src/cmd/compile/internal/ssa/html.go - go - Git at Google

 // 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 ssa

 import (
 	"bytes"
 	"fmt"
 	"html"
 	"io"
 	"os"
 )

 type HTMLWriter struct {
 	Logger
 	*os.File
 }

 func NewHTMLWriter(path string, logger Logger, funcname string) *HTMLWriter {
 	out, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 	if err != nil {
 		logger.Fatalf(0, "%v", err)
 	}
 	html := HTMLWriter{File: out, Logger: logger}
 	html.start(funcname)
 	return &html
 }

 func (w *HTMLWriter) start(name string) {
 	if w == nil {
 		return
 	}
 	w.WriteString("<html>")
 	w.WriteString(`<head>
 <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
 <style>

 #helplink {
     margin-bottom: 15px;
     display: block;
     margin-top: -15px;
 }

 #help {
     display: none;
 }

 .stats {
 	font-size: 60%;
 }

 table {
     border: 1px solid black;
     table-layout: fixed;
     width: 300px;
 }

 th, td {
     border: 1px solid black;
     overflow: hidden;
     width: 400px;
     vertical-align: top;
     padding: 5px;
 }

 li {
     list-style-type: none;
 }

 li.ssa-long-value {
     text-indent: -2em;  /* indent wrapped lines */
 }

 li.ssa-value-list {
     display: inline;
 }

 li.ssa-start-block {
     padding: 0;
     margin: 0;
 }

 li.ssa-end-block {
     padding: 0;
     margin: 0;
 }

 ul.ssa-print-func {
     padding-left: 0;
 }

 dl.ssa-gen {
     padding-left: 0;
 }

 dt.ssa-prog-src {
     padding: 0;
     margin: 0;
     float: left;
     width: 4em;
 }

 dd.ssa-prog {
     padding: 0;
     margin-right: 0;
     margin-left: 4em;
 }

 .dead-value {
     color: gray;
 }

 .dead-block {
     opacity: 0.5;
 }

 .depcycle {
     font-style: italic;
 }

 .highlight-yellow         { background-color: yellow; }
 .highlight-aquamarine     { background-color: aquamarine; }
 .highlight-coral          { background-color: coral; }
 .highlight-lightpink      { background-color: lightpink; }
 .highlight-lightsteelblue { background-color: lightsteelblue; }
 .highlight-palegreen      { background-color: palegreen; }
 .highlight-powderblue     { background-color: powderblue; }
 .highlight-lightgray      { background-color: lightgray; }

 .outline-blue           { outline: blue solid 2px; }
 .outline-red            { outline: red solid 2px; }
 .outline-blueviolet     { outline: blueviolet solid 2px; }
 .outline-darkolivegreen { outline: darkolivegreen solid 2px; }
 .outline-fuchsia        { outline: fuchsia solid 2px; }
 .outline-sienna         { outline: sienna solid 2px; }
 .outline-gold           { outline: gold solid 2px; }

 </style>

 <script type="text/javascript">
 // ordered list of all available highlight colors
 var highlights = [
     "highlight-yellow",
     "highlight-aquamarine",
     "highlight-coral",
     "highlight-lightpink",
     "highlight-lightsteelblue",
     "highlight-palegreen",
     "highlight-lightgray"
 ];

 // state: which value is highlighted this color?
 var highlighted = {};
 for (var i = 0; i < highlights.length; i++) {
     highlighted[highlights[i]] = "";
 }

 // ordered list of all available outline colors
 var outlines = [
     "outline-blue",
     "outline-red",
     "outline-blueviolet",
     "outline-darkolivegreen",
     "outline-fuchsia",
     "outline-sienna",
     "outline-gold"
 ];

 // state: which value is outlined this color?
 var outlined = {};
 for (var i = 0; i < outlines.length; i++) {
     outlined[outlines[i]] = "";
 }

 window.onload = function() {
     var ssaElemClicked = function(elem, event, selections, selected) {
         event.stopPropagation()

         // TODO: pushState with updated state and read it on page load,
         // so that state can survive across reloads

         // find all values with the same name
         var c = elem.classList.item(0);
         var x = document.getElementsByClassName(c);

         // if selected, remove selections from all of them
         // otherwise, attempt to add

         var remove = "";
         for (var i = 0; i < selections.length; i++) {
             var color = selections[i];
             if (selected[color] == c) {
                 remove = color;
                 break;
             }
         }

         if (remove != "") {
             for (var i = 0; i < x.length; i++) {
                 x[i].classList.remove(remove);
             }
             selected[remove] = "";
             return;
         }

