forked from vikunja/vikunja
71 lines
1.5 KiB
Go
71 lines
1.5 KiB
Go
package functions
|
||
|
||
import (
|
||
"go/types"
|
||
|
||
"honnef.co/go/tools/ir"
|
||
)
|
||
|
||
// Terminates reports whether fn is supposed to return, that is if it
|
||
// has at least one theoretic path that returns from the function.
|
||
// Explicit panics do not count as terminating.
|
||
func Terminates(fn *ir.Function) bool {
|
||
if fn.Blocks == nil {
|
||
// assuming that a function terminates is the conservative
|
||
// choice
|
||
return true
|
||
}
|
||
|
||
for _, block := range fn.Blocks {
|
||
if _, ok := block.Control().(*ir.Return); ok {
|
||
if len(block.Preds) == 0 {
|
||
return true
|
||
}
|
||
for _, pred := range block.Preds {
|
||
switch ctrl := pred.Control().(type) {
|
||
case *ir.Panic:
|
||
// explicit panics do not count as terminating
|
||
case *ir.If:
|
||
// Check if we got here by receiving from a closed
|
||
// time.Tick channel – this cannot happen at
|
||
// runtime and thus doesn't constitute termination
|
||
iff := ctrl
|
||
if !ok {
|
||
return true
|
||
}
|
||
ex, ok := iff.Cond.(*ir.Extract)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if ex.Index != 1 {
|
||
return true
|
||
}
|
||
recv, ok := ex.Tuple.(*ir.Recv)
|
||
if !ok {
|
||
return true
|
||
}
|
||
call, ok := recv.Chan.(*ir.Call)
|
||
if !ok {
|
||
return true
|
||
}
|
||
fn, ok := call.Common().Value.(*ir.Function)
|
||
if !ok {
|
||
return true
|
||
}
|
||
fn2, ok := fn.Object().(*types.Func)
|
||
if !ok {
|
||
return true
|
||
}
|
||
if fn2.FullName() != "time.Tick" {
|
||
return true
|
||
}
|
||
default:
|
||
// we've reached the exit block
|
||
return true
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return false
|
||
}
|