[dev.regabi] cmd/compile: separate dowidth better

Having a global MaxWidth lets us avoid needing to
refer to thearch from split-out packages when all
they need is thearch.MAXWIDTH.

And make a couple interface changes to let dowidth
avoid importing package ir directly.
Then it can move into package types.

Change-Id: I2c12e8e22252597530e648848320e19bdd490a01
Reviewed-on: https://go-review.googlesource.com/c/go/+/279302
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/types/type.go b/src/cmd/compile/internal/types/type.go
index 4d1d30133c..752c268fa2 100644
--- a/src/cmd/compile/internal/types/type.go
+++ b/src/cmd/compile/internal/types/type.go
@@ -20,6 +20,18 @@ type Object interface {
 	Type() *Type
 }
 
+// A TypeObject is an Object representing a named type.
+type TypeObject interface {
+	Object
+	TypeDefn() *Type // for "type T Defn", returns Defn
+}
+
+// A VarObject is an Object representing a function argument, variable, or struct field.
+type VarObject interface {
+	Object
+	RecordFrameOffset(int64) // save frame offset
+}
+
 //go:generate stringer -type EType -trimprefix T
 
 // EType describes a kind of type.