reader.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package doc
     6  
     7  import (
     8  	"cmp"
     9  	"fmt"
    10  	"go/ast"
    11  	"go/token"
    12  	"internal/lazyregexp"
    13  	"path"
    14  	"slices"
    15  	"strconv"
    16  	"strings"
    17  	"unicode"
    18  	"unicode/utf8"
    19  )
    20  
    21  // ----------------------------------------------------------------------------
    22  // function/method sets
    23  //
    24  // Internally, we treat functions like methods and collect them in method sets.
    25  
    26  // A methodSet describes a set of methods. Entries where Decl == nil are conflict
    27  // entries (more than one method with the same name at the same embedding level).
    28  type methodSet map[string]*Func
    29  
    30  // recvString returns a string representation of recv of the form "T", "*T",
    31  // "T[A, ...]", "*T[A, ...]" or "BADRECV" (if not a proper receiver type).
    32  func recvString(recv ast.Expr) string {
    33  	switch t := recv.(type) {
    34  	case *ast.Ident:
    35  		return t.Name
    36  	case *ast.StarExpr:
    37  		return "*" + recvString(t.X)
    38  	case *ast.IndexExpr:
    39  		// Generic type with one parameter.
    40  		return fmt.Sprintf("%s[%s]", recvString(t.X), recvParam(t.Index))
    41  	case *ast.IndexListExpr:
    42  		// Generic type with multiple parameters.
    43  		if len(t.Indices) > 0 {
    44  			var b strings.Builder
    45  			b.WriteString(recvString(t.X))
    46  			b.WriteByte('[')
    47  			b.WriteString(recvParam(t.Indices[0]))
    48  			for _, e := range t.Indices[1:] {
    49  				b.WriteString(", ")
    50  				b.WriteString(recvParam(e))
    51  			}
    52  			b.WriteByte(']')
    53  			return b.String()
    54  		}
    55  	}
    56  	return "BADRECV"
    57  }
    58  
    59  func recvParam(p ast.Expr) string {
    60  	if id, ok := p.(*ast.Ident); ok {
    61  		return id.Name
    62  	}
    63  	return "BADPARAM"
    64  }
    65  
    66  // set creates the corresponding Func for f and adds it to mset.
    67  // If there are multiple f's with the same name, set keeps the first
    68  // one with documentation; conflicts are ignored. The boolean
    69  // specifies whether to leave the AST untouched.
    70  func (mset methodSet) set(f *ast.FuncDecl, preserveAST bool) {
    71  	name := f.Name.Name
    72  	if g := mset[name]; g != nil && g.Doc != "" {
    73  		// A function with the same name has already been registered;
    74  		// since it has documentation, assume f is simply another
    75  		// implementation and ignore it. This does not happen if the
    76  		// caller is using go/build.ScanDir to determine the list of
    77  		// files implementing a package.
    78  		return
    79  	}
    80  	// function doesn't exist or has no documentation; use f
    81  	recv := ""
    82  	if f.Recv != nil {
    83  		var typ ast.Expr
    84  		// be careful in case of incorrect ASTs
    85  		if list := f.Recv.List; len(list) == 1 {
    86  			typ = list[0].Type
    87  		}
    88  		recv = recvString(typ)
    89  	}
    90  	mset[name] = &Func{
    91  		Doc:  f.Doc.Text(),
    92  		Name: name,
    93  		Decl: f,
    94  		Recv: recv,
    95  		Orig: recv,
    96  	}
    97  	if !preserveAST {
    98  		f.Doc = nil // doc consumed - remove from AST
    99  	}
   100  }
   101  
   102  // add adds method m to the method set; m is ignored if the method set
   103  // already contains a method with the same name at the same or a higher
   104  // level than m.
   105  func (mset methodSet) add(m *Func) {
   106  	old := mset[m.Name]
   107  	if old == nil || m.Level < old.Level {
   108  		mset[m.Name] = m
   109  		return
   110  	}
   111  	if m.Level == old.Level {
   112  		// conflict - mark it using a method with nil Decl
   113  		mset[m.Name] = &Func{
   114  			Name:  m.Name,
   115  			Level: m.Level,
   116  		}
   117  	}
   118  }
   119  
   120  // ----------------------------------------------------------------------------
   121  // Named types
   122  
   123  // baseTypeName returns the name of the base type of x (or "")
   124  // and whether the type is imported or not.
