update dependencies

Signed-off-by: hongming <talonwan@yunify.com>

vendor/honnef.co/go/tools/functions/loops.go

@@ -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
+}

vendor/honnef.co/go/tools/functions/stub.go

@@ -0,0 +1,32 @@
+package functions
+
+import (
+	"honnef.co/go/tools/ir"
+)
+
+// IsStub reports whether a function is a stub. A function is
+// considered a stub if it has no instructions or if all it does is
+// return a constant value.
+func IsStub(fn *ir.Function) bool {
+	for _, b := range fn.Blocks {
+		for _, instr := range b.Instrs {
+			switch instr.(type) {
+			case *ir.Const:
+				// const naturally has no side-effects
+			case *ir.Panic:
+				// panic is a stub if it only uses constants
+			case *ir.Return:
+				// return is a stub if it only uses constants
+			case *ir.DebugRef:
+			case *ir.Jump:
+				// if there are no disallowed instructions, then we're
+				// only jumping to the exit block (or possibly
+				// somewhere else that's stubby?)
+			default:
+				// all other instructions are assumed to do actual work
+				return false
+			}
+		}
+	}
+	return true
+}

vendor/honnef.co/go/tools/functions/terminates.go

@@ -0,0 +1,70 @@
+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
+}