cmd/go/internal/modload: factor smaller files out of load.go and init.go

No semantic changes intended: just structural cleanup.

Updates #36460

Change-Id: I405bc2572d3ff00f595dae645e673a11e01621ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/222340
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

1 files changed, 0 insertions, 355 deletions

diff --git a/src/cmd/go/internal/modload/load.go b/src/cmd/go/internal/modload/load.go
index 6ea7d8c69b..21601cb13e 100644
--- a/src/cmd/go/internal/modload/load.go
+++ b/src/cmd/go/internal/modload/load.go
@@ -9,14 +9,12 @@ import (
 	"errors"
 	"fmt"
 	"go/build"
-	"io/ioutil"
 	"os"
 	"path"
 	pathpkg "path"
 	"path/filepath"
 	"sort"
 	"strings"
-	"sync"
 
 	"cmd/go/internal/base"
 	"cmd/go/internal/cfg"
@@ -27,9 +25,7 @@ import (
 	"cmd/go/internal/search"
 	"cmd/go/internal/str"
 
-	"golang.org/x/mod/modfile"
 	"golang.org/x/mod/module"
-	"golang.org/x/mod/semver"
 )
 
 // buildList is the list of modules to use for building packages.
@@ -1033,354 +1029,3 @@ func WhyDepth(path string) int {
 	}
 	return n
 }
-
-// Replacement returns the replacement for mod, if any, from go.mod.
-// If there is no replacement for mod, Replacement returns
-// a module.Version with Path == "".
-func Replacement(mod module.Version) module.Version {
-	if index != nil {
-		if r, ok := index.replace[mod]; ok {
-			return r
-		}
-		if r, ok := index.replace[module.Version{Path: mod.Path}]; ok {
-			return r
-		}
-	}
-	return module.Version{}
-}
-
-// mvsReqs implements mvs.Reqs for module semantic versions,
-// with any exclusions or replacements applied internally.
-type mvsReqs struct {
-	buildList []module.Version
-	cache     par.Cache
-	versions  sync.Map
-}
-
-// Reqs returns the current module requirement graph.
-// Future calls to SetBuildList do not affect the operation
-// of the returned Reqs.
-func Reqs() mvs.Reqs {
-	r := &mvsReqs{
-		buildList: buildList,
-	}
-	return r
-}
-
-func (r *mvsReqs) Required(mod module.Version) ([]module.Version, error) {
-	type cached struct {
-		list []module.Version
-		err  error
-	}
-
-	c := r.cache.Do(mod, func() interface{} {
-		list, err := r.required(mod)
-		if err != nil {
-			return cached{nil, err}
-		}
-		for i, mv := range list {
-			if index != nil {
-				for index.exclude[mv] {
-					mv1, err := r.next(mv)
-					if err != nil {
-						return cached{nil, err}
-					}
-					if mv1.Version == "none" {
-						return cached{nil, fmt.Errorf("%s(%s) depends on excluded %s(%s) with no newer version available", mod.Path, mod.Version, mv.Path, mv.Version)}
-					}
-					mv = mv1
-				}
-			}
-			list[i] = mv
-		}
-
-		return cached{list, nil}
-	}).(cached)
-
-	return c.list, c.err
-}
-
-var vendorOnce sync.Once
-
-type vendorMetadata struct {
-	Explicit    bool
-	Replacement module.Version
-}
-
-var (
-	vendorList      []module.Version          // modules that contribute packages to the build, in order of appearance
-	vendorReplaced  []module.Version          // all replaced modules; may or may not also contribute packages
-	vendorVersion   map[string]string         // module path → selected version (if known)
-	vendorPkgModule map[string]module.Version // package → containing module
-	vendorMeta      map[module.Version]vendorMetadata
-)
-
-// readVendorList reads the list of vendored modules from vendor/modules.txt.
-func readVendorList() {
-	vendorOnce.Do(func() {
-		vendorList = nil
-		vendorPkgModule = make(map[string]module.Version)
-		vendorVersion = make(map[string]string)
-		vendorMeta = make(map[module.Version]vendorMetadata)
-		data, err := ioutil.ReadFile(filepath.Join(ModRoot(), "vendor/modules.txt"))
-		if err != nil {
-			if !errors.Is(err, os.ErrNotExist) {
-				base.Fatalf("go: %s", err)
-			}
-			return
-		}
-
-		var mod module.Version
-		for _, line := range strings.Split(string(data), "\n") {
-			if strings.HasPrefix(line, "# ") {
-				f := strings.Fields(line)
-
-				if len(f) < 3 {
-					continue
-				}
