go/src/cmd/compile/internal/ssa/html.go

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// 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"
"cmd/internal/src"
"fmt"
"html"
"io"
"os"
"path/filepath"
"strconv"
[dev.debug] cmd/compile: better DWARF with optimizations on Debuggers use DWARF information to find local variables on the stack and in registers. Prior to this CL, the DWARF information for functions claimed that all variables were on the stack at all times. That's incorrect when optimizations are enabled, and results in debuggers showing data that is out of date or complete gibberish. After this CL, the compiler is capable of representing variable locations more accurately, and attempts to do so. Due to limitations of the SSA backend, it's not possible to be completely correct. There are a number of problems in the current design. One of the easier to understand is that variable names currently must be attached to an SSA value, but not all assignments in the source code actually result in machine code. For example: type myint int var a int b := myint(int) and b := (*uint64)(unsafe.Pointer(a)) don't generate machine code because the underlying representation is the same, so the correct value of b will not be set when the user would expect. Generating the more precise debug information is behind a flag, dwarflocationlists. Because of the issues described above, setting the flag may not make the debugging experience much better, and may actually make it worse in cases where the variable actually is on the stack and the more complicated analysis doesn't realize it. A number of changes are included: - Add a new pseudo-instruction, RegKill, which indicates that the value in the register has been clobbered. - Adjust regalloc to emit RegKills in the right places. Significantly, this means that phis are mixed with StoreReg and RegKills after regalloc. - Track variable decomposition in ssa.LocalSlots. - After the SSA backend is done, analyze the result and build location lists for each LocalSlot. - After assembly is done, update the location lists with the assembled PC offsets, recompose variables, and build DWARF location lists. Emit the list as a new linker symbol, one per function. - In the linker, aggregate the location lists into a .debug_loc section. TODO: - currently disabled for non-X86/AMD64 because there are no data tables. go build -toolexec 'toolstash -cmp' -a std succeeds. With -dwarflocationlists false: before: f02812195637909ff675782c0b46836a8ff01976 after: 06f61e8112a42ac34fb80e0c818b3cdb84a5e7ec benchstat -geomean /tmp/220352263 /tmp/621364410 completed 15 of 15, estimated time remaining 0s (eta 3:52PM) name old time/op new time/op delta Template 199ms ± 3% 198ms ± 2% ~ (p=0.400 n=15+14) Unicode 96.6ms ± 5% 96.4ms ± 5% ~ (p=0.838 n=15+15) GoTypes 653ms ± 2% 647ms ± 2% ~ (p=0.102 n=15+14) Flate 133ms ± 6% 129ms ± 3% -2.62% (p=0.041 n=15+15) GoParser 164ms ± 5% 159ms ± 3% -3.05% (p=0.000 n=15+15) Reflect 428ms ± 4% 422ms ± 3% ~ (p=0.156 n=15+13) Tar 123ms ±10% 124ms ± 8% ~ (p=0.461 n=15+15) XML 228ms ± 3% 224ms ± 3% -1.57% (p=0.045 n=15+15) [Geo mean] 206ms 377ms +82.86% name old user-time/op new user-time/op delta Template 292ms ±10% 301ms ±12% ~ (p=0.189 n=15+15) Unicode 166ms ±37% 158ms ±14% ~ (p=0.418 n=15+14) GoTypes 962ms ± 6% 963ms ± 7% ~ (p=0.976 n=15+15) Flate 207ms ±19% 200ms ±14% ~ (p=0.345 n=14+15) GoParser 246ms ±22% 240ms ±15% ~ (p=0.587 n=15+15) Reflect 611ms ±13% 587ms ±14% ~ (p=0.085 n=15+13) Tar 211ms ±12% 