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|
package irutil
import (
"go/types"
"strings"
"honnef.co/go/tools/go/ir"
"honnef.co/go/tools/go/types/typeutil"
)
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
alloc, ok := ir.Unwrap(x.X).(*ir.Alloc)
if !ok {
return nil, false
}
var checkAlloc func(alloc ir.Value) bool
checkAlloc = func(alloc ir.Value) bool {
for _, ref := range *alloc.Referrers() {
if ref == x {
continue
}
if ref.Block() != x.Block() {
return false
}
switch ref := ref.(type) {
case *ir.IndexAddr:
idx := ref
if len(*idx.Referrers()) != 1 {
return false
}
store, ok := (*idx.Referrers())[0].(*ir.Store)
if !ok {
return false
}
out = append(out, store.Val)
case *ir.Copy:
if !checkAlloc(ref) {
return false
}
default:
return false
}
}
return true
}
if !checkAlloc(alloc) {
return nil, false
}
return out, true
}
func CallName(call *ir.CallCommon) string {
if call.IsInvoke() {
return ""
}
switch v := call.Value.(type) {
case *ir.Function:
fn, ok := v.Object().(*types.Func)
if !ok {
return ""
}
return typeutil.FuncName(fn)
case *ir.Builtin:
return v.Name()
}
return ""
}
func IsCallTo(call *ir.CallCommon, name string) bool { return CallName(call) == name }
func IsCallToAny(call *ir.CallCommon, names ...string) bool {
q := CallName(call)
for _, name := range names {
if q == name {
return true
}
}
return false
}
func FilterDebug(instr []ir.Instruction) []ir.Instruction {
var out []ir.Instruction
for _, ins := range instr {
if _, ok := ins.(*ir.DebugRef); !ok {
out = append(out, ins)
}
}
return out
}
func IsExample(fn *ir.Function) bool {
if !strings.HasPrefix(fn.Name(), "Example") {
return false
}
f := fn.Prog.Fset.File(fn.Pos())
if f == nil {
return false
}
return strings.HasSuffix(f.Name(), "_test.go")
}
// Flatten recursively returns the underlying value of an ir.Sigma or
// ir.Phi node. If all edges in an ir.Phi node are the same (after
// flattening), the flattened edge will get returned. If flattening is
// not possible, nil is returned.
func Flatten(v ir.Value) ir.Value {
failed := false
seen := map[ir.Value]struct{}{}
var out ir.Value
var dfs func(v ir.Value)
dfs = func(v ir.Value) {
if failed {
return
}
if _, ok := seen[v]; ok {
return
}
seen[v] = struct{}{}
switch v := v.(type) {
case *ir.Sigma:
dfs(v.X)
case *ir.Phi:
for _, e := range v.Edges {
dfs(e)
}
default:
if out == nil {
out = v
} else if out != v {
failed = true
}
}
}
dfs(v)
if failed {
return nil
}
return out
}
|
