Update megacheck to the latest version

Also do following improvements:
  - show proper sublinter name for megacheck sublinters
  - refactor and make more simple and robust megacheck
  merging/optimizing
  - improve handling of unknown linter names in //nolint directives
  - minimize diff of our megacheck version from the upstream,
  golang/go#29612 blocks usage of the upstream
  version
  - support the new `stylecheck` linter
  - improve tests coverage for megacheck and nolint related cases
  - update and use upstream versions of unparam and interfacer instead of forked
  ones
  - don't use golangci/tools repo anymore
  - fix newly found issues after updating linters

Also should be noted that megacheck works much faster and consumes less
memory in the newest release, therefore golangci-lint works noticeably
faster and consumes less memory for large repos.

Relates: #314

Author: jirfag

README.md

@@ -166,7 +166,7 @@ GolangCI-Lint can be used with zero configuration. By default the following lint
 ```bash
 $ golangci-lint help linters
 Enabled by default linters:
-govet: Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string [fast: true]
+govet (vet, vetshadow): Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string [fast: true]
 errcheck: Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases [fast: true]
 staticcheck: Staticcheck is a go vet on steroids, applying a ton of static analysis checks [fast: false]
 unused: Checks Go code for unused constants, variables, functions and types [fast: false]
@@ -185,6 +185,7 @@ $ golangci-lint help linters
 ...
 Disabled by default linters:
 golint: Golint differs from gofmt. Gofmt reformats Go source code, whereas golint prints out style mistakes [fast: true]
+stylecheck: Stylecheck is a replacement for golint [fast: false]
 gosec (gas): Inspects source code for security problems [fast: true]
 interfacer: Linter that suggests narrower interface types [fast: false]
 unconvert: Remove unnecessary type conversions [fast: true]
@@ -194,7 +195,6 @@ gocyclo: Computes and checks the cyclomatic complexity of functions [fast: true]
 gofmt: Gofmt checks whether code was gofmt-ed. By default this tool runs with -s option to check for code simplification [fast: true]
 goimports: Goimports does everything that gofmt does. Additionally it checks unused imports [fast: true]
 maligned: Tool to detect Go structs that would take less memory if their fields were sorted [fast: true]
-megacheck: 3 sub-linters in one: unused, gosimple and staticcheck [fast: false]
 depguard: Go linter that checks if package imports are in a list of acceptable packages [fast: true]
 misspell: Finds commonly misspelled English words in comments [fast: true]
 lll: Reports long lines [fast: true]
@@ -388,6 +388,7 @@ golangci-lint help linters
 ### Disabled By Default Linters (`-E/--enable`)
 
 - [golint](https://github.com/golang/lint) - Golint differs from gofmt. Gofmt reformats Go source code, whereas golint prints out style mistakes
+- [stylecheck](https://github.com/dominikh/go-tools/tree/master/stylecheck) - Stylecheck is a replacement for golint
 - [gosec](https://github.com/securego/gosec) - Inspects source code for security problems
 - [interfacer](https://github.com/mvdan/interfacer) - Linter that suggests narrower interface types
 - [unconvert](https://github.com/mdempsky/unconvert) - Remove unnecessary type conversions