217ms ±14% ~ (p=0.355 n=14+15) XML 335ms ±15% 320ms ±18% ~ (p=0.169 n=15+15) [Geo mean] 317ms 583ms +83.72% name old alloc/op new alloc/op delta Template 40.2MB ± 0% 40.2MB ± 0% -0.15% (p=0.000 n=14+15) Unicode 29.2MB ± 0% 29.3MB ± 0% ~ (p=0.624 n=15+15) GoTypes 114MB ± 0% 114MB ± 0% -0.15% (p=0.000 n=15+14) Flate 25.7MB ± 0% 25.6MB ± 0% -0.18% (p=0.000 n=13+15) GoParser 32.2MB ± 0% 32.2MB ± 0% -0.14% (p=0.003 n=15+15) Reflect 77.8MB ± 0% 77.9MB ± 0% ~ (p=0.061 n=15+15) Tar 27.1MB ± 0% 27.0MB ± 0% -0.11% (p=0.029 n=15+15) XML 42.7MB ± 0% 42.5MB ± 0% -0.29% (p=0.000 n=15+15) [Geo mean] 42.1MB 75.0MB +78.05% name old allocs/op new allocs/op delta Template 402k ± 1% 398k ± 0% -0.91% (p=0.000 n=15+15) Unicode 344k ± 1% 344k ± 0% ~ (p=0.715 n=15+14) GoTypes 1.18M ± 0% 1.17M ± 0% -0.91% (p=0.000 n=15+14) Flate 243k ± 0% 240k ± 1% -1.05% (p=0.000 n=13+15) GoParser 327k ± 1% 324k ± 1% -0.96% (p=0.000 n=15+15) Reflect 984k ± 1% 982k ± 0% ~ (p=0.050 n=15+15) Tar 261k ± 1% 259k ± 1% -0.77% (p=0.000 n=15+15) XML 411k ± 0% 404k ± 1% -1.55% (p=0.000 n=15+15) [Geo mean] 439k 755k +72.01% name old text-bytes new text-bytes delta HelloSize 694kB ± 0% 694kB ± 0% -0.00% (p=0.000 n=15+15) name old data-bytes new data-bytes delta HelloSize 5.55kB ± 0% 5.55kB ± 0% ~ (all equal) name old bss-bytes new bss-bytes delta HelloSize 133kB ± 0% 133kB ± 0% ~ (all equal) name old exe-bytes new exe-bytes delta HelloSize 1.04MB ± 0% 1.04MB ± 0% ~ (all equal) Change-Id: I991fc553ef175db46bb23b2128317bbd48de70d8 Reviewed-on: https://go-review.googlesource.com/41770 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-07-21 18:30:19 -04:00
"strings"
)
type HTMLWriter struct {
Logger
w io.WriteCloser
path string
}
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 {
2016-12-15 17:17:01 -08:00
logger.Fatalf(src.NoXPos, "%v", err)
}
pwd, err := os.Getwd()
if err != nil {
logger.Fatalf(src.NoXPos, "%v", err)
}
html := HTMLWriter{w: out, Logger: logger, path: filepath.Join(pwd, path)}
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>
body {
font-size: 14px;
font-family: Arial, sans-serif;
}
#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;
}
td > h2 {
cursor: pointer;
font-size: 120%;
}
td.collapsed {
font-size: 12px;
width: 12px;
border: 0px;
padding: 0;
cursor: pointer;
background: #fafafa;
}
td.collapsed div {
-moz-transform: rotate(-90.0deg); /* FF3.5+ */
-o-transform: rotate(-90.0deg); /* Opera 10.5 */
-webkit-transform: rotate(-90.0deg); /* Saf3.1+, Chrome */
filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=0.083); /* IE6,IE7 */
-ms-filter: "progid:DXImageTransform.Microsoft.BasicImage(rotation=0.083)"; /* IE8 */
margin-top: 10.3em;
margin-left: -10em;
margin-right: -10em;
text-align: right;
}
code, pre, .lines, .ast {
font-family: Menlo, monospace;
font-size: 12px;
}
.allow-x-scroll {
overflow-x: scroll;
}
.lines {
float: left;
overflow: hidden;
text-align: right;
}
.lines div {
padding-right: 10px;
color: gray;
}
div.line-number {
font-size: 12px;
}
.ast {
white-space: nowrap;
}
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
td.ssa-prog {
width: 600px;
word-wrap: break-word;
}
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;
}
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
.line-number {
font-size: 11px;
}
.no-line-number {
font-size: 11px;
color: gray;
}
.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-skyblue { background-color: skyblue; }
.highlight-lightgray { background-color: lightgray; }
.highlight-yellow { background-color: yellow; }
