cmd/compile: add typWrapper and Type.Wrapped

Passes toolstash -cmp.

Change-Id: I7dffd9bc5bab323590df6fb591bf1e73edf2e465
Reviewed-on: https://go-review.googlesource.com/21305
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/compile/internal/gc/align.go b/src/cmd/compile/internal/gc/align.go
index 1ca7dd4d20b1cb32a27b7dd4a9ddb9e792f8e158..351ca73aa4c3b1b08413c511d6b6256d27d7aab7 100644 (file)
--- a/src/cmd/compile/internal/gc/align.go
+++ b/src/cmd/compile/internal/gc/align.go
@@ -198,14 +198,12 @@ func dowidth(t *Type) {
 
                // make fake type to check later to
                // trigger channel argument check.
-               t1 := typ(TCHANARGS)
-
-               t1.Type = t
+               t1 := typWrapper(TCHANARGS, t)
                checkwidth(t1)
 
        case TCHANARGS:
-               t1 := t.Type
-               dowidth(t.Type) // just in case
+               t1 := t.Wrapped()
+               dowidth(t1) // just in case
                if t1.Type.Width >= 1<<16 {
                        Yyerror("channel element type too large (>64kB)")
                }
@@ -273,22 +271,17 @@ func dowidth(t *Type) {
        // make fake type to check later to
        // trigger function argument computation.
        case TFUNC:
-               t1 := typ(TFUNCARGS)
-
-               t1.Type = t
+               t1 := typWrapper(TFUNCARGS, t)
                checkwidth(t1)
-
-               // width of func type is pointer
-               w = int64(Widthptr)
+               w = int64(Widthptr) // width of func type is pointer
 
        // function is 3 cated structures;
        // compute their widths as side-effect.
        case TFUNCARGS:
-               t1 := t.Type
-
-               w = widstruct(t.Type, t1.Recvs(), 0, 0)
-               w = widstruct(t.Type, t1.Params(), w, Widthreg)
-               w = widstruct(t.Type, t1.Results(), w, Widthreg)
+               t1 := t.Wrapped()
+               w = widstruct(t1, t1.Recvs(), 0, 0)
+               w = widstruct(t1, t1.Params(), w, Widthreg)
+               w = widstruct(t1, t1.Results(), w, Widthreg)
                t1.Argwid = w
                if w%int64(Widthreg) != 0 {
                        Warn("bad type %v %d\n", t1, w)

diff --git a/src/cmd/compile/internal/gc/bexport.go b/src/cmd/compile/internal/gc/bexport.go
index f47d7bb06ec154aeda6f8bae84bbf8624ce9cd3a..f14f12fdc06d45d3ad87f506c9f5267af537c476 100644 (file)
--- a/src/cmd/compile/internal/gc/bexport.go
+++ b/src/cmd/compile/internal/gc/bexport.go
@@ -517,7 +517,7 @@ func (p *exporter) typ(t *Type) {
        case TDDDFIELD:
                // see p.param use of TDDDFIELD
                p.tag(dddTag)
-               p.typ(t.Type)
+               p.typ(t.Wrapped())
 
        case TSTRUCT:
                p.tag(structTag)
@@ -666,7 +666,7 @@ func (p *exporter) param(q *Field, n int, numbered bool) {
        t := q.Type
        if q.Isddd {
                // create a fake type to encode ... just for the p.typ call
-               t = &Type{Etype: TDDDFIELD, Type: t.Type}
+               t = typWrapper(TDDDFIELD, t.Type)
        }
        p.typ(t)
        if n > 0 {

diff --git a/src/cmd/compile/internal/gc/type.go b/src/cmd/compile/internal/gc/type.go
index 6d0476eedb6d4ba1f464d0c60b897ec7e1790dfb..c6a2dd92a32c0b85513790faaddad4c5480cf8b2 100644 (file)
--- a/src/cmd/compile/internal/gc/type.go
+++ b/src/cmd/compile/internal/gc/type.go
@@ -267,6 +267,18 @@ func typeChan(elem *Type, dir uint8) *Type {
        return t
 }
 
+// typWrapper returns a new wrapper psuedo-type.
+func typWrapper(et EType, wrapped *Type) *Type {
+       switch et {
+       case TCHANARGS, TFUNCARGS, TDDDFIELD:
+       default:
+               Fatalf("typWrapper bad etype %s", et)
+       }
+       t := typ(et)
+       t.Type = wrapped
+       return t
+}
+
 func newField() *Field {
        return &Field{
                Offset: BADWIDTH,
@@ -474,6 +486,16 @@ func (t *Type) Val() *Type {
        return t.Type
 }
 
+// Wrapped returns the type that pseudo-type t wraps.
+func (t *Type) Wrapped() *Type {
+       switch t.Etype {
+       case TCHANARGS, TFUNCARGS, TDDDFIELD:
+       default:
+               Fatalf("Type.Wrapped %s", t.Etype)
+       }
+       return t.Type
+}
+
 func (t *Type) Methods() *Fields {
        // TODO(mdempsky): Validate t?
        return &t.methods