add nilassign linter (#2131)

Co-authored-by: Fernandez Ludovic <[email protected]>

Author: sivchari

go.mod

@@ -66,6 +66,7 @@ require (
 	github.com/shazow/go-diff v0.0.0-20160112020656-b6b7b6733b8c
 	github.com/shirou/gopsutil/v3 v3.21.6
 	github.com/sirupsen/logrus v1.8.1
+	github.com/sivchari/nilassign v0.1.0
 	github.com/sonatard/noctx v0.0.1
 	github.com/sourcegraph/go-diff v0.6.1
 	github.com/spf13/cobra v1.2.1

go.sum

@@ -0,0 +1,21 @@
+package golinters
+
+import (
+	"github.com/sivchari/nilassign"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+)
+
+func NewNilAssign() *goanalysis.Linter {
+	analyzers := []*analysis.Analyzer{
+		nilassign.Analyzer,
+	}
+
+	return goanalysis.NewLinter(
+		"nilassign",
+		"Finds that assigning to invalid memory address or nil pointer dereference.",
+		analyzers,
+		nil,
+	).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}

pkg/golinters/nilassign.go

@@ -485,6 +485,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithLoadForGoAnalysis().
 			WithPresets(linter.PresetBugs).
 			WithURL("https://github.com/gostaticanalysis/nilerr"),
+		linter.NewConfig(golinters.NewNilAssign()).
+			WithSince("v1.42.0").
+			WithLoadForGoAnalysis().
+			WithPresets(linter.PresetBugs).
+			WithURL("https://github.com/sivchari/nilassign"),
 		linter.NewConfig(golinters.NewForceTypeAssert()).
 			WithSince("v1.38.0").
 			WithPresets(linter.PresetStyle).

pkg/lint/lintersdb/manager.go

@@ -0,0 +1,28 @@
+//args: -Enilassign
+package testdata
+
+var num = 1
+
+func pvar() {
+	var ii *int
+	*ii = 1 // ERROR "this assignment occurs invalid memory address or nil pointer dereference"
+
+	var i *int
+	i = &num // OK
+	_ = i    // OK
+}
+
+func pstruct() {
+	n := new(Node)
+
+	*n.PVal = 1           // ERROR "this assignment occurs invalid memory address or nil pointer dereference"
+	*n.ChildNode.PVal = 1 // ERROR "this assignment occurs invalid memory address or nil pointer dereference"
+
+	n.ChildNode = &Node{PVal: &num} // OK
+	n.PVal = &num                   // OK
+}
+
+type Node struct {
+	PVal      *int
+	ChildNode *Node
+}