diff options
Diffstat (limited to '')
-rw-r--r-- | src/cmd/doc/pkg.go | 1085 |
1 files changed, 1085 insertions, 0 deletions
diff --git a/src/cmd/doc/pkg.go b/src/cmd/doc/pkg.go new file mode 100644 index 0000000..c2e06eb --- /dev/null +++ b/src/cmd/doc/pkg.go @@ -0,0 +1,1085 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +import ( + "bufio" + "bytes" + "fmt" + "go/ast" + "go/build" + "go/doc" + "go/format" + "go/parser" + "go/printer" + "go/token" + "io" + "io/fs" + "log" + "path/filepath" + "strings" + "unicode" + "unicode/utf8" +) + +const ( + punchedCardWidth = 80 // These things just won't leave us alone. + indentedWidth = punchedCardWidth - len(indent) + indent = " " +) + +type Package struct { + writer io.Writer // Destination for output. + name string // Package name, json for encoding/json. + userPath string // String the user used to find this package. + pkg *ast.Package // Parsed package. + file *ast.File // Merged from all files in the package + doc *doc.Package + build *build.Package + typedValue map[*doc.Value]bool // Consts and vars related to types. + constructor map[*doc.Func]bool // Constructors. + fs *token.FileSet // Needed for printing. + buf pkgBuffer +} + +// pkgBuffer is a wrapper for bytes.Buffer that prints a package clause the +// first time Write is called. +type pkgBuffer struct { + pkg *Package + printed bool // Prevent repeated package clauses. + bytes.Buffer +} + +func (pb *pkgBuffer) Write(p []byte) (int, error) { + pb.packageClause() + return pb.Buffer.Write(p) +} + +func (pb *pkgBuffer) packageClause() { + if !pb.printed { + pb.printed = true + // Only show package clause for commands if requested explicitly. + if pb.pkg.pkg.Name != "main" || showCmd { + pb.pkg.packageClause() + } + } +} + +type PackageError string // type returned by pkg.Fatalf. + +func (p PackageError) Error() string { + return string(p) +} + +// prettyPath returns a version of the package path that is suitable for an +// error message. It obeys the import comment if present. Also, since +// pkg.build.ImportPath is sometimes the unhelpful "" or ".", it looks for a +// directory name in GOROOT or GOPATH if that happens. +func (pkg *Package) prettyPath() string { + path := pkg.build.ImportComment + if path == "" { + path = pkg.build.ImportPath + } + if path != "." && path != "" { + return path + } + // Convert the source directory into a more useful path. + // Also convert everything to slash-separated paths for uniform handling. + path = filepath.Clean(filepath.ToSlash(pkg.build.Dir)) + // Can we find a decent prefix? + goroot := filepath.Join(buildCtx.GOROOT, "src") + if p, ok := trim(path, filepath.ToSlash(goroot)); ok { + return p + } + for _, gopath := range splitGopath() { + if p, ok := trim(path, filepath.ToSlash(gopath)); ok { + return p + } + } + return path +} + +// trim trims the directory prefix from the path, paying attention +// to the path separator. If they are the same string or the prefix +// is not present the original is returned. The boolean reports whether +// the prefix is present. That path and prefix have slashes for separators. +func trim(path, prefix string) (string, bool) { + if !strings.HasPrefix(path, prefix) { + return path, false + } + if path == prefix { + return path, true + } + if path[len(prefix)] == '/' { + return path[len(prefix)+1:], true + } + return path, false // Textual prefix but not a path prefix. +} + +// pkg.Fatalf is like log.Fatalf, but panics so it can be recovered in the +// main do function, so it doesn't cause an exit. Allows testing to work +// without running a subprocess. The log prefix will be added when +// logged in main; it is not added here. +func (pkg *Package) Fatalf(format string, args ...interface{}) { + panic(PackageError(fmt.Sprintf(format, args...))) +} + +// parsePackage turns the build package we found into a parsed package +// we can then use to generate documentation. +func parsePackage(writer io.Writer, pkg *build.Package, userPath string) *Package { + // include tells parser.ParseDir which files to include. + // That means the file must be in the build package's GoFiles or CgoFiles + // list only (no tag-ignored files, tests, swig or other non-Go files). + include := func(info fs.FileInfo) bool { + for _, name := range pkg.GoFiles { + if name == info.Name() { + return true + } + } + for _, name := range pkg.CgoFiles { + if name == info.Name() { + return true + } + } + return false + } + fset := token.NewFileSet() + pkgs, err := parser.ParseDir(fset, pkg.Dir, include, parser.ParseComments) + if err != nil { + log.Fatal(err) + } + // Make sure they are all in one package. + if len(pkgs) == 0 { + log.Fatalf("no source-code package in directory %s", pkg.Dir) + } + if len(pkgs) > 1 { + log.Fatalf("multiple packages in directory %s", pkg.Dir) + } + astPkg := pkgs[pkg.Name] + + // TODO: go/doc does not include typed constants in the constants + // list, which is what we want. For instance, time.Sunday is of type + // time.Weekday, so it is defined in the type but not in the + // Consts list for the package. This prevents + // go doc time.Sunday + // from finding the symbol. Work around this for now, but we + // should fix it in go/doc. + // A similar story applies to factory functions. + mode := doc.AllDecls + if showSrc { + mode |= doc.PreserveAST // See comment for Package.emit. + } + docPkg := doc.New(astPkg, pkg.ImportPath, mode) + typedValue := make(map[*doc.Value]bool) + constructor := make(map[*doc.Func]bool) + for _, typ := range docPkg.Types { + docPkg.Consts = append(docPkg.Consts, typ.Consts...) + docPkg.Vars = append(docPkg.Vars, typ.Vars...) + docPkg.Funcs = append(docPkg.Funcs, typ.Funcs...) + if isExported(typ.Name) { + for _, value := range typ.Consts { + typedValue[value] = true + } + for _, value := range typ.Vars { + typedValue[value] = true + } + for _, fun := range typ.Funcs { + // We don't count it as a constructor bound to the type + // if the type itself is not exported. + constructor[fun] = true + } + } + } + + p := &Package{ + writer: writer, + name: pkg.Name, + userPath: userPath, + pkg: astPkg, + file: ast.MergePackageFiles(astPkg, 0), + doc: docPkg, + typedValue: typedValue, + constructor: constructor, + build: pkg, + fs: fset, + } + p.buf.pkg = p + return p +} + +func (pkg *Package) Printf(format string, args ...interface{}) { + fmt.Fprintf(&pkg.buf, format, args...) +} + +func (pkg *Package) flush() { + _, err := pkg.writer.Write(pkg.buf.Bytes()) + if err != nil { + log.Fatal(err) + } + pkg.buf.Reset() // Not needed, but it's a flush. +} + +var newlineBytes = []byte("\n\n") // We never ask for more than 2. + +// newlines guarantees there are n newlines at the end of the buffer. +func (pkg *Package) newlines(n int) { + for !bytes.HasSuffix(pkg.buf.Bytes(), newlineBytes[:n]) { + pkg.buf.WriteRune('\n') + } +} + +// emit prints the node. If showSrc is true, it ignores the provided comment, +// assuming the comment is in the node itself. Otherwise, the go/doc package +// clears the stuff we don't want to print anyway. It's a bit of a magic trick. +func (pkg *Package) emit(comment string, node ast.Node) { + if node != nil { + var arg interface{} = node + if showSrc { + // Need an extra little dance to get internal comments to appear. + arg = &printer.CommentedNode{ + Node: node, + Comments: pkg.file.Comments, + } + } + err := format.Node(&pkg.buf, pkg.fs, arg) + if err != nil { + log.Fatal(err) + } + if comment != "" && !showSrc { + pkg.newlines(1) + doc.ToText(&pkg.buf, comment, indent, indent+indent, indentedWidth) + pkg.newlines(2) // Blank line after comment to separate from next item. + } else { + pkg.newlines(1) + } + } +} + +// oneLineNode returns a one-line summary of the given input node. +func (pkg *Package) oneLineNode(node ast.Node) string { + const maxDepth = 10 + return pkg.oneLineNodeDepth(node, maxDepth) +} + +// oneLineNodeDepth returns a one-line summary of the given input node. +// The depth specifies the maximum depth when traversing the AST. +func (pkg *Package) oneLineNodeDepth(node ast.Node, depth int) string { + const dotDotDot = "..." + if depth == 0 { + return dotDotDot + } + depth-- + + switch n := node.