cmd/go: eliminate additional global variable

Move global variable to a field on the State type.

Change-Id: I1edd32e1d28ce814bcd75501098ee4b22227546b
Reviewed-on: https://go-review.googlesource.com/c/go/+/716162
Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Matloob <matloob@google.com>

src/cmd/go/internal/modget/get.go

@@ -308,7 +308,7 @@ func runGet(ctx context.Context, cmd *base.Command, args []string) {
 
 	// Allow looking up modules for import paths when outside of a module.
 	// 'go get' is expected to do this, unlike other commands.
-	modload.AllowMissingModuleImports(moduleLoaderState)
+	moduleLoaderState.AllowMissingModuleImports()
 
 	// 'go get' no longer builds or installs packages, so there's nothing to do
 	// if there's no go.mod file.

src/cmd/go/internal/modload/import.go

@@ -33,6 +33,7 @@ type ImportMissingError struct {
 	Module                    module.Version
 	QueryErr                  error
 	modContainingCWD          module.Version
+	allowMissingModuleImports bool
 
 	// modRoot is dependent on the value of ImportingMainModule and should be
 	// kept in sync.
@@ -70,7 +71,7 @@ func (e *ImportMissingError) Error() string {
 		if e.QueryErr != nil && !errors.Is(e.QueryErr, ErrNoModRoot) {
 			return fmt.Sprintf("cannot find module providing package %s: %v", e.Path, e.QueryErr)
 		}
-		if cfg.BuildMod == "mod" || (cfg.BuildMod == "readonly" && allowMissingModuleImports) {
+		if cfg.BuildMod == "mod" || (cfg.BuildMod == "readonly" && e.allowMissingModuleImports) {
 			return "cannot find module providing package " + e.Path
 		}
 
@@ -375,6 +376,7 @@ func importFromModules(loaderstate *State, ctx context.Context, path string, rs
 			return module.Version{}, "", "", nil, &ImportMissingError{
 				Path:                      path,
 				modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+				allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 			}
 		}
 
@@ -498,6 +500,7 @@ func importFromModules(loaderstate *State, ctx context.Context, path string, rs
 				QueryErr:                  queryErr,
 				isStd:                     pathIsStd,
 				modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+				allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 			}
 		}
 
@@ -574,6 +577,7 @@ func queryImport(loaderstate *State, ctx context.Context, path string, rs *Requi
 					Path:                      path,
 					replaced:                  m,
 					modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+					allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 				}
 			}
 			return m, nil
@@ -604,10 +608,11 @@ func queryImport(loaderstate *State, ctx context.Context, path string, rs *Requi
 			Path:                      path,
 			isStd:                     true,
 			modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+			allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 		}
 	}
 
-	if (cfg.BuildMod == "readonly" || cfg.BuildMod == "vendor") && !allowMissingModuleImports {
+	if (cfg.BuildMod == "readonly" || cfg.BuildMod == "vendor") && !loaderstate.allowMissingModuleImports {
 		// In readonly mode, we can't write go.mod, so we shouldn't try to look up
 		// the module. If readonly mode was enabled explicitly, include that in
 		// the error message.
@@ -623,6 +628,7 @@ func queryImport(loaderstate *State, ctx context.Context, path string, rs *Requi
 			Path:                      path,
 			QueryErr:                  queryErr,
 			modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+			allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 		}
 	}
 
@@ -645,6 +651,7 @@ func queryImport(loaderstate *State, ctx context.Context, path string, rs *Requi
 				Path:                      path,
 				QueryErr:                  err,
 				modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+				allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 			}
 		} else {
 			return module.Version{}, err
@@ -674,6 +681,7 @@ func queryImport(loaderstate *State, ctx context.Context, path string, rs *Requi
 		Module:                    candidates[0].Mod,
 		newMissingVersion:         candidate0MissingVersion,
 		modContainingCWD:          loaderstate.MainModules.ModContainingCWD(),
+		allowMissingModuleImports: loaderstate.allowMissingModuleImports,
 	}
 }
 