.highlight-lime { background-color: lime; }
.highlight-khaki { background-color: khaki; }
.highlight-aqua { background-color: aqua; }
.highlight-salmon { background-color: salmon; }
.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; }
.outline-orangered { outline: orangered solid 2px; }
.outline-teal { outline: teal solid 2px; }
.outline-maroon { outline: maroon solid 2px; }
.outline-black { outline: black solid 2px; }
</style>
<script type="text/javascript">
// ordered list of all available highlight colors
var highlights = [
"highlight-aquamarine",
"highlight-coral",
"highlight-lightpink",
"highlight-lightsteelblue",
"highlight-palegreen",
"highlight-skyblue",
"highlight-lightgray",
"highlight-yellow",
"highlight-lime",
"highlight-khaki",
"highlight-aqua",
"highlight-salmon"
];
// 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",
"outline-orangered",
"outline-teal",
"outline-maroon",
"outline-black"
];
// 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);
}
var lines = document.getElementsByClassName("line-number");
for (var i = 0; i < lines.length; i++) {
lines[i].addEventListener('click', ssaValueClicked);
}
// Contains phase names which are expanded by default. Other columns are collapsed.
var expandedDefault = [
"start",
"deadcode",
"opt",
"lower",
"late deadcode",
"regalloc",
"genssa",
];
function toggler(phase) {
return function() {
toggle_cell(phase+'-col');
toggle_cell(phase+'-exp');
};
}
function toggle_cell(id) {
var e = document.getElementById(id);
if (e.style.display == 'table-cell') {
e.style.display = 'none';
} else {
e.style.display = 'table-cell';
}
}
// Go through all columns and collapse needed phases.
var td = document.getElementsByTagName("td");
for (var i = 0; i < td.length; i++) {
var id = td[i].id;
var phase = id.substr(0, id.length-4);
var show = expandedDefault.indexOf(phase) !== -1
if (id.endsWith("-exp")) {
var h2 = td[i].getElementsByTagName("h2");
if (h2 && h2[0]) {
h2[0].addEventListener('click', toggler(phase));
}
} else {
td[i].addEventListener('click', toggler(phase));
}
if (id.endsWith("-col") && show || id.endsWith("-exp") && !show) {
td[i].style.display = 'none';
continue;
}
td[i].style.display = 'table-cell';
}
};
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>`)
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
}
io.WriteString(w.w, "</tr>")
io.WriteString(w.w, "</table>")
io.WriteString(w.w, "</body>")
io.WriteString(w.w, "</html>")
w.w.Close()
fmt.Printf("dumped SSA to %v\n", w.path)
}
// WriteFunc writes f in a column headed by title.
// phase is used for collapsing columns and should be unique across the table.
func (w *HTMLWriter) WriteFunc(phase, title string, f *Func) {
if w == nil {
return // avoid generating HTML just to discard it
}
w.WriteColumn(phase, title, "", f.HTML())
// TODO: Add visual representation of f's CFG.
}
// FuncLines contains source code for a function to be displayed
// in sources column.
type FuncLines struct {
Filename string
StartLineno uint
Lines []string
}
// ByTopo sorts topologically: target function is on top,
// followed by inlined functions sorted by filename and line numbers.
type ByTopo []*FuncLines
func (x ByTopo) Len() int { return len(x) }
func (x ByTopo) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x ByTopo) Less(i, j int) bool {
a := x[i]
b := x[j]
if a.Filename == b.Filename {
return a.StartLineno < b.StartLineno
}
return a.Filename < b.Filename
}
// WriteSources writes lines as source code in a column headed by title.
