cmd/compile: add sliceBound

Add a constant for the magic -1 for slice bounds.
Use it.
Enforce more aggressively that bounds must be
slice, ddd, or non-negative.
Remove ad hoc check in plive.go.
Check bounds before constructing an array type
when typechecking.

All changes are manual.

Passes toolstash -cmp.

Change-Id: I9fd9cc789d7d4b4eea3b30b24037a254d3788add
Reviewed-on: https://go-review.googlesource.com/21348
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This commit is contained in:
Josh Bleecher Snyder 2016-03-31 09:29:39 -07:00
parent 4b95575bd4
commit e775b8df7a
5 changed files with 26 additions and 16 deletions

View file

@ -277,7 +277,7 @@ func (p *importer) typ() *Type {
case arrayTag, sliceTag:
t = p.newtyp(TARRAY)
t.Bound = -1
t.Bound = sliceBound
if i == arrayTag {
t.Bound = p.int64()
}
@ -285,7 +285,7 @@ func (p *importer) typ() *Type {
case dddTag:
t = p.newtyp(TDDDFIELD)
t.Bound = -1
t.Bound = sliceBound
t.Type = p.typ()
case structTag: