--- /dev/null
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The unitchecker package defines the main function for an analysis
+// driver that analyzes a single compilation unit during a build.
+// It is invoked by a build system such as "go vet":
+//
+// $ go vet -vettool=$(which vet)
+//
+// It supports the following command-line protocol:
+//
+// -V=full describe executable (to the build tool)
+// -flags describe flags (to the build tool)
+// foo.cfg description of compilation unit (from the build tool)
+//
+// This package does not depend on go/packages.
+// If you need a standalone tool, use multichecker,
+// which supports this mode but can also load packages
+// from source using go/packages.
+package unitchecker
+
+// TODO(adonovan):
+// - with gccgo, go build does not build standard library,
+// so we will not get to analyze it. Yet we must in order
+// to create base facts for, say, the fmt package for the
+// printf checker.
+
+import (
+ "encoding/gob"
+ "encoding/json"
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "go/types"
+ "io"
+ "io/ioutil"
+ "log"
+ "os"
+ "path/filepath"
+ "reflect"
+ "sort"
+ "strings"
+ "sync"
+ "time"
+
+ "golang.org/x/tools/go/analysis"
+ "golang.org/x/tools/go/analysis/internal/analysisflags"
+ "golang.org/x/tools/go/analysis/internal/facts"
+)
+
+// A Config describes a compilation unit to be analyzed.
+// It is provided to the tool in a JSON-encoded file
+// whose name ends with ".cfg".
+type Config struct {
+ ID string // e.g. "fmt [fmt.test]"
+ Compiler string
+ Dir string
+ ImportPath string
+ GoFiles []string
+ NonGoFiles []string
+ IgnoredFiles []string
+ ImportMap map[string]string
+ PackageFile map[string]string
+ Standard map[string]bool
+ PackageVetx map[string]string
+ VetxOnly bool
+ VetxOutput string
+ SucceedOnTypecheckFailure bool
+}
+
+// Main is the main function of a vet-like analysis tool that must be
+// invoked by a build system to analyze a single package.
+//
+// The protocol required by 'go vet -vettool=...' is that the tool must support:
+//
+// -flags describe flags in JSON
+// -V=full describe executable for build caching
+// foo.cfg perform separate modular analyze on the single
+// unit described by a JSON config file foo.cfg.
+//
+func Main(analyzers ...*analysis.Analyzer) {
+ progname := filepath.Base(os.Args[0])
+ log.SetFlags(0)
+ log.SetPrefix(progname + ": ")
+
+ if err := analysis.Validate(analyzers); err != nil {
+ log.Fatal(err)
+ }
+
+ flag.Usage = func() {
+ fmt.Fprintf(os.Stderr, `%[1]s is a tool for static analysis of Go programs.
+
+Usage of %[1]s:
+ %.16[1]s unit.cfg # execute analysis specified by config file
+ %.16[1]s help # general help
+ %.16[1]s help name # help on specific analyzer and its flags
+`, progname)
+ os.Exit(1)
+ }
+
+ analyzers = analysisflags.Parse(analyzers, true)
+
+ args := flag.Args()
+ if len(args) == 0 {
+ flag.Usage()
+ }
+ if args[0] == "help" {
+ analysisflags.Help(progname, analyzers, args[1:])
+ os.Exit(0)
+ }
+ if len(args) != 1 || !strings.HasSuffix(args[0], ".cfg") {
+ log.Fatalf(`invoking "go tool vet" directly is unsupported; use "go vet"`)
+ }
+ Run(args[0], analyzers)
+}
+
+// Run reads the *.cfg file, runs the analysis,
+// and calls os.Exit with an appropriate error code.
+// It assumes flags have already been set.
+func Run(configFile string, analyzers []*analysis.Analyzer) {
+ cfg, err := readConfig(configFile)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ fset := token.NewFileSet()
+ results, err := run(fset, cfg, analyzers)
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ // In VetxOnly mode, the analysis is run only for facts.