-				if semver.IsValid(f[2]) {
-					// A module, but we don't yet know whether it is in the build list or
-					// only included to indicate a replacement.
-					mod = module.Version{Path: f[1], Version: f[2]}
-					f = f[3:]
-				} else if f[2] == "=>" {
-					// A wildcard replacement found in the main module's go.mod file.
-					mod = module.Version{Path: f[1]}
-					f = f[2:]
-				} else {
-					// Not a version or a wildcard replacement.
-					// We don't know how to interpret this module line, so ignore it.
-					mod = module.Version{}
-					continue
-				}
-
-				if len(f) >= 2 && f[0] == "=>" {
-					meta := vendorMeta[mod]
-					if len(f) == 2 {
-						// File replacement.
-						meta.Replacement = module.Version{Path: f[1]}
-						vendorReplaced = append(vendorReplaced, mod)
-					} else if len(f) == 3 && semver.IsValid(f[2]) {
-						// Path and version replacement.
-						meta.Replacement = module.Version{Path: f[1], Version: f[2]}
-						vendorReplaced = append(vendorReplaced, mod)
-					} else {
-						// We don't understand this replacement. Ignore it.
-					}
-					vendorMeta[mod] = meta
-				}
-				continue
-			}
-
-			// Not a module line. Must be a package within a module or a metadata
-			// directive, either of which requires a preceding module line.
-			if mod.Path == "" {
-				continue
-			}
-
-			if strings.HasPrefix(line, "## ") {
-				// Metadata. Take the union of annotations across multiple lines, if present.
-				meta := vendorMeta[mod]
-				for _, entry := range strings.Split(strings.TrimPrefix(line, "## "), ";") {
-					entry = strings.TrimSpace(entry)
-					if entry == "explicit" {
-						meta.Explicit = true
-					}
-					// All other tokens are reserved for future use.
-				}
-				vendorMeta[mod] = meta
-				continue
-			}
-
-			if f := strings.Fields(line); len(f) == 1 && module.CheckImportPath(f[0]) == nil {
-				// A package within the current module.
-				vendorPkgModule[f[0]] = mod
-
-				// Since this module provides a package for the build, we know that it
-				// is in the build list and is the selected version of its path.
-				// If this information is new, record it.
-				if v, ok := vendorVersion[mod.Path]; !ok || semver.Compare(v, mod.Version) < 0 {
-					vendorList = append(vendorList, mod)
-					vendorVersion[mod.Path] = mod.Version
-				}
-			}
-		}
-	})
-}
-
-func (r *mvsReqs) modFileToList(f *modfile.File) []module.Version {
-	list := make([]module.Version, 0, len(f.Require))
-	for _, r := range f.Require {
-		list = append(list, r.Mod)
-	}
-	return list
-}
-
-// required returns a unique copy of the requirements of mod.
-func (r *mvsReqs) required(mod module.Version) ([]module.Version, error) {
-	if mod == Target {
-		if modFile != nil && modFile.Go != nil {
-			r.versions.LoadOrStore(mod, modFile.Go.Version)
-		}
-		return append([]module.Version(nil), r.buildList[1:]...), nil
-	}
-
-	if cfg.BuildMod == "vendor" {
-		// For every module other than the target,
-		// return the full list of modules from modules.txt.
-		readVendorList()
-		return append([]module.Version(nil), vendorList...), nil
-	}
-
-	origPath := mod.Path
-	if repl := Replacement(mod); repl.Path != "" {
-		if repl.Version == "" {
-			// TODO: need to slip the new version into the tags list etc.
-			dir := repl.Path
-			if !filepath.IsAbs(dir) {
-				dir = filepath.Join(ModRoot(), dir)
-			}
-			gomod := filepath.Join(dir, "go.mod")
-			data, err := ioutil.ReadFile(gomod)
-			if err != nil {
-				return nil, fmt.Errorf("parsing %s: %v", base.ShortPath(gomod), err)
-			}
-			f, err := modfile.ParseLax(gomod, data, nil)
-			if err != nil {
-				return nil, fmt.Errorf("parsing %s: %v", base.ShortPath(gomod), err)
-			}
-			if f.Go != nil {
-				r.versions.LoadOrStore(mod, f.Go.Version)
-			}
-			return r.modFileToList(f), nil
-		}
-		mod = repl
-	}
-
-	if mod.Version == "none" {
-		return nil, nil
-	}
-
-	if !semver.IsValid(mod.Version) {
-		// Disallow the broader queries supported by fetch.Lookup.