   125  func baseTypeName(x ast.Expr) (name string, imported bool) {
   126  	switch t := x.(type) {
   127  	case *ast.Ident:
   128  		return t.Name, false
   129  	case *ast.IndexExpr:
   130  		return baseTypeName(t.X)
   131  	case *ast.IndexListExpr:
   132  		return baseTypeName(t.X)
   133  	case *ast.SelectorExpr:
   134  		if _, ok := t.X.(*ast.Ident); ok {
   135  			// only possible for qualified type names;
   136  			// assume type is imported
   137  			return t.Sel.Name, true
   138  		}
   139  	case *ast.ParenExpr:
   140  		return baseTypeName(t.X)
   141  	case *ast.StarExpr:
   142  		return baseTypeName(t.X)
   143  	}
   144  	return "", false
   145  }
   146  
   147  // An embeddedSet describes a set of embedded types.
   148  type embeddedSet map[*namedType]bool
   149  
   150  // A namedType represents a named unqualified (package local, or possibly
   151  // predeclared) type. The namedType for a type name is always found via
   152  // reader.lookupType.
   153  type namedType struct {
   154  	doc  string       // doc comment for type
   155  	name string       // type name
   156  	decl *ast.GenDecl // nil if declaration hasn't been seen yet
   157  
   158  	isEmbedded bool        // true if this type is embedded
   159  	isStruct   bool        // true if this type is a struct
   160  	embedded   embeddedSet // true if the embedded type is a pointer
   161  
   162  	// associated declarations
   163  	values  []*Value // consts and vars
   164  	funcs   methodSet
   165  	methods methodSet
   166  }
   167  
   168  // ----------------------------------------------------------------------------
   169  // AST reader
   170  
   171  // reader accumulates documentation for a single package.
   172  // It modifies the AST: Comments (declaration documentation)
   173  // that have been collected by the reader are set to nil
   174  // in the respective AST nodes so that they are not printed
   175  // twice (once when printing the documentation and once when
   176  // printing the corresponding AST node).
   177  type reader struct {
   178  	mode Mode
   179  
   180  	// package properties
   181  	doc       string // package documentation, if any
   182  	filenames []string
   183  	notes     map[string][]*Note
   184  
   185  	// imports
   186  	imports      map[string]int
   187  	hasDotImp    bool // if set, package contains a dot import
   188  	importByName map[string]string
   189  
   190  	// declarations
   191  	values []*Value // consts and vars
   192  	order  int      // sort order of const and var declarations (when we can't use a name)
   193  	types  map[string]*namedType
   194  	funcs  methodSet
   195  
   196  	// support for package-local shadowing of predeclared types
   197  	shadowedPredecl map[string]bool
   198  	fixmap          map[string][]*ast.InterfaceType
   199  }
   200  
   201  func (r *reader) isVisible(name string) bool {
   202  	return r.mode&AllDecls != 0 || token.IsExported(name)
   203  }
   204  
   205  // lookupType returns the base type with the given name.
   206  // If the base type has not been encountered yet, a new
   207  // type with the given name but no associated declaration
   208  // is added to the type map.
   209  func (r *reader) lookupType(name string) *namedType {
   210  	if name == "" || name == "_" {
   211  		return nil // no type docs for anonymous types
   212  	}
   213  	if typ, found := r.types[name]; found {
   214  		return typ
   215  	}
   216  	// type not found - add one without declaration
   217  	typ := &namedType{
   218  		name:     name,
   219  		embedded: make(embeddedSet),
   220  		funcs:    make(methodSet),
   221  		methods:  make(methodSet),
   222  	}
   223  	r.types[name] = typ
   224  	return typ
   225  }
   226  
   227  // recordAnonymousField registers fieldType as the type of an
   228  // anonymous field in the parent type. If the field is imported
   229  // (qualified name) or the parent is nil, the field is ignored.
   230  // The function returns the field name.
   231  func (r *reader) recordAnonymousField(parent *namedType, fieldType ast.Expr) (fname string) {
   232  	fname, imp := baseTypeName(fieldType)
   233  	if parent == nil || imp {
   234  		return
   235  	}
   236  	if ftype := r.lookupType(fname); ftype != nil {
   237  		ftype.isEmbedded = true
   238  		_, ptr := fieldType.(*ast.StarExpr)
   239  		parent.embedded[ftype] = ptr
   240  	}
   241  	return
   242  }
   243  
   244  func (r *reader) readDoc(comment *ast.CommentGroup) {
   245  	// By convention there should be only one package comment
   246  	// but collect all of them if there are more than one.