         // we're adding a selection
         // find first available color
         var avail = "";
         for (var i = 0; i < selections.length; i++) {
             var color = selections[i];
             if (selected[color] == "") {
                 avail = color;
                 break;
             }
         }
         if (avail == "") {
             alert("out of selection colors; go add more");
             return;
         }

         // set that as the selection
         for (var i = 0; i < x.length; i++) {
             x[i].classList.add(avail);
         }
         selected[avail] = c;
     };

     var ssaValueClicked = function(event) {
         ssaElemClicked(this, event, highlights, highlighted);
     }

     var ssaBlockClicked = function(event) {
         ssaElemClicked(this, event, outlines, outlined);
     }

     var ssavalues = document.getElementsByClassName("ssa-value");
     for (var i = 0; i < ssavalues.length; i++) {
         ssavalues[i].addEventListener('click', ssaValueClicked);
     }

     var ssalongvalues = document.getElementsByClassName("ssa-long-value");
     for (var i = 0; i < ssalongvalues.length; i++) {
         // don't attach listeners to li nodes, just the spans they contain
         if (ssalongvalues[i].nodeName == "SPAN") {
             ssalongvalues[i].addEventListener('click', ssaValueClicked);
         }
     }

     var ssablocks = document.getElementsByClassName("ssa-block");
     for (var i = 0; i < ssablocks.length; i++) {
         ssablocks[i].addEventListener('click', ssaBlockClicked);
     }
 };

 function toggle_visibility(id) {
    var e = document.getElementById(id);
    if(e.style.display == 'block')
       e.style.display = 'none';
    else
       e.style.display = 'block';
 }
 </script>

 </head>`)
 	// TODO: Add javascript click handlers for blocks
 	// to outline that block across all phases
 	w.WriteString("<body>")
 	w.WriteString("<h1>")
 	w.WriteString(html.EscapeString(name))
 	w.WriteString("</h1>")
 	w.WriteString(`
 <a href="#" onclick="toggle_visibility('help');" id="helplink">help</a>
 <div id="help">

 <p>
 Click on a value or block to toggle highlighting of that value/block
 and its uses.  (Values and blocks are highlighted by ID, and IDs of
 dead items may be reused, so not all highlights necessarily correspond
 to the clicked item.)
 </p>

 <p>
 Faded out values and blocks are dead code that has not been eliminated.
 </p>

 <p>
 Values printed in italics have a dependency cycle.
 </p>

 </div>
 `)
 	w.WriteString("<table>")
 	w.WriteString("<tr>")
 }

 func (w *HTMLWriter) Close() {
 	if w == nil {
 		return
 	}
 	w.WriteString("</tr>")
 	w.WriteString("</table>")
 	w.WriteString("</body>")
 	w.WriteString("</html>")
 	w.File.Close()
 }

 // WriteFunc writes f in a column headed by title.
 func (w *HTMLWriter) WriteFunc(title string, f *Func) {
 	if w == nil {
 		return // avoid generating HTML just to discard it
 	}
 	w.WriteColumn(title, f.HTML())
 	// TODO: Add visual representation of f's CFG.
 }

 // WriteColumn writes raw HTML in a column headed by title.
 // It is intended for pre- and post-compilation log output.
 func (w *HTMLWriter) WriteColumn(title string, html string) {
 	if w == nil {
 		return
 	}
 	w.WriteString("<td>")
 	w.WriteString("<h2>" + title + "</h2>")
 	w.WriteString(html)
 	w.WriteString("</td>")
 }

 func (w *HTMLWriter) Printf(msg string, v ...interface{}) {
 	if _, err := fmt.Fprintf(w.File, msg, v...); err != nil {
 		w.Fatalf(0, "%v", err)
 	}
 }

 func (w *HTMLWriter) WriteString(s string) {
 	if _, err := w.File.WriteString(s); err != nil {
 		w.Fatalf(0, "%v", err)
 	}
 }

 func (v *Value) HTML() string {
 	// TODO: Using the value ID as the class ignores the fact
 	// that value IDs get recycled and that some values
 	// are transmuted into other values.
 	s := v.String()
 	return fmt.Sprintf("<span class=\"%s ssa-value\">%s</span>", s, s)
 }