// phase is used for collapsing columns and should be unique across the table.
func (w *HTMLWriter) WriteSources(phase string, all []*FuncLines) {
if w == nil {
return // avoid generating HTML just to discard it
}
var buf bytes.Buffer
fmt.Fprint(&buf, "<div class=\"lines\" style=\"width: 8%\">")
filename := ""
for _, fl := range all {
fmt.Fprint(&buf, "<div>&nbsp;</div>")
if filename != fl.Filename {
fmt.Fprint(&buf, "<div>&nbsp;</div>")
filename = fl.Filename
}
for i := range fl.Lines {
ln := int(fl.StartLineno) + i
fmt.Fprintf(&buf, "<div class=\"l%v line-number\">%v</div>", ln, ln)
}
}
fmt.Fprint(&buf, "</div><div style=\"width: 92%\"><pre>")
filename = ""
for _, fl := range all {
fmt.Fprint(&buf, "<div>&nbsp;</div>")
if filename != fl.Filename {
fmt.Fprintf(&buf, "<div><strong>%v</strong></div>", fl.Filename)
filename = fl.Filename
}
for i, line := range fl.Lines {
ln := int(fl.StartLineno) + i
var escaped string
if strings.TrimSpace(line) == "" {
escaped = "&nbsp;"
} else {
escaped = html.EscapeString(line)
}
fmt.Fprintf(&buf, "<div class=\"l%v line-number\">%v</div>", ln, escaped)
}
}
fmt.Fprint(&buf, "</pre></div>")
w.WriteColumn(phase, phase, "allow-x-scroll", buf.String())
}
func (w *HTMLWriter) WriteAST(phase string, buf *bytes.Buffer) {
if w == nil {
return // avoid generating HTML just to discard it
}
lines := strings.Split(buf.String(), "\n")
var out bytes.Buffer
fmt.Fprint(&out, "<div>")
for _, l := range lines {
l = strings.TrimSpace(l)
var escaped string
var lineNo string
if l == "" {
escaped = "&nbsp;"
} else {
if strings.HasPrefix(l, "buildssa") {
escaped = fmt.Sprintf("<b>%v</b>", l)
} else {
// Parse the line number from the format l(123).
idx := strings.Index(l, " l(")
if idx != -1 {
subl := l[idx+3:]
idxEnd := strings.Index(subl, ")")
if idxEnd != -1 {
if _, err := strconv.Atoi(subl[:idxEnd]); err == nil {
lineNo = subl[:idxEnd]
}
}
}
escaped = html.EscapeString(l)
}
}
if lineNo != "" {
fmt.Fprintf(&out, "<div class=\"l%v line-number ast\">%v</div>", lineNo, escaped)
} else {
fmt.Fprintf(&out, "<div class=\"ast\">%v</div>", escaped)
}
}
fmt.Fprint(&out, "</div>")
w.WriteColumn(phase, phase, "allow-x-scroll", out.String())
}
// WriteColumn writes raw HTML in a column headed by title.
// It is intended for pre- and post-compilation log output.
