- Ignition js解释器(改进脚本执行,内存开销,提升网页加载速度)
- full codegen v8 baseline compiler
- crankshaft v8 classic optimizing compiler
- TurboFan
- gdbinit
- gdb-v8-support.py
- lldbinit
- lldb_commands.py
新建了annotated分支,用于加注解,debug代码
master分支用于merge from upsteam/master
如何update fork
gclient sync
gclient runhooks
git fetch upstream
git co master
git merge upstream/master
- https://help.github.com/articles/syncing-a-fork/
- https://help.github.com/articles/merging-an-upstream-repository-into-your-fork/
- Local
Local<String> script_name = ...;
v8管理的String对象,让v8对String进行GC
访问Local的IsEmpty
(lldb) p script_name.IsEmpty()
(bool) $12 = false
访问String类的Length
(lldb) p script_name->Length()
(int) $14 = 7
-
Handle 泛型,Handle, 重写了
operator ->和operator *,使用 operator -> 访问类型T真实的成员 -
Isolate 独立的v8运行时,拥有自己的内存,支持并行
-
V8_EXPORT
class V8_EXPORT ArrayBuffer : public Object {
// Setup for Windows DLL export/import. When building the V8 DLL the
// BUILDING_V8_SHARED needs to be defined. When building a program which uses
// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
// static library or building a program which uses the V8 static library neither
// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
#ifdef BUILDING_V8_SHARED
# define V8_EXPORT __declspec(dllexport)
#elif USING_V8_SHARED
# define V8_EXPORT __declspec(dllimport)
#else
# define V8_EXPORT
#endif // BUILDING_V8_SHARED可见性,给外部的shared对象调用函数
default visibility -> global scope,可以从其他shared对象调用
hidden visibility -> local scope,不能从其他shared对象调用
默认的话,是public, gcc编译时提供-fvisibility=hidden,那么默认的就是hidden的,在build/common.gypi配置
-
ToLocalChecked
-
Small Integers
v8.h里描述了Smi是如何定义的.从32bit里借最右一位.一个Small integer是由一个32位直接数和64位数的指针.
// Formats of Object*:
// Smi: [31 bit signed int] 0
// HeapObject: [32 bit direct pointer] (4 byte aligned) | 01
- Hidden classes
给d8加上--trace-maps
比如:
lldb -- out.gn/x64.debug/d8 --trace-maps --allow-natives-syntax demo/test16.js
(lldb) r
Process 26464 launched: '/home/zhujianchen/work/git/v8/out.gn/x64.debug/d8' (x86_64)
[TraceMap: InitialMap map= 0x3afea78032d9 SFI= 0_Object ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea7803331 name= testExtraShouldReturnFive ]
[TraceMaps: Transition from= 0x3afea7803331 to= 0x3afea7803389 name= testExtraShouldCallToRuntime ]
[TraceMaps: Transition from= 0x3afea7803389 to= 0x3afea78033e1 name= testFunctionToString ]
[TraceMaps: Transition from= 0x3afea78033e1 to= 0x3afea7803439 name= testStackTrace ]
[TraceMaps: Transition from= 0x3afea7803439 to= 0x3afea7803491 name= testExtraCanUseUtils ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea7803cd1 name= pop ]
[TraceMaps: Transition from= 0x3afea7803cd1 to= 0x3afea7803d29 name= push ]
[TraceMaps: Transition from= 0x3afea7803d29 to= 0x3afea7803d81 name= shift ]
[TraceMaps: Transition from= 0x3afea7803d81 to= 0x3afea7803dd9 name= unshift ]
[TraceMaps: Transition from= 0x3afea7803dd9 to= 0x3afea7803e31 name= slice ]
[TraceMaps: Transition from= 0x3afea7803e31 to= 0x3afea7803e89 name= splice ]
[TraceMaps: Transition from= 0x3afea7803e89 to= 0x3afea7803ee1 name= includes ]
[TraceMaps: Transition from= 0x3afea7803ee1 to= 0x3afea7803f39 name= indexOf ]
[TraceMaps: Transition from= 0x3afea7803f39 to= 0x3afea7803f91 name= keys ]
[TraceMaps: Transition from= 0x3afea7803f91 to= 0x3afea7803fe9 name= values ]
[TraceMaps: Transition from= 0x3afea7803fe9 to= 0x3afea7804041 name= entries ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea7804099 name= defineProperty ]
[TraceMaps: Transition from= 0x3afea7804099 to= 0x3afea78040f1 name= deleteProperty ]
[TraceMaps: Transition from= 0x3afea78040f1 to= 0x3afea7804149 name= apply ]
[TraceMaps: Transition from= 0x3afea7804149 to= 0x3afea78041a1 name= construct ]
[TraceMaps: Transition from= 0x3afea78041a1 to= 0x3afea78041f9 name= get ]
[TraceMaps: Transition from= 0x3afea78041f9 to= 0x3afea7804251 name= getOwnPropertyDescriptor ]
[TraceMaps: Transition from= 0x3afea7804251 to= 0x3afea78042a9 name= getPrototypeOf ]
[TraceMaps: Transition from= 0x3afea78042a9 to= 0x3afea7804301 name= has ]
[TraceMaps: Transition from= 0x3afea7804301 to= 0x3afea7804359 name= isExtensible ]
[TraceMaps: Transition from= 0x3afea7804359 to= 0x3afea78043b1 name= ownKeys ]
[TraceMaps: Transition from= 0x3afea78043b1 to= 0x3afea7804409 name= preventExtensions ]
[TraceMaps: Transition from= 0x3afea7804409 to= 0x3afea7804461 name= set ]