+ if !cfg.VetxOnly {
+ if analysisflags.JSON {
+ // JSON output
+ tree := make(analysisflags.JSONTree)
+ for _, res := range results {
+ tree.Add(fset, cfg.ID, res.a.Name, res.diagnostics, res.err)
+ }
+ tree.Print()
+ } else {
+ // plain text
+ exit := 0
+ for _, res := range results {
+ if res.err != nil {
+ log.Println(res.err)
+ exit = 1
+ }
+ }
+ for _, res := range results {
+ for _, diag := range res.diagnostics {
+ analysisflags.PrintPlain(fset, diag)
+ exit = 1
+ }
+ }
+ os.Exit(exit)
+ }
+ }
+
+ os.Exit(0)
+}
+
+func readConfig(filename string) (*Config, error) {
+ data, err := ioutil.ReadFile(filename)
+ if err != nil {
+ return nil, err
+ }
+ cfg := new(Config)
+ if err := json.Unmarshal(data, cfg); err != nil {
+ return nil, fmt.Errorf("cannot decode JSON config file %s: %v", filename, err)
+ }
+ if len(cfg.GoFiles) == 0 {
+ // The go command disallows packages with no files.
+ // The only exception is unsafe, but the go command
+ // doesn't call vet on it.
+ return nil, fmt.Errorf("package has no files: %s", cfg.ImportPath)
+ }
+ return cfg, nil
+}
+
+var importerForCompiler = func(_ *token.FileSet, compiler string, lookup importer.Lookup) types.Importer {
+ // broken legacy implementation (https://golang.org/issue/28995)
+ return importer.For(compiler, lookup)
+}
+
+func run(fset *token.FileSet, cfg *Config, analyzers []*analysis.Analyzer) ([]result, error) {
+ // Load, parse, typecheck.
+ var files []*ast.File
+ for _, name := range cfg.GoFiles {
+ f, err := parser.ParseFile(fset, name, nil, parser.ParseComments)
+ if err != nil {
+ if cfg.SucceedOnTypecheckFailure {
+ // Silently succeed; let the compiler
+ // report parse errors.
+ err = nil
+ }
+ return nil, err
+ }
+ files = append(files, f)
+ }
+ compilerImporter := importerForCompiler(fset, cfg.Compiler, func(path string) (io.ReadCloser, error) {
+ // path is a resolved package path, not an import path.
+ file, ok := cfg.PackageFile[path]
+ if !ok {
+ if cfg.Compiler == "gccgo" && cfg.Standard[path] {
+ return nil, nil // fall back to default gccgo lookup
+ }
+ return nil, fmt.Errorf("no package file for %q", path)
+ }
+ return os.Open(file)
+ })
+ importer := importerFunc(func(importPath string) (*types.Package, error) {
+ path, ok := cfg.ImportMap[importPath] // resolve vendoring, etc
+ if !ok {
+ return nil, fmt.Errorf("can't resolve import %q", path)
+ }
+ return compilerImporter.Import(path)
+ })
+ tc := &types.Config{
+ Importer: importer,
+ Sizes: types.SizesFor("gc", build.Default.GOARCH), // assume gccgo ≡ gc?
+ }
+ info := &types.Info{
+ Types: make(map[ast.Expr]types.TypeAndValue),
+ Defs: make(map[*ast.Ident]types.Object),
+ Uses: make(map[*ast.Ident]types.Object),
+ Implicits: make(map[ast.Node]types.Object),
+ Scopes: make(map[ast.Node]*types.Scope),
+ Selections: make(map[*ast.SelectorExpr]*types.Selection),
+ }
+ pkg, err := tc.Check(cfg.ImportPath, fset, files, info)
+ if err != nil {
+ if cfg.SucceedOnTypecheckFailure {
+ // Silently succeed; let the compiler
+ // report type errors.
+ err = nil
+ }
+ return nil, err
+ }
+
+ // Register fact types with gob.
+ // In VetxOnly mode, analyzers are only for their facts,
+ // so we can skip any analysis that neither produces facts
+ // nor depends on any analysis that produces facts.
+ // Also build a map to hold working state and result.
+ type action struct {
+ once sync.Once
+ result interface{}
+ err error
+ usesFacts bool // (transitively uses)
+ diagnostics []analysis.Diagnostic
+ }
+ actions := make(map[*analysis.Analyzer]*action)
+ var registerFacts func(a *analysis.Analyzer) bool
+ registerFacts = func(a *analysis.Analyzer) bool {
+ act, ok := actions[a]
+ if !ok {
+ act = new(action)
+ var usesFacts bool
+ for _, f := range a.FactTypes {
+ usesFacts = true
+ gob.Register(f)
+ }
+ for _, req := range a.Requires {
+ if registerFacts(req) {
+ usesFacts = true
+ }
+ }
+ act.usesFacts = usesFacts
+ actions[a] = act
+ }
+ return act.usesFacts
+ }
+ var filtered []*analysis.Analyzer
+ for _, a := range analyzers {
+ if registerFacts(a) || !cfg.VetxOnly {
+ filtered = append(filtered, a)
+ }
+ }
+ analyzers = filtered
+
+ // Read facts from imported packages.
