+++ /dev/null
-// Copyright 2013 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.
-
-// Package buildtag defines an Analyzer that checks build tags.
-package buildtag
-
-import (
- "bytes"
- "fmt"
- "go/ast"
- "go/parser"
- "strings"
- "unicode"
-
- "golang.org/x/tools/go/analysis"
- "golang.org/x/tools/go/analysis/passes/internal/analysisutil"
-)
-
-const Doc = "check that +build tags are well-formed and correctly located"
-
-var Analyzer = &analysis.Analyzer{
- Name: "buildtag",
- Doc: Doc,
- Run: runBuildTag,
-}
-
-func runBuildTag(pass *analysis.Pass) (interface{}, error) {
- for _, f := range pass.Files {
- checkGoFile(pass, f)
- }
- for _, name := range pass.OtherFiles {
- if err := checkOtherFile(pass, name); err != nil {
- return nil, err
- }
- }
- for _, name := range pass.IgnoredFiles {
- if strings.HasSuffix(name, ".go") {
- f, err := parser.ParseFile(pass.Fset, name, nil, parser.ParseComments)
- if err != nil {
- // Not valid Go source code - not our job to diagnose, so ignore.
- return nil, nil
- }
- checkGoFile(pass, f)
- } else {
- if err := checkOtherFile(pass, name); err != nil {
- return nil, err
- }
- }
- }
- return nil, nil
-}
-
-func checkGoFile(pass *analysis.Pass, f *ast.File) {
- pastCutoff := false
- for _, group := range f.Comments {
- // A +build comment is ignored after or adjoining the package declaration.
- if group.End()+1 >= f.Package {
- pastCutoff = true
- }
-
- // "+build" is ignored within or after a /*...*/ comment.
- if !strings.HasPrefix(group.List[0].Text, "//") {
- pastCutoff = true
- continue
- }
-
- // Check each line of a //-comment.
- for _, c := range group.List {
- if !strings.Contains(c.Text, "+build") {
- continue
- }
- if err := checkLine(c.Text, pastCutoff); err != nil {
- pass.Reportf(c.Pos(), "%s", err)
- }
- }
- }
-}
-
-func checkOtherFile(pass *analysis.Pass, filename string) error {
- content, tf, err := analysisutil.ReadFile(pass.Fset, filename)
- if err != nil {
- return err
- }
-
- // We must look at the raw lines, as build tags may appear in non-Go
- // files such as assembly files.
- lines := bytes.SplitAfter(content, nl)
-
- // Determine cutpoint where +build comments are no longer valid.
- // They are valid in leading // comments in the file followed by
- // a blank line.
- //
- // This must be done as a separate pass because of the
- // requirement that the comment be followed by a blank line.
- var cutoff int
- for i, line := range lines {
- line = bytes.TrimSpace(line)
- if !bytes.HasPrefix(line, slashSlash) {
- if len(line) > 0 {
- break
- }
- cutoff = i
- }
- }
-
- for i, line := range lines {
- line = bytes.TrimSpace(line)
- if !bytes.HasPrefix(line, slashSlash) {
- continue
- }
- if !bytes.Contains(line, []byte("+build")) {
- continue
- }
- if err := checkLine(string(line), i >= cutoff); err != nil {
- pass.Reportf(analysisutil.LineStart(tf, i+1), "%s", err)
- continue
- }
- }
- return nil
-}
-
-// checkLine checks a line that starts with "//" and contains "+build".
-func checkLine(line string, pastCutoff bool) error {
- line = strings.TrimPrefix(line, "//")
- line = strings.TrimSpace(line)
-
- if strings.HasPrefix(line, "+build") {
- fields := strings.Fields(line)
- if fields[0] != "+build" {
- // Comment is something like +buildasdf not +build.
- return fmt.Errorf("possible malformed +build comment")
- }
- if pastCutoff {
- return fmt.Errorf("+build comment must appear before package clause and be followed by a blank line")
- }
- if err := checkArguments(fields); err != nil {
- return err
- }
- } else {
- // Comment with +build but not at beginning.
- if !pastCutoff {
- return fmt.Errorf("possible malformed +build comment")
- }
- }
- return nil
-}
-
-func checkArguments(fields []string) error {
- for _, arg := range fields[1:] {
- for _, elem := range strings.Split(arg, ",") {
- if strings.HasPrefix(elem, "!!") {
- return fmt.Errorf("invalid double negative in build constraint: %s", arg)
- }
- elem = strings.TrimPrefix(elem, "!")
- for _, c := range elem {
- if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
- return fmt.Errorf("invalid non-alphanumeric build constraint: %s", arg)
- }
- }
- }
- }
- return nil
-}
-
-var (
- nl = []byte("\n")
- slashSlash = []byte("//")
-)
projects / dotfiles / .git / blobdiff