(type) { + case nil: + return "" + + case *ast.GenDecl: + // Formats const and var declarations. + trailer := "" + if len(n.Specs) > 1 { + trailer = " " + dotDotDot + } + + // Find the first relevant spec. + typ := "" + for i, spec := range n.Specs { + valueSpec := spec.(*ast.ValueSpec) // Must succeed; we can't mix types in one GenDecl. + + // The type name may carry over from a previous specification in the + // case of constants and iota. + if valueSpec.Type != nil { + typ = fmt.Sprintf(" %s", pkg.oneLineNodeDepth(valueSpec.Type, depth)) + } else if len(valueSpec.Values) > 0 { + typ = "" + } + + if !isExported(valueSpec.Names[0].Name) { + continue + } + val := "" + if i < len(valueSpec.Values) && valueSpec.Values[i] != nil { + val = fmt.Sprintf(" = %s", pkg.oneLineNodeDepth(valueSpec.Values[i], depth)) + } + return fmt.Sprintf("%s %s%s%s%s", n.Tok, valueSpec.Names[0], typ, val, trailer) + } + return "" + + case *ast.FuncDecl: + // Formats func declarations. + name := n.Name.Name + recv := pkg.oneLineNodeDepth(n.Recv, depth) + if len(recv) > 0 { + recv = "(" + recv + ") " + } + fnc := pkg.oneLineNodeDepth(n.Type, depth) + if strings.Index(fnc, "func") == 0 { + fnc = fnc[4:] + } + return fmt.Sprintf("func %s%s%s", recv, name, fnc) + + case *ast.TypeSpec: + sep := " " + if n.Assign.IsValid() { + sep = " = " + } + return fmt.Sprintf("type %s%s%s", n.Name.Name, sep, pkg.oneLineNodeDepth(n.Type, depth)) + + case *ast.FuncType: + var params []string + if n.Params != nil { + for _, field := range n.Params.List { + params = append(params, pkg.oneLineField(field, depth)) + } + } + needParens := false + var results []string + if n.Results != nil { + needParens = needParens || len(n.Results.List) > 1 + for _, field := range n.Results.List { + needParens = needParens || len(field.Names) > 0 + results = append(results, pkg.oneLineField(field, depth)) + } + } + + param := joinStrings(params) + if len(results) == 0 { + return fmt.Sprintf("func(%s)", param) + } + result := joinStrings(results) + if !needParens { + return fmt.Sprintf("func(%s) %s", param, result) + } + return fmt.Sprintf("func(%s) (%s)", param, result) + + case *ast.StructType: + if n.Fields == nil || len(n.Fields.List) == 0 { + return "struct{}" + } + return "struct{ ... }" + + case *ast.InterfaceType: + if n.Methods == nil || len(n.Methods.List) == 0 { + return "interface{}" + } + return "interface{ ... }" + + case *ast.FieldList: + if n == nil || len(n.List) == 0 { + return "" + } + if len(n.List) == 1 { + return pkg.oneLineField(n.List[0], depth) + } + return dotDotDot + + case *ast.FuncLit: + return pkg.oneLineNodeDepth(n.Type, depth) + " { ... }" + + case *ast.CompositeLit: + typ := pkg.oneLineNodeDepth(n.Type, depth) + if len(n.Elts) == 0 { + return fmt.Sprintf("%s{}", typ) + } + return fmt.Sprintf("%s{ %s }", typ, dotDotDot) + + case *ast.ArrayType: + length := pkg.oneLineNodeDepth(n.Len, depth) + element := pkg.oneLineNodeDepth(n.Elt, depth) + return fmt.Sprintf("[%s]%s", length, element) + + case *ast.MapType: + key := pkg.oneLineNodeDepth(n.Key, depth) + value := pkg.oneLineNodeDepth(n.Value, depth) + return fmt.Sprintf("map[%s]%s", key, value) + + case *ast.CallExpr: + fnc := pkg.oneLineNodeDepth(n.Fun, depth) + var args []string + for _, arg := range n.Args { + args = append(args, pkg.oneLineNodeDepth(arg, depth)) + } + return