Adding upstream version 1.20.14.upstream/1.20.14upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 285 insertions, 0 deletions

diff --git a/src/cmd/go/internal/modindex/scan.go b/src/cmd/go/internal/modindex/scan.go
new file mode 100644
index 0000000..712257a
--- /dev/null
+++ b/src/cmd/go/internal/modindex/scan.go
@@ -0,0 +1,285 @@
+// Copyright 2022 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 modindex
+
+import (
+	"cmd/go/internal/base"
+	"cmd/go/internal/fsys"
+	"cmd/go/internal/par"
+	"cmd/go/internal/str"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go/doc"
+	"go/scanner"
+	"go/token"
+	"io/fs"
+	"path/filepath"
+	"strings"
+)
+
+// moduleWalkErr returns filepath.SkipDir if the directory isn't relevant
+// when indexing a module or generating a filehash, ErrNotIndexed,
+// if the module shouldn't be indexed, and nil otherwise.
+func moduleWalkErr(modroot string, path string, info fs.FileInfo, err error) error {
+	if err != nil {
+		return ErrNotIndexed
+	}
+	// stop at module boundaries
+	if info.IsDir() && path != modroot {
+		if fi, err := fsys.Stat(filepath.Join(path, "go.mod")); err == nil && !fi.IsDir() {
+			return filepath.SkipDir
+		}
+	}
+	if info.Mode()&fs.ModeSymlink != 0 {
+		if target, err := fsys.Stat(path); err == nil && target.IsDir() {
+			// return an error to make the module hash invalid.
+			// Symlink directories in modules are tricky, so we won't index
+			// modules that contain them.
+			// TODO(matloob): perhaps don't return this error if the symlink leads to
+			// a directory with a go.mod file.
+			return ErrNotIndexed
+		}
+	}
+	return nil
+}
+
+// indexModule indexes the module at the given directory and returns its
+// encoded representation. It returns ErrNotIndexed if the module can't
+// be indexed because it contains symlinks.
+func indexModule(modroot string) ([]byte, error) {
+	fsys.Trace("indexModule", modroot)
+	var packages []*rawPackage
+	err := fsys.Walk(modroot, func(path string, info fs.FileInfo, err error) error {
+		if err := moduleWalkErr(modroot, path, info, err); err != nil {
+			return err
+		}
+
+		if !info.IsDir() {
+			return nil
+		}
+		if !str.HasFilePathPrefix(path, modroot) {
+			panic(fmt.Errorf("path %v in walk doesn't have modroot %v as prefix", path, modroot))
+		}
+		rel := str.TrimFilePathPrefix(path, modroot)
+		packages = append(packages, importRaw(modroot, rel))
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return encodeModuleBytes(packages), nil
+}
+
+// indexPackage indexes the package at the given directory and returns its
+// encoded representation. It returns ErrNotIndexed if the package can't
+// be indexed.
+func indexPackage(modroot, pkgdir string) []byte {
+	fsys.Trace("indexPackage", pkgdir)
+	p := importRaw(modroot, relPath(pkgdir, modroot))
+	return encodePackageBytes(p)
+}
+
+// rawPackage holds the information from each package that's needed to
+// fill a build.Package once the context is available.
+type rawPackage struct {
+	error string
+	dir   string // directory containing package sources, relative to the module root
+
+	// Source files
+	sourceFiles []*rawFile
+}
+
+type parseError struct {
+	ErrorList   *scanner.ErrorList
+	ErrorString string
+}
+
+// parseErrorToString converts the error from parsing the file into a string
+// representation. A nil error is converted to an empty string, and all other
+// errors are converted to a JSON-marshalled parseError struct, with ErrorList
+// set for errors of type scanner.ErrorList, and ErrorString set to the error's
+// string representation for all other errors.
+func parseErrorToString(err error) string {
+	if err == nil {
+		return ""
+	}
+	var p parseError
+	if e, ok := err.(scanner.ErrorList); ok {
+		p.ErrorList = &e
+	} else {
+		p.ErrorString = e.Error()
+	}
+	s, err := json.Marshal(p)
+	if err != nil {
+		panic(err) // This should be impossible because scanner.Error contains only strings and ints.
+	}
+	return string(s)
+}
+
+// parseErrorFromString converts a string produced by parseErrorToString back
+// to an error.  An empty string is converted to a nil error, and all
+// other strings are expected to be JSON-marshalled parseError structs.
+// The two functions are meant to preserve the structure of an
+// error of type scanner.ErrorList in a round trip, but may not preserve the
+// structure of other errors.
+func parseErrorFromString(s string) error {
+	if s == "" {
+		return nil
+	}
+	var p parseError
+	if err := json.Unmarshal([]byte(s), &p); err != nil {
+		base.Fatalf(`go: invalid parse error value in index: %q. This indicates a corrupted index. Run "go clean -cache" to reset the module cache.`, s)
+	}
+	if p.ErrorList != nil {
+		return *p.ErrorList
+	}
+	return errors.New(p.ErrorString)
+}
+
+// rawFile is the struct representation of the file holding all
+// information in its fields.
