Fix #237, fix #178: use go/packages

Use go/packages instead of x/tools/loader: it allows to work
with go modules and speedups loading of packages with the help
of build cache.

A lot of linters became "fast": they are enabled by --fast now and
work in 1-2 seconds. Only unparam, interfacer and megacheck
are "slow" linters now.

Average project is analyzed 20-40% faster than before if all linters are
enabled! If we enable all linters except unparam, interfacer and
megacheck analysis is 10-20x faster!

Author: jirfag

.golangci.example.yml

@@ -62,20 +62,6 @@ linters-settings:
   govet:
     # report about shadowed variables
     check-shadowing: true
-
-    # Obtain type information from installed (to $GOPATH/pkg) package files:
-    # golangci-lint will execute `go install -i` and `go test -i` for analyzed packages
-    # before analyzing them.
-    # By default this option is disabled and govet gets type information by loader from source code.
-    # Loading from source code is slow, but it's done only once for all linters.
-    # Go-installing of packages first time is much slower than loading them from source code,
-    # therefore this option is disabled by default.
-    # But repeated installation is fast in go >= 1.10 because of build caching.
-    # Enable this option only if all conditions are met:
-    #  1. you use only "fast" linters (--fast e.g.): no program loading occurs
-    #  2. you use go >= 1.10
-    #  3. you do repeated runs (false for CI) or cache $GOPATH/pkg or `go env GOCACHE` dir in CI.
-    use-installed-packages: false
   golint:
     # minimal confidence for issues, default is 0.8
     min-confidence: 0.8

.golangci.yml

@@ -20,6 +20,8 @@ linters-settings:
       - github.com/sirupsen/logrus
   misspell:
     locale: US
+  lll:
+    line-length: 140
 
 linters:
   enable-all: true

Gopkg.lock

@@ -113,16 +113,16 @@ GolangCI-Lint can be used with zero configuration. By default the following lint
 ```
 $ 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: false]
-errcheck: Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases [fast: false]
+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]
+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]
 gosimple: Linter for Go source code that specializes in simplifying a code [fast: false]
-structcheck: Finds an unused struct fields [fast: false]
-varcheck: Finds unused global variables and constants [fast: false]
+structcheck: Finds an unused struct fields [fast: true]
+varcheck: Finds unused global variables and constants [fast: true]
 ineffassign: Detects when assignments to existing variables are not used [fast: true]
-deadcode: Finds unused code [fast: false]
-typecheck: Like the front-end of a Go compiler, parses and type-checks Go code [fast: false]
+deadcode: Finds unused code [fast: true]
+typecheck: Like the front-end of a Go compiler, parses and type-checks Go code [fast: true]
 ```
 
 and the following linters are disabled by default:
@@ -131,17 +131,17 @@ $ 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]
-gosec (gas): Inspects source code for security problems [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: false]
+unconvert: Remove unnecessary type conversions [fast: true]
 dupl: Tool for code clone detection [fast: true]
 goconst: Finds repeated strings that could be replaced by a constant [fast: true]
 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: false]
+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: 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]
 unparam: Reports unused function parameters [fast: false]
@@ -372,7 +372,7 @@ Flags:
       --enable-all                  Enable all linters
       --disable-all                 Disable all linters
   -p, --presets strings             Enable presets (bugs|unused|format|style|complexity|performance) of linters. Run 'golangci-lint linters' to see them. This option implies option --disable-all
-      --fast                        Run only fast linters from enabled linters set
+      --fast                        Run only fast linters from enabled linters set (first run won't be fast)
   -e, --exclude strings             Exclude issue by regexp
       --exclude-use-default         Use or not use default excludes:
                                       # errcheck: Almost all programs ignore errors on these functions and in most cases it's ok
@@ -502,20 +502,6 @@ linters-settings:
   govet:
     # report about shadowed variables
     check-shadowing: true
-
-    # Obtain type information from installed (to $GOPATH/pkg) package files:
-    # golangci-lint will execute `go install -i` and `go test -i` for analyzed packages
-    # before analyzing them.
-    # By default this option is disabled and govet gets type information by loader from source code.
-    # Loading from source code is slow, but it's done only once for all linters.
-    # Go-installing of packages first time is much slower than loading them from source code,
-    # therefore this option is disabled by default.
-    # But repeated installation is fast in go >= 1.10 because of build caching.
-    # Enable this option only if all conditions are met:
-    #  1. you use only "fast" linters (--fast e.g.): no program loading occurs
-    #  2. you use go >= 1.10
-    #  3. you do repeated runs (false for CI) or cache $GOPATH/pkg or `go env GOCACHE` dir in CI.
-    use-installed-packages: false
   golint:
     # minimal confidence for issues, default is 0.8
     min-confidence: 0.8
@@ -657,6 +643,8 @@ linters-settings:
       - github.com/sirupsen/logrus
   misspell:
     locale: US
+  lll:
+    line-length: 140
 
 linters:
   enable-all: true
@@ -701,9 +689,7 @@ We don't recommend vendoring `golangci-lint` in your repo: you will get troubles
 
 **Does I need to run `go install`?**
 
-No, you don't need to do it anymore. We will run `go install -i` and `go test -i`
-for analyzed packages ourselves. We will run them only
-if option `govet.use-installed-packages` is `true`.
+No, you don't need to do it anymore.
 