fmt.Sprintf("%s(%s)", fnc, joinStrings(args)) + + case *ast.UnaryExpr: + return fmt.Sprintf("%s%s", n.Op, pkg.oneLineNodeDepth(n.X, depth)) + + case *ast.Ident: + return n.Name + + default: + // As a fallback, use default formatter for all unknown node types. + buf := new(bytes.Buffer) + format.Node(buf, pkg.fs, node) + s := buf.String() + if strings.Contains(s, "\n") { + return dotDotDot + } + return s + } +} + +// oneLineField returns a one-line summary of the field. +func (pkg *Package) oneLineField(field *ast.Field, depth int) string { + var names []string + for _, name := range field.Names { + names = append(names, name.Name) + } + if len(names) == 0 { + return pkg.oneLineNodeDepth(field.Type, depth) + } + return joinStrings(names) + " " + pkg.oneLineNodeDepth(field.Type, depth) +} + +// joinStrings formats the input as a comma-separated list, +// but truncates the list at some reasonable length if necessary. +func joinStrings(ss []string) string { + var n int + for i, s := range ss { + n += len(s) + len(", ") + if n > punchedCardWidth { + ss = append(ss[:i:i], "...") + break + } + } + return strings.Join(ss, ", ") +} + +// allDoc prints all the docs for the package. +func (pkg *Package) allDoc() { + pkg.Printf("") // Trigger the package clause; we know the package exists. + doc.ToText(&pkg.buf, pkg.doc.Doc, "", indent, indentedWidth) + pkg.newlines(1) + + printed := make(map[*ast.GenDecl]bool) + + hdr := "" + printHdr := func(s string) { + if hdr != s { + pkg.Printf("\n%s\n\n", s) + hdr = s + } + } + + // Constants. + for _, value := range pkg.doc.Consts { + // Constants and variables come in groups, and valueDoc prints + // all the items in the group. We only need to find one exported symbol. + for _, name := range value.Names { + if isExported(name) && !pkg.typedValue[value] { + printHdr("CONSTANTS") + pkg.valueDoc(value, printed) + break + } + } + } + + // Variables. + for _, value := range pkg.doc.Vars { + // Constants and variables come in groups, and valueDoc prints + // all the items in the group. We only need to find one exported symbol. + for _, name := range value.Names { + if isExported(name) && !pkg.typedValue[value] { + printHdr("VARIABLES") + pkg.valueDoc(value, printed) + break + } + } + } + + // Functions. + for _, fun := range pkg.doc.Funcs { + if isExported(fun.Name) && !pkg.constructor[fun] { + printHdr("FUNCTIONS") + pkg.emit(fun.Doc, fun.Decl) + } + } + + // Types. + for _, typ := range pkg.doc.Types { + if isExported(typ.Name) { + printHdr("TYPES") + pkg.typeDoc(typ) + } + } +} + +// packageDoc prints the docs for the package (package doc plus one-liners of the rest). +func (pkg *Package) packageDoc() { + pkg.Printf("") // Trigger the package clause; we know the package exists. + if !short { + doc.ToText(&pkg.buf, pkg.doc.Doc, "", indent, indentedWidth) + pkg.newlines(1) + } + + if pkg.pkg.Name == "main" && !showCmd { + // Show only package docs for commands. + return + } + + if !short { + pkg.newlines(2) // Guarantee blank line before the components. + } + + pkg.valueSummary(pkg.doc.Consts, false) + pkg.valueSummary(pkg.doc.Vars, false) + pkg.funcSummary(pkg.doc.Funcs, false) + pkg.typeSummary() + if !short { + pkg.bugs() + } +} + +// packageClause prints the package clause. +func (pkg *Package) packageClause() { + if short { + return + } + importPath := pkg.build.ImportComment + if importPath == "" { + importPath = pkg.build.ImportPath + } + + // If we're using modules, the import path derived from module code locations wins. + // If we did a file system scan, we knew the import path when we found the directory. + // But if we started with a directory name, we never knew the import path. + // Either way, we don't know it now, and it's cheap to (re)compute it. + if usingModules { + for _, root := range codeRoots() { + if