   247  	text := comment.Text()
   248  	if r.doc == "" {
   249  		r.doc = text
   250  		return
   251  	}
   252  	r.doc += "\n" + text
   253  }
   254  
   255  func (r *reader) remember(predecl string, typ *ast.InterfaceType) {
   256  	if r.fixmap == nil {
   257  		r.fixmap = make(map[string][]*ast.InterfaceType)
   258  	}
   259  	r.fixmap[predecl] = append(r.fixmap[predecl], typ)
   260  }
   261  
   262  func specNames(specs []ast.Spec) []string {
   263  	names := make([]string, 0, len(specs)) // reasonable estimate
   264  	for _, s := range specs {
   265  		// s guaranteed to be an *ast.ValueSpec by readValue
   266  		for _, ident := range s.(*ast.ValueSpec).Names {
   267  			names = append(names, ident.Name)
   268  		}
   269  	}
   270  	return names
   271  }
   272  
   273  // readValue processes a const or var declaration.
   274  func (r *reader) readValue(decl *ast.GenDecl) {
   275  	// determine if decl should be associated with a type
   276  	// Heuristic: For each typed entry, determine the type name, if any.
   277  	//            If there is exactly one type name that is sufficiently
   278  	//            frequent, associate the decl with the respective type.
   279  	domName := ""
   280  	domFreq := 0
   281  	prev := ""
   282  	n := 0
   283  	for _, spec := range decl.Specs {
   284  		s, ok := spec.(*ast.ValueSpec)
   285  		if !ok {
   286  			continue // should not happen, but be conservative
   287  		}
   288  		name := ""
   289  		switch {
   290  		case s.Type != nil:
   291  			// a type is present; determine its name
   292  			if n, imp := baseTypeName(s.Type); !imp {
   293  				name = n
   294  			}
   295  		case decl.Tok == token.CONST && len(s.Values) == 0:
   296  			// no type or value is present but we have a constant declaration;
   297  			// use the previous type name (possibly the empty string)
   298  			name = prev
   299  		}
   300  		if name != "" {
   301  			// entry has a named type
   302  			if domName != "" && domName != name {
   303  				// more than one type name - do not associate
   304  				// with any type
   305  				domName = ""
   306  				break
   307  			}
   308  			domName = name
   309  			domFreq++
   310  		}
   311  		prev = name
   312  		n++
   313  	}
   314  
   315  	// nothing to do w/o a legal declaration
   316  	if n == 0 {
   317  		return
   318  	}
   319  
   320  	// determine values list with which to associate the Value for this decl
   321  	values := &r.values
   322  	const threshold = 0.75
   323  	if domName != "" && r.isVisible(domName) && domFreq >= int(float64(len(decl.Specs))*threshold) {
   324  		// typed entries are sufficiently frequent
   325  		if typ := r.lookupType(domName); typ != nil {
   326  			values = &typ.values // associate with that type
   327  		}
   328  	}
   329  
   330  	*values = append(*values, &Value{
   331  		Doc:   decl.Doc.Text(),
   332  		Names: specNames(decl.Specs),
   333  		Decl:  decl,
   334  		order: r.order,
   335  	})
   336  	if r.mode&PreserveAST == 0 {
   337  		decl.Doc = nil // doc consumed - remove from AST
   338  	}
   339  	// Note: It's important that the order used here is global because the cleanupTypes
   340  	// methods may move values associated with types back into the global list. If the
   341  	// order is list-specific, sorting is not deterministic because the same order value
   342  	// may appear multiple times (was bug, found when fixing #16153).
   343  	r.order++
   344  }
   345  
   346  // fields returns a struct's fields or an interface's methods.
   347  func fields(typ ast.Expr) (list []*ast.Field, isStruct bool) {
   348  	var fields *ast.FieldList
   349  	switch t := typ.(type) {
   350  	case *ast.StructType:
   351  		fields = t.Fields
   352  		isStruct = true
   353  	case *ast.InterfaceType:
   354  		fields = t.Methods
   355  	}
   356  	if fields != nil {
   357  		list = fields.List
   358  	}
   359  	return
   360  }
   361  
   362  // readType processes a type declaration.
   363  func (r *reader) readType(decl *ast.GenDecl, spec *ast.TypeSpec) {
   364  	typ := r.lookupType(spec.Name.Name)
   365  	if typ == nil {
   366  		return // no name or blank name - ignore the type
   367  	}
   368  
   369  	// A type should be added at most once, so typ.decl
   370  	// should be nil - if it is not, simply overwrite it.
   371  	typ.decl = decl
   372  
   373  	// compute documentation
   374  	doc := spec.Doc
   375  	if doc == nil {
   376  		// no doc associated with the spec, use the declaration doc, if any
   377  		doc = decl.Doc
   378  	}
   379  	if r.mode&PreserveAST == 0 {
   380  		spec.Doc = nil // doc consumed - remove from AST
   381  		decl.Doc = nil // doc consumed - remove from AST
   382  	}
   383  	typ.doc = doc.Text()
   384  
   385  	// record anonymous fields (they may contribute methods)
   386  	// (some fields may have been recorded already when filtering
   387  	// exports, but that's ok)
   388  	var list []*ast.Field
   389  	list, typ.isStruct = fields(spec.Type)
   390  	for _, field := range list {
   391  		if len(field.Names) == 0 {
   392  			r.recordAnonymousField(typ, field.Type)
   393  		}
   394  	}
   395  }
   396  
   397  // isPredeclared reports whether n denotes a predeclared type.
