godoc: pass *PageInfos instead of *token.FileSets in templates

- convert all formatters that require a *token.FileSet to
  consistenly use a *PageInfo as first argument instead
- adjust templates correspondingly
- fix outstanding bug from previous CL 8005044

Going forward, with this change the affected functions have
access to the full page "context" (PageInfo), not just the
respective file set. This will permit better context-dependent
formatting in the future.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7860049

lib/godoc/package.html

@@ -40,7 +40,7 @@
 				{{comment_html .Doc}}
 			</div>
 		</div>
-		{{example_html "" $.Examples $.FSet}}
+		{{example_html $ ""}}
 
 		<div id="pkg-index" class="toggleVisible">
 		<div class="collapsed">
@@ -60,18 +60,18 @@
 			{{end}}
 			{{range .Funcs}}
 				{{$name_html := html .Name}}
-				<dd><a href="#{{$name_html}}">{{node_html .Decl $.FSet}}</a></dd>
+				<dd><a href="#{{$name_html}}">{{node_html $ .Decl}}</a></dd>
 			{{end}}
 			{{range .Types}}
 				{{$tname_html := html .Name}}
 				<dd><a href="#{{$tname_html}}">type {{$tname_html}}</a></dd>
 				{{range .Funcs}}
 					{{$name_html := html .Name}}
-					<dd>&nbsp; &nbsp; <a href="#{{$name_html}}">{{node_html .Decl $.FSet}}</a></dd>
+					<dd>&nbsp; &nbsp; <a href="#{{$name_html}}">{{node_html $ .Decl}}</a></dd>
 				{{end}}
 				{{range .Methods}}
 					{{$name_html := html .Name}}
-					<dd>&nbsp; &nbsp; <a href="#{{$tname_html}}.{{$name_html}}">{{node_html .Decl $.FSet}}</a></dd>
+					<dd>&nbsp; &nbsp; <a href="#{{$tname_html}}.{{$name_html}}">{{node_html $ .Decl}}</a></dd>
 				{{end}}
 			{{end}}
 			{{if $.Notes}}
@@ -109,59 +109,59 @@
 		{{with .Consts}}
 			<h2 id="pkg-constants">Constants</h2>
 			{{range .}}
-				<pre>{{node_html .Decl $.FSet}}</pre>
+				<pre>{{node_html $ .Decl}}</pre>
 				{{comment_html .Doc}}
 			{{end}}
 		{{end}}
 		{{with .Vars}}
 			<h2 id="pkg-variables">Variables</h2>
 			{{range .}}
-				<pre>{{node_html .Decl $.FSet}}</pre>
+				<pre>{{node_html $ .Decl}}</pre>
 				{{comment_html .Doc}}
 			{{end}}
 		{{end}}
 		{{range .Funcs}}
 			{{/* Name is a string - no need for FSet */}}
 			{{$name_html := html .Name}}
-			<h2 id="{{$name_html}}">func <a href="{{posLink_url .Decl $.FSet}}">{{$name_html}}</a></h2>
-			<pre>{{node_html .Decl $.FSet}}</pre>
+			<h2 id="{{$name_html}}">func <a href="{{posLink_url $ .Decl}}">{{$name_html}}</a></h2>
+			<pre>{{node_html $ .Decl}}</pre>
 			{{comment_html .Doc}}
-			{{example_html .Name $.Examples $.FSet}}
+			{{example_html $ .Name}}
 		{{end}}
 		{{range .Types}}
 			{{$tname := .Name}}
 			{{$tname_html := html .Name}}
-			<h2 id="{{$tname_html}}">type <a href="{{posLink_url .Decl $.FSet}}">{{$tname_html}}</a></h2>
-			<pre>{{node_html .Decl $.FSet}}</pre>
+			<h2 id="{{$tname_html}}">type <a href="{{posLink_url $ .Decl}}">{{$tname_html}}</a></h2>
+			<pre>{{node_html $ .Decl}}</pre>
 			{{comment_html .Doc}}
 
