cmd/go: add tools to "all"

Packages referenced by tool lines in go.mod files will now be included
in the module graph for the new "tool" package pattern and the "all"
package pattern.

For golang/go#48429

Change-Id: I128f6a50880814bd5395674426c9a7ee2ddc19bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/521959
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

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

@@ -108,6 +108,8 @@ type MainModuleSet struct {
 
 	modFiles map[module.Version]*modfile.File
 
+	tools map[string]bool
+
 	modContainingCWD module.Version
 
 	workFile *modfile.WorkFile
@@ -135,6 +137,15 @@ func (mms *MainModuleSet) Versions() []module.Version {
 	return mms.versions
 }
 
+// Tools returns the tools defined by all the main modules.
+// The key is the absolute package path of the tool.
+func (mms *MainModuleSet) Tools() map[string]bool {
+	if mms == nil {
+		return nil
+	}
+	return mms.tools
+}
+
 func (mms *MainModuleSet) Contains(path string) bool {
 	if mms == nil {
 		return false
@@ -1219,6 +1230,7 @@ func makeMainModules(ms []module.Version, rootDirs []string, modFiles []*modfile
 		modFiles:        map[module.Version]*modfile.File{},
 		indices:         map[module.Version]*modFileIndex{},
 		highestReplaced: map[string]string{},
+		tools:           map[string]bool{},
 		workFile:        workFile,
 	}
 	var workFileReplaces []*modfile.Replace
@@ -1301,6 +1313,17 @@ func makeMainModules(ms []module.Version, rootDirs []string, modFiles []*modfile
 					mainModules.highestReplaced[r.Old.Path] = r.Old.Version
 				}
 			}
+
+			for _, t := range modFiles[i].Tool {
+				if err := module.CheckImportPath(t.Path); err != nil {
+					if e, ok := err.(*module.InvalidPathError); ok {
+						e.Kind = "tool"
+					}
+					base.Fatal(err)
+				}
+
+				mainModules.tools[t.Path] = true
+			}
 		}
 	}
 

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

@@ -36,6 +36,7 @@ package modload
 // A package matches the "all" pattern if:
 // 	- it is in the main module, or
 // 	- it is imported by any test in the main module, or
+// 	- it is imported by a tool of the main module, or
 // 	- it is imported by another package in "all", or
 // 	- the main module specifies a go version ≤ 1.15, and the package is imported
 // 	  by a *test of* another package in "all".
@@ -324,7 +325,7 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 
 			case m.Pattern() == "all":
 				if ld == nil {
-					// The initial roots are the packages in the main module.
+					// The initial roots are the packages and tools in the main module.
 					// loadFromRoots will expand that to "all".
 					m.Errs = m.Errs[:0]
 					matchModules := MainModules.Versions()
@@ -332,6 +333,9 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 						matchModules = []module.Version{opts.MainModule}
 					}
 					matchPackages(ctx, m, opts.Tags, omitStd, matchModules)
+					for tool := range MainModules.Tools() {
+						m.Pkgs = append(m.Pkgs, tool)
+					}
 				} else {
 					// Starting with the packages in the main module,
 					// enumerate the full list of "all".
@@ -343,6 +347,10 @@ func LoadPackages(ctx context.Context, opts PackageOpts, patterns ...string) (ma
 					m.MatchPackages() // Locate the packages within GOROOT/src.
 				}
 
+			case m.Pattern() == "tool":
+				for tool, _ := range MainModules.Tools() {
+					m.Pkgs = append(m.Pkgs, tool)
+				}
 			default:
 				panic(fmt.Sprintf("internal error: modload missing case for pattern %s", m.Pattern()))
 			}
@@ -1864,6 +1872,9 @@ func (ld *loader) load(ctx context.Context, pkg *loadPkg) {
 		// essentially nothing (these atomic flag ops are essentially free compared
 		// to scanning source code for imports).
 		ld.applyPkgFlags(ctx, pkg, pkgInAll)
+	} else if MainModules.Tools()[pkg.path] {
+		// Tools declared by main modules are always in "all".
+		ld.applyPkgFlags(ctx, pkg, pkgInAll)
 	}
 	if ld.AllowPackage != nil {
 		if err := ld.AllowPackage(ctx, pkg.path, pkg.mod); err != nil {

src/cmd/go/internal/search/search.go

@@ -60,14 +60,14 @@ func (m *Match) IsLocal() bool {
 }
 
 // IsMeta reports whether the pattern is a “meta-package” keyword that represents
-// multiple packages, such as "std", "cmd", or "all".
+// multiple packages, such as "std", "cmd", "tool", or "all".
 func (m *Match) IsMeta() bool {
 	return IsMetaPackage(m.pattern)
 }
 
 // IsMetaPackage checks if name is a reserved package name that expands to multiple packages.
 func IsMetaPackage(name string) bool {
-	return name == "std" || name == "cmd" || name == "all"
+	return name == "std" || name == "cmd" || name == "tool" || name == "all"
 }
 
 // A MatchError indicates an error that occurred while attempting to match a

src/cmd/go/testdata/script/list_tool.txt

@@ -0,0 +1,82 @@
+go list tool
+stdout example.com/foo/cmd
+stdout example.com/dependency/cmd/bar
+go list all
+stdout example.com/foo/cmd
+stdout example.com/foo/lib
+stdout example.com/dependency/cmd/bar
+
+cd workspace
+go list tool
+stdout example.com/foo/cmd
+stdout example.com/dependency/cmd/bar
+stdout example.com/dependency/cmd/baz
+go list all
+stdout example.com/foo/cmd
+stdout example.com/foo/lib
+stdout example.com/other
+stdout example.com/dependency/cmd/bar
+stdout example.com/dependency/cmd/baz
+
+cd ../invalid_path
+! go list all
+stderr 'malformed tool path'
+
+-- go.mod --
+module example.com/foo
+
+go 1.24
+
+tool example.com/foo/cmd/eg
+tool example.com/dependency/cmd/bar
+
+replace example.com/dependency => ./dependency
+
+require example.com/dependency v1.0.0
+
+-- lib/main.go --
+package lib
+
+-- cmd/eg/main.go --
+package main
+
+func main(){}
+
+-- dependency/go.mod --
+module example.com/dependency
+
+go 1.24
+-- dependency/cmd/bar/main.go --
+package main
+
+func main(){}
+-- dependency/cmd/baz/main.go --
+package main
+
+func main() {}
+-- other/go.mod --
+module example.com/other
+
+go 1.24
+
+tool example.com/dependency/cmd/baz
+
+replace example.com/dependency => ../dependency
+
+require example.com/dependency v1.0.0
+-- other/lib.go --
+package other
+-- workspace/go.work --
+go 1.24
+
+use (
+    ../
+    ../other
+)
+
+-- invalid_path/go.mod --
+module example.com/invalid_path
+
+go 1.24
+
+tool ./invalid_path