func (w *HTMLWriter) WriteColumn(phase, title, class, html string) {
if w == nil {
return
}
id := strings.Replace(phase, " ", "-", -1)
// collapsed column
w.Printf("<td id=\"%v-col\" class=\"collapsed\"><div>%v</div></td>", id, phase)
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
if class == "" {
w.Printf("<td id=\"%v-exp\">", id)
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
} else {
w.Printf("<td id=\"%v-exp\" class=\"%v\">", id, class)
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
}
w.WriteString("<h2>" + title + "</h2>")
w.WriteString(html)
w.WriteString("</td>")
}
func (w *HTMLWriter) Printf(msg string, v ...interface{}) {
if _, err := fmt.Fprintf(w.w, msg, v...); err != nil {
2016-12-15 17:17:01 -08:00
w.Fatalf(src.NoXPos, "%v", err)
}
}
func (w *HTMLWriter) WriteString(s string) {
if _, err := io.WriteString(w.w, s); err != nil {
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w.Fatalf(src.NoXPos, "%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())
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
linenumber := "<span class=\"no-line-number\">(?)</span>"
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
if v.Pos.IsKnown() {
linenumber = fmt.Sprintf("<span class=\"l%v line-number\">(%s)</span>", v.Pos.LineNumber(), v.Pos.LineNumberHTML())
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
}
s += fmt.Sprintf("%s %s = %s", v.HTML(), linenumber, 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].String())
}
[dev.debug] cmd/compile: better DWARF with optimizations on Debuggers use DWARF information to find local variables on the stack and in registers. Prior to this CL, the DWARF information for functions claimed that all variables were on the stack at all times. That's incorrect when optimizations are enabled, and results in debuggers showing data that is out of date or complete gibberish. After this CL, the compiler is capable of representing variable locations more accurately, and attempts to do so. Due to limitations of the SSA backend, it's not possible to be completely correct. There are a number of problems in the current design. One of the easier to understand is that variable names currently must be attached to an SSA value, but not all assignments in the source code actually result in machine code. For example: type myint int var a int b := myint(int) and b := (*uint64)(unsafe.Pointer(a)) don't generate machine code because the underlying representation is the same, so the correct value of b will not be set when the user would expect. Generating the more precise debug information is behind a flag, dwarflocationlists. Because of the issues described above, setting the flag may not make the debugging experience much better, and may actually make it worse in cases where the variable actually is on the stack and the more complicated analysis doesn't realize it. A number of changes are included: - Add a new pseudo-instruction, RegKill, which indicates that the value in the register has been clobbered. - Adjust regalloc to emit RegKills in the right places. Significantly, this means that phis are mixed with StoreReg and RegKills after regalloc. - Track variable decomposition in ssa.LocalSlots. - After the SSA backend is done, analyze the result and build location lists for each LocalSlot. - After assembly is done, update the location lists with the assembled PC offsets, recompose variables, and build DWARF location lists. Emit the list as a new linker symbol, one per function. - In the linker, aggregate the location lists into a .debug_loc section. TODO: - currently disabled for non-X86/AMD64 because there are no data tables. go build -toolexec 'toolstash -cmp' -a std succeeds. With -dwarflocationlists false: before: f02812195637909ff675782c0b46836a8ff01976 after: 06f61e8112a42ac34fb80e0c818b3cdb84a5e7ec benchstat -geomean /tmp/220352263 /tmp/621364410 completed 15 of 15, estimated time remaining 0s (eta 3:52PM) name old time/op new time/op delta Template 199ms ± 3% 198ms ± 2% ~ (p=0.400 n=15+14) Unicode 96.6ms ± 5% 96.4ms ± 5% ~ (p=0.838 n=15+15) GoTypes 653ms ± 2% 647ms ± 2% ~ (p=0.102 n=15+14) Flate 133ms ± 6% 129ms ± 3% -2.62% (p=0.041 n=15+15) GoParser 164ms ± 5% 159ms ± 3% -3.05% (p=0.000 n=15+15) Reflect 428ms ± 4% 422ms ± 3% ~ (p=0.156 n=15+13) Tar 123ms ±10% 124ms ± 8% ~ (p=0.461 n=15+15) XML 228ms ± 3% 224ms ± 3% -1.57% (p=0.045 n=15+15) [Geo mean] 206ms 377ms +82.86% name old user-time/op new user-time/op delta Template 292ms ±10% 301ms ±12% ~ (p=0.189 n=15+15) Unicode 166ms ±37% 158ms ±14% ~ (p=0.418 n=15+14) GoTypes 962ms ± 6% 963ms ± 7% ~ (p=0.976 n=15+15) Flate 207ms ±19% 200ms ±14% ~ (p=0.345 n=14+15) GoParser 246ms ±22% 240ms ±15% ~ (p=0.587 n=15+15) Reflect 611ms ±13% 587ms ±14% ~ (p=0.085 n=15+13) Tar 211ms ±12% 217ms ±14% ~ (p=0.355 n=14+15) XML 335ms ±15% 320ms ±18% ~ (p=0.169 n=15+15) [Geo mean] 317ms 583ms +83.72% name old alloc/op new alloc/op delta Template 40.2MB ± 0% 40.2MB ± 0% -0.15% (p=0.000 n=14+15) Unicode 29.2MB ± 0% 29.3MB ± 0% ~ (p=0.624 n=15+15) GoTypes 114MB ± 0% 114MB ± 0% -0.15% (p=0.000 n=15+14) Flate 25.7MB ± 0% 25.6MB ± 0% -0.18% (p=0.000 n=13+15) GoParser 32.2MB ± 0% 32.2MB ± 0% -0.14% (p=0.003 n=15+15) Reflect 77.8MB ± 0% 77.9MB ± 0% ~ (p=0.061 n=15+15) Tar 27.1MB ± 0% 27.0MB ± 0% -0.11% (p=0.029 n=15+15) XML 42.7MB ± 0% 42.5MB ± 0% -0.29% (p=0.000 n=15+15) [Geo mean] 42.1MB 75.0MB +78.05% name old allocs/op new allocs/op delta Template 402k ± 1% 398k ± 0% -0.91% (p=0.000 n=15+15) Unicode 344k ± 1% 344k ± 0% ~ (p=0.715 n=15+14) GoTypes 1.18M ± 0% 1.17M ± 0% -0.91% (p=0.000 n=15+14) Flate 243k ± 0% 240k ± 1% -1.05% (p=0.000 n=13+15) GoParser 327k ± 1% 324k ± 1% -0.96% (p=0.000 n=15+15) Reflect 984k ± 1% 982k ± 0% ~ (p=0.050 n=15+15) Tar 261k ± 1% 259k ± 1% -0.77% (p=0.000 n=15+15) XML 411k ± 0% 404k ± 1% -1.55% (p=0.000 n=15+15) [Geo mean] 439k 755k +72.01% name old text-bytes new text-bytes delta HelloSize 694kB ± 0% 694kB ± 0% -0.00% (p=0.000 n=15+15) name old data-bytes new data-bytes delta HelloSize 5.55kB ± 0% 5.55kB ± 0% ~ (all equal) name old bss-bytes new bss-bytes delta HelloSize 133kB ± 0% 133kB ± 0% ~ (all equal) name old exe-bytes new exe-bytes delta HelloSize 1.04MB ± 0% 1.04MB ± 0% ~ (all equal) Change-Id: I991fc553ef175db46bb23b2128317bbd48de70d8 Reviewed-on: https://go-review.googlesource.com/41770 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-07-21 18:30:19 -04:00
var names []string
for name, values := range v.Block.Func.NamedValues {
for _, value := range values {
if value == v {
names = append(names, name.String())
[dev.debug] cmd/compile: better DWARF with optimizations on Debuggers use DWARF information to find local variables on the stack and in registers. Prior to this CL, the DWARF information for functions claimed that all variables were on the stack at all times. That's incorrect when optimizations are enabled, and results in debuggers showing data that is out of date or complete gibberish. After this CL, the compiler is capable of representing variable locations more accurately, and attempts to do so. Due to limitations of the SSA backend, it's not possible to be completely correct. There are a number of problems in the current design. One of the easier to understand is that variable names currently must be attached to an SSA value, but not all assignments in the source code actually result in machine code. For example: type myint int var a int b := myint(int) and b := (*uint64)(unsafe.Pointer(a)) don't generate machine code because the underlying representation is the same, so the correct value of b will not be set when the user would expect. Generating the more precise debug information is behind