   398  func (r *reader) isPredeclared(n string) bool {
   399  	return predeclaredTypes[n] && r.types[n] == nil
   400  }
   401  
   402  // readFunc processes a func or method declaration.
   403  func (r *reader) readFunc(fun *ast.FuncDecl) {
   404  	// strip function body if requested.
   405  	if r.mode&PreserveAST == 0 {
   406  		fun.Body = nil
   407  	}
   408  
   409  	// associate methods with the receiver type, if any
   410  	if fun.Recv != nil {
   411  		// method
   412  		if len(fun.Recv.List) == 0 {
   413  			// should not happen (incorrect AST); (See issue 17788)
   414  			// don't show this method
   415  			return
   416  		}
   417  		recvTypeName, imp := baseTypeName(fun.Recv.List[0].Type)
   418  		if imp {
   419  			// should not happen (incorrect AST);
   420  			// don't show this method
   421  			return
   422  		}
   423  		if typ := r.lookupType(recvTypeName); typ != nil {
   424  			typ.methods.set(fun, r.mode&PreserveAST != 0)
   425  		}
   426  		// otherwise ignore the method
   427  		// TODO(gri): There may be exported methods of non-exported types
   428  		// that can be called because of exported values (consts, vars, or
   429  		// function results) of that type. Could determine if that is the
   430  		// case and then show those methods in an appropriate section.
   431  		return
   432  	}
   433  
   434  	// Associate factory functions with the first visible result type, as long as
   435  	// others are predeclared types.
   436  	if fun.Type.Results.NumFields() >= 1 {
   437  		var typ *namedType // type to associate the function with
   438  		numResultTypes := 0
   439  		for _, res := range fun.Type.Results.List {
   440  			factoryType := res.Type
   441  			if t, ok := factoryType.(*ast.ArrayType); ok {
   442  				// We consider functions that return slices or arrays of type
   443  				// T (or pointers to T) as factory functions of T.
   444  				factoryType = t.Elt
   445  			}
   446  			if n, imp := baseTypeName(factoryType); !imp && r.isVisible(n) && !r.isPredeclared(n) {
   447  				if lookupTypeParam(n, fun.Type.TypeParams) != nil {
   448  					// Issue #49477: don't associate fun with its type parameter result.
   449  					// A type parameter is not a defined type.
   450  					continue
   451  				}
   452  				if t := r.lookupType(n); t != nil {
   453  					typ = t
   454  					numResultTypes++
   455  					if numResultTypes > 1 {
   456  						break
   457  					}
   458  				}
   459  			}
   460  		}
   461  		// If there is exactly one result type,
   462  		// associate the function with that type.
   463  		if numResultTypes == 1 {
   464  			typ.funcs.set(fun, r.mode&PreserveAST != 0)
   465  			return
   466  		}
   467  	}
   468  
   469  	// just an ordinary function
   470  	r.funcs.set(fun, r.mode&PreserveAST != 0)
   471  }
   472  
   473  // lookupTypeParam searches for type parameters named name within the tparams
   474  // field list, returning the relevant identifier if found, or nil if not.
   475  func lookupTypeParam(name string, tparams *ast.FieldList) *ast.Ident {
   476  	if tparams == nil {
   477  		return nil
   478  	}
   479  	for _, field := range tparams.List {
   480  		for _, id := range field.Names {
   481  			if id.Name == name {
   482  				return id
   483  			}
   484  		}
   485  	}
   486  	return nil
   487  }
   488  
   489  var (
   490  	noteMarker    = `([A-Z][A-Z]+)\(([^)]+)\):?`                // MARKER(uid), MARKER at least 2 chars, uid at least 1 char
   491  	noteMarkerRx  = lazyregexp.New(`^[ \t]*` + noteMarker)      // MARKER(uid) at text start
   492  	noteCommentRx = lazyregexp.New(`^/[/*][ \t]*` + noteMarker) // MARKER(uid) at comment start
   493  )
   494  
   495  // clean replaces each sequence of space, \r, or \t characters
   496  // with a single space and removes any trailing and leading spaces.
