cmd/go: refactor usage of RootMode

This commit refactors usage of the global variable `RootMode` to the
global LoaderState variable of the same name.

This commit is part of the overall effort to eliminate global
modloader state.

[git-generate]
cd src/cmd/go/internal/modload
rf 'mv State.rootMode State.RootMode'
for dir in load modcmd run tool toolchain work ; do
  cd ../${dir}
  rf 'ex {
    import "cmd/go/internal/modload";
    modload.RootMode -> modload.LoaderState.RootMode
  }'
done
cd ../modload
rf 'ex { RootMode -> LoaderState.RootMode }'
rf 'add State.ForceUseModules \
// RootMode determines whether a module root is needed.'
rf 'rm RootMode'

Change-Id: Ib5e513ee570dfc3b01cc974fe32944e5e391fd82
Reviewed-on: https://go-review.googlesource.com/c/go/+/698058
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Matloob <matloob@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>

src/cmd/go/internal/load/godebug.go

@@ -50,7 +50,7 @@ func defaultGODEBUG(p *Package, directives, testDirectives, xtestDirectives []bu
 		return ""
 	}
 	goVersion := modload.MainModules.GoVersion()
-	if modload.RootMode == modload.NoRoot && p.Module != nil {
+	if modload.LoaderState.RootMode == modload.NoRoot && p.Module != nil {
 		// This is go install pkg@version or go run pkg@version.
 		// Use the Go version from the package.
 		// If there isn't one, then assume Go 1.20,

src/cmd/go/internal/load/pkg.go

@@ -3351,7 +3351,7 @@ func PackagesAndErrorsOutsideModule(ctx context.Context, opts PackageOpts, args
 	if !modload.LoaderState.ForceUseModules {
 		panic("modload.ForceUseModules must be true")
 	}
-	if modload.RootMode != modload.NoRoot {
+	if modload.LoaderState.RootMode != modload.NoRoot {
 		panic("modload.RootMode must be NoRoot")
 	}
 

src/cmd/go/internal/modcmd/graph.go

@@ -58,7 +58,7 @@ func runGraph(ctx context.Context, cmd *base.Command, args []string) {
 		base.Fatalf("go: 'go mod graph' accepts no arguments")
 	}
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NeedRoot
+	modload.LoaderState.RootMode = modload.NeedRoot
 
 	goVersion := graphGo.String()
 	if goVersion != "" && gover.Compare(gover.Local(), goVersion) < 0 {

src/cmd/go/internal/modcmd/tidy.go

@@ -120,7 +120,7 @@ func runTidy(ctx context.Context, cmd *base.Command, args []string) {
 	// that are in 'all' but outside of the main module, we must explicitly
 	// request that their test dependencies be included.
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NeedRoot
+	modload.LoaderState.RootMode = modload.NeedRoot
 
 	goVersion := tidyGo.String()
 	if goVersion != "" && gover.Compare(gover.Local(), goVersion) < 0 {

src/cmd/go/internal/modcmd/vendor.go

@@ -78,7 +78,7 @@ func RunVendor(ctx context.Context, vendorE bool, vendorO string, args []string)
 		base.Fatalf("go: 'go mod vendor' accepts no arguments")
 	}
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NeedRoot
+	modload.LoaderState.RootMode = modload.NeedRoot
 
 	loadOpts := modload.PackageOpts{
 		Tags:                     imports.AnyTags(),

src/cmd/go/internal/modcmd/verify.go

@@ -51,7 +51,7 @@ func runVerify(ctx context.Context, cmd *base.Command, args []string) {
 		base.Fatalf("go: verify takes no arguments")
 	}
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NeedRoot
+	modload.LoaderState.RootMode = modload.NeedRoot
 
 	// Only verify up to GOMAXPROCS zips at once.
 	type token struct{}

src/cmd/go/internal/modcmd/why.go

@@ -65,7 +65,7 @@ func init() {
 func runWhy(ctx context.Context, cmd *base.Command, args []string) {
 	modload.InitWorkfile()
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NeedRoot
+	modload.LoaderState.RootMode = modload.NeedRoot
 	modload.ExplicitWriteGoMod = true // don't write go.mod in ListModules
 
 	loadOpts := modload.PackageOpts{

src/cmd/go/internal/modload/import_test.go

@@ -60,13 +60,13 @@ func TestQueryImport(t *testing.T) {
 	testenv.MustHaveExecPath(t, "git")
 
 	oldAllowMissingModuleImports := allowMissingModuleImports
-	oldRootMode := RootMode
+	oldRootMode := LoaderState.RootMode
 	defer func() {
 		allowMissingModuleImports = oldAllowMissingModuleImports
-		RootMode = oldRootMode
+		LoaderState.RootMode = oldRootMode
 	}()
 	allowMissingModuleImports = true
-	RootMode = NoRoot
+	LoaderState.RootMode = NoRoot
 
 	ctx := context.Background()
 	rs := LoadModFile(ctx)

src/cmd/go/internal/modload/init.go

@@ -38,9 +38,6 @@ import (
 //
 // TODO(#40775): See if these can be plumbed as explicit parameters.
 var (
-	// RootMode determines whether a module root is needed.
-	RootMode Root
-
 	allowMissingModuleImports bool
 
 	// ExplicitWriteGoMod prevents LoadPackages, ListModules, and other functions
@@ -370,7 +367,7 @@ func InitWorkfile() {
 // It is exported mainly for Go toolchain switching, which must process
 // the go.work very early at startup.
 func FindGoWork(wd string) string {
-	if RootMode == NoRoot {
+	if LoaderState.RootMode == NoRoot {
 		return ""
 	}
 
