cmd/go: inject State parameter into modcmd.runDownload

This command modifies the call tree starting at `modcmd.runDownload`
to inject a `State` parameter to every function that is currently
using the global `modload.LoaderState` variable.  By explicilty
passing a `State` parameter, we can begin to eliminate the usage of
the global `modload.LoaderState`.

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

[git-generate]
cd src/cmd/go/internal/modcmd
rf 'inject modload.LoaderState runDownload'
cd ..
./rf-cleanup.zsh

Change-Id: I64cce3e631a2614b7fabe49205d9d41fc9ba24de
Reviewed-on: https://go-review.googlesource.com/c/go/+/710299
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: Michael Matloob <matloob@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/cmd/go/internal/modcmd/download.go

@@ -153,7 +153,7 @@ func runDownload(ctx context.Context, cmd *base.Command, args []string) {
 				// However, we also need to load the full module graph, to ensure that
 				// we have downloaded enough of the module graph to run 'go list all',
 				// 'go mod graph', and similar commands.
-				_, err := modload.LoadModGraph(ctx, "")
+				_, err := modload.LoadModGraph(modload.LoaderState, ctx, "")
 				if err != nil {
 					// TODO(#64008): call base.Fatalf instead of toolchain.SwitchOrFatal
 					// here, since we can only reach this point with an outdated toolchain
@@ -231,7 +231,7 @@ func runDownload(ctx context.Context, cmd *base.Command, args []string) {
 		// TODO(#64008): In the future, report an error if go.mod or go.sum need to
 		// be updated after loading the build list. This may require setting
 		// the mode to "mod" or "readonly" depending on haveExplicitArgs.
-		if err := modload.WriteGoMod(ctx, modload.WriteOpts{}); err != nil {
+		if err := modload.WriteGoMod(modload.LoaderState, ctx, modload.WriteOpts{}); err != nil {
 			base.Fatal(err)
 		}
 	}
@@ -348,7 +348,7 @@ func runDownload(ctx context.Context, cmd *base.Command, args []string) {
 	// Don't save sums for 'go mod download' without arguments unless we're in
 	// workspace mode; see comment above.
 	if haveExplicitArgs || modload.WorkFilePath(modload.LoaderState) != "" {
-		if err := modload.WriteGoMod(ctx, modload.WriteOpts{}); err != nil {
+		if err := modload.WriteGoMod(modload.LoaderState, ctx, modload.WriteOpts{}); err != nil {
 			base.Error(err)
 		}
 	}

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

@@ -68,7 +68,7 @@ func runGraph(ctx context.Context, cmd *base.Command, args []string) {
 		})
 	}
 
-	mg, err := modload.LoadModGraph(ctx, goVersion)
+	mg, err := modload.LoadModGraph(modload.LoaderState, ctx, goVersion)
 	if err != nil {
 		base.Fatal(err)
 	}

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

@@ -57,7 +57,7 @@ func runVerify(ctx context.Context, cmd *base.Command, args []string) {
 	type token struct{}
 	sem := make(chan token, runtime.GOMAXPROCS(0))
 
-	mg, err := modload.LoadModGraph(ctx, "")
+	mg, err := modload.LoadModGraph(modload.LoaderState, ctx, "")
 	if err != nil {
 		base.Fatal(err)
 	}

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

@@ -412,7 +412,7 @@ func runGet(ctx context.Context, cmd *base.Command, args []string) {
 	// Everything succeeded. Update go.mod.
 	oldReqs := reqsFromGoMod(modload.ModFile())
 
-	if err := modload.WriteGoMod(ctx, opts); err != nil {
+	if err := modload.WriteGoMod(modload.LoaderState, ctx, opts); err != nil {
 		// A TooNewError can happen for 'go get go@newversion'
 		// when all the required modules are old enough
 		// but the command line is not.
@@ -556,7 +556,7 @@ type matchInModuleKey struct {
 func newResolver(ctx context.Context, queries []*query) *resolver {
 	// LoadModGraph also sets modload.Target, which is needed by various resolver
 	// methods.
-	mg, err := modload.LoadModGraph(ctx, "")
+	mg, err := modload.LoadModGraph(modload.LoaderState, ctx, "")
 	if err != nil {
 		toolchain.SwitchOrFatal(modload.LoaderState, ctx, err)
 	}
@@ -2033,7 +2033,7 @@ func (r *resolver) updateBuildList(ctx context.Context, additions []module.Versi
 		return false
 	}
 