   497  func clean(s string) string {
   498  	var b []byte
   499  	p := byte(' ')
   500  	for i := 0; i < len(s); i++ {
   501  		q := s[i]
   502  		if q == '\r' || q == '\t' {
   503  			q = ' '
   504  		}
   505  		if q != ' ' || p != ' ' {
   506  			b = append(b, q)
   507  			p = q
   508  		}
   509  	}
   510  	// remove trailing blank, if any
   511  	if n := len(b); n > 0 && p == ' ' {
   512  		b = b[0 : n-1]
   513  	}
   514  	return string(b)
   515  }
   516  
   517  // readNote collects a single note from a sequence of comments.
   518  func (r *reader) readNote(list []*ast.Comment) {
   519  	text := (&ast.CommentGroup{List: list}).Text()
   520  	if m := noteMarkerRx.FindStringSubmatchIndex(text); m != nil {
   521  		// The note body starts after the marker.
   522  		// We remove any formatting so that we don't
   523  		// get spurious line breaks/indentation when
   524  		// showing the TODO body.
   525  		body := clean(text[m[1]:])
   526  		if body != "" {
   527  			marker := text[m[2]:m[3]]
   528  			r.notes[marker] = append(r.notes[marker], &Note{
   529  				Pos:  list[0].Pos(),
   530  				End:  list[len(list)-1].End(),
   531  				UID:  text[m[4]:m[5]],
   532  				Body: body,
   533  			})
   534  		}
   535  	}
   536  }
   537  
   538  // readNotes extracts notes from comments.
   539  // A note must start at the beginning of a comment with "MARKER(uid):"
   540  // and is followed by the note body (e.g., "// BUG(gri): fix this").
   541  // The note ends at the end of the comment group or at the start of
   542  // another note in the same comment group, whichever comes first.
   543  func (r *reader) readNotes(comments []*ast.CommentGroup) {
   544  	for _, group := range comments {
   545  		i := -1 // comment index of most recent note start, valid if >= 0
   546  		list := group.List
   547  		for j, c := range list {
   548  			if noteCommentRx.MatchString(c.Text) {
   549  				if i >= 0 {
   550  					r.readNote(list[i:j])
   551  				}
   552  				i = j
   553  			}
   554  		}
   555  		if i >= 0 {
   556  			r.readNote(list[i:])
   557  		}
   558  	}
   559  }
   560  
   561  // readFile adds the AST for a source file to the reader.
   562  func (r *reader) readFile(src *ast.File) {
   563  	// add package documentation
   564  	if src.Doc != nil {
   565  		r.readDoc(src.Doc)
   566  		if r.mode&PreserveAST == 0 {
   567  			src.Doc = nil // doc consumed - remove from AST
   568  		}
   569  	}
   570  
   571  	// add all declarations but for functions which are processed in a separate pass
   572  	for _, decl := range src.Decls {
   573  		switch d := decl.(type) {
   574  		case *ast.GenDecl:
   575  			switch d.Tok {
   576  			case token.IMPORT:
   577  				// imports are handled individually
   578  				for _, spec := range d.Specs {
   579  					if s, ok := spec.(*ast.ImportSpec); ok {
   580  						if import_, err := strconv.Unquote(s.Path.Value); err == nil {
   581  							r.imports[import_] = 1
   582  							var name string
   583  							if s.Name != nil {
   584  								name = s.Name.Name
   585  								if name == "." {
   586  									r.hasDotImp = true
   587  								}
   588  							}
   589  							if name != "." {
   590  								if name == "" {
   591  									name = assumedPackageName(import_)
   592  								}
   593  								old, ok := r.importByName[name]
   594  								if !ok {
   595  									r.importByName[name] = import_
   596  								} else if old != import_ && old != "" {
   597  									r.importByName[name] = "" // ambiguous
   598  								}
   599  							}
   600  						}
   601  					}
   602  				}
   603  			case token.CONST, token.VAR:
   604  				// constants and variables are always handled as a group
   605  				r.readValue(d)
   606  			case token.TYPE:
   607  				// types are handled individually
   608  				if len(d.Specs) == 1 && !d.Lparen.IsValid() {
   609  					// common case: single declaration w/o parentheses
   610  					// (if a single declaration is parenthesized,
   611  					// create a new fake declaration below, so that
   612  					// go/doc type declarations always appear w/o
   613  					// parentheses)
   614  					if s, ok := d.Specs[0].(*ast.TypeSpec); ok {
   615  						r.readType(d, s)
   616  					}
   617  					break
   618  				}
   619  				for _, spec := range d.Specs {
   620  					if s, ok := spec.(*ast.TypeSpec); ok {
   621  						// use an individual (possibly fake) declaration