 **Which go versions are supported**
 Golangci-lint versions > 1.10.2 supports Go 1.10 and 1.11.
@@ -715,7 +701,12 @@ Golangci-lint versions <= v1.10.2 supported Go 1.9, 1.10, 1.11.
 2. Run it with `-v` option and check the output.
 3. If it doesn't help create a [GitHub issue](https://github.com/golangci/golangci-lint/issues/new) with the output from the error and #2 above.
 
+**Why running with `--fast` is slow on the first run?**
+Because the first run caches type information. All subsequent runs will be fast.
+Usually this options is used during development on local machine and compilation was already performed.
+
 # Thanks
+
 Thanks to [alecthomas/gometalinter](https://github.com/alecthomas/gometalinter) for inspiration and amazing work.
 Thanks to [bradleyfalzon/revgrep](https://github.com/bradleyfalzon/revgrep) for cool diff tool.
 

README.md

@@ -361,9 +361,7 @@ We don't recommend vendoring `golangci-lint` in your repo: you will get troubles
 
 **Does I need to run `go install`?**
 
-No, you don't need to do it anymore. We will run `go install -i` and `go test -i`
-for analyzed packages ourselves. We will run them only
-if option `govet.use-installed-packages` is `true`.
+No, you don't need to do it anymore.
 
 **Which go versions are supported**
 Golangci-lint versions > 1.10.2 supports Go 1.10 and 1.11.
@@ -375,7 +373,12 @@ Golangci-lint versions <= v1.10.2 supported Go 1.9, 1.10, 1.11.
 2. Run it with `-v` option and check the output.
 3. If it doesn't help create a [GitHub issue](https://github.com/golangci/golangci-lint/issues/new) with the output from the error and #2 above.
 
+**Why running with `--fast` is slow on the first run?**
+Because the first run caches type information. All subsequent runs will be fast.
+Usually this options is used during development on local machine and compilation was already performed.
+
 # Thanks
+
 Thanks to [alecthomas/gometalinter](https://github.com/alecthomas/gometalinter) for inspiration and amazing work.
 Thanks to [bradleyfalzon/revgrep](https://github.com/bradleyfalzon/revgrep) for cool diff tool.
 

README.tmpl.md

@@ -28,7 +28,7 @@ require (
 	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 v0.0.0-20180902102414-98e75f53b4b9
+	github.com/golangci/tools v0.0.0-20180902102414-01dd7756e01d
 	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
@@ -56,7 +56,7 @@ require (
 	github.com/spf13/viper v1.0.2
 	github.com/stretchr/testify v1.2.1
 	golang.org/x/crypto v0.0.0-20180505025534-4ec37c66abab // indirect
-	golang.org/x/tools v0.0.0-20180831211245-5d4988d199e2
+	golang.org/x/tools v0.0.0-20180831211245-3e7aa9e59977
 	gopkg.in/airbrake/gobrake.v2 v2.0.9 // indirect
 	gopkg.in/gemnasium/logrus-airbrake-hook.v2 v2.1.2 // indirect
 	sourcegraph.com/sourcegraph/go-diff v0.0.0-20171119081133-3f415a150aec

go.mod

@@ -59,6 +59,7 @@ 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 v0.0.0-20180902102414-01dd7756e01d/go.mod h1:zgj6NOYXOC1cexsdtDceI4/mj3aXK4JOVg9AV3C5LWI=
 github.com/golangci/tools v0.0.0-20180902102414-98e75f53b4b9 h1:JGHGJqnbD9OMyjgQqyja7DZd0/to1LKFpN31Fq8byxc=
 github.com/golangci/tools v0.0.0-20180902102414-98e75f53b4b9/go.mod h1:zgj6NOYXOC1cexsdtDceI4/mj3aXK4JOVg9AV3C5LWI=
 github.com/golangci/unconvert v0.0.0-20180507085042-28b1c447d1f4 h1:zwtduBRr5SSWhqsYNgcuWO2kFlpdOZbP0+yRjmvPGys=
@@ -131,6 +132,7 @@ 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 v0.0.0-20180831211245-3e7aa9e59977/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180831211245-5d4988d199e2 h1:DpCOQ3KV1qfJ60hZlyxHUgKvOehh5A/F9Fznu08v5Yw=
 golang.org/x/tools v0.0.0-20180831211245-5d4988d199e2/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180831211245-7ca132754999 h1:mf2VYfMpSMTlp0I/UXrX13w5LejDx34QeUUHH4TrUA8=