pkg.build.Dir == root.dir { + importPath = root.importPath + break + } + if strings.HasPrefix(pkg.build.Dir, root.dir+string(filepath.Separator)) { + suffix := filepath.ToSlash(pkg.build.Dir[len(root.dir)+1:]) + if root.importPath == "" { + importPath = suffix + } else { + importPath = root.importPath + "/" + suffix + } + break + } + } + } + + pkg.Printf("package %s // import %q\n\n", pkg.name, importPath) + if !usingModules && importPath != pkg.build.ImportPath { + pkg.Printf("WARNING: package source is installed in %q\n", pkg.build.ImportPath) + } +} + +// valueSummary prints a one-line summary for each set of values and constants. +// If all the types in a constant or variable declaration belong to the same +// type they can be printed by typeSummary, and so can be suppressed here. +func (pkg *Package) valueSummary(values []*doc.Value, showGrouped bool) { + var isGrouped map[*doc.Value]bool + if !showGrouped { + isGrouped = make(map[*doc.Value]bool) + for _, typ := range pkg.doc.Types { + if !isExported(typ.Name) { + continue + } + for _, c := range typ.Consts { + isGrouped[c] = true + } + for _, v := range typ.Vars { + isGrouped[v] = true + } + } + } + + for _, value := range values { + if !isGrouped[value] { + if decl := pkg.oneLineNode(value.Decl); decl != "" { + pkg.Printf("%s\n", decl) + } + } + } +} + +// funcSummary prints a one-line summary for each function. Constructors +// are printed by typeSummary, below, and so can be suppressed here. +func (pkg *Package) funcSummary(funcs []*doc.Func, showConstructors bool) { + for _, fun := range funcs { + // Exported functions only. The go/doc package does not include methods here. + if isExported(fun.Name) { + if showConstructors || !pkg.constructor[fun] { + pkg.Printf("%s\n", pkg.oneLineNode(fun.Decl)) + } + } + } +} + +// typeSummary prints a one-line summary for each type, followed by its constructors. +func (pkg *Package) typeSummary() { + for _, typ := range pkg.doc.Types { + for _, spec := range typ.Decl.Specs { + typeSpec := spec.(*ast.TypeSpec) // Must succeed. + if isExported(typeSpec.Name.Name) { + pkg.Printf("%s\n", pkg.oneLineNode(typeSpec)) + // Now print the consts, vars, and constructors. + for _, c := range typ.Consts { + if decl := pkg.oneLineNode(c.Decl); decl != "" { + pkg.Printf(indent+"%s\n", decl) + } + } + for _, v := range typ.Vars { + if decl := pkg.oneLineNode(v.Decl); decl != "" { + pkg.Printf(indent+"%s\n", decl) + } + } + for _, constructor := range typ.Funcs { + if isExported(constructor.Name) { + pkg.Printf(indent+"%s\n", pkg.oneLineNode(constructor.Decl)) + } + } + } + } + } +} + +// bugs prints the BUGS information for the package. +// TODO: Provide access to TODOs and NOTEs as well (very noisy so off by default)? +func (pkg *Package) bugs() { + if pkg.doc.Notes["BUG"] == nil { + return + } + pkg.Printf("\n") + for _, note := range pkg.doc.Notes["BUG"] { + pkg.Printf("%s: %v\n", "BUG", note.Body) + } +} + +// findValues finds the doc.Values that describe the symbol. +func (pkg *Package) findValues(symbol string, docValues []*doc.Value) (values []*doc.Value) { + for _, value := range docValues { + for _, name := range value.Names { + if match(symbol, name) { + values = append(values, value) + } + } + } + return +} + +// findFuncs finds the doc.Funcs that describes the symbol. +func (pkg *Package) findFuncs(symbol string) (funcs []*doc.Func) { + for _, fun := range pkg.doc.Funcs { + if match(symbol, fun.Name) { + funcs = append(funcs, fun) + } + } + return +} + +// findTypes finds the doc.Types that describes the symbol. +// If symbol is empty, it finds all exported types. +func (pkg *Package) findTypes(symbol string) (types []*doc.Type) { + for _, typ := range pkg.doc.Types { + if symbol == "" && isExported(typ.Name) || match(symbol, typ.Name) { + types = append(types, typ) + } + } + return +} + +// findTypeSpec returns the ast.TypeSpec within the declaration that defines the symbol. +// The name must match exactly. +func (pkg *Package) findTypeSpec(decl *ast.GenDecl, symbol string) *ast.TypeSpec { + for _, spec := range decl.Specs { + typeSpec := spec.