a flag, dwarflocationlists. Because of the issues described above, setting the flag may not make the debugging experience much better, and may actually make it worse in cases where the variable actually is on the stack and the more complicated analysis doesn't realize it. A number of changes are included: - Add a new pseudo-instruction, RegKill, which indicates that the value in the register has been clobbered. - Adjust regalloc to emit RegKills in the right places. Significantly, this means that phis are mixed with StoreReg and RegKills after regalloc. - Track variable decomposition in ssa.LocalSlots. - After the SSA backend is done, analyze the result and build location lists for each LocalSlot. - After assembly is done, update the location lists with the assembled PC offsets, recompose variables, and build DWARF location lists. Emit the list as a new linker symbol, one per function. - In the linker, aggregate the location lists into a .debug_loc section. TODO: - currently disabled for non-X86/AMD64 because there are no data tables. go build -toolexec 'toolstash -cmp' -a std succeeds. With -dwarflocationlists false: before: f02812195637909ff675782c0b46836a8ff01976 after: 06f61e8112a42ac34fb80e0c818b3cdb84a5e7ec benchstat -geomean /tmp/220352263 /tmp/621364410 completed 15 of 15, estimated time remaining 0s (eta 3:52PM) name old time/op new time/op delta Template 199ms ± 3% 198ms ± 2% ~ (p=0.400 n=15+14) Unicode 96.6ms ± 5% 96.4ms ± 5% ~ (p=0.838 n=15+15) GoTypes 653ms ± 2% 647ms ± 2% ~ (p=0.102 n=15+14) Flate 133ms ± 6% 129ms ± 3% -2.62% (p=0.041 n=15+15) GoParser 164ms ± 5% 159ms ± 3% -3.05% (p=0.000 n=15+15) Reflect 428ms ± 4% 422ms ± 3% ~ (p=0.156 n=15+13) Tar 123ms ±10% 124ms ± 8% ~ (p=0.461 n=15+15) XML 228ms ± 3% 224ms ± 3% -1.57% (p=0.045 n=15+15) [Geo mean] 206ms 377ms +82.86% name old user-time/op new user-time/op delta Template 292ms ±10% 301ms ±12% ~ (p=0.189 n=15+15) Unicode 166ms ±37% 158ms ±14% ~ (p=0.418 n=15+14) GoTypes 962ms ± 6% 963ms ± 7% ~ (p=0.976 n=15+15) Flate 207ms ±19% 200ms ±14% ~ (p=0.345 n=14+15) GoParser 246ms ±22% 240ms ±15% ~ (p=0.587 n=15+15) Reflect 611ms ±13% 587ms ±14% ~ (p=0.085 n=15+13) Tar 211ms ±12% 217ms ±14% ~ (p=0.355 n=14+15) XML 335ms ±15% 320ms ±18% ~ (p=0.169 n=15+15) [Geo mean] 317ms 583ms +83.72% name old alloc/op new alloc/op delta Template 40.2MB ± 0% 40.2MB ± 0% -0.15% (p=0.000 n=14+15) Unicode 29.2MB ± 0% 29.3MB ± 0% ~ (p=0.624 n=15+15) GoTypes 114MB ± 0% 114MB ± 0% -0.15% (p=0.000 n=15+14) Flate 25.7MB ± 0% 25.6MB ± 0% -0.18% (p=0.000 n=13+15) GoParser 32.2MB ± 0% 32.2MB ± 0% -0.14% (p=0.003 n=15+15) Reflect 77.8MB ± 0% 77.9MB ± 0% ~ (p=0.061 n=15+15) Tar 27.1MB ± 0% 27.0MB ± 0% -0.11% (p=0.029 n=15+15) XML 42.7MB ± 0% 42.5MB ± 0% -0.29% (p=0.000 n=15+15) [Geo mean] 42.1MB 75.0MB +78.05% name old allocs/op new allocs/op delta Template 402k ± 1% 398k ± 0% -0.91% (p=0.000 n=15+15) Unicode 344k ± 1% 344k ± 0% ~ (p=0.715 n=15+14) GoTypes 1.18M ± 0% 1.17M ± 0% -0.91% (p=0.000 n=15+14) Flate 243k ± 0% 240k ± 1% -1.05% (p=0.000 n=13+15) GoParser 327k ± 1% 324k ± 1% -0.96% (p=0.000 n=15+15) Reflect 984k ± 1% 982k ± 0% ~ (p=0.050 n=15+15) Tar 261k ± 1% 259k ± 1% -0.77% (p=0.000 n=15+15) XML 411k ± 0% 404k ± 1% -1.55% (p=0.000 n=15+15) [Geo mean] 439k 755k +72.01% name old text-bytes new text-bytes delta HelloSize 694kB ± 0% 694kB ± 0% -0.00% (p=0.000 n=15+15) name old data-bytes new data-bytes delta HelloSize 5.55kB ± 0% 5.55kB ± 0% ~ (all equal) name old bss-bytes new bss-bytes delta HelloSize 133kB ± 0% 133kB ± 0% ~ (all equal) name old exe-bytes new exe-bytes delta HelloSize 1.04MB ± 0% 1.04MB ± 0% ~ (all equal) Change-Id: I991fc553ef175db46bb23b2128317bbd48de70d8 Reviewed-on: https://go-review.googlesource.com/41770 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-07-21 18:30:19 -04:00
break // drop duplicates.