 func (v *Value) LongHTML() string {
 	// TODO: Any intra-value formatting?
 	// I'm wary of adding too much visual noise,
 	// but a little bit might be valuable.
 	// We already have visual noise in the form of punctuation
 	// maybe we could replace some of that with formatting.
 	s := fmt.Sprintf("<span class=\"%s ssa-long-value\">", v.String())
 	s += fmt.Sprintf("%s = %s", v.HTML(), v.Op.String())
 	s += " &lt;" + html.EscapeString(v.Type.String()) + "&gt;"
 	s += html.EscapeString(v.auxString())
 	for _, a := range v.Args {
 		s += fmt.Sprintf(" %s", a.HTML())
 	}
 	r := v.Block.Func.RegAlloc
 	if int(v.ID) < len(r) && r[v.ID] != nil {
 		s += " : " + html.EscapeString(r[v.ID].Name())
 	}
 	s += "</span>"
 	return s
 }

 func (b *Block) HTML() string {
 	// TODO: Using the value ID as the class ignores the fact
 	// that value IDs get recycled and that some values
 	// are transmuted into other values.
 	s := html.EscapeString(b.String())
 	return fmt.Sprintf("<span class=\"%s ssa-block\">%s</span>", s, s)
 }

 func (b *Block) LongHTML() string {
 	// TODO: improve this for HTML?
 	s := fmt.Sprintf("<span class=\"%s ssa-block\">%s</span>", html.EscapeString(b.String()), html.EscapeString(b.Kind.String()))
 	if b.Aux != nil {
 		s += html.EscapeString(fmt.Sprintf(" {%v}", b.Aux))
 	}
 	if b.Control != nil {
 		s += fmt.Sprintf(" %s", b.Control.HTML())
 	}
 	if len(b.Succs) > 0 {
 		s += " &#8594;" // right arrow
 		for _, e := range b.Succs {
 			c := e.b
 			s += " " + c.HTML()
 		}
 	}
 	switch b.Likely {
 	case BranchUnlikely:
 		s += " (unlikely)"
 	case BranchLikely:
 		s += " (likely)"
 	}
 	return s
 }

 func (f *Func) HTML() string {
 	var buf bytes.Buffer
 	fmt.Fprint(&buf, "<code>")
 	p := htmlFuncPrinter{w: &buf}
 	fprintFunc(p, f)

 	// fprintFunc(&buf, f) // TODO: HTML, not text, <br /> for line breaks, etc.
 	fmt.Fprint(&buf, "</code>")
 	return buf.String()
 }

 type htmlFuncPrinter struct {
 	w io.Writer
 }

 func (p htmlFuncPrinter) header(f *Func) {}

 func (p htmlFuncPrinter) startBlock(b *Block, reachable bool) {
 	// TODO: Make blocks collapsable?
 	var dead string
 	if !reachable {
 		dead = "dead-block"
 	}
 	fmt.Fprintf(p.w, "<ul class=\"%s ssa-print-func %s\">", b, dead)
 	fmt.Fprintf(p.w, "<li class=\"ssa-start-block\">%s:", b.HTML())
 	if len(b.Preds) > 0 {
 		io.WriteString(p.w, " &#8592;") // left arrow
 		for _, e := range b.Preds {
 			pred := e.b
 			fmt.Fprintf(p.w, " %s", pred.HTML())
 		}
 	}
 	io.WriteString(p.w, "</li>")
 	if len(b.Values) > 0 { // start list of values
 		io.WriteString(p.w, "<li class=\"ssa-value-list\">")
 		io.WriteString(p.w, "<ul>")
 	}
 }

 func (p htmlFuncPrinter) endBlock(b *Block) {
 	if len(b.Values) > 0 { // end list of values
 		io.WriteString(p.w, "</ul>")
 		io.WriteString(p.w, "</li>")
 	}
 	io.WriteString(p.w, "<li class=\"ssa-end-block\">")
 	fmt.Fprint(p.w, b.LongHTML())
 	io.WriteString(p.w, "</li>")
 	io.WriteString(p.w, "</ul>")
 	// io.WriteString(p.w, "</span>")
 }

 func (p htmlFuncPrinter) value(v *Value, live bool) {
 	var dead string
 	if !live {
 		dead = "dead-value"
 	}
 	fmt.Fprintf(p.w, "<li class=\"ssa-long-value %s\">", dead)
 	fmt.Fprint(p.w, v.LongHTML())
 	io.WriteString(p.w, "</li>")
 }

 func (p htmlFuncPrinter) startDepCycle() {
 	fmt.Fprintln(p.w, "<span class=\"depcycle\">")
 }