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

@@ -58,16 +58,11 @@ var importTests = []struct {
 func TestQueryImport(t *testing.T) {
 	loaderstate := NewState()
 	loaderstate.RootMode = NoRoot
+	loaderstate.AllowMissingModuleImports()
 
 	testenv.MustHaveExternalNetwork(t)
 	testenv.MustHaveExecPath(t, "git")
 
-	oldAllowMissingModuleImports := allowMissingModuleImports
-	defer func() {
-		allowMissingModuleImports = oldAllowMissingModuleImports
-	}()
-	allowMissingModuleImports = true
-
 	ctx := context.Background()
 	rs := LoadModFile(loaderstate, ctx)
 

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

@@ -38,8 +38,6 @@ import (
 //
 // TODO(#40775): See if these can be plumbed as explicit parameters.
 var (
-	allowMissingModuleImports bool
-
 	// ExplicitWriteGoMod prevents LoadPackages, ListModules, and other functions
 	// from updating go.mod and go.sum or reporting errors when updates are
 	// needed. A package should set this if it would cause go.mod to be written
@@ -416,6 +414,7 @@ func (s *State) setState(new State) State {
 
 type State struct {
 	initialized               bool
+	allowMissingModuleImports bool
 
 	// ForceUseModules may be set to force modules to be enabled when
 	// GO111MODULE=auto or to report an error when GO111MODULE=off.
@@ -1292,11 +1291,11 @@ func fixVersion(loaderstate *State, ctx context.Context, fixed *bool) modfile.Ve
 //
 // This function affects the default cfg.BuildMod when outside of a module,
 // so it can only be called prior to Init.
-func AllowMissingModuleImports(loaderstate *State) {
+func (s *State) AllowMissingModuleImports() {
-	if loaderstate.initialized {
+	if s.initialized {
 		panic("AllowMissingModuleImports after Init")
 	}
-	allowMissingModuleImports = true
+	s.allowMissingModuleImports = true
 }
 
 // makeMainModules creates a MainModuleSet and associated variables according to
@@ -1553,7 +1552,7 @@ func setDefaultBuildMod(loaderstate *State) {
 		return
 	}
 	if loaderstate.modRoots == nil {
-		if allowMissingModuleImports {
+		if loaderstate.allowMissingModuleImports {
 			cfg.BuildMod = "mod"
 		} else {
 			cfg.BuildMod = "readonly"

src/cmd/go/internal/modload/load.go

@@ -1184,7 +1184,7 @@ func loadFromRoots(loaderstate *State, ctx context.Context, params loaderParams)
 			continue
 		}
 
-		if !ld.ResolveMissingImports || (!HasModRoot(loaderstate) && !allowMissingModuleImports) {
+		if !ld.ResolveMissingImports || (!HasModRoot(loaderstate) && !loaderstate.allowMissingModuleImports) {
 			// We've loaded as much as we can without resolving missing imports.
 			break
 		}

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

@@ -79,7 +79,7 @@ func runRun(ctx context.Context, cmd *base.Command, args []string) {
 		// for -race and -msan.
 		moduleLoaderState.ForceUseModules = true
 		moduleLoaderState.RootMode = modload.NoRoot
-		modload.AllowMissingModuleImports(moduleLoaderState)
+		moduleLoaderState.AllowMissingModuleImports()
 		modload.Init(moduleLoaderState)
 	} else {
 		modload.InitWorkfile(moduleLoaderState)

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

@@ -863,7 +863,7 @@ func InstallPackages(loaderstate *modload.State, ctx context.Context, patterns [
 func installOutsideModule(loaderstate *modload.State, ctx context.Context, args []string) {
 	loaderstate.ForceUseModules = true
 	loaderstate.RootMode = modload.NoRoot
-	modload.AllowMissingModuleImports(loaderstate)
+	loaderstate.AllowMissingModuleImports()
 	modload.Init(loaderstate)
 	BuildInit(loaderstate)