 			{{range .Consts}}
-				<pre>{{node_html .Decl $.FSet}}</pre>
+				<pre>{{node_html $ .Decl}}</pre>
 				{{comment_html .Doc}}
 			{{end}}
 
 			{{range .Vars}}
-				<pre>{{node_html .Decl $.FSet}}</pre>
+				<pre>{{node_html $ .Decl}}</pre>
 				{{comment_html .Doc}}
 			{{end}}
 
-			{{example_html $tname $.Examples $.FSet}}
+			{{example_html $ $tname}}
 
 			{{range .Funcs}}
 				{{$name_html := html .Name}}
-				<h3 id="{{$name_html}}">func <a href="{{posLink_url .Decl $.FSet}}">{{$name_html}}</a></h3>
-				<pre>{{node_html .Decl $.FSet}}</pre>
+				<h3 id="{{$name_html}}">func <a href="{{posLink_url $ .Decl}}">{{$name_html}}</a></h3>
+				<pre>{{node_html $ .Decl}}</pre>
 				{{comment_html .Doc}}
-				{{example_html .Name $.Examples $.FSet}}
+				{{example_html $ .Name}}
 			{{end}}
 
 			{{range .Methods}}
 				{{$name_html := html .Name}}
-				<h3 id="{{$tname_html}}.{{$name_html}}">func ({{html .Recv}}) <a href="{{posLink_url .Decl $.FSet}}">{{$name_html}}</a></h3>
-				<pre>{{node_html .Decl $.FSet}}</pre>
+				<h3 id="{{$tname_html}}.{{$name_html}}">func ({{html .Recv}}) <a href="{{posLink_url $ .Decl}}">{{$name_html}}</a></h3>
+				<pre>{{node_html $ .Decl}}</pre>
 				{{comment_html .Doc}}
 				{{$name := printf "%s_%s" $tname .Name}}
-				{{example_html $name $.Examples $.FSet}}
+				{{example_html $ $name}}
 			{{end}}
 		{{end}}
 	{{end}}
@@ -179,7 +179,7 @@
 {{end}}
 
 {{with .PAst}}
-	<pre>{{node_html . $.FSet}}</pre>
+	<pre>{{node_html $ .}}</pre>
 {{end}}
 
 {{with .Dirs}}

lib/godoc/package.txt

-{{with .PAst}}{{node . $.FSet}}{{end}}{{/*
+{{with .PAst}}{{node $ .}}{{end}}{{/*
 
 ---------------------------------------
 
@@ -11,14 +11,14 @@ package {{.Name}}
     import "{{.ImportPath}}"
 
 {{comment_text .Doc "    " "\t"}}
-{{example_text "" $.Examples $.FSet "    "}}{{/*
+{{example_text $ "" "    "}}{{/*
 
 ---------------------------------------
 
 */}}{{with .Consts}}
 CONSTANTS
 
-{{range .}}{{node .Decl $.FSet}}
+{{range .}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}{{end}}
 {{end}}{{/*
 
@@ -27,7 +27,7 @@ CONSTANTS
 */}}{{with .Vars}}
 VARIABLES
 
-{{range .}}{{node .Decl $.FSet}}
+{{range .}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}{{end}}
 {{end}}{{/*
 
@@ -36,9 +36,9 @@ VARIABLES
 */}}{{with .Funcs}}
 FUNCTIONS
 
-{{range .}}{{node .Decl $.FSet}}
+{{range .}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}
-{{example_text .Name $.Examples $.FSet "    "}}
+{{example_text $ .Name "    "}}
 {{end}}{{end}}{{/*
 
 ---------------------------------------
@@ -46,19 +46,19 @@ FUNCTIONS
 */}}{{with .Types}}
 TYPES
 