+ read := func(path string) ([]byte, error) {
+ if vetx, ok := cfg.PackageVetx[path]; ok {
+ return ioutil.ReadFile(vetx)
+ }
+ return nil, nil // no .vetx file, no facts
+ }
+ facts, err := facts.Decode(pkg, read)
+ if err != nil {
+ return nil, err
+ }
+
+ // In parallel, execute the DAG of analyzers.
+ var exec func(a *analysis.Analyzer) *action
+ var execAll func(analyzers []*analysis.Analyzer)
+ exec = func(a *analysis.Analyzer) *action {
+ act := actions[a]
+ act.once.Do(func() {
+ execAll(a.Requires) // prefetch dependencies in parallel
+
+ // The inputs to this analysis are the
+ // results of its prerequisites.
+ inputs := make(map[*analysis.Analyzer]interface{})
+ var failed []string
+ for _, req := range a.Requires {
+ reqact := exec(req)
+ if reqact.err != nil {
+ failed = append(failed, req.String())
+ continue
+ }
+ inputs[req] = reqact.result
+ }
+
+ // Report an error if any dependency failed.
+ if failed != nil {
+ sort.Strings(failed)
+ act.err = fmt.Errorf("failed prerequisites: %s", strings.Join(failed, ", "))
+ return
+ }
+
+ factFilter := make(map[reflect.Type]bool)
+ for _, f := range a.FactTypes {
+ factFilter[reflect.TypeOf(f)] = true
+ }
+
+ pass := &analysis.Pass{
+ Analyzer: a,
+ Fset: fset,
+ Files: files,
+ OtherFiles: cfg.NonGoFiles,
+ IgnoredFiles: cfg.IgnoredFiles,
+ Pkg: pkg,
+ TypesInfo: info,
+ TypesSizes: tc.Sizes,
+ ResultOf: inputs,
+ Report: func(d analysis.Diagnostic) { act.diagnostics = append(act.diagnostics, d) },
+ ImportObjectFact: facts.ImportObjectFact,
+ ExportObjectFact: facts.ExportObjectFact,
+ AllObjectFacts: func() []analysis.ObjectFact { return facts.AllObjectFacts(factFilter) },
+ ImportPackageFact: facts.ImportPackageFact,
+ ExportPackageFact: facts.ExportPackageFact,
+ AllPackageFacts: func() []analysis.PackageFact { return facts.AllPackageFacts(factFilter) },
+ }
+
+ t0 := time.Now()
+ act.result, act.err = a.Run(pass)
+ if false {
+ log.Printf("analysis %s = %s", pass, time.Since(t0))
+ }
+ })
+ return act
+ }
+ execAll = func(analyzers []*analysis.Analyzer) {
+ var wg sync.WaitGroup
+ for _, a := range analyzers {
+ wg.Add(1)
+ go func(a *analysis.Analyzer) {
+ _ = exec(a)
+ wg.Done()
+ }(a)
+ }
+ wg.Wait()
+ }
+
+ execAll(analyzers)
+
+ // Return diagnostics and errors from root analyzers.
+ results := make([]result, len(analyzers))
+ for i, a := range analyzers {
+ act := actions[a]
+ results[i].a = a
+ results[i].err = act.err
+ results[i].diagnostics = act.diagnostics
+ }
+
+ data := facts.Encode()
+ if err := ioutil.WriteFile(cfg.VetxOutput, data, 0666); err != nil {
+ return nil, fmt.Errorf("failed to write analysis facts: %v", err)
+ }
+
+ return results, nil
+}
+
+type result struct {
+ a *analysis.Analyzer
+ diagnostics []analysis.Diagnostic
+ err error
+}
+
+type importerFunc func(path string) (*types.Package, error)
+
+func (f importerFunc) Import(path string) (*types.Package, error) { return f(path) }
projects / dotfiles / .git / blobdiff