 func (p htmlFuncPrinter) endDepCycle() {
 	fmt.Fprintln(p.w, "</span>")
 }

 func (p htmlFuncPrinter) named(n LocalSlot, vals []*Value) {
 	// TODO
 }
	// 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 ssa

	import (
	"bytes"
	"fmt"
	"html"
	"io"
	"os"
	)

	type HTMLWriter struct {
	Logger
	*os.File
	}

	func NewHTMLWriter(path string, logger Logger, funcname string) *HTMLWriter {
	out, err := os.OpenFile(path, os.O_WRONLY\|os.O_CREATE\|os.O_TRUNC, 0644)
	if err != nil {
	logger.Fatalf(0, "%v", err)
	}
	html := HTMLWriter{File: out, Logger: logger}
	html.start(funcname)
	return &html
	}

	func (w *HTMLWriter) start(name string) {
	if w == nil {
	return
	}
	w.WriteString("<html>")
	w.WriteString(`<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<style>

	#helplink {
	margin-bottom: 15px;
	display: block;
	margin-top: -15px;
	}

	#help {
	display: none;
	}

	.stats {
	font-size: 60%;
	}

	table {
	border: 1px solid black;
	table-layout: fixed;
	width: 300px;
	}

	th, td {
	border: 1px solid black;
	overflow: hidden;
	width: 400px;
	vertical-align: top;
	padding: 5px;
	}

	li {
	list-style-type: none;
	}

	li.ssa-long-value {
	text-indent: -2em; /* indent wrapped lines */
	}

	li.ssa-value-list {
	display: inline;
	}

	li.ssa-start-block {
	padding: 0;
	margin: 0;
	}

	li.ssa-end-block {
	padding: 0;
	margin: 0;
	}

	ul.ssa-print-func {
	padding-left: 0;
	}

	dl.ssa-gen {
	padding-left: 0;
	}

	dt.ssa-prog-src {
	padding: 0;
	margin: 0;
	float: left;
	width: 4em;
	}

	dd.ssa-prog {
	padding: 0;
	margin-right: 0;
	margin-left: 4em;
	}

	.dead-value {
	color: gray;
	}

	.dead-block {
	opacity: 0.5;
	}

	.depcycle {
	font-style: italic;
	}

	.highlight-yellow { background-color: yellow; }
	.highlight-aquamarine { background-color: aquamarine; }
	.highlight-coral { background-color: coral; }
	.highlight-lightpink { background-color: lightpink; }
	.highlight-lightsteelblue { background-color: lightsteelblue; }
	.highlight-palegreen { background-color: palegreen; }
	.highlight-powderblue { background-color: powderblue; }
	.highlight-lightgray { background-color: lightgray; }

	.outline-blue { outline: blue solid 2px; }
	.outline-red { outline: red solid 2px; }
	.outline-blueviolet { outline: blueviolet solid 2px; }
	.outline-darkolivegreen { outline: darkolivegreen solid 2px; }
	.outline-fuchsia { outline: fuchsia solid 2px; }
	.outline-sienna { outline: sienna solid 2px; }
	.outline-gold { outline: gold solid 2px; }

	</style>

	<script type="text/javascript">
	// ordered list of all available highlight colors
	var highlights = [
	"highlight-yellow",
	"highlight-aquamarine",
	"highlight-coral",
	"highlight-lightpink",
	"highlight-lightsteelblue",
	"highlight-palegreen",
	"highlight-lightgray"
	];

	// state: which value is highlighted this color?
	var highlighted = {};
	for (var i = 0; i < highlights.length; i++) {
	highlighted[highlights[i]] = "";
	}

	// ordered list of all available outline colors
	var outlines = [
	"outline-blue",
	"outline-red",
	"outline-blueviolet",
	"outline-darkolivegreen",
	"outline-fuchsia",
	"outline-sienna",
	"outline-gold"
	];

	// state: which value is outlined this color?
	var outlined = {};
	for (var i = 0; i < outlines.length; i++) {
	outlined[outlines[i]] = "";
	}

	window.onload = function() {
	var ssaElemClicked = function(elem, event, selections, selected) {
	event.stopPropagation()

	// TODO: pushState with updated state and read it on page load,
	// so that state can survive across reloads

	// find all values with the same name
	var c = elem.classList.item(0);
	var x = document.getElementsByClassName(c);