go.sum

@@ -2,6 +2,8 @@ package commands
 
 import (
 	"github.com/golangci/golangci-lint/pkg/config"
+	"github.com/golangci/golangci-lint/pkg/goutil"
+	"github.com/golangci/golangci-lint/pkg/lint"
 	"github.com/golangci/golangci-lint/pkg/lint/lintersdb"
 	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/report"
@@ -21,6 +23,8 @@ type Executor struct {
 	reportData        report.Data
 	DBManager         *lintersdb.Manager
 	EnabledLintersSet *lintersdb.EnabledSet
+	contextLoader     *lint.ContextLoader
+	goenv             *goutil.Env
 }
 
 func NewExecutor(version, commit, date string) *Executor {
@@ -65,6 +69,8 @@ func NewExecutor(version, commit, date string) *Executor {
 
 	e.EnabledLintersSet = lintersdb.NewEnabledSet(e.DBManager,
 		lintersdb.NewValidator(e.DBManager), e.log.Child("lintersdb"), e.cfg)
+	e.goenv = goutil.NewEnv(e.log.Child("goenv"))
+	e.contextLoader = lint.NewContextLoader(e.cfg, e.log.Child("loader"), e.goenv)
 
 	return e
 }

pkg/commands/executor.go

@@ -38,7 +38,7 @@ func printLinterConfigs(lcs []linter.Config) {
 			altNamesStr = fmt.Sprintf(" (%s)", strings.Join(lc.AlternativeNames, ", "))
 		}
 		fmt.Fprintf(logutils.StdOut, "%s%s: %s [fast: %t]\n", color.YellowString(lc.Name()),
-			altNamesStr, lc.Linter.Desc(), !lc.DoesFullImport)
+			altNamesStr, lc.Linter.Desc(), !lc.NeedsSSARepr)
 	}
 }
 

pkg/commands/help.go

@@ -141,7 +141,7 @@ func initFlagSet(fs *pflag.FlagSet, cfg *config.Config, m *lintersdb.Manager) {
 	fs.StringSliceVarP(&lc.Presets, "presets", "p", nil,
 		wh(fmt.Sprintf("Enable presets (%s) of linters. Run 'golangci-lint linters' to see "+
 			"them. This option implies option --disable-all", strings.Join(m.AllPresets(), "|"))))
-	fs.BoolVar(&lc.Fast, "fast", false, wh("Run only fast linters from enabled linters set"))
+	fs.BoolVar(&lc.Fast, "fast", false, wh("Run only fast linters from enabled linters set (first run won't be fast)"))
 
 	// Issues config
 	ic := &cfg.Issues
@@ -257,12 +257,13 @@ func (e *Executor) runAnalysis(ctx context.Context, args []string) (<-chan resul
 		e.reportData.AddLinter(lc.Name(), isEnabled, lc.EnabledByDefault)
 	}
 
-	lintCtx, err := lint.LoadContext(enabledLinters, e.cfg, e.log.Child("load"))
+	lintCtx, err := e.contextLoader.Load(ctx, enabledLinters)
 	if err != nil {
 		return nil, errors.Wrap(err, "context loading failed")
 	}
+	lintCtx.Log = e.log.Child("linters context")
 
-	runner, err := lint.NewRunner(lintCtx.ASTCache, e.cfg, e.log.Child("runner"))
+	runner, err := lint.NewRunner(lintCtx.ASTCache, e.cfg, e.log.Child("runner"), e.goenv)
 	if err != nil {
 		return nil, err
 	}
@@ -303,6 +304,10 @@ func (e *Executor) setExitCodeIfIssuesFound(issues <-chan result.Issue) <-chan r
 }
 
 func (e *Executor) runAndPrint(ctx context.Context, args []string) error {
+	if err := e.goenv.Discover(ctx); err != nil {
+		e.log.Warnf("Failed to discover go env: %s", err)
+	}
+
 	if !logutils.HaveDebugTag("linters_output") {
 		// Don't allow linters and loader to print anything
 		log.SetOutput(ioutil.Discard)
@@ -379,8 +384,20 @@ func (e *Executor) executeRun(cmd *cobra.Command, args []string) {
 		}
 	}
 
-	if e.exitCode == exitcodes.Success && ctx.Err() != nil {
+	e.setupExitCode(ctx)
+}
+
+func (e *Executor) setupExitCode(ctx context.Context) {
+	if ctx.Err() != nil {
 		e.exitCode = exitcodes.Timeout
+		e.log.Errorf("Deadline exceeded: try increase it by passing --deadline option")
+	}
+
+	if e.exitCode == exitcodes.Success &&
+		os.Getenv("GL_TEST_RUN") == "1" &&
+		len(e.reportData.Warnings) != 0 {
+
+		e.exitCode = exitcodes.WarningInTest
 	}
 }