Author Archives: neohope

1、测试文件test.js

function log(msg){
    console.log(msg)
}

hi = "hello"
log(hi)

2、输出AST语法树

d8 --print-ast test.js
[generating bytecode for function: ]
--- AST ---
FUNC at 0
. KIND 0
. LITERAL ID 0
. SUSPEND COUNT 0
. NAME ""
. INFERRED NAME ""
. DECLS
. . FUNCTION "log" = function log
. EXPRESSION STATEMENT at 47
. . ASSIGN at 50
. . . VAR PROXY unallocated (0000022CC5A21D98) (mode = DYNAMIC_GLOBAL, assigned = true) "hi"
. . . LITERAL "hello"
. EXPRESSION STATEMENT at 61
. . ASSIGN at -1
. . . VAR PROXY local[0] (0000022CC5A21CC8) (mode = TEMPORARY, assigned = true) ".result"
. . . CALL
. . . . VAR PROXY unallocated (0000022CC5A21B10) (mode = VAR, assigned = true) "log"
. . . . VAR PROXY unallocated (0000022CC5A21D98) (mode = DYNAMIC_GLOBAL, assigned = true) "hi"
. RETURN at -1
. . VAR PROXY local[0] (0000022CC5A21CC8) (mode = TEMPORARY, assigned = true) ".result"

[generating bytecode for function: log]
--- AST ---
FUNC at 12
. KIND 0
. LITERAL ID 1
. SUSPEND COUNT 0
. NAME "log"
. PARAMS
. . VAR (0000022CC5A21B68) (mode = VAR, assigned = false) "msg"
. DECLS
. . VARIABLE (0000022CC5A21B68) (mode = VAR, assigned = false) "msg"
. EXPRESSION STATEMENT at 24
. . CALL
. . . PROPERTY at 32
. . . . VAR PROXY unallocated (0000022CC5A21D18) (mode = DYNAMIC_GLOBAL, assigned = false) "console"
. . . . NAME log
. . . VAR PROXY parameter[0] (0000022CC5A21B68) (mode = VAR, assigned = false) "msg"

hello

3、输出作用域

d8 --print-scopes test.js
Inner function scope:
function log () { // (000001E067B50EA8) (12, 43)
  // 2 heap slots
  // local vars:
  VAR msg;  // (000001E067B54E18) never assigned
}
Global scope:
global { // (000001E067B50C88) (0, 68)
  // will be compiled
  // 1 stack slots
  // temporary vars:
  TEMPORARY .result;  // (000001E067B51288) local[0]
  // local vars:
  VAR log;  // (000001E067B510D0)
  // dynamic vars:
  DYNAMIC_GLOBAL hi;  // (000001E067B51358)

  function log () { // (000001E067B50EA8) (12, 43)
    // lazily parsed
    // 2 heap slots
  }
}
Global scope:
function log (msg) { // (000001E067B50EA8) (12, 43)
  // will be compiled
  // local vars:
  VAR msg;  // (000001E067B51128) parameter[0], never assigned
}
hello

4、输出字节码

d8 --print-bytecode test.js
[generated bytecode for function:  (0x03970824fc39 <SharedFunctionInfo>)]
Parameter count 1
Register count 3
Frame size 24
         000003970824FCEA @    0 : 12 00             LdaConstant [0]
         000003970824FCEC @    2 : 26 fa             Star r1
         000003970824FCEE @    4 : 27 fe f9          Mov <closure>, r2
         000003970824FCF1 @    7 : 61 37 01 fa 02    CallRuntime [DeclareGlobals], r1-r2
         000003970824FCF6 @   12 : 12 01             LdaConstant [1]
         000003970824FCF8 @   14 : 15 02 00          StaGlobal [2], [0]
         000003970824FCFB @   17 : 13 03 02          LdaGlobal [3], [2]
         000003970824FCFE @   20 : 26 fa             Star r1
         000003970824FD00 @   22 : 13 02 04          LdaGlobal [2], [4]
         000003970824FD03 @   25 : 26 f9             Star r2
         000003970824FD05 @   27 : 5d fa f9 06       CallUndefinedReceiver1 r1, r2, [6]
         000003970824FD09 @   31 : 26 fb             Star r0
         000003970824FD0B @   33 : aa                Return
Constant pool (size = 4)
000003970824FCB1: [FixedArray] in OldSpace
 - map: 0x0397080404b1 <Map>
 - length: 4
           0: 0x03970824fc61 <FixedArray[2]>
           1: 0x03970824fc01 <String[#5]: hello>
           2: 0x03970824fbf1 <String[#2]: hi>
           3: 0x0397081c692d <String[#3]: log>
Handler Table (size = 0)
Source Position Table (size = 0)
[generated bytecode for function: log (0x03970824fc71 <SharedFunctionInfo log>)]
Parameter count 2
Register count 2
Frame size 16
         000003970824FE4E @    0 : 13 00 00          LdaGlobal [0], [0]
         000003970824FE51 @    3 : 26 fa             Star r1
         000003970824FE53 @    5 : 28 fa 01 02       LdaNamedProperty r1, [1], [2]
         000003970824FE57 @    9 : 26 fb             Star r0
         000003970824FE59 @   11 : 59 fb fa 02 04    CallProperty1 r0, r1, a0, [4]
         000003970824FE5E @   16 : 0d                LdaUndefined
         000003970824FE5F @   17 : aa                Return
Constant pool (size = 2)
000003970824FE1D: [FixedArray] in OldSpace
 - map: 0x0397080404b1 <Map>
 - length: 2
           0: 0x0397081c68b9 <String[#7]: console>
           1: 0x0397081c692d <String[#3]: log>
Handler Table (size = 0)
Source Position Table (size = 0)
hello

