go/analysis/passes/buildtag: split out of vet
buildtag checker: - This checker has been modified from the version in vet to handle Go and non-Go files differently, to avoid having to re-read-and-parse Go files in the common case. - The old cmd/vet driver would run this check on all the files in a directory whereas new drivers will run it only on the files selected for a particular configuration, so some of the checks (those in checkArguments) will never fire. But this is not a regression relative to 'go vet', because it too presents cmd/vet with only the files selected as part of the package. analysistest: - fix bug that processed a block of //-comments as one. - treat "...// want..." within a //-comment as a want comment. This is required for adding expectations on lines that are already comments. Change-Id: Iacf3684864e07532f77176481afbf059a9638f3b Reviewed-on: https://go-review.googlesource.com/c/139797 Reviewed-by: Michael Matloob <matloob@golang.org> Run-TryBot: Michael Matloob <matloob@golang.org>
This commit is contained in:
Alan Donovan
parent
1ca53e67e5
commit
8a9223ac31
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@ -159,23 +159,38 @@ func check(t Testing, gopath string, pass *analysis.Pass, diagnostics []analysis
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}
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want := make(map[key][]expectation)
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for _, f := range pass.Files {
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for _, c := range f.Comments {
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posn := pass.Fset.Position(c.Pos())
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sanitize(gopath, &posn)
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text := strings.TrimSpace(c.Text())
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for _, cgroup := range f.Comments {
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for _, c := range cgroup.List {
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posn := pass.Fset.Position(c.Pos())
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sanitize(gopath, &posn)
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// Any comment starting with "want" is treated
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// as an expectation, even without following whitespace.
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if rest := strings.TrimPrefix(text, "want"); rest != text {
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expects, err := parseExpectations(rest)
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if err != nil {
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t.Errorf("%s: in 'want' comment: %s", posn, err)
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continue
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text := strings.TrimPrefix(c.Text, "//")
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if text == c.Text {
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continue // not a //-comment
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}
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if false {
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log.Printf("%s: %v", posn, expects)
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text = strings.TrimSpace(text)
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// Hack: treat a comment of the form "//...// want..."
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// as if it starts after the second "//".
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// This allows us to add comments on comments,
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// as required when testing the buildtag analyzer.
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if i := strings.Index(text, "// want"); i >= 0 {
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text = text[i+len("// "):]
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}
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// Any comment starting with "want" is treated
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// as an expectation, even without following whitespace.
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if rest := strings.TrimPrefix(text, "want"); rest != text {
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expects, err := parseExpectations(rest)
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if err != nil {
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t.Errorf("%s: in 'want' comment: %s", posn, err)
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continue
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}
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if false {
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log.Printf("%s: %v", posn, expects)
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}
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want[key{posn.Filename, posn.Line}] = expects
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}
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want[key{posn.Filename, posn.Line}] = expects
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}
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}
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}
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@ -15,6 +15,7 @@ import (
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"golang.org/x/tools/go/analysis/multichecker"
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// analysis plug-ins
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"golang.org/x/tools/go/analysis/passes/buildtag"
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"golang.org/x/tools/go/analysis/passes/findcall"
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)
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@ -22,5 +23,8 @@ func main() {
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log.SetFlags(0)
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log.SetPrefix("analyze: ")
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multichecker.Main(findcall.Analyzer)
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multichecker.Main(
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findcall.Analyzer,
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buildtag.Analyzer,
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)
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}
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@ -0,0 +1,204 @@
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package buildtag
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import (
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"bytes"
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"fmt"
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"go/ast"
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"go/token"
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"io/ioutil"
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"strings"
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"unicode"
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"golang.org/x/tools/go/analysis"
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)
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var Analyzer = &analysis.Analyzer{
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Name: "buildtag",
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Doc: "check that +build tags are well-formed and correctly located",
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Run: runBuildTag,
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}
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func runBuildTag(pass *analysis.Pass) (interface{}, error) {
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for _, f := range pass.Files {
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checkGoFile(pass, f)
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}
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for _, name := range pass.OtherFiles {
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if err := checkOtherFile(pass, name); err != nil {
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return nil, err
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}
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}
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return nil, nil
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}
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func checkGoFile(pass *analysis.Pass, f *ast.File) {
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pastCutoff := false
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for _, group := range f.Comments {
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// A +build comment is ignored after or adjoining the package declaration.
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if group.End()+1 >= f.Package {
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pastCutoff = true
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}
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// "+build" is ignored within or after a /*...*/ comment.
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if !strings.HasPrefix(group.List[0].Text, "//") {
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pastCutoff = true
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continue
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}
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// Check each line of a //-comment.