@@ -397,7 +398,6 @@ golangci-lint help linters
 - [gofmt](https://golang.org/cmd/gofmt/) - Gofmt checks whether code was gofmt-ed. By default this tool runs with -s option to check for code simplification
 - [goimports](https://godoc.org/golang.org/x/tools/cmd/goimports) - Goimports does everything that gofmt does. Additionally it checks unused imports
 - [maligned](https://github.com/mdempsky/maligned) - Tool to detect Go structs that would take less memory if their fields were sorted
-- [megacheck](https://github.com/dominikh/go-tools/tree/master/cmd/megacheck) - 3 sub-linters in one: unused, gosimple and staticcheck
 - [depguard](https://github.com/OpenPeeDeeP/depguard) - Go linter that checks if package imports are in a list of acceptable packages
 - [misspell](https://github.com/client9/misspell) - Finds commonly misspelled English words in comments
 - [lll](https://github.com/walle/lll) - Reports long lines
@@ -461,7 +461,7 @@ Flags:
                                       # govet: Common false positives
                                       - (possible misuse of unsafe.Pointer|should have signature)
                                     
-                                      # megacheck: Developers tend to write in C-style with an explicit 'break' in a 'switch', so it's ok to ignore
+                                      # staticcheck: Developers tend to write in C-style with an explicit 'break' in a 'switch', so it's ok to ignore
                                       - ineffective break statement. Did you mean to break out of the outer loop
                                     
                                       # gosec: Too many false-positives on 'unsafe' usage

go.mod

@@ -21,23 +21,19 @@ require (
 	github.com/golangci/dupl v0.0.0-20180902072040-3e9179ac440a
 	github.com/golangci/errcheck v0.0.0-20181003203344-ef45e06d44b6
 	github.com/golangci/go-misc v0.0.0-20180628070357-927a3d87b613
-	github.com/golangci/go-tools v0.0.0-20180902103155-93eecd106a0b
+	github.com/golangci/go-tools v0.0.0-20180109140146-be4842e24b95
 	github.com/golangci/goconst v0.0.0-20180610141641-041c5f2b40f3
 	github.com/golangci/gocyclo v0.0.0-20180528134321-2becd97e67ee
 	github.com/golangci/gofmt v0.0.0-20181105071733-0b8337e80d98
 	github.com/golangci/gosec v0.0.0-20180901114220-8afd9cbb6cfb
 	github.com/golangci/govet v0.0.0-20180818181408-44ddbe260190
 	github.com/golangci/ineffassign v0.0.0-20180808204949-2ee8f2867dde
-	github.com/golangci/interfacer v0.0.0-20180902080945-01958817a6ec
-	github.com/golangci/lint v0.0.0-20180902080404-c2187e7932b5 // indirect
 	github.com/golangci/lint-1 v0.0.0-20180610141402-4bf9709227d1
 	github.com/golangci/maligned v0.0.0-20180506175553-b1d89398deca
 	github.com/golangci/misspell v0.0.0-20180809174111-950f5d19e770
 	github.com/golangci/prealloc v0.0.0-20180630174525-215b22d4de21
 	github.com/golangci/revgrep v0.0.0-20180526074752-d9c87f5ffaf0
-	github.com/golangci/tools v0.0.0-20180902102414-2cefd77fef9b
 	github.com/golangci/unconvert v0.0.0-20180507085042-28b1c447d1f4
-	github.com/golangci/unparam v0.0.0-20180902112548-7ad9dbcccc16
 	github.com/hashicorp/hcl v0.0.0-20180404174102-ef8a98b0bbce // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/magiconair/properties v1.7.6 // indirect
@@ -68,6 +64,9 @@ require (
