open-nomad/vendor/honnef.co/go/tools/ir/irutil/util.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

71 lines
1.1 KiB
Go

package irutil
import (
"honnef.co/go/tools/ir"
)
func Reachable(from, to *ir.BasicBlock) bool {
if from == to {
return true
}
if from.Dominates(to) {
return true
}
found := false
Walk(from, func(b *ir.BasicBlock) bool {
if b == to {
found = true
return false
}
return true
})
return found
}
func Walk(b *ir.BasicBlock, fn func(*ir.BasicBlock) bool) {
seen := map[*ir.BasicBlock]bool{}
wl := []*ir.BasicBlock{b}
for len(wl) > 0 {
b := wl[len(wl)-1]
wl = wl[:len(wl)-1]
if seen[b] {
continue
}
seen[b] = true
if !fn(b) {
continue
}
wl = append(wl, b.Succs...)
}
}
func Vararg(x *ir.Slice) ([]ir.Value, bool) {
var out []ir.Value
slice, ok := x.X.(*ir.Alloc)
if !ok {
return nil, false
}
for _, ref := range *slice.Referrers() {
if ref == x {
continue
}
if ref.Block() != x.Block() {
return nil, false
}
idx, ok := ref.(*ir.IndexAddr)
if !ok {
return nil, false
}
if len(*idx.Referrers()) != 1 {
return nil, false
}
store, ok := (*idx.Referrers())[0].(*ir.Store)
if !ok {
return nil, false
}
out = append(out, store.Val)
}
return out, true
}