   622  						// for each type; this also ensures that each type
   623  						// gets to (re-)use the declaration documentation
   624  						// if there's none associated with the spec itself
   625  						fake := &ast.GenDecl{
   626  							Doc: d.Doc,
   627  							// don't use the existing TokPos because it
   628  							// will lead to the wrong selection range for
   629  							// the fake declaration if there are more
   630  							// than one type in the group (this affects
   631  							// src/cmd/godoc/godoc.go's posLink_urlFunc)
   632  							TokPos: s.Pos(),
   633  							Tok:    token.TYPE,
   634  							Specs:  []ast.Spec{s},
   635  						}
   636  						r.readType(fake, s)
   637  					}
   638  				}
   639  			}
   640  		}
   641  	}
   642  
   643  	// collect MARKER(...): annotations
   644  	r.readNotes(src.Comments)
   645  	if r.mode&PreserveAST == 0 {
   646  		src.Comments = nil // consumed unassociated comments - remove from AST
   647  	}
   648  }
   649  
   650  func (r *reader) readPackage(pkg *ast.Package, mode Mode) {
   651  	// initialize reader
   652  	r.filenames = make([]string, len(pkg.Files))
   653  	r.imports = make(map[string]int)
   654  	r.mode = mode
   655  	r.types = make(map[string]*namedType)
   656  	r.funcs = make(methodSet)
   657  	r.notes = make(map[string][]*Note)
   658  	r.importByName = make(map[string]string)
   659  
   660  	// sort package files before reading them so that the
   661  	// result does not depend on map iteration order
   662  	i := 0
   663  	for filename := range pkg.Files {
   664  		r.filenames[i] = filename
   665  		i++
   666  	}
   667  	slices.Sort(r.filenames)
   668  
   669  	// process files in sorted order
   670  	for _, filename := range r.filenames {
   671  		f := pkg.Files[filename]
   672  		if mode&AllDecls == 0 {
   673  			r.fileExports(f)
   674  		}
   675  		r.readFile(f)
   676  	}
   677  
   678  	for name, path := range r.importByName {
   679  		if path == "" {
   680  			delete(r.importByName, name)
   681  		}
   682  	}
   683  
   684  	// process functions now that we have better type information
   685  	for _, f := range pkg.Files {
   686  		for _, decl := range f.Decls {
   687  			if d, ok := decl.(*ast.FuncDecl); ok {
   688  				r.readFunc(d)
   689  			}
   690  		}
   691  	}
   692  }
   693  
   694  // ----------------------------------------------------------------------------
   695  // Types
   696  
   697  func customizeRecv(f *Func, recvTypeName string, embeddedIsPtr bool, level int) *Func {
   698  	if f == nil || f.Decl == nil || f.Decl.Recv == nil || len(f.Decl.Recv.List) != 1 {
   699  		return f // shouldn't happen, but be safe
   700  	}
   701  
   702  	// copy existing receiver field and set new type
   703  	newField := *f.Decl.Recv.List[0]
   704  	origPos := newField.Type.Pos()
   705  	_, origRecvIsPtr := newField.Type.(*ast.StarExpr)
   706  	newIdent := &ast.Ident{NamePos: origPos, Name: recvTypeName}
   707  	var typ ast.Expr = newIdent
   708  	if !embeddedIsPtr && origRecvIsPtr {
   709  		newIdent.NamePos++ // '*' is one character
   710  		typ = &ast.StarExpr{Star: origPos, X: newIdent}
   711  	}
   712  	newField.Type = typ
   713  
   714  	// copy existing receiver field list and set new receiver field
   715  	newFieldList := *f.Decl.Recv
   716  	newFieldList.List = []*ast.Field{&newField}
   717  
   718  	// copy existing function declaration and set new receiver field list
   719  	newFuncDecl := *f.Decl
   720  	newFuncDecl.Recv = &newFieldList
   721  
   722  	// copy existing function documentation and set new declaration
   723  	newF := *f
   724  	newF.Decl = &newFuncDecl
   725  	newF.Recv = recvString(typ)
   726  	// the Orig field never changes
   727  	newF.Level = level
   728  
   729  	return &newF
   730  }
   731  
   732  // collectEmbeddedMethods collects the embedded methods of typ in mset.
   733  func (r *reader) collectEmbeddedMethods(mset methodSet, typ *namedType, recvTypeName string, embeddedIsPtr bool, level int, visited embeddedSet) {
   734  	visited[typ] = true
   735  	for embedded, isPtr := range typ.embedded {
   736  		// Once an embedded type is embedded as a pointer type
   737  		// all embedded types in those types are treated like
   738  		// pointer types for the purpose of the receiver type
   739  		// computation; i.e., embeddedIsPtr is sticky for this
   740  		// embedding hierarchy.