 	gopkg.in/airbrake/gobrake.v2 v2.0.9 // indirect
 	gopkg.in/gemnasium/logrus-airbrake-hook.v2 v2.1.2 // indirect
 	gopkg.in/yaml.v2 v2.2.1
+	mvdan.cc/interfacer v0.0.0-20180901003855-c20040233aed
+	mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b // indirect
+	mvdan.cc/unparam v0.0.0-20181201214637-68701730a1d7
 	sourcegraph.com/sourcegraph/go-diff v0.0.0-20171119081133-3f415a150aec
 	sourcegraph.com/sqs/pbtypes v0.0.0-20160107090929-4d1b9dc7ffc3 // indirect
 )

go.sum

@@ -49,8 +49,8 @@ github.com/golangci/errcheck v0.0.0-20181003203344-ef45e06d44b6 h1:i2jIkQFb8RG45
 github.com/golangci/errcheck v0.0.0-20181003203344-ef45e06d44b6/go.mod h1:DbHgvLiFKX1Sh2T1w8Q/h4NAI8MHIpzCdnBUDTXU3I0=
 github.com/golangci/go-misc v0.0.0-20180628070357-927a3d87b613 h1:WadunOE/TeHR8U7f0TXiJACHeU3cuFOXuKafw4rozqU=
 github.com/golangci/go-misc v0.0.0-20180628070357-927a3d87b613/go.mod h1:SyvUF2NxV+sN8upjjeVYr5W7tyxaT1JVtvhKhOn2ii8=
-github.com/golangci/go-tools v0.0.0-20180902103155-93eecd106a0b h1:FSrt9JBK7JINu5UobyIF6epfpjL66H+67KZoTbE0zwk=
-github.com/golangci/go-tools v0.0.0-20180902103155-93eecd106a0b/go.mod h1:unzUULGw35sjyOYjUt0jMTXqHlZPpPc6e+xfO4cd6mM=
+github.com/golangci/go-tools v0.0.0-20180109140146-be4842e24b95 h1:msnLojqdJ37Bszm2D+srIkHJZvTKPFQWuyJAeMU6Ilo=
+github.com/golangci/go-tools v0.0.0-20180109140146-be4842e24b95/go.mod h1:unzUULGw35sjyOYjUt0jMTXqHlZPpPc6e+xfO4cd6mM=
 github.com/golangci/goconst v0.0.0-20180610141641-041c5f2b40f3 h1:pe9JHs3cHHDQgOFXJJdYkK6fLz2PWyYtP4hthoCMvs8=
 github.com/golangci/goconst v0.0.0-20180610141641-041c5f2b40f3/go.mod h1:JXrF4TWy4tXYn62/9x8Wm/K/dm06p8tCKwFRDPZG/1o=
 github.com/golangci/gocyclo v0.0.0-20180528134321-2becd97e67ee h1:J2XAy40+7yz70uaOiMbNnluTg7gyQhtGqLQncQh+4J8=
@@ -63,11 +63,6 @@ github.com/golangci/govet v0.0.0-20180818181408-44ddbe260190 h1:SLIgprnxQNjBpkz5
 github.com/golangci/govet v0.0.0-20180818181408-44ddbe260190/go.mod h1:pPwb+AK755h3/r73avHz5bEN6sa51/2HEZlLaV53hCo=
 github.com/golangci/ineffassign v0.0.0-20180808204949-2ee8f2867dde h1:qEGp3ZF1Qw6TkbWKn6GdJ12Ssu/CpJBaBcJ4hrUjrSo=
 github.com/golangci/ineffassign v0.0.0-20180808204949-2ee8f2867dde/go.mod h1:e5tpTHCfVze+7EpLEozzMB3eafxo2KT5veNg1k6byQU=
-github.com/golangci/interfacer v0.0.0-20180902080945-01958817a6ec h1:rvg392QhtAd/yOevPRX4wzYMIDYyq99j9MV+Mb1uVHs=
-github.com/golangci/interfacer v0.0.0-20180902080945-01958817a6ec/go.mod h1:yBorupihJ5OYDFE7/EZwrslyNyZaaidqqVptYTcNxnk=
-github.com/golangci/lint v0.0.0-20170908181259-c2187e7932b5/go.mod h1:zs8jPuoOp76KrjiydDqO3CGeS4v9gq77HNNiYcxxTGw=
-github.com/golangci/lint v0.0.0-20180902080404-c2187e7932b5 h1:9NYm50bkzER4RayDaggNjxF5kesUJREASyFgk4AcIis=
-github.com/golangci/lint v0.0.0-20180902080404-c2187e7932b5/go.mod h1:zs8jPuoOp76KrjiydDqO3CGeS4v9gq77HNNiYcxxTGw=
 github.com/golangci/lint-1 v0.0.0-20180610141402-4bf9709227d1 h1:PHK2kIh21Zt4IcG0bBRzQwEDVKF64LnkoSXnm8lfJUk=
 github.com/golangci/lint-1 v0.0.0-20180610141402-4bf9709227d1/go.mod h1:/X8TswGSh1pIozq4ZwCfxS0WA5JGXguxk94ar/4c87Y=
 github.com/golangci/maligned v0.0.0-20180506175553-b1d89398deca h1:kNY3/svz5T29MYHubXix4aDDuE3RWHkPvopM/EDv/MA=
@@ -78,12 +73,8 @@ github.com/golangci/prealloc v0.0.0-20180630174525-215b22d4de21 h1:leSNB7iYzLYSS
 github.com/golangci/prealloc v0.0.0-20180630174525-215b22d4de21/go.mod h1:tf5+bzsHdTM0bsB7+8mt0GUMvjCgwLpTapNZHU8AajI=