(*ast.TypeSpec) // Must succeed. + if symbol == typeSpec.Name.Name { + return typeSpec + } + } + return nil +} + +// symbolDoc prints the docs for symbol. There may be multiple matches. +// If symbol matches a type, output includes its methods factories and associated constants. +// If there is no top-level symbol, symbolDoc looks for methods that match. +func (pkg *Package) symbolDoc(symbol string) bool { + found := false + // Functions. + for _, fun := range pkg.findFuncs(symbol) { + // Symbol is a function. + decl := fun.Decl + pkg.emit(fun.Doc, decl) + found = true + } + // Constants and variables behave the same. + values := pkg.findValues(symbol, pkg.doc.Consts) + values = append(values, pkg.findValues(symbol, pkg.doc.Vars)...) + // A declaration like + // const ( c = 1; C = 2 ) + // could be printed twice if the -u flag is set, as it matches twice. + // So we remember which declarations we've printed to avoid duplication. + printed := make(map[*ast.GenDecl]bool) + for _, value := range values { + pkg.valueDoc(value, printed) + found = true + } + // Types. + for _, typ := range pkg.findTypes(symbol) { + pkg.typeDoc(typ) + found = true + } + if !found { + // See if there are methods. + if !pkg.printMethodDoc("", symbol) { + return false + } + } + return true +} + +// valueDoc prints the docs for a constant or variable. +func (pkg *Package) valueDoc(value *doc.Value, printed map[*ast.GenDecl]bool) { + if printed[value.Decl] { + return + } + // Print each spec only if there is at least one exported symbol in it. + // (See issue 11008.) + // TODO: Should we elide unexported symbols from a single spec? + // It's an unlikely scenario, probably not worth the trouble. + // TODO: Would be nice if go/doc did this for us. + specs := make([]ast.Spec, 0, len(value.Decl.Specs)) + var typ ast.Expr + for _, spec := range value.Decl.Specs { + vspec := spec.(*ast.ValueSpec) + + // The type name may carry over from a previous specification in the + // case of constants and iota. + if vspec.Type != nil { + typ = vspec.Type + } + + for _, ident := range vspec.Names { + if showSrc || isExported(ident.Name) { + if vspec.Type == nil && vspec.Values == nil && typ != nil { + // This a standalone identifier, as in the case of iota usage. + // Thus, assume the type comes from the previous type. + vspec.Type = &ast.Ident{ + Name: pkg.oneLineNode(typ), + NamePos: vspec.End() - 1, + } + } + + specs = append(specs, vspec) + typ = nil // Only inject type on first exported identifier + break + } + } + } + if len(specs) == 0 { + return + } + value.Decl.Specs = specs + pkg.emit(value.Doc, value.Decl) + printed[value.Decl] = true +} + +// typeDoc prints the docs for a type, including constructors and other items +// related to it. +func (pkg *Package) typeDoc(typ *doc.Type) { + decl := typ.Decl + spec := pkg.findTypeSpec(decl, typ.Name) + trimUnexportedElems(spec) + // If there are multiple types defined, reduce to just this one. + if len(decl.Specs) > 1 { + decl.Specs = []ast.Spec{spec} + } + pkg.emit(typ.Doc, decl) + pkg.newlines(2) + // Show associated methods, constants, etc. + if showAll { + printed := make(map[*ast.GenDecl]bool) + // We can use append here to print consts, then vars. Ditto for funcs and methods. + values := typ.Consts + values = append(values, typ.Vars...) + for _, value := range values { + for _, name := range value.Names { + if isExported(name) { + pkg.valueDoc(value, printed) + break + } + } + } + funcs := typ.Funcs + funcs = append(funcs, typ.Methods...) + for _, fun := range funcs { + if