-{{range .}}{{$tname := .Name}}{{node .Decl $.FSet}}
+{{range .}}{{$tname := .Name}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}
-{{range .Consts}}{{node .Decl $.FSet}}
+{{range .Consts}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}
-{{end}}{{range .Vars}}{{node .Decl $.FSet}}
+{{end}}{{range .Vars}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}
-{{end}}{{example_text .Name $.Examples $.FSet "    "}}
-{{range .Funcs}}{{node .Decl $.FSet}}
+{{end}}{{example_text $ .Name "    "}}
+{{range .Funcs}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}
-{{example_text .Name $.Examples $.FSet "    "}}
-{{end}}{{range .Methods}}{{node .Decl $.FSet}}
+{{example_text $ .Name "    "}}
+{{end}}{{range .Methods}}{{node $ .Decl}}
 {{comment_text .Doc "    " "\t"}}
-{{$name := printf "%s_%s" $tname .Name}}{{example_text $name $.Examples $.FSet "    "}}
+{{$name := printf "%s_%s" $tname .Name}}{{example_text $ $name "    "}}
 {{end}}{{end}}{{end}}{{end}}{{/*
 
 ---------------------------------------

src/cmd/godoc/godoc.go

@@ -273,25 +273,20 @@ func infoSnippet_htmlFunc(info SpotInfo) string {
 	return `<span class="alert">no snippet text available</span>`
 }
 
-func nodeFunc(node interface{}, fset *token.FileSet) string {
+func nodeFunc(info *PageInfo, node interface{}) string {
 	var buf bytes.Buffer
-	writeNode(&buf, fset, node)
+	writeNode(&buf, info.FSet, node)
 	return buf.String()
 }
 
-func node_htmlFunc(node interface{}, fset *token.FileSet) string {
+func node_htmlFunc(info *PageInfo, node interface{}) string {
 	var buf1 bytes.Buffer
-	writeNode(&buf1, fset, node)
+	writeNode(&buf1, info.FSet, node)
 
 	var buf2 bytes.Buffer
-	// BUG(gri):  When showing full source text (?m=src),
-	//            identifier links are incorrect.
-	// TODO(gri): Only linkify exported code snippets, not the
-	//            full source text: identifier resolution is
-	//            not sufficiently strong w/o type checking.
-	//            Need to check if info.PAst != nil - requires
-	//            to pass *PageInfo around instead of fset.
-	if n, _ := node.(ast.Node); n != nil && *declLinks {
+	// Don't linkify full source text (info.PAst != nil) - identifier
+	// resolution is not strong enough without full type checking.
+	if n, _ := node.(ast.Node); n != nil && *declLinks && info.PAst == nil {
 		LinkifyText(&buf2, buf1.Bytes(), n)
 	} else {
 		FormatText(&buf2, buf1.Bytes(), -1, true, "", nil)
@@ -347,14 +342,14 @@ func stripExampleSuffix(name string) string {
 	return name
 }
 
-func example_textFunc(funcName string, examples []*doc.Example, fset *token.FileSet, indent string) string {
+func example_textFunc(info *PageInfo, funcName, indent string) string {
 	if !*showExamples {
 		return ""
 	}
 
 	var buf bytes.Buffer
 	first := true
-	for _, eg := range examples {
+	for _, eg := range info.Examples {
 		name := stripExampleSuffix(eg.Name)
 		if name != funcName {
 			continue
@@ -368,7 +363,7 @@ func example_textFunc(funcName string, examples []*doc.Example, fset *token.File
 		// print code
 		cnode := &printer.CommentedNode{Node: eg.Code, Comments: eg.Comments}
 		var buf1 bytes.Buffer
-		writeNode(&buf1, fset, cnode)
+		writeNode(&buf1, info.FSet, cnode)
 		code := buf1.String()
 		// Additional formatting if this is a function body.
 		if n := len(code); n >= 2 && code[0] == '{' && code[n-1] == '}' {
@@ -388,9 +383,9 @@ func example_textFunc(funcName string, examples []*doc.Example, fset *token.File
 	return buf.String()
 }
 
-func example_htmlFunc(funcName string, examples []*doc.Example, fset *token.FileSet) string {
+func example_htmlFunc(info *PageInfo, funcName string) string {
 	var buf bytes.Buffer
-	for _, eg := range examples {
+	for _, eg := range info.Examples {
 		name := stripExampleSuffix(eg.Name)
 
 		if name != funcName {
@@ -399,7 +394,7 @@ func example_htmlFunc(funcName string, examples []*doc.Example, fset *token.File
 