 github.com/golangci/revgrep v0.0.0-20180526074752-d9c87f5ffaf0 h1:HVfrLniijszjS1aiNg8JbBMO2+E1WIQ+j/gL4SQqGPg=
 github.com/golangci/revgrep v0.0.0-20180526074752-d9c87f5ffaf0/go.mod h1:qOQCunEYvmd/TLamH+7LlVccLvUH5kZNhbCgTHoBbp4=
-github.com/golangci/tools v0.0.0-20180902102414-2cefd77fef9b h1:3hI7NZ9D3edEBVbN6V1urHWbFKJfcIlOFvX5m10jB88=
-github.com/golangci/tools v0.0.0-20180902102414-2cefd77fef9b/go.mod h1:zgj6NOYXOC1cexsdtDceI4/mj3aXK4JOVg9AV3C5LWI=
 github.com/golangci/unconvert v0.0.0-20180507085042-28b1c447d1f4 h1:zwtduBRr5SSWhqsYNgcuWO2kFlpdOZbP0+yRjmvPGys=
 github.com/golangci/unconvert v0.0.0-20180507085042-28b1c447d1f4/go.mod h1:Izgrg8RkN3rCIMLGE9CyYmU9pY2Jer6DgANEnZ/L/cQ=
-github.com/golangci/unparam v0.0.0-20180902112548-7ad9dbcccc16 h1:QURX/XMP2uJUzzEvfJ291v1snmbJuyznAJLSQVnPyko=
-github.com/golangci/unparam v0.0.0-20180902112548-7ad9dbcccc16/go.mod h1:KW2L33j82vo0S0U6RP6uUQSuat+0Q457Yf+1mXC98/M=
 github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/hashicorp/hcl v0.0.0-20180404174102-ef8a98b0bbce h1:xdsDDbiBDQTKASoGEZ+pEmF1OnWuu8AQ9I8iNbHNeno=
@@ -154,8 +145,8 @@ golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20180826000951-f6ba57429505/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20181117154741-2ddaf7f79a09/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20181201035826-d0ca3933b724/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20181220024903-92cdcd90bf52 h1:oOIe9Zzq27JsS/3ACpGF1HwWnWNflZWT/3EvM7mtcEk=
 golang.org/x/tools v0.0.0-20181220024903-92cdcd90bf52/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/airbrake/gobrake.v2 v2.0.9 h1:7z2uVWwn7oVeeugY1DtlPAy5H+KYgB1KeKTnqjNatLo=
@@ -170,6 +161,12 @@ gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkep
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+mvdan.cc/interfacer v0.0.0-20180901003855-c20040233aed h1:WX1yoOaKQfddO/mLzdV4wptyWgoH/6hwLs7QHTixo0I=
+mvdan.cc/interfacer v0.0.0-20180901003855-c20040233aed/go.mod h1:Xkxe497xwlCKkIaQYRfC7CSLworTXY9RMqwhhCm+8Nc=
+mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b h1:DxJ5nJdkhDlLok9K6qO+5290kphDJbHOQO1DFFFTeBo=
+mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b/go.mod h1:2odslEg/xrtNQqCYg2/jCoyKnw3vv5biOc3JnIcYfL4=
+mvdan.cc/unparam v0.0.0-20181201214637-68701730a1d7 h1:AHc3hAmhXTHwSA40I4CJW2w2iirqwLzZuFgC6LdbtJk=
+mvdan.cc/unparam v0.0.0-20181201214637-68701730a1d7/go.mod h1:N4YHaPPCFjRU1vNrla2C9eoyqLxMaHmrsI8Th4iuQMY=
 sourcegraph.com/sourcegraph/go-diff v0.0.0-20171119081133-3f415a150aec h1:wAAdENPXC7bE1oxY4VqSDdhaA+XQ8TgQHsZMMnrXjEk=
 sourcegraph.com/sourcegraph/go-diff v0.0.0-20171119081133-3f415a150aec/go.mod h1:R09mWeb9JcPbO+A3cYDc11xjz0wp6r9+KnqdqROAoRU=
 sourcegraph.com/sqs/pbtypes v0.0.0-20160107090929-4d1b9dc7ffc3 h1:hXy8YsgVLDz5mlngKhNHQhAsAGrSp3dlXZN4b0/4UUI=

pkg/commands/config.go

@@ -17,6 +17,9 @@ func (e *Executor) initConfig() {
 		Use:   "config",
 		Short: "Config",
 		Run: func(cmd *cobra.Command, args []string) {
+			if len(args) != 0 {
+				e.log.Fatalf("Usage: golangci-lint config")
+			}
 			if err := cmd.Help(); err != nil {
 				e.log.Fatalf("Can't run help: %s", err)
 			}
@@ -34,7 +37,11 @@ func (e *Executor) initConfig() {
 
 }
 
-func (e *Executor) executePathCmd(cmd *cobra.Command, args []string) {
+func (e *Executor) executePathCmd(_ *cobra.Command, args []string) {
+	if len(args) != 0 {
+		e.log.Fatalf("Usage: golangci-lint config path")