	// if selected, remove selections from all of them
	// otherwise, attempt to add

	var remove = "";
	for (var i = 0; i < selections.length; i++) {
	var color = selections[i];
	if (selected[color] == c) {
	remove = color;
	break;
	}
	}

	if (remove != "") {
	for (var i = 0; i < x.length; i++) {
	x[i].classList.remove(remove);
	}
	selected[remove] = "";
	return;
	}

	// we're adding a selection
	// find first available color
	var avail = "";
	for (var i = 0; i < selections.length; i++) {
	var color = selections[i];
	if (selected[color] == "") {
	avail = color;
	break;
	}
	}
	if (avail == "") {
	alert("out of selection colors; go add more");
	return;
	}

	// set that as the selection
	for (var i = 0; i < x.length; i++) {
	x[i].classList.add(avail);
	}
	selected[avail] = c;
	};

	var ssaValueClicked = function(event) {
	ssaElemClicked(this, event, highlights, highlighted);
	}

	var ssaBlockClicked = function(event) {
	ssaElemClicked(this, event, outlines, outlined);
	}

	var ssavalues = document.getElementsByClassName("ssa-value");
	for (var i = 0; i < ssavalues.length; i++) {
	ssavalues[i].addEventListener('click', ssaValueClicked);
	}

	var ssalongvalues = document.getElementsByClassName("ssa-long-value");
	for (var i = 0; i < ssalongvalues.length; i++) {
	// don't attach listeners to li nodes, just the spans they contain
	if (ssalongvalues[i].nodeName == "SPAN") {
	ssalongvalues[i].addEventListener('click', ssaValueClicked);
	}
	}

	var ssablocks = document.getElementsByClassName("ssa-block");
	for (var i = 0; i < ssablocks.length; i++) {
	ssablocks[i].addEventListener('click', ssaBlockClicked);
	}
	};

	function toggle_visibility(id) {
	var e = document.getElementById(id);
	if(e.style.display == 'block')
	e.style.display = 'none';
	else
	e.style.display = 'block';
	}
	</script>

	</head>`)
	// TODO: Add javascript click handlers for blocks
	// to outline that block across all phases
	w.WriteString("<body>")
	w.WriteString("<h1>")
	w.WriteString(html.EscapeString(name))
	w.WriteString("</h1>")
	w.WriteString(`
	<a href="#" onclick="toggle_visibility('help');" id="helplink">help</a>
	<div id="help">

	<p>
	Click on a value or block to toggle highlighting of that value/block
	and its uses. (Values and blocks are highlighted by ID, and IDs of
	dead items may be reused, so not all highlights necessarily correspond
	to the clicked item.)
	</p>

	<p>
	Faded out values and blocks are dead code that has not been eliminated.
	</p>

	<p>
	Values printed in italics have a dependency cycle.
	</p>

	</div>
	`)
	w.WriteString("<table>")
	w.WriteString("<tr>")
	}

	func (w *HTMLWriter) Close() {
	if w == nil {
	return
	}
	w.WriteString("</tr>")
	w.WriteString("</table>")
	w.WriteString("</body>")
	w.WriteString("</html>")
	w.File.Close()
	}

	// WriteFunc writes f in a column headed by title.
	func (w HTMLWriter) WriteFunc(title string, f Func) {
	if w == nil {
	return // avoid generating HTML just to discard it
	}
	w.WriteColumn(title, f.HTML())
	// TODO: Add visual representation of f's CFG.
	}

	// WriteColumn writes raw HTML in a column headed by title.
	// It is intended for pre- and post-compilation log output.
	func (w *HTMLWriter) WriteColumn(title string, html string) {
	if w == nil {
	return
	}
	w.WriteString("<td>")
	w.WriteString("<h2>" + title + "</h2>")
	w.WriteString(html)
	w.WriteString("</td>")
	}

	func (w *HTMLWriter) Printf(msg string, v ...interface{}) {
	if _, err := fmt.Fprintf(w.File, msg, v...); err != nil {
	w.Fatalf(0, "%v", err)
	}
	}

	func (w *HTMLWriter) WriteString(s string) {
	if _, err := w.File.WriteString(s); err != nil {
	w.Fatalf(0, "%v", err)
	}
	}

	func (v *Value) HTML() string {
	// TODO: Using the value ID as the class ignores the fact
	// that value IDs get recycled and that some values
	// are transmuted into other values.
	s := v.String()
	return fmt.Sprintf("<span class=\"%s ssa-value\">%s</span>", s, s)
	}