   741  		thisEmbeddedIsPtr := embeddedIsPtr || isPtr
   742  		for _, m := range embedded.methods {
   743  			// only top-level methods are embedded
   744  			if m.Level == 0 {
   745  				mset.add(customizeRecv(m, recvTypeName, thisEmbeddedIsPtr, level))
   746  			}
   747  		}
   748  		if !visited[embedded] {
   749  			r.collectEmbeddedMethods(mset, embedded, recvTypeName, thisEmbeddedIsPtr, level+1, visited)
   750  		}
   751  	}
   752  	delete(visited, typ)
   753  }
   754  
   755  // computeMethodSets determines the actual method sets for each type encountered.
   756  func (r *reader) computeMethodSets() {
   757  	for _, t := range r.types {
   758  		// collect embedded methods for t
   759  		if t.isStruct {
   760  			// struct
   761  			r.collectEmbeddedMethods(t.methods, t, t.name, false, 1, make(embeddedSet))
   762  		} else {
   763  			// interface
   764  			// TODO(gri) fix this
   765  		}
   766  	}
   767  
   768  	// For any predeclared names that are declared locally, don't treat them as
   769  	// exported fields anymore.
   770  	for predecl := range r.shadowedPredecl {
   771  		for _, ityp := range r.fixmap[predecl] {
   772  			removeAnonymousField(predecl, ityp)
   773  		}
   774  	}
   775  }
   776  
   777  // cleanupTypes removes the association of functions and methods with
   778  // types that have no declaration. Instead, these functions and methods
   779  // are shown at the package level. It also removes types with missing
   780  // declarations or which are not visible.
   781  func (r *reader) cleanupTypes() {
   782  	for _, t := range r.types {
   783  		visible := r.isVisible(t.name)
   784  		predeclared := predeclaredTypes[t.name]
   785  
   786  		if t.decl == nil && (predeclared || visible && (t.isEmbedded || r.hasDotImp)) {
   787  			// t.name is a predeclared type (and was not redeclared in this package),
   788  			// or it was embedded somewhere but its declaration is missing (because
   789  			// the AST is incomplete), or we have a dot-import (and all bets are off):
   790  			// move any associated values, funcs, and methods back to the top-level so
   791  			// that they are not lost.
   792  			// 1) move values
   793  			r.values = append(r.values, t.values...)
   794  			// 2) move factory functions
   795  			for name, f := range t.funcs {
   796  				// in a correct AST, package-level function names
   797  				// are all different - no need to check for conflicts
   798  				r.funcs[name] = f
   799  			}
   800  			// 3) move methods
   801  			if !predeclared {
   802  				for name, m := range t.methods {
   803  					// don't overwrite functions with the same name - drop them
   804  					if _, found := r.funcs[name]; !found {
   805  						r.funcs[name] = m
   806  					}
   807  				}
   808  			}
   809  		}
   810  		// remove types w/o declaration or which are not visible
   811  		if t.decl == nil || !visible {
   812  			delete(r.types, t.name)
   813  		}
   814  	}
   815  }
   816  
   817  // ----------------------------------------------------------------------------
   818  // Sorting
   819  
   820  func sortedKeys(m map[string]int) []string {
   821  	list := make([]string, len(m))
   822  	i := 0
   823  	for key := range m {
   824  		list[i] = key
   825  		i++
   826  	}
   827  	slices.Sort(list)
   828  	return list
   829  }
   830  
   831  // sortingName returns the name to use when sorting d into place.
   832  func sortingName(d *ast.GenDecl) string {
   833  	if len(d.Specs) == 1 {
   834  		if s, ok := d.Specs[0].(*ast.ValueSpec); ok {
   835  			return s.Names[0].Name
   836  		}
   837  	}
   838  	return ""
   839  }
   840  
   841  func sortedValues(m []*Value, tok token.Token) []*Value {
   842  	list := make([]*Value, len(m)) // big enough in any case
   843  	i := 0
   844  	for _, val := range m {
   845  		if val.Decl.Tok == tok {
   846  			list[i] = val
   847  			i++
   848  		}
   849  	}
   850  	list = list[0:i]
   851  
   852  	slices.SortFunc(list, func(a, b *Value) int {
   853  		r := strings.Compare(sortingName(a.Decl), sortingName(b.Decl))
   854  		if r != 0 {
   855  			return r
   856  		}
   857  		return cmp.Compare(a.order, b.order)
   858  	})
   859  
   860  	return list
   861  }
   862  
   863  func sortedTypes(m map[string]*namedType, allMethods bool) []*Type {
   864  	list := make([]*Type, len(m))
   865  	i := 0
   866  	for _, t := range m {
   867  		list[i] = &Type{
   868  			Doc:     t.doc,
