Add cmplint linter

cmplint is a Go linter (static analysis tool) that detects comparisons against
the address of newly created values, such as ptr == &MyStruct{} or ptr == new(MyStruct).

https://pkg.go.dev/fillmore-labs.com/cmplint
Signed-off-by: Oliver Eikemeier <[email protected]>

Author: eikemeier

go.mod

@@ -5,6 +5,7 @@ go 1.23.0
 require (
 	4d63.com/gocheckcompilerdirectives v1.3.0
 	4d63.com/gochecknoglobals v0.2.2
+	fillmore-labs.com/cmplint v0.0.2
 	github.com/4meepo/tagalign v1.4.2
 	github.com/Abirdcfly/dupword v0.1.6
 	github.com/AlwxSin/noinlineerr v1.0.3

go.sum

@@ -728,6 +728,7 @@
             "bidichk",
             "bodyclose",
             "canonicalheader",
+            "cmplint",
             "containedctx",
             "contextcheck",
             "copyloopvar",
@@ -945,6 +946,17 @@
             }
           }
         },
+        "cmplintSettings": {
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "check-is": {
+              "description": "Suppress check for errors with \"Is\" method",
+              "type": "boolean",
+              "default": true
+            }
+          }
+        },
         "cyclopSettings": {
           "type": "object",
           "additionalProperties": false,
@@ -4362,6 +4374,9 @@
             "bidichk": {
               "$ref": "#/definitions/settings/definitions/bidichkSettings"
             },
+            "cmplint": {
+              "$ref": "#/definitions/settings/definitions/cmplintSettings"
+            },
             "cyclop": {
               "$ref": "#/definitions/settings/definitions/cyclopSettings"
             },

jsonschema/golangci.next.jsonschema.json

@@ -12,6 +12,9 @@ var defaultLintersSettings = LintersSettings{
 	Asasalint: AsasalintSettings{
 		UseBuiltinExclusions: true,
 	},
+	Cmplint: CmplintSettings{
+		CheckIs: true,
+	},
 	Decorder: DecorderSettings{
 		DecOrder:                  []string{"type", "const", "var", "func"},
 		DisableDecNumCheck:        true,
@@ -209,6 +212,7 @@ type LintersSettings struct {
 	BiDiChk                  BiDiChkSettings                  `mapstructure:"bidichk"`
 	CopyLoopVar              CopyLoopVarSettings              `mapstructure:"copyloopvar"`
 	Cyclop                   CyclopSettings                   `mapstructure:"cyclop"`
+	Cmplint                  CmplintSettings                  `mapstructure:"cmplint"`
 	Decorder                 DecorderSettings                 `mapstructure:"decorder"`
 	Depguard                 DepGuardSettings                 `mapstructure:"depguard"`
 	Dogsled                  DogsledSettings                  `mapstructure:"dogsled"`
@@ -319,6 +323,10 @@ type BiDiChkSettings struct {
 	PopDirectionalIsolate    bool `mapstructure:"pop-directional-isolate"`
 }
 
+type CmplintSettings struct {
+	CheckIs bool `mapstructure:"check-is"`
+}
+
 type CopyLoopVarSettings struct {
 	CheckAlias bool `mapstructure:"check-alias"`
 }

pkg/config/linters_settings.go

@@ -0,0 +1,16 @@
+package cmplint
+
+import (
+	cmplint "fillmore-labs.com/cmplint/analyzer"
+
+	"github.com/golangci/golangci-lint/v2/pkg/config"
+	"github.com/golangci/golangci-lint/v2/pkg/goanalysis"
+)
+
+func New(settings *config.CmplintSettings) *goanalysis.Linter {
+	cmplint.CheckIs = settings.CheckIs
+
+	return goanalysis.
+		NewLinterFromAnalyzer(cmplint.Analyzer).
+		WithLoadMode(goanalysis.LoadModeTypesInfo)
+}

pkg/golinters/cmplint/cmplint.go

@@ -0,0 +1,11 @@
+package cmplint
+
+import (
+	"testing"
+
+	"github.com/golangci/golangci-lint/v2/test/testshared/integration"
+)
+
+func TestFromTestdata(t *testing.T) {
+	integration.RunTestdata(t)
+}

pkg/golinters/cmplint/cmplint_integration_test.go

@@ -0,0 +1,22 @@
+//golangcitest:args -Ecmplint
+//golangcitest:config_path testdata/cmplint.yml
+package main
+
+import (
+	"errors"
+	"log"
+	"net/url"
+)
+
+func main() {
+	_, err := url.Parse("://example.com")
+
+	if errors.Is(err, &url.Error{}) { // want "is always false"
+		log.Fatal("Cannot parse URL")
+	}
+
+	var urlErr *url.Error
+	if errors.As(err, &urlErr) {
+		log.Fatalf("Cannot parse URL: %v", urlErr)
+	}
+}

pkg/golinters/cmplint/testdata/cmplint.go

@@ -0,0 +1,6 @@
+version: "2"
+
+linters:
+  settings:
+    cmplint:
+      check-is: false

pkg/golinters/cmplint/testdata/cmplint.yml

@@ -9,6 +9,7 @@ import (
 	"github.com/golangci/golangci-lint/v2/pkg/golinters/bidichk"
 	"github.com/golangci/golangci-lint/v2/pkg/golinters/bodyclose"
 	"github.com/golangci/golangci-lint/v2/pkg/golinters/canonicalheader"
+	"github.com/golangci/golangci-lint/v2/pkg/golinters/cmplint"
 	"github.com/golangci/golangci-lint/v2/pkg/golinters/containedctx"
 	"github.com/golangci/golangci-lint/v2/pkg/golinters/contextcheck"
 	"github.com/golangci/golangci-lint/v2/pkg/golinters/copyloopvar"
@@ -168,6 +169,11 @@ func (LinterBuilder) Build(cfg *config.Config) ([]*linter.Config, error) {
 			WithAutoFix().
 			WithURL("https://github.com/lasiar/canonicalheader"),
 
+		linter.NewConfig(cmplint.New(&cfg.Linters.Settings.Cmplint)).
+			WithSince("v2.2.0").
+			WithLoadForGoAnalysis().
+			WithURL("https://github.com/fillmore-labs/cmplint"),
+
 		linter.NewConfig(containedctx.New()).
 			WithSince("v1.44.0").
 			WithLoadForGoAnalysis().