+	}
+
 	usedConfigFile := viper.ConfigFileUsed()
 	if usedConfigFile == "" {
 		e.log.Warnf("No config file detected")

pkg/commands/help.go

@@ -17,6 +17,9 @@ func (e *Executor) initHelp() {
 		Use:   "help",
 		Short: "Help",
 		Run: func(cmd *cobra.Command, args []string) {
+			if len(args) != 0 {
+				e.log.Fatalf("Usage: golangci-lint help")
+			}
 			if err := cmd.Help(); err != nil {
 				e.log.Fatalf("Can't run help: %s", err)
 			}
@@ -43,7 +46,7 @@ func printLinterConfigs(lcs []*linter.Config) {
 	}
 }
 
-func (e *Executor) executeLintersHelp(cmd *cobra.Command, args []string) {
+func (e *Executor) executeLintersHelp(_ *cobra.Command, args []string) {
 	if len(args) != 0 {
 		e.log.Fatalf("Usage: golangci-lint help linters")
 	}

pkg/commands/linters.go

@@ -30,7 +30,7 @@ func IsLinterInConfigsList(name string, linters []*linter.Config) bool {
 	return false
 }
 
-func (e *Executor) executeLinters(cmd *cobra.Command, args []string) {
+func (e *Executor) executeLinters(_ *cobra.Command, args []string) {
 	if len(args) != 0 {
 		e.log.Fatalf("Usage: golangci-lint linters")
 	}

pkg/commands/root.go

@@ -13,7 +13,7 @@ import (
 	"github.com/golangci/golangci-lint/pkg/logutils"
 )
 
-func (e *Executor) persistentPreRun(cmd *cobra.Command, args []string) {
+func (e *Executor) persistentPreRun(_ *cobra.Command, _ []string) {
 	if e.cfg.Run.PrintVersion {
 		fmt.Fprintf(logutils.StdOut, "golangci-lint has version %s built from %s on %s\n", e.version, e.commit, e.date)
 		os.Exit(0)
@@ -32,7 +32,7 @@ func (e *Executor) persistentPreRun(cmd *cobra.Command, args []string) {
 	}
 }
 
-func (e *Executor) persistentPostRun(cmd *cobra.Command, args []string) {
+func (e *Executor) persistentPostRun(_ *cobra.Command, _ []string) {
 	if e.cfg.Run.CPUProfilePath != "" {
 		pprof.StopCPUProfile()
 	}
@@ -64,6 +64,9 @@ func (e *Executor) initRoot() {
 		Short: "golangci-lint is a smart linters runner.",
 		Long:  `Smart, fast linters runner. Run it in cloud for every GitHub pull request on https://golangci.com`,
 		Run: func(cmd *cobra.Command, args []string) {
+			if len(args) != 0 {
+				e.log.Fatalf("Usage: golangci-lint")
+			}
 			if err := cmd.Help(); err != nil {
 				e.log.Fatalf("Can't run help: %s", err)
 			}

pkg/commands/run.go

@@ -370,7 +370,7 @@ func (e *Executor) createPrinter() (printers.Printer, error) {
 	return p, nil
 }
 
-func (e *Executor) executeRun(cmd *cobra.Command, args []string) {
+func (e *Executor) executeRun(_ *cobra.Command, args []string) {
 	needTrackResources := e.cfg.Run.IsVerbose || e.cfg.Run.PrintResourcesUsage
 	trackResourcesEndCh := make(chan struct{})
 	defer func() { // XXX: this defer must be before ctx.cancel defer

pkg/config/config.go

@@ -55,7 +55,7 @@ var DefaultExcludePatterns = []ExcludePattern{
 	},
 	{
 		Pattern: "ineffective break statement. Did you mean to break out of the outer loop",
-		Linter:  "megacheck",
+		Linter:  "staticcheck",
 		Why:     "Developers tend to write in C-style with an explicit 'break' in a 'switch', so it's ok to ignore",
 	},
 	{

pkg/golinters/gas.go renamed to pkg/golinters/gosec.go

@@ -3,7 +3,7 @@ package golinters
 import (
 	"context"
 
-	"github.com/golangci/interfacer/check"
+	"mvdan.cc/interfacer/check"
 
 	"github.com/golangci/golangci-lint/pkg/lint/linter"
 	"github.com/golangci/golangci-lint/pkg/result"