From fcc6d71be2c3ce7d9305c04fc2e87af554571bac Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Mon, 22 Feb 2021 20:37:25 +0100
Subject: go.mod: update golangci-lint to v1.37

---
 .../gostaticanalysis/analysisutil/ssa.go           | 65 +++++++++++++++++++++-
 1 file changed, 64 insertions(+), 1 deletion(-)

(limited to 'vendor/github.com/gostaticanalysis/analysisutil/ssa.go')

diff --git a/vendor/github.com/gostaticanalysis/analysisutil/ssa.go b/vendor/github.com/gostaticanalysis/analysisutil/ssa.go
index ce3af580b..517f6b9b4 100644
--- a/vendor/github.com/gostaticanalysis/analysisutil/ssa.go
+++ b/vendor/github.com/gostaticanalysis/analysisutil/ssa.go
@@ -72,7 +72,7 @@ func returnsInBlock(b *ssa.BasicBlock, done map[*ssa.BasicBlock]bool) (rets []*s
 }
 
 // BinOp returns binary operator values which are contained in the block b.
-func BinOp(b *ssa.BasicBlock) ([]*ssa.BinOp) {
+func BinOp(b *ssa.BasicBlock) []*ssa.BinOp {
 	var binops []*ssa.BinOp
 	for _, instr := range b.Instrs {
 		if binop, ok := instr.(*ssa.BinOp); ok {
@@ -81,3 +81,66 @@ func BinOp(b *ssa.BasicBlock) ([]*ssa.BinOp) {
 	}
 	return binops
 }
+
+// Used returns an instruction which uses the value in the instructions.
+func Used(v ssa.Value, instrs []ssa.Instruction) ssa.Instruction {
+	if len(instrs) == 0 || v.Referrers() == nil {
+		return nil
+	}
+
+	for _, instr := range instrs {
+		if used := usedInInstr(v, instr); used != nil {
+			return used
+		}
+	}
+
+	return nil
+}
+
+func usedInInstr(v ssa.Value, instr ssa.Instruction) ssa.Instruction {
+	switch instr := instr.(type) {
+	case *ssa.MakeClosure:
+		return usedInClosure(v, instr)
+	default:
+		operands := instr.Operands(nil)
+		for _, x := range operands {
+			if x != nil && *x == v {
+				return instr
+			}
+		}
+	}
+
+	switch v := v.(type) {
+	case *ssa.UnOp:
+		return usedInInstr(v.X, instr)
+	}
+
+	return nil
+}
+
+func usedInClosure(v ssa.Value, instr *ssa.MakeClosure) ssa.Instruction {
+	fn, _ := instr.Fn.(*ssa.Function)
+	if fn == nil {
+		return nil
+	}
+
+	var fv *ssa.FreeVar
+	for i := range instr.Bindings {
+		if instr.Bindings[i] == v {
+			fv = fn.FreeVars[i]
+			break
+		}
+	}
+
+	if fv == nil {
+		return nil
+	}
+
+	for _, b := range fn.Blocks {
+		if used := Used(fv, b.Instrs); used != nil {
+			return used
+		}
+	}
+
+	return nil
+}
-- 
cgit mrf-deployment