go/analysis: Add modules to Pass

Adds optional Module information to Pass. Module contains
the go module information for the package of the Pass.
It contains the module's path, the module version, and the
GoVersion of the module.

Updates packages.PrintErrors to additionally print module
errors.

Fixes golang/go#66315

Change-Id: I7005b8e2f6290f16416c2438af0e6de2940ba9fc
Reviewed-on: https://go-review.googlesource.com/c/tools/+/577996
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

go/analysis/analysis.go

@@ -100,6 +100,8 @@ type Pass struct {
 	TypesSizes   types.Sizes    // function for computing sizes of types
 	TypeErrors   []types.Error  // type errors (only if Analyzer.RunDespiteErrors)
 
+	Module *Module // the package's enclosing module (possibly nil in some drivers)
+
 	// Report reports a Diagnostic, a finding about a specific location
 	// in the analyzed source code such as a potential mistake.
 	// It may be called by the Run function.
@@ -238,3 +240,10 @@ func (pass *Pass) String() string {
 type Fact interface {
 	AFact() // dummy method to avoid type errors
 }
+
+// A Module describes the module to which a package belongs.
+type Module struct {
+	Path      string // module path
+	Version   string // module version ("" if unknown, such as for workspace modules)
+	GoVersion string // go version used in module (e.g. "go1.22.0")
+}

go/analysis/analysistest/analysistest_test.go

@@ -17,6 +17,8 @@ import (
 	"golang.org/x/tools/go/analysis/analysistest"
 	"golang.org/x/tools/go/analysis/passes/findcall"
 	"golang.org/x/tools/internal/testenv"
+	"golang.org/x/tools/internal/testfiles"
+	"golang.org/x/tools/txtar"
 )
 
 func init() {
@@ -202,6 +204,62 @@ func F() {} // want "say hello"`,
 	analysistest.RunWithSuggestedFixes(t, dir, noend, "a")
 }
 
+func TestModule(t *testing.T) {
+	const content = `
+Test that analysis.pass.Module is populated.
+
+-- go.mod --
+module golang.org/fake/mod
+
+go 1.21
+
+require golang.org/xyz/fake v0.12.34
+
+-- mod.go --
+// We expect a module.Path and a module.GoVersion, but an empty module.Version.
+
+package mod // want "golang.org/fake/mod,,1.21"
+
+import "golang.org/xyz/fake/ver"
+
+var _ ver.T
+
+-- vendor/modules.txt --
+# golang.org/xyz/fake v0.12.34
+## explicit; go 1.18
+golang.org/xyz/fake/ver
+
+-- vendor/golang.org/xyz/fake/ver/ver.go --
+// This package is vendored so that we can populate a non-empty
+// Pass.Module.Version is in a test.
+
+package ver //want "golang.org/xyz/fake,v0.12.34,1.18"
+
+type T string
+`
+	fs, err := txtar.FS(txtar.Parse([]byte(content)))
+	if err != nil {
+		t.Fatal(err)
+	}
+	dir := testfiles.CopyToTmp(t, fs)
+
+	filever := &analysis.Analyzer{
+		Name: "mod",
+		Doc:  "reports module information",
+		Run: func(pass *analysis.Pass) (any, error) {
+			msg := "no module info"
+			if m := pass.Module; m != nil {
+				msg = fmt.Sprintf("%s,%s,%s", m.Path, m.Version, m.GoVersion)
+			}
+			for _, file := range pass.Files {
+				pass.Reportf(file.Package, "%s", msg)
+			}
+			return nil, nil
+		},
+	}
+	analysistest.Run(t, dir, filever, "golang.org/fake/mod", "golang.org/xyz/fake/ver")
+}
+
 type errorfunc func(string)
 
 func (f errorfunc) Errorf(format string, args ...interface{}) {

go/analysis/internal/checker/checker.go

@@ -138,7 +138,7 @@ func Run(args []string, analyzers []*analysis.Analyzer) (exitcode int) {
 	}
 
 	pkgsExitCode := 0
-	// Print package errors regardless of RunDespiteErrors.
+	// Print package and module errors regardless of RunDespiteErrors.
 	// Do not exit if there are errors, yet.
 	if n := packages.PrintErrors(initial); n > 0 {
 		pkgsExitCode = 1
@@ -720,6 +720,13 @@ func (act *action) execOnce() {
 		}
 	}
 