 		// print code
 		cnode := &printer.CommentedNode{Node: eg.Code, Comments: eg.Comments}
-		code := node_htmlFunc(cnode, fset)
+		code := node_htmlFunc(info, cnode)
 		out := eg.Output
 		wholeFile := true
 
@@ -421,7 +416,7 @@ func example_htmlFunc(funcName string, examples []*doc.Example, fset *token.File
 		play := ""
 		if eg.Play != nil && *showPlayground {
 			var buf bytes.Buffer
-			if err := format.Node(&buf, fset, eg.Play); err != nil {
+			if err := format.Node(&buf, info.FSet, eg.Play); err != nil {
 				log.Print(err)
 			} else {
 				play = buf.String()
@@ -486,19 +481,19 @@ func pkgLinkFunc(path string) string {
 	return pkgHandler.pattern[1:] + relpath // remove trailing '/' for relative URL
 }
 
-func posLink_urlFunc(node ast.Node, fset *token.FileSet) string {
+func posLink_urlFunc(info *PageInfo, node ast.Node) string {
 	var relpath string
 	var line int
 	var low, high int // selection
 
 	if p := node.Pos(); p.IsValid() {
-		pos := fset.Position(p)
+		pos := info.FSet.Position(p)
 		relpath = pos.Filename
 		line = pos.Line
 		low = pos.Offset
 	}
 	if p := node.End(); p.IsValid() {
-		high = fset.Position(p).Offset
+		high = info.FSet.Position(p).Offset
 	}
 
 	var buf bytes.Buffer
@@ -1059,8 +1054,8 @@ func poorMansImporter(imports map[string]*ast.Object, path string) (*ast.Object,
 // directories, PageInfo.Dirs is nil. If an error occurred, PageInfo.Err is
 // set to the respective error but the error is not logged.
 //
-func (h *docServer) getPageInfo(abspath, relpath string, mode PageInfoMode) (info PageInfo) {
-	info.Dirname = abspath
+func (h *docServer) getPageInfo(abspath, relpath string, mode PageInfoMode) *PageInfo {
+	info := &PageInfo{Dirname: abspath}
 
 	// Restrict to the package files that would be used when building
 	// the package on this system.  This makes sure that if there are
@@ -1077,7 +1072,7 @@ func (h *docServer) getPageInfo(abspath, relpath string, mode PageInfoMode) (inf
 	// continue if there are no Go source files; we still want the directory info
 	if _, nogo := err.(*build.NoGoError); err != nil && !nogo {
 		info.Err = err
-		return
+		return info
 	}
 
 	// collect package files
@@ -1100,7 +1095,7 @@ func (h *docServer) getPageInfo(abspath, relpath string, mode PageInfoMode) (inf
 		files, err := parseFiles(fset, abspath, pkgfiles)
 		if err != nil {
 			info.Err = err
-			return
+			return info
 		}
 
 		// ignore any errors - they are due to unresolved identifiers
@@ -1176,7 +1171,7 @@ func (h *docServer) getPageInfo(abspath, relpath string, mode PageInfoMode) (inf
 	info.DirTime = timestamp
 	info.DirFlat = mode&flatDir != 0
 
-	return
+	return info
 }
 
 func (h *docServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {

src/cmd/godoc/main.go

@@ -374,14 +374,14 @@ func main() {
 	}
 
 	// first, try as package unless forced as command
-	var info PageInfo
+	var info *PageInfo
 	if !forceCmd {
 		info = pkgHandler.getPageInfo(abspath, relpath, mode)
 	}
 
 	// second, try as command unless the path is absolute
 	// (the go command invokes godoc w/ absolute paths; don't override)
-	var cinfo PageInfo
+	var cinfo *PageInfo
 	if !filepath.IsAbs(path) {
 		abspath = pathpkg.Join(cmdHandler.fsRoot, path)
 		cinfo = cmdHandler.getPageInfo(abspath, relpath, mode)