isExported(fun.Name) { + pkg.emit(fun.Doc, fun.Decl) + if fun.Doc == "" { + pkg.newlines(2) + } + } + } + } else { + pkg.valueSummary(typ.Consts, true) + pkg.valueSummary(typ.Vars, true) + pkg.funcSummary(typ.Funcs, true) + pkg.funcSummary(typ.Methods, true) + } +} + +// trimUnexportedElems modifies spec in place to elide unexported fields from +// structs and methods from interfaces (unless the unexported flag is set or we +// are asked to show the original source). +func trimUnexportedElems(spec *ast.TypeSpec) { + if unexported || showSrc { + return + } + switch typ := spec.Type.(type) { + case *ast.StructType: + typ.Fields = trimUnexportedFields(typ.Fields, false) + case *ast.InterfaceType: + typ.Methods = trimUnexportedFields(typ.Methods, true) + } +} + +// trimUnexportedFields returns the field list trimmed of unexported fields. +func trimUnexportedFields(fields *ast.FieldList, isInterface bool) *ast.FieldList { + what := "methods" + if !isInterface { + what = "fields" + } + + trimmed := false + list := make([]*ast.Field, 0, len(fields.List)) + for _, field := range fields.List { + names := field.Names + if len(names) == 0 { + // Embedded type. Use the name of the type. It must be of the form ident or + // pkg.ident (for structs and interfaces), or *ident or *pkg.ident (structs only). + // Nothing else is allowed. + ty := field.Type + if se, ok := field.Type.(*ast.StarExpr); !isInterface && ok { + // The form *ident or *pkg.ident is only valid on + // embedded types in structs. + ty = se.X + } + switch ident := ty.(type) { + case *ast.Ident: + if isInterface && ident.Name == "error" && ident.Obj == nil { + // For documentation purposes, we consider the builtin error + // type special when embedded in an interface, such that it + // always gets shown publicly. + list = append(list, field) + continue + } + names = []*ast.Ident{ident} + case *ast.SelectorExpr: + // An embedded type may refer to a type in another package. + names = []*ast.Ident{ident.Sel} + } + if names == nil { + // Can only happen if AST is incorrect. Safe to continue with a nil list. + log.Print("invalid program: unexpected type for embedded field") + } + } + // Trims if any is unexported. Good enough in practice. + ok := true + for _, name := range names { + if !isExported(name.Name) { + trimmed = true + ok = false + break + } + } + if ok { + list = append(list, field) + } + } + if !trimmed { + return fields + } + unexportedField := &ast.Field{ + Type: &ast.Ident{ + // Hack: printer will treat this as a field with a named type. + // Setting Name and NamePos to ("", fields.Closing-1) ensures that + // when Pos and End are called on this field, they return the + // position right before closing '}' character. + Name: "", + NamePos: fields.Closing - 1, + }, + Comment: &ast.CommentGroup{ + List: []*ast.Comment{{Text: fmt.Sprintf("// Has unexported %s.\n", what)}}, + }, + } + return &ast.FieldList{ + Opening: fields.Opening, + List: append(list, unexportedField), + Closing: fields.Closing, + } +} + +// printMethodDoc prints the docs for matches of symbol.method. +// If symbol is empty, it prints all methods for any concrete type +// that match the name. It reports whether it found any methods. +func (pkg *Package) printMethodDoc(symbol, method string) bool { + types := pkg.findTypes(symbol) + if types == nil { + if symbol == "" { + return false + } + pkg.Fatalf("symbol %s is not a type in package %s installed in %q", symbol, pkg.name, pkg.build.ImportPath) + } + found := false + for _, typ := range types { + if len(typ.Methods) > 0 { + for _, meth := range typ.Methods { + if match(method, meth.Name) { + decl := meth.Decl + pkg.emit(meth.Doc, decl) + found = true + } + } + continue + } + if symbol == "" { + continue + } + // Type may be an interface. The go/doc package does not attach + // an interface's methods to the doc.Type. We need to dig around. + spec := pkg.findTypeSpec(typ.Decl, typ.Name) + inter, ok := spec.Type.