@@ -403,7 +400,7 @@ func setState(s State) State {
 	oldState := State{
 		initialized:     LoaderState.initialized,
 		ForceUseModules: LoaderState.ForceUseModules,
-		rootMode:        RootMode,
+		RootMode:        LoaderState.RootMode,
 		modRoots:        modRoots,
 		modulesEnabled:  cfg.ModulesEnabled,
 		mainModules:     MainModules,
@@ -411,7 +408,7 @@ func setState(s State) State {
 	}
 	LoaderState.initialized = s.initialized
 	LoaderState.ForceUseModules = s.ForceUseModules
-	RootMode = s.rootMode
+	LoaderState.RootMode = s.RootMode
 	modRoots = s.modRoots
 	cfg.ModulesEnabled = s.modulesEnabled
 	MainModules = s.mainModules
@@ -430,7 +427,9 @@ type State struct {
 	// ForceUseModules may be set to force modules to be enabled when
 	// GO111MODULE=auto or to report an error when GO111MODULE=off.
 	ForceUseModules bool
-	rootMode        Root
+
+	// RootMode determines whether a module root is needed.
+	RootMode       Root
 	modRoots       []string
 	modulesEnabled bool
 	mainModules    *MainModuleSet
@@ -495,7 +494,7 @@ func Init() {
 	if modRoots != nil {
 		// modRoot set before Init was called ("go mod init" does this).
 		// No need to search for go.mod.
-	} else if RootMode == NoRoot {
+	} else if LoaderState.RootMode == NoRoot {
 		if cfg.ModFile != "" && !base.InGOFLAGS("-modfile") {
 			base.Fatalf("go: -modfile cannot be used with commands that ignore the current module")
 		}
@@ -510,7 +509,7 @@ func Init() {
 			if cfg.ModFile != "" {
 				base.Fatalf("go: cannot find main module, but -modfile was set.\n\t-modfile cannot be used to set the module root directory.")
 			}
-			if RootMode == NeedRoot {
+			if LoaderState.RootMode == NeedRoot {
 				base.Fatal(ErrNoModRoot)
 			}
 			if !mustUseModules {
@@ -525,7 +524,7 @@ func Init() {
 			// It's a bit of a peculiar thing to disallow but quite mysterious
 			// when it happens. See golang.org/issue/26708.
 			fmt.Fprintf(os.Stderr, "go: warning: ignoring go.mod in system temp root %v\n", os.TempDir())
-			if RootMode == NeedRoot {
+			if LoaderState.RootMode == NeedRoot {
 				base.Fatal(ErrNoModRoot)
 			}
 			if !mustUseModules {
@@ -547,7 +546,7 @@ func Init() {
 		gopath = list[0]
 		if _, err := fsys.Stat(filepath.Join(gopath, "go.mod")); err == nil {
 			fmt.Fprintf(os.Stderr, "go: warning: ignoring go.mod in $GOPATH %v\n", gopath)
-			if RootMode == NeedRoot {
+			if LoaderState.RootMode == NeedRoot {
 				base.Fatal(ErrNoModRoot)
 			}
 			if !mustUseModules {

src/cmd/go/internal/run/run.go

@@ -77,7 +77,7 @@ func runRun(ctx context.Context, cmd *base.Command, args []string) {
 		// before loading packages, since it affects package locations, e.g.,
 		// for -race and -msan.
 		modload.LoaderState.ForceUseModules = true
-		modload.RootMode = modload.NoRoot
+		modload.LoaderState.RootMode = modload.NoRoot
 		modload.AllowMissingModuleImports()
 		modload.Init()
 	} else {

src/cmd/go/internal/tool/tool.go

@@ -308,7 +308,7 @@ func buildAndRunBuiltinTool(ctx context.Context, toolName, tool string, args []s
 	// Ignore go.mod and go.work: we don't need them, and we want to be able
 	// to run the tool even if there's an issue with the module or workspace the
 	// user happens to be in.
-	modload.RootMode = modload.NoRoot
+	modload.LoaderState.RootMode = modload.NoRoot
 
 	runFunc := func(b *work.Builder, ctx context.Context, a *work.Action) error {
 		cmdline := str.StringList(builtTool(a), a.Args)

src/cmd/go/internal/toolchain/select.go

@@ -354,7 +354,7 @@ func Exec(gotoolchain string) {
 	// Set up modules without an explicit go.mod, to download distribution.
 	modload.Reset()
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NoRoot
+	modload.LoaderState.RootMode = modload.NoRoot
 	modload.Init()
 
 	// Download and unpack toolchain module into module cache.
@@ -693,7 +693,7 @@ func maybeSwitchForGoInstallVersion(minVers string) {
 
 	// Set up modules without an explicit go.mod, to download go.mod.
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NoRoot
+	modload.LoaderState.RootMode = modload.NoRoot
 	modload.Init()
 	defer modload.Reset()
 

src/cmd/go/internal/work/build.go

@@ -860,7 +860,7 @@ func InstallPackages(ctx context.Context, patterns []string, pkgs []*load.Packag
 // See golang.org/issue/40276 for details and rationale.
 func installOutsideModule(ctx context.Context, args []string) {
 	modload.LoaderState.ForceUseModules = true
-	modload.RootMode = modload.NoRoot
+	modload.LoaderState.RootMode = modload.NoRoot
 	modload.AllowMissingModuleImports()
 	modload.Init()
 	BuildInit()