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for _, c := range group.List {
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if !strings.Contains(c.Text, "+build") {
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continue
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}
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if err := checkLine(c.Text, pastCutoff); err != nil {
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pass.Reportf(c.Pos(), "%s", err)
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}
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}
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}
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}
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func checkOtherFile(pass *analysis.Pass, filename string) error {
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content, tf, err := readFile(pass.Fset, filename)
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if err != nil {
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return err
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}
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// We must look at the raw lines, as build tags may appear in non-Go
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// files such as assembly files.
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lines := bytes.SplitAfter(content, nl)
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// Determine cutpoint where +build comments are no longer valid.
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// They are valid in leading // comments in the file followed by
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// a blank line.
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//
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// This must be done as a separate pass because of the
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// requirement that the comment be followed by a blank line.
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var cutoff int
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for i, line := range lines {
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line = bytes.TrimSpace(line)
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if !bytes.HasPrefix(line, slashSlash) {
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if len(line) > 0 {
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break
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}
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cutoff = i
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}
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}
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for i, line := range lines {
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line = bytes.TrimSpace(line)
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if !bytes.HasPrefix(line, slashSlash) {
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continue
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}
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if !bytes.Contains(line, []byte("+build")) {
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continue
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}
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if err := checkLine(string(line), i >= cutoff); err != nil {
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pass.Reportf(lineStart(tf, i+1), "%s", err)
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continue
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}
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}
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return nil
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}
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// checkLine checks a line that starts with "//" and contains "+build".
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func checkLine(line string, pastCutoff bool) error {
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line = strings.TrimPrefix(line, "//")
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line = strings.TrimSpace(line)
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if strings.HasPrefix(line, "+build") {
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fields := strings.Fields(line)
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if fields[0] != "+build" {
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// Comment is something like +buildasdf not +build.
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return fmt.Errorf("possible malformed +build comment")
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}
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if pastCutoff {
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return fmt.Errorf("+build comment must appear before package clause and be followed by a blank line")
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}
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if err := checkArguments(fields); err != nil {
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return err
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}
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} else {
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// Comment with +build but not at beginning.
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if !pastCutoff {
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return fmt.Errorf("possible malformed +build comment")
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}
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}
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return nil
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}
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func checkArguments(fields []string) error {
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// The original version of this checker in vet could examine
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// files with malformed build tags that would cause the file to
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// be always ignored by "go build". However, drivers for the new
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// analysis API will analyze only the files selected to form a
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// package, so these checks will never fire.
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// TODO(adonovan): rethink this.
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for _, arg := range fields[1:] {
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for _, elem := range strings.Split(arg, ",") {
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if strings.HasPrefix(elem, "!!") {
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return fmt.Errorf("invalid double negative in build constraint: %s", arg)
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}
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elem = strings.TrimPrefix(elem, "!")
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for _, c := range elem {
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if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
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return fmt.Errorf("invalid non-alphanumeric build constraint: %s", arg)
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}
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}
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}
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}
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return nil
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}
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var (
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nl = []byte("\n")
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slashSlash = []byte("//")
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)
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// -- these declarations are copied from asmdecl --
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// readFile reads a file and adds it to the FileSet
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// so that we can report errors against it using lineStart.
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func readFile(fset *token.FileSet, filename string) ([]byte, *token.File, error) {
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content, err := ioutil.ReadFile(filename)
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if err != nil {
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return nil, nil, err
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}
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tf := fset.AddFile(filename, -1, len(content))
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tf.SetLinesForContent(content)
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return content, tf, nil
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}
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// lineStart returns the position of the start of the specified line
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// within file f, or NoPos if there is no line of that number.
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func lineStart(f *token.File, line int) token.Pos {
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// Use binary search to find the start offset of this line.
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//
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// TODO(adonovan): eventually replace this function with the
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// simpler and more efficient (*go/token.File).LineStart, added
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// in go1.12.
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min := 0 // inclusive
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max := f.Size() // exclusive
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for {
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offset := (min + max) / 2
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pos := f.Pos(offset)
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posn := f.Position(pos)
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if posn.Line == line {
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return pos - (token.Pos(posn.Column) - 1)
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}
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if min+1 >= max {
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return token.NoPos
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}
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if posn.Line < line {
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min = offset
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} else {
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max = offset
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}
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}
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}
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@ -0,0 +1,14 @@
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package buildtag_test
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import (
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"testing"
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"golang.org/x/tools/go/analysis/analysistest"
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"golang.org/x/tools/go/analysis/passes/buildtag"
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)
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func Test(t *testing.T) {
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testdata := analysistest.TestData()
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// loads testdata/src/a/a.go
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analysistest.Run(t, testdata, buildtag.Analyzer, "a")
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}
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@ -0,0 +1,21 @@
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// This file contains tests for the buildtag checker.