(*ast.InterfaceType) + if !ok { + // Not an interface type. + continue + } + for _, iMethod := range inter.Methods.List { + // This is an interface, so there can be only one name. + // TODO: Anonymous methods (embedding) + if len(iMethod.Names) == 0 { + continue + } + name := iMethod.Names[0].Name + if match(method, name) { + if iMethod.Doc != nil { + for _, comment := range iMethod.Doc.List { + doc.ToText(&pkg.buf, comment.Text, "", indent, indentedWidth) + } + } + s := pkg.oneLineNode(iMethod.Type) + // Hack: s starts "func" but there is no name present. + // We could instead build a FuncDecl but it's not worthwhile. + lineComment := "" + if iMethod.Comment != nil { + lineComment = fmt.Sprintf(" %s", iMethod.Comment.List[0].Text) + } + pkg.Printf("func %s%s%s\n", name, s[4:], lineComment) + found = true + } + } + } + return found +} + +// printFieldDoc prints the docs for matches of symbol.fieldName. +// It reports whether it found any field. +// Both symbol and fieldName must be non-empty or it returns false. +func (pkg *Package) printFieldDoc(symbol, fieldName string) bool { + if symbol == "" || fieldName == "" { + return false + } + types := pkg.findTypes(symbol) + if types == nil { + pkg.Fatalf("symbol %s is not a type in package %s installed in %q", symbol, pkg.name, pkg.build.ImportPath) + } + found := false + numUnmatched := 0 + for _, typ := range types { + // Type must be a struct. + spec := pkg.findTypeSpec(typ.Decl, typ.Name) + structType, ok := spec.Type.(*ast.StructType) + if !ok { + // Not a struct type. + continue + } + for _, field := range structType.Fields.List { + // TODO: Anonymous fields. + for _, name := range field.Names { + if !match(fieldName, name.Name) { + numUnmatched++ + continue + } + if !found { + pkg.Printf("type %s struct {\n", typ.Name) + } + if field.Doc != nil { + // To present indented blocks in comments correctly, process the comment as + // a unit before adding the leading // to each line. + docBuf := bytes.Buffer{} + doc.ToText(&docBuf, field.Doc.Text(), "", indent, indentedWidth) + scanner := bufio.NewScanner(&docBuf) + for scanner.Scan() { + fmt.Fprintf(&pkg.buf, "%s// %s\n", indent, scanner.Bytes()) + } + } + s := pkg.oneLineNode(field.Type) + lineComment := "" + if field.Comment != nil { + lineComment = fmt.Sprintf(" %s", field.Comment.List[0].Text) + } + pkg.Printf("%s%s %s%s\n", indent, name, s, lineComment) + found = true + } + } + } + if found { + if numUnmatched > 0 { + pkg.Printf("\n // ... other fields elided ...\n") + } + pkg.Printf("}\n") + } + return found +} + +// methodDoc prints the docs for matches of symbol.method. +func (pkg *Package) methodDoc(symbol, method string) bool { + return pkg.printMethodDoc(symbol, method) +} + +// fieldDoc prints the docs for matches of symbol.field. +func (pkg *Package) fieldDoc(symbol, field string) bool { + return pkg.printFieldDoc(symbol, field) +} + +// match reports whether the user's symbol matches the program's. +// A lower-case character in the user's string matches either case in the program's. +// The program string must be exported. +func match(user, program string) bool { + if !isExported(program) { + return false + } + if matchCase { + return user == program + } + for _, u := range user { + p, w := utf8.DecodeRuneInString(program) + program = program[w:] + if u == p { + continue + } + if unicode.IsLower(u) && simpleFold(u) == simpleFold(p) { + continue + } + return false + } + return program == "" +} + +// simpleFold returns the minimum rune equivalent to r +// under Unicode-defined simple case folding. +func simpleFold(r rune) rune { + for { + r1 := unicode.SimpleFold(r) + if r1 <= r { + return r1 // wrapped around, found min + } + r = r1 + } +} |