	func (v *Value) LongHTML() string {
	// TODO: Any intra-value formatting?
	// I'm wary of adding too much visual noise,
	// but a little bit might be valuable.
	// We already have visual noise in the form of punctuation
	// maybe we could replace some of that with formatting.
	s := fmt.Sprintf("<span class=\"%s ssa-long-value\">", v.String())
	s += fmt.Sprintf("%s = %s", v.HTML(), v.Op.String())
	s += " <" + html.EscapeString(v.Type.String()) + ">"
	s += html.EscapeString(v.auxString())
	for _, a := range v.Args {
	s += fmt.Sprintf(" %s", a.HTML())
	}
	r := v.Block.Func.RegAlloc
	if int(v.ID) < len(r) && r[v.ID] != nil {
	s += " : " + html.EscapeString(r[v.ID].Name())
	}
	s += "</span>"
	return s
	}

	func (b *Block) HTML() string {
	// TODO: Using the value ID as the class ignores the fact
	// that value IDs get recycled and that some values
	// are transmuted into other values.
	s := html.EscapeString(b.String())
	return fmt.Sprintf("<span class=\"%s ssa-block\">%s</span>", s, s)
	}

	func (b *Block) LongHTML() string {
	// TODO: improve this for HTML?
	s := fmt.Sprintf("<span class=\"%s ssa-block\">%s</span>", html.EscapeString(b.String()), html.EscapeString(b.Kind.String()))
	if b.Aux != nil {
	s += html.EscapeString(fmt.Sprintf(" {%v}", b.Aux))
	}
	if b.Control != nil {
	s += fmt.Sprintf(" %s", b.Control.HTML())
	}
	if len(b.Succs) > 0 {
	s += " →" // right arrow
	for _, e := range b.Succs {
	c := e.b
	s += " " + c.HTML()
	}
	}
	switch b.Likely {
	case BranchUnlikely:
	s += " (unlikely)"
	case BranchLikely:
	s += " (likely)"
	}
	return s
	}

	func (f *Func) HTML() string {
	var buf bytes.Buffer
	fmt.Fprint(&buf, "<code>")
	p := htmlFuncPrinter{w: &buf}
	fprintFunc(p, f)

	// fprintFunc(&buf, f) // TODO: HTML, not text, <br /> for line breaks, etc.
	fmt.Fprint(&buf, "</code>")
	return buf.String()
	}

	type htmlFuncPrinter struct {
	w io.Writer
	}

	func (p htmlFuncPrinter) header(f *Func) {}

	func (p htmlFuncPrinter) startBlock(b *Block, reachable bool) {
	// TODO: Make blocks collapsable?
	var dead string
	if !reachable {
	dead = "dead-block"
	}
	fmt.Fprintf(p.w, "<ul class=\"%s ssa-print-func %s\">", b, dead)
	fmt.Fprintf(p.w, "<li class=\"ssa-start-block\">%s:", b.HTML())
	if len(b.Preds) > 0 {
	io.WriteString(p.w, " ←") // left arrow
	for _, e := range b.Preds {
	pred := e.b
	fmt.Fprintf(p.w, " %s", pred.HTML())
	}
	}
	io.WriteString(p.w, "</li>")
	if len(b.Values) > 0 { // start list of values
	io.WriteString(p.w, "<li class=\"ssa-value-list\">")
	io.WriteString(p.w, "<ul>")
	}
	}

	func (p htmlFuncPrinter) endBlock(b *Block) {
	if len(b.Values) > 0 { // end list of values
	io.WriteString(p.w, "</ul>")
	io.WriteString(p.w, "</li>")
	}
	io.WriteString(p.w, "<li class=\"ssa-end-block\">")
	fmt.Fprint(p.w, b.LongHTML())
	io.WriteString(p.w, "</li>")
	io.WriteString(p.w, "</ul>")
	// io.WriteString(p.w, "</span>")
	}

	func (p htmlFuncPrinter) value(v *Value, live bool) {
	var dead string
	if !live {
	dead = "dead-value"
	}
	fmt.Fprintf(p.w, "<li class=\"ssa-long-value %s\">", dead)
	fmt.Fprint(p.w, v.LongHTML())
	io.WriteString(p.w, "</li>")
	}

	func (p htmlFuncPrinter) startDepCycle() {
	fmt.Fprintln(p.w, "<span class=\"depcycle\">")
	}

	func (p htmlFuncPrinter) endDepCycle() {
	fmt.Fprintln(p.w, "</span>")
	}

	func (p htmlFuncPrinter) named(n LocalSlot, vals []*Value) {
	// TODO
	}