-	mg, err := modload.LoadModGraph(ctx, "")
+	mg, err := modload.LoadModGraph(modload.LoaderState, ctx, "")
 	if err != nil {
 		toolchain.SwitchOrFatal(modload.LoaderState, ctx, err)
 	}

src/cmd/go/internal/modload/buildlist.go

@@ -552,14 +552,14 @@ func (mg *ModuleGraph) allRootsSelected(loaderstate *State) bool {
 // Modules are loaded automatically (and lazily) in LoadPackages:
 // LoadModGraph need only be called if LoadPackages is not,
 // typically in commands that care about modules but no particular package.
-func LoadModGraph(ctx context.Context, goVersion string) (*ModuleGraph, error) {
+func LoadModGraph(loaderstate *State, ctx context.Context, goVersion string) (*ModuleGraph, error) {
-	rs, err := loadModFile(LoaderState, ctx, nil)
+	rs, err := loadModFile(loaderstate, ctx, nil)
 	if err != nil {
 		return nil, err
 	}
 
 	if goVersion != "" {
-		v, _ := rs.rootSelected(LoaderState, "go")
+		v, _ := rs.rootSelected(loaderstate, "go")
 		if gover.Compare(v, gover.GoStrictVersion) >= 0 && gover.Compare(goVersion, v) < 0 {
 			return nil, fmt.Errorf("requested Go version %s cannot load module graph (requires Go >= %s)", goVersion, v)
 		}
@@ -569,17 +569,17 @@ func LoadModGraph(ctx context.Context, goVersion string) (*ModuleGraph, error) {
 			// Use newRequirements instead of convertDepth because convertDepth
 			// also updates roots; here, we want to report the unmodified roots
 			// even though they may seem inconsistent.
-			rs = newRequirements(LoaderState, unpruned, rs.rootModules, rs.direct)
+			rs = newRequirements(loaderstate, unpruned, rs.rootModules, rs.direct)
 		}
 
-		return rs.Graph(LoaderState, ctx)
+		return rs.Graph(loaderstate, ctx)
 	}
 
-	rs, mg, err := expandGraph(LoaderState, ctx, rs)
+	rs, mg, err := expandGraph(loaderstate, ctx, rs)
 	if err != nil {
 		return nil, err
 	}
-	LoaderState.requirements = rs
+	loaderstate.requirements = rs
 	return mg, nil
 }
 

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

@@ -1808,9 +1808,9 @@ type WriteOpts struct {
 }
 
 // WriteGoMod writes the current build list back to go.mod.
-func WriteGoMod(ctx context.Context, opts WriteOpts) error {
+func WriteGoMod(loaderstate *State, ctx context.Context, opts WriteOpts) error {
-	LoaderState.requirements = LoadModFile(LoaderState, ctx)
+	loaderstate.requirements = LoadModFile(loaderstate, ctx)
-	return commitRequirements(LoaderState, ctx, opts)
+	return commitRequirements(loaderstate, ctx, opts)
 }
 
 var errNoChange = errors.New("no update needed")

src/cmd/go/internal/workcmd/sync.go

@@ -54,7 +54,7 @@ func runSync(ctx context.Context, cmd *base.Command, args []string) {
 		base.Fatalf("go: no go.work file found\n\t(run 'go work init' first or specify path using GOWORK environment variable)")
 	}
 
-	_, err := modload.LoadModGraph(ctx, "")
+	_, err := modload.LoadModGraph(modload.LoaderState, ctx, "")
 	if err != nil {
 		toolchain.SwitchOrFatal(modload.LoaderState, ctx, err)
 	}
@@ -129,7 +129,7 @@ func runSync(ctx context.Context, cmd *base.Command, args []string) {
 				SilenceMissingStdImports: true,
 				SilencePackageErrors:     true,
 			}, "all")
-			modload.WriteGoMod(ctx, modload.WriteOpts{})
+			modload.WriteGoMod(modload.LoaderState, ctx, modload.WriteOpts{})
 		}
 		goV = gover.Max(goV, modload.LoaderState.MainModules.GoVersion(modload.LoaderState))
 	}