54
vendor/honnef.co/go/tools/functions/loops.go
vendored
Normal file
54
vendor/honnef.co/go/tools/functions/loops.go
vendored
Normal file
@@ -0,0 +1,54 @@
|
||||
package functions
|
||||
|
||||
import "honnef.co/go/tools/ir"
|
||||
|
||||
type Loop struct{ *ir.BlockSet }
|
||||
|
||||
func FindLoops(fn *ir.Function) []Loop {
|
||||
if fn.Blocks == nil {
|
||||
return nil
|
||||
}
|
||||
tree := fn.DomPreorder()
|
||||
var sets []Loop
|
||||
for _, h := range tree {
|
||||
for _, n := range h.Preds {
|
||||
if !h.Dominates(n) {
|
||||
continue
|
||||
}
|
||||
// n is a back-edge to h
|
||||
// h is the loop header
|
||||
if n == h {
|
||||
set := Loop{ir.NewBlockSet(len(fn.Blocks))}
|
||||
set.Add(n)
|
||||
sets = append(sets, set)
|
||||
continue
|
||||
}
|
||||
set := Loop{ir.NewBlockSet(len(fn.Blocks))}
|
||||
set.Add(h)
|
||||
set.Add(n)
|
||||
for _, b := range allPredsBut(n, h, nil) {
|
||||
set.Add(b)
|
||||
}
|
||||
sets = append(sets, set)
|
||||
}
|
||||
}
|
||||
return sets
|
||||
}
|
||||
|
||||
func allPredsBut(b, but *ir.BasicBlock, list []*ir.BasicBlock) []*ir.BasicBlock {
|
||||
outer:
|
||||
for _, pred := range b.Preds {
|
||||
if pred == but {
|
||||
continue
|
||||
}
|
||||
for _, p := range list {
|
||||
// TODO improve big-o complexity of this function
|
||||
if pred == p {
|
||||
continue outer
|
||||
}
|
||||
}
|
||||
list = append(list, pred)
|
||||
list = allPredsBut(pred, but, list)
|
||||
}
|
||||
return list
|
||||
}
|
||||
Reference in New Issue
Block a user