-		base.Fatalf("go: internal error: %s@%s: unexpected invalid semantic version", mod.Path, mod.Version)
-	}
-
-	data, err := modfetch.GoMod(mod.Path, mod.Version)
-	if err != nil {
-		return nil, err
-	}
-	f, err := modfile.ParseLax("go.mod", data, nil)
-	if err != nil {
-		return nil, module.VersionError(mod, fmt.Errorf("parsing go.mod: %v", err))
-	}
-
-	if f.Module == nil {
-		return nil, module.VersionError(mod, errors.New("parsing go.mod: missing module line"))
-	}
-	if mpath := f.Module.Mod.Path; mpath != origPath && mpath != mod.Path {
-		return nil, module.VersionError(mod, fmt.Errorf(`parsing go.mod:
-	module declares its path as: %s
-	        but was required as: %s`, mpath, mod.Path))
-	}
-	if f.Go != nil {
-		r.versions.LoadOrStore(mod, f.Go.Version)
-	}
-
-	return r.modFileToList(f), nil
-}
-
-func (*mvsReqs) Max(v1, v2 string) string {
-	if v1 != "" && semver.Compare(v1, v2) == -1 {
-		return v2
-	}
-	return v1
-}
-
-// Upgrade is a no-op, here to implement mvs.Reqs.
-// The upgrade logic for go get -u is in ../modget/get.go.
-func (*mvsReqs) Upgrade(m module.Version) (module.Version, error) {
-	return m, nil
-}
-
-func versions(path string) ([]string, error) {
-	// Note: modfetch.Lookup and repo.Versions are cached,
-	// so there's no need for us to add extra caching here.
-	var versions []string
-	err := modfetch.TryProxies(func(proxy string) error {
-		repo, err := modfetch.Lookup(proxy, path)
-		if err == nil {
-			versions, err = repo.Versions("")
-		}
-		return err
-	})
-	return versions, err
-}
-
-// Previous returns the tagged version of m.Path immediately prior to
-// m.Version, or version "none" if no prior version is tagged.
-func (*mvsReqs) Previous(m module.Version) (module.Version, error) {
-	list, err := versions(m.Path)
-	if err != nil {
-		return module.Version{}, err
-	}
-	i := sort.Search(len(list), func(i int) bool { return semver.Compare(list[i], m.Version) >= 0 })
-	if i > 0 {
-		return module.Version{Path: m.Path, Version: list[i-1]}, nil
-	}
-	return module.Version{Path: m.Path, Version: "none"}, nil
-}
-
-// next returns the next version of m.Path after m.Version.
-// It is only used by the exclusion processing in the Required method,
-// not called directly by MVS.
-func (*mvsReqs) next(m module.Version) (module.Version, error) {
-	list, err := versions(m.Path)
-	if err != nil {
-		return module.Version{}, err
-	}
-	i := sort.Search(len(list), func(i int) bool { return semver.Compare(list[i], m.Version) > 0 })
-	if i < len(list) {
-		return module.Version{Path: m.Path, Version: list[i]}, nil
-	}
-	return module.Version{Path: m.Path, Version: "none"}, nil
-}
-
-// fetch downloads the given module (or its replacement)
-// and returns its location.
-//
-// The isLocal return value reports whether the replacement,
-// if any, is local to the filesystem.
-func fetch(mod module.Version) (dir string, isLocal bool, err error) {
-	if mod == Target {
-		return ModRoot(), true, nil
-	}
-	if r := Replacement(mod); r.Path != "" {
-		if r.Version == "" {
-			dir = r.Path
-			if !filepath.IsAbs(dir) {
-				dir = filepath.Join(ModRoot(), dir)
-			}
-			// Ensure that the replacement directory actually exists:
-			// dirInModule does not report errors for missing modules,
-			// so if we don't report the error now, later failures will be
-			// very mysterious.
-			if _, err := os.Stat(dir); err != nil {
-				if os.IsNotExist(err) {
-					// Semantically the module version itself “exists” — we just don't
-					// have its source code. Remove the equivalence to os.ErrNotExist,
-					// and make the message more concise while we're at it.
-					err = fmt.Errorf("replacement directory %s does not exist", r.Path)
-				} else {
-					err = fmt.Errorf("replacement directory %s: %w", r.Path, err)
-				}
-				return dir, true, module.VersionError(mod, err)
-			}
-			return dir, true, nil
-		}
-		mod = r
-	}
-
-	dir, err = modfetch.Download(mod)
-	return dir, false, err
-}