}
}
}
if len(names) != 0 {
s += " (" + strings.Join(names, ", ") + ")"
}
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
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)"
}
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
if b.Pos.IsKnown() {
// TODO does not begin to deal with the full complexity of line numbers.
// Maybe we want a string/slice instead, of outer-inner when inlining.
s += fmt.Sprintf(" <span class=\"l%v line-number\">(%s)</span>", b.Pos.LineNumber(), b.Pos.LineNumberHTML())
cmd/compile: add line numbers to values & blocks in ssa.html In order to improve the line numbering for debuggers, it's necessary to trace lines through compilation. This makes it (much) easier to follow. The format of the last column of the ssa.html output was also changed to reduce the spamminess of the file name, which is usually the same and makes it far harder to read instructions and line numbers, and to make it wider and also able to break words when wrapping (long path names still can push off the end otherwise; side-to-side scrolling was tried but was more annoying than the occasional wrapped line). Sample output now, where [...] is elision for sake of making the CL character-counter happy -- and the (##) line numbers are rendered in italics and a smaller font (11 point) under control of a CSS class "line-number". genssa # /Users/drchase/[...]/ssa/testdata/hist.go 00000 (35) TEXT "".main(SB) 00001 (35) FUNCDATA $0, gclocals·7be4bb[...]1e8b(SB) 00002 (35) FUNCDATA $1, gclocals·9ab98a[...]4568(SB) v920 00003 (36) LEAQ ""..autotmp_31-640(SP), DI v858 00004 (36) XORPS X0, X0 v6 00005 (36) LEAQ -48(DI), DI v6 00006 (36) DUFFZERO $277 v576 00007 (36) LEAQ ""..autotmp_31-640(SP), AX v10 00008 (36) TESTB AX, (AX) b1 00009 (36) JMP 10 and from an earlier phase: b18: ← b17 v242 (47) = Copy <mem> v238 v243 (47) = VarKill <mem> {.autotmp_16} v242 v244 (48) = Addr <**bufio.Scanner> {scanner} v2 v245 (48) = Load <*bufio.Scanner> v244 v243 [...] v279 (49) = Store <mem> {int64} v277 v276 v278 v280 (49) = Addr <*error> {.autotmp_18} v2 v281 (49) = Load <error> v280 v279 v282 (49) = Addr <*error> {err} v2 v283 (49) = VarDef <mem> {err} v279 v284 (49) = Store <mem> {error} v282 v281 v283 v285 (47) = VarKill <mem> {.autotmp_18} v284 v286 (47) = VarKill <mem> {.autotmp_17} v285 v287 (50) = Addr <*error> {err} v2 v288 (50) = Load <error> v287 v286 v289 (50) = NeqInter <bool> v288 v51 If v289 → b21 b22 (line 50) Change-Id: I3f46310918f965761f59e6f03ea53067237c28a8 Reviewed-on: https://go-review.googlesource.com/69591 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-10-10 14:44:15 -04:00
}
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) {
fmt.Fprintf(p.w, "<li>name %s: ", n)
for _, val := range vals {
fmt.Fprintf(p.w, "%s ", val.HTML())
}
fmt.Fprintf(p.w, "</li>")
}