+	module := &analysis.Module{} // possibly empty (non nil) in go/analysis drivers.
+	if mod := act.pkg.Module; mod != nil {
+		module.Path = mod.Path
+		module.Version = mod.Version
+		module.GoVersion = mod.GoVersion
+	}
+
 	// Run the analysis.
 	pass := &analysis.Pass{
 		Analyzer:     act.a,
@@ -731,6 +738,7 @@ func (act *action) execOnce() {
 		TypesInfo:    act.pkg.TypesInfo,
 		TypesSizes:   act.pkg.TypesSizes,
 		TypeErrors:   act.pkg.TypeErrors,
+		Module:       module,
 
 		ResultOf:          inputs,
 		Report:            func(d analysis.Diagnostic) { act.diagnostics = append(act.diagnostics, d) },

go/analysis/unitchecker/separate_test.go

@@ -15,6 +15,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 	"sync/atomic"
 	"testing"
@@ -167,6 +168,8 @@ func MyPrintf(format string, args ...any) {
 			if v := pkg.Module.GoVersion; v != "" {
 				cfg.GoVersion = "go" + v
 			}
+			cfg.ModulePath = pkg.Module.Path
+			cfg.ModuleVersion = pkg.Module.Version
 		}
 
 		// Write the JSON configuration message to a file.
@@ -220,6 +223,7 @@ func MyPrintf(format string, args ...any) {
 	// from separate analysis of "main", "lib", and "fmt":
 
 	const want = `/main/main.go:6:2: [printf] separate/lib.MyPrintf format %s has arg 123 of wrong type int`
+	sort.Strings(allDiagnostics)
 	if got := strings.Join(allDiagnostics, "\n"); got != want {
 		t.Errorf("Got: %s\nWant: %s", got, want)
 	}

go/analysis/unitchecker/unitchecker.go

@@ -66,6 +66,8 @@ type Config struct {
 	GoFiles                   []string
 	NonGoFiles                []string
 	IgnoredFiles              []string
+	ModulePath                string            // module path
+	ModuleVersion             string            // module version
 	ImportMap                 map[string]string // maps import path to package path
 	PackageFile               map[string]string // maps package path to file of type information
 	Standard                  map[string]bool   // package belongs to standard library
@@ -359,6 +361,12 @@ func run(fset *token.FileSet, cfg *Config, analyzers []*analysis.Analyzer) ([]re
 				factFilter[reflect.TypeOf(f)] = true
 			}
 
+			module := &analysis.Module{
+				Path:      cfg.ModulePath,
+				Version:   cfg.ModuleVersion,
+				GoVersion: cfg.GoVersion,
+			}
+
 			pass := &analysis.Pass{
 				Analyzer:          a,
 				Fset:              fset,
@@ -377,6 +385,7 @@ func run(fset *token.FileSet, cfg *Config, analyzers []*analysis.Analyzer) ([]re
 				ImportPackageFact: facts.ImportPackageFact,
 				ExportPackageFact: facts.ExportPackageFact,
 				AllPackageFacts:   func() []analysis.PackageFact { return facts.AllPackageFacts(factFilter) },
+				Module:            module,
 			}
 			pass.ReadFile = analysisinternal.MakeReadFile(pass)
 

go/packages/visit.go

@@ -49,11 +49,20 @@ func Visit(pkgs []*Package, pre func(*Package) bool, post func(*Package)) {
 // PrintErrors returns the number of errors printed.
 func PrintErrors(pkgs []*Package) int {
 	var n int
+	errModules := make(map[*Module]bool)
 	Visit(pkgs, nil, func(pkg *Package) {
 		for _, err := range pkg.Errors {
 			fmt.Fprintln(os.Stderr, err)
 			n++
 		}
+
+		// Print pkg.Module.Error once if present.
+		mod := pkg.Module
+		if mod != nil && mod.Error != nil && !errModules[mod] {
+			errModules[mod] = true
+			fmt.Fprintln(os.Stderr, mod.Error.Err)
+			n++
+		}
 	})
 	return n
 }