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// +builder // want `possible malformed \+build comment`
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// +build !ignore
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// Mention +build // want `possible malformed \+build comment`
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// +build nospace // want "build comment must appear before package clause and be followed by a blank line"
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package a
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// +build toolate // want "build comment must appear before package clause and be followed by a blank line$"
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var _ = 3
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var _ = `
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// +build notacomment
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`
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@ -1,128 +0,0 @@
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// +build ignore
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"bytes"
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"fmt"
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"os"
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"strings"
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"unicode"
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)
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var (
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nl = []byte("\n")
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slashSlash = []byte("//")
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plusBuild = []byte("+build")
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)
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func badfLine(f *File, line int, format string, args ...interface{}) {
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msg := fmt.Sprintf(format, args...)
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fmt.Fprintf(os.Stderr, "%s:%d: %s\n", f.name, line, msg)
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setExit(1)
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}
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// checkBuildTag checks that build tags are in the correct location and well-formed.
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func checkBuildTag(f *File) {
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if !vet("buildtags") {
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return
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}
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// we must look at the raw lines, as build tags may appear in non-Go
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// files such as assembly files.
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lines := bytes.SplitAfter(f.content, nl)
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// lineWithComment reports whether a line corresponds to a comment in
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// the source file. If the source file wasn't Go, the function always
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// returns true.
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lineWithComment := func(line int) bool {
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if f.file == nil {
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// Current source file is not Go, so be conservative.
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return true
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}
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for _, group := range f.file.Comments {
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startLine := f.fset.Position(group.Pos()).Line
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endLine := f.fset.Position(group.End()).Line
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if startLine <= line && line <= endLine {
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return true
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}
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}
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return false
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}
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// Determine cutpoint where +build comments are no longer valid.
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// They are valid in leading // comments in the file followed by
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// a blank line.
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var cutoff int
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for i, line := range lines {
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line = bytes.TrimSpace(line)
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if len(line) == 0 {
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cutoff = i
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continue
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}
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if bytes.HasPrefix(line, slashSlash) {
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continue
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}
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break
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}
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for i, line := range lines {
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line = bytes.TrimSpace(line)
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if !bytes.HasPrefix(line, slashSlash) {
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continue
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}
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if !bytes.Contains(line, plusBuild) {
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// Check that the comment contains "+build" early, to
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// avoid unnecessary lineWithComment calls that may
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// incur linear searches.
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continue
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}
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if !lineWithComment(i + 1) {
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// This is a line in a Go source file that looks like a
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// comment, but actually isn't - such as part of a raw
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// string.
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continue
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}
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text := bytes.TrimSpace(line[2:])
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if bytes.HasPrefix(text, plusBuild) {
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fields := bytes.Fields(text)
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if !bytes.Equal(fields[0], plusBuild) {
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// Comment is something like +buildasdf not +build.
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badfLine(f, i+1, "possible malformed +build comment")
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continue
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}
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if i >= cutoff {
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badfLine(f, i+1, "+build comment must appear before package clause and be followed by a blank line")
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continue
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}
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// Check arguments.
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Args:
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for _, arg := range fields[1:] {
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for _, elem := range strings.Split(string(arg), ",") {
|
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if strings.HasPrefix(elem, "!!") {
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badfLine(f, i+1, "invalid double negative in build constraint: %s", arg)
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break Args
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}
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elem = strings.TrimPrefix(elem, "!")
|
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for _, c := range elem {
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if !unicode.IsLetter(c) && !unicode.IsDigit(c) && c != '_' && c != '.' {
|
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badfLine(f, i+1, "invalid non-alphanumeric build constraint: %s", arg)
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break Args
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||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
continue
|
||||
}
|
||||
// Comment with +build but not at beginning.
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if i < cutoff {
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badfLine(f, i+1, "possible malformed +build comment")
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continue
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||||
}
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||||
}
|
||||
}
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||||
|
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@ -1,18 +0,0 @@
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|||
// 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.
|
||||
|
||||
// This file contains tests for the buildtag checker.
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|
||||
// +builder // ERROR "possible malformed \+build comment"
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// +build !ignore
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package testdata
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||||
|
||||
// +build toolate // ERROR "build comment must appear before package clause and be followed by a blank line$"
|
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|
||||
var _ = 3
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||||
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||||
var _ = `
|
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// +build notacomment
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||||
`
|
||||
|
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@ -1,15 +0,0 @@
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|||
// This file contains misplaced or malformed build constraints.
|
||||
// The Go tool will skip it, because the constraints are invalid.
|
||||
// It serves only to test the tag checker during make test.
|
||||
|
||||
// Mention +build // ERROR "possible malformed \+build comment"
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||||
|
||||
// +build !!bang // ERROR "invalid double negative in build constraint"
|
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// +build @#$ // ERROR "invalid non-alphanumeric build constraint"
|
||||
|
||||
// +build toolate // ERROR "build comment must appear before package clause and be followed by a blank line"
|
||||
package bad
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||||
|
||||
// This is package 'bad' rather than 'main' so the erroneous build
|
||||
// tag doesn't end up looking like a package doc for the vet command
|
||||
// when examined by godoc.
|
||||
Loading…
Reference in New Issue