+type rawFile struct {
+	error      string
+	parseError string
+
+	name                 string
+	synopsis             string // doc.Synopsis of package comment... Compute synopsis on all of these?
+	pkgName              string
+	ignoreFile           bool   // starts with _ or . or should otherwise always be ignored
+	binaryOnly           bool   // cannot be rebuilt from source (has //go:binary-only-package comment)
+	cgoDirectives        string // the #cgo directive lines in the comment on import "C"
+	goBuildConstraint    string
+	plusBuildConstraints []string
+	imports              []rawImport
+	embeds               []embed
+}
+
+type rawImport struct {
+	path     string
+	position token.Position
+}
+
+type embed struct {
+	pattern  string
+	position token.Position
+}
+
+var pkgcache par.Cache // for packages not in modcache
+
+// importRaw fills the rawPackage from the package files in srcDir.
+// dir is the package's path relative to the modroot.
+func importRaw(modroot, reldir string) *rawPackage {
+	p := &rawPackage{
+		dir: reldir,
+	}
+
+	absdir := filepath.Join(modroot, reldir)
+
+	// We still haven't checked
+	// that p.dir directory exists. This is the right time to do that check.
+	// We can't do it earlier, because we want to gather partial information for the
+	// non-nil *Package returned when an error occurs.
+	// We need to do this before we return early on FindOnly flag.
+	if !isDir(absdir) {
+		// package was not found
+		p.error = fmt.Errorf("cannot find package in:\n\t%s", absdir).Error()
+		return p
+	}
+
+	entries, err := fsys.ReadDir(absdir)
+	if err != nil {
+		p.error = err.Error()
+		return p
+	}
+
+	fset := token.NewFileSet()
+	for _, d := range entries {
+		if d.IsDir() {
+			continue
+		}
+		if d.Mode()&fs.ModeSymlink != 0 {
+			if isDir(filepath.Join(absdir, d.Name())) {
+				// Symlinks to directories are not source files.
+				continue
+			}
+		}
+
+		name := d.Name()
+		ext := nameExt(name)
+
+		if strings.HasPrefix(name, "_") || strings.HasPrefix(name, ".") {
+			continue
+		}
+		info, err := getFileInfo(absdir, name, fset)
+		if err == errNonSource {
+			// not a source or object file. completely ignore in the index
+			continue
+		} else if err != nil {
+			p.sourceFiles = append(p.sourceFiles, &rawFile{name: name, error: err.Error()})
+			continue
+		} else if info == nil {
+			p.sourceFiles = append(p.sourceFiles, &rawFile{name: name, ignoreFile: true})
+			continue
+		}
+		rf := &rawFile{
+			name:                 name,
+			goBuildConstraint:    info.goBuildConstraint,
+			plusBuildConstraints: info.plusBuildConstraints,
+			binaryOnly:           info.binaryOnly,
+		}
+		if info.parsed != nil {
+			rf.pkgName = info.parsed.Name.Name
+		}
+
+		// Going to save the file. For non-Go files, can stop here.
+		p.sourceFiles = append(p.sourceFiles, rf)
+		if ext != ".go" {
+			continue
+		}
+
+		if info.parseErr != nil {
+			rf.parseError = parseErrorToString(info.parseErr)
+			// Fall through: we might still have a partial AST in info.Parsed,
+			// and we want to list files with parse errors anyway.
+		}
+
+		if info.parsed != nil && info.parsed.Doc != nil {
+			rf.synopsis = doc.Synopsis(info.parsed.Doc.Text())
+		}
+
+		var cgoDirectives []string
+		for _, imp := range info.imports {
+			if imp.path == "C" {
+				cgoDirectives = append(cgoDirectives, extractCgoDirectives(imp.doc.Text())...)
+			}
+			rf.imports = append(rf.imports, rawImport{path: imp.path, position: fset.Position(imp.pos)})
+		}
+		rf.cgoDirectives = strings.Join(cgoDirectives, "\n")
+		for _, emb := range info.embeds {
+			rf.embeds = append(rf.embeds, embed{emb.pattern, emb.pos})
+		}
+
+	}
+	return p
+}
+
+// extractCgoDirectives filters only the lines containing #cgo directives from the input,
+// which is the comment on import "C".
+func extractCgoDirectives(doc string) []string {
+	var out []string
+	for _, line := range strings.Split(doc, "\n") {
+		// Line is
+		//	#cgo [GOOS/GOARCH...] LDFLAGS: stuff
+		//
+		line = strings.TrimSpace(line)
+		if len(line) < 5 || line[:4] != "#cgo" || (line[4] != ' ' && line[4] != '\t') {
+			continue
+		}
+
+		out = append(out, line)
+	}
+	return out
+}