   869  			Name:    t.name,
   870  			Decl:    t.decl,
   871  			Consts:  sortedValues(t.values, token.CONST),
   872  			Vars:    sortedValues(t.values, token.VAR),
   873  			Funcs:   sortedFuncs(t.funcs, true),
   874  			Methods: sortedFuncs(t.methods, allMethods),
   875  		}
   876  		i++
   877  	}
   878  
   879  	slices.SortFunc(list, func(a, b *Type) int {
   880  		return strings.Compare(a.Name, b.Name)
   881  	})
   882  
   883  	return list
   884  }
   885  
   886  func removeStar(s string) string {
   887  	if len(s) > 0 && s[0] == '*' {
   888  		return s[1:]
   889  	}
   890  	return s
   891  }
   892  
   893  func sortedFuncs(m methodSet, allMethods bool) []*Func {
   894  	list := make([]*Func, len(m))
   895  	i := 0
   896  	for _, m := range m {
   897  		// determine which methods to include
   898  		switch {
   899  		case m.Decl == nil:
   900  			// exclude conflict entry
   901  		case allMethods, m.Level == 0, !token.IsExported(removeStar(m.Orig)):
   902  			// forced inclusion, method not embedded, or method
   903  			// embedded but original receiver type not exported
   904  			list[i] = m
   905  			i++
   906  		}
   907  	}
   908  	list = list[0:i]
   909  	slices.SortFunc(list, func(a, b *Func) int {
   910  		return strings.Compare(a.Name, b.Name)
   911  	})
   912  	return list
   913  }
   914  
   915  // noteBodies returns a list of note body strings given a list of notes.
   916  // This is only used to populate the deprecated Package.Bugs field.
   917  func noteBodies(notes []*Note) []string {
   918  	var list []string
   919  	for _, n := range notes {
   920  		list = append(list, n.Body)
   921  	}
   922  	return list
   923  }
   924  
   925  // ----------------------------------------------------------------------------
   926  // Predeclared identifiers
   927  
   928  // IsPredeclared reports whether s is a predeclared identifier.
   929  func IsPredeclared(s string) bool {
   930  	return predeclaredTypes[s] || predeclaredFuncs[s] || predeclaredConstants[s]
   931  }
   932  
   933  var predeclaredTypes = map[string]bool{
   934  	"any":        true,
   935  	"bool":       true,
   936  	"byte":       true,
   937  	"comparable": true,
   938  	"complex64":  true,
   939  	"complex128": true,
   940  	"error":      true,
   941  	"float32":    true,
   942  	"float64":    true,
   943  	"int":        true,
   944  	"int8":       true,
   945  	"int16":      true,
   946  	"int32":      true,
   947  	"int64":      true,
   948  	"rune":       true,
   949  	"string":     true,
   950  	"uint":       true,
   951  	"uint8":      true,
   952  	"uint16":     true,
   953  	"uint32":     true,
   954  	"uint64":     true,
   955  	"uintptr":    true,
   956  }
   957  
   958  var predeclaredFuncs = map[string]bool{
   959  	"append":  true,
   960  	"cap":     true,
   961  	"clear":   true,
   962  	"close":   true,
   963  	"complex": true,
   964  	"copy":    true,
   965  	"delete":  true,
   966  	"imag":    true,
   967  	"len":     true,
   968  	"make":    true,
   969  	"max":     true,
   970  	"min":     true,
   971  	"new":     true,
   972  	"panic":   true,
   973  	"print":   true,
   974  	"println": true,
   975  	"real":    true,
   976  	"recover": true,
   977  }
   978  
   979  var predeclaredConstants = map[string]bool{
   980  	"false": true,
   981  	"iota":  true,
   982  	"nil":   true,
   983  	"true":  true,
   984  }
   985  
   986  // assumedPackageName returns the assumed package name
   987  // for a given import path. This is a copy of
   988  // golang.org/x/tools/internal/imports.ImportPathToAssumedName.
   989  func assumedPackageName(importPath string) string {
   990  	notIdentifier := func(ch rune) bool {
   991  		return !('a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' ||
   992  			'0' <= ch && ch <= '9' ||
   993  			ch == '_' ||
   994  			ch >= utf8.RuneSelf && (unicode.IsLetter(ch) || unicode.IsDigit(ch)))
   995  	}
   996  
   997  	base := path.Base(importPath)
   998  	if strings.HasPrefix(base, "v") {
   999  		if _, err := strconv.Atoi(base[1:]); err == nil {
  1000  			dir := path.Dir(importPath)
  1001  			if dir != "." {
  1002  				base = path.Base(dir)
  1003  			}
  1004  		}
  1005  	}
  1006  	base = strings.TrimPrefix(base, "go-")
  1007  	if i := strings.IndexFunc(base, notIdentifier); i >= 0 {
  1008  		base = base[:i]
  1009  	}
  1010  	return base
  1011  }
  1012
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