@ func goTypeName(typ Type) string {
 }
 
 // typInternal drives type checking of types.
-// Must only be called by definedType or genericType.
+// Must only be called by declaredType or genericType.
 func (check *Checker) typInternal(e0 syntax.Expr, def *TypeName) (T Type) {
 	if check.conf.Trace {
 		check.trace(e0.Pos(), "-- type %s", e0)
@@ -296,7 +296,7 @@ func (check *Checker) typInternal(e0 syntax.Expr, def *TypeName) (T Type) {
 	case *syntax.ParenExpr:
 		// Generic types must be instantiated before they can be used in any form.
 		// Consequently, generic types cannot be parenthesized.
-		return check.definedType(e.X, def)
+		return check.declaredType(e.X, def)
 
 	case *syntax.ArrayType:
 		typ := new(Array)