5、测试文件test1.js

let a = {x:1}

function bar(obj) { 
  return obj.x 
}

function foo (count) { 
  let ret = 0
  for(let i = 1; i < count; i++) {
    ret += bar(a)
  }
  return ret
}

//foo(7049)
//foo(100000)

6、输出优化信息

//foo(7049)
d8 --trace-opt-verbose test1.js
[not yet optimizing foo, not enough ticks: 0/2 and ICs changed]

//foo(10000)
[not yet optimizing foo, not enough ticks: 0/2 and ICs changed]
[marking 0x01410824fe35 <JSFunction foo (sfi = 000001410824FCD9)> for optimized recompilation, reason: small function]
[compiling method 0x01410824fe35 <JSFunction foo (sfi = 000001410824FCD9)> using TurboFan OSR]
[optimizing 0x01410824fe35 <JSFunction foo (sfi = 000001410824FCD9)> - took 141.370, 62.753, 1.551 ms]

7、输出反优化信息

//没有输出。。。
d8 --trace-deopt test1.js

8、test2.js

function strToArray(str) {
  let i = 0
  const len = str.length
  let arr = new Uint16Array(str.length)
  for (; i < len; ++i) {
    arr[i] = str.charCodeAt(i)
  }
  return arr;
}

function foo() {
  let i = 0
  let str = 'test V8 GC'
  while (i++ < 1e5) {
    strToArray(str);
  }
}

foo()

9、输出反优化信息

d8 --trace-gc test2.js
[4600:0000019D00000000]      490 ms: Scavenge 1.2 (2.4) -> 0.3 (3.4) MB, 14.5 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      500 ms: Scavenge 1.2 (3.4) -> 0.3 (3.6) MB, 2.0 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      501 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      503 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      505 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      506 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      508 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      509 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      511 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      513 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      515 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      516 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      518 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure
[4600:0000019D00000000]      520 ms: Scavenge 1.3 (3.6) -> 0.3 (3.6) MB, 0.1 / 0.0 ms  (average mu = 1.000, current mu = 1.000) allocation failure

10、test3.js

function Foo(property_num,element_num) {
  //添加可索引属性
  for (let i = 0; i < element_num; i++) {
      this[i] = `element${i}`
  }
  //添加常规属性
  for (let i = 0; i < property_num; i++) {
      let ppt = `property${i}`
      this[ppt] = ppt
  }
}
var bar = new Foo(10,10)
console.log(%HasFastProperties(bar));
delete bar.property2
console.log(%HasFastProperties(bar));

11、使用内部方法

//%HasFastProperties测试是否有快属性
d8 --allow-natives-syntax test3.js
true
false

1、安装Visual Studio 2017

2、从微软下载Windows 10 SDK，安装“Debugging Tools for Windows”

https://developer.microsoft.com/en-US/windows/downloads/windows-10-sdk/

3、设置代理

# git的http代理设置
git config --global http.proxy 127.0.0.1:9528
git config --global https.proxy 127.0.0.1:9528

# 可以通过操作系统设置http代理
# 也可以通过通过命令行设置http代理设置（管理员权限）
netsh winhttp set proxy 127.0.0.1:9528

# 设置cipd_client的http代理设置
set HTTP_PROXY=127.0.0.1:9528
set HTTPS_PROXY=127.0.0.1:9528

4、环境变量

# 启动 VS2017 x86_amd64 命令行环境
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Auxiliary\Build\vcvarsx86_amd64.bat"

# 环境变量
set PATH=D:\GitGoogleV8\depot_tools_win;D:\NeoLang\Python\Python37;%PATH%
set DEPOT_TOOLS_WIN_TOOLCHAIN=0

5、下载源码

mkdir V8Build
cd V8Build
# V8Build
fetch v8

cd v8
# V8Build/v8
git pull origin 8.3.82
cd ..

6、同步环境

# V8Build
gclient sync

7、生成解决方案

cd v8/src
# V8Build/v8/src
gn gen --ide=vs out\Default
# 也可以设置filters，如果是看chrome源码，最好设置一下，因为有几千个项目
# gn gen --ide=vs --filters=//chrome --no-deps out\Default

8、编译

# 用vs打开sln，并编译
# 编译过程中，有时会出现文件无法访问等情况
# 可以在命令行中执行，然后用VS继续编译就可以成功了
# V8Build/v8/src
devenv out\Default\all.sln

9、测试

# V8Build/v8/src
cd out\Default
# V8Build/v8/src/out/Default
v8_shell.exe