[TraceMaps: Transition from= 0x3afea7804461 to= 0x3afea78044b9 name= setPrototypeOf ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea780aef1 name= constructor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780aef1 to= 0x3afea780afa1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780af49 SFI= 0_ ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea780b051 name= constructor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b101 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b0a9 SFI= 1_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b1b1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b159 SFI= 0_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b159 to= 0x3afea780b209 reason= CopyAsPrototype ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b2b9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b261 SFI= 2_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b209 to= 0x3afea780b311 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b3c1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b369 SFI= 3_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b311 to= 0x3afea780b419 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b4c9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b471 SFI= 4_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b419 to= 0x3afea780b521 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b5d1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b579 SFI= 5_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b521 to= 0x3afea780b629 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b6d9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b681 SFI= 6_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b629 to= 0x3afea780b731 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b7e1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b789 SFI= 7_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b731 to= 0x3afea780b839 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b8e9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b891 SFI= 8_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b839 to= 0x3afea780b941 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780b9f1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780b999 SFI= 9_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b941 to= 0x3afea780ba49 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780baf9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780baa1 SFI= 10_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780ba49 to= 0x3afea780bb51 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780bb51 to= 0x3afea780bba9 reason= CopyAddDescriptor ]
[TraceMaps: Normalize from= 0x3afea78032d9 to= 0x3afea780bc01 reason= TransitionToAccessorPair ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780bcb1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780bc59 SFI= 11_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780bd61 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780bd09 SFI= 12_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780be11 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780bdb9 SFI= 13_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780bec1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780be69 SFI= 14_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780bf71 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780bf19 SFI= 15_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c021 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780bfc9 SFI= 16_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c0d1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c079 SFI= 17_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c181 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c129 SFI= 18_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c231 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c1d9 SFI= 19_ ]
[TraceMaps: SlowToFast from= 0x3afea780bc01 to= 0x3afea780c289 reason= ApiNatives::InstantiateObject ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780bba9 to= 0x3afea780c2e1 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c391 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c339 SFI= 20_ ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea780c3e9 name= now ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c2e1 to= 0x3afea780c441 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78032d9 to= 0x3afea780c499 reason= CopyAsPrototype ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c549 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c4f1 SFI= 21_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c499 to= 0x3afea780c5a1 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c651 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c5f9 SFI= 22_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c5a1 to= 0x3afea780c6a9 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c759 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c701 SFI= 23_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c6a9 to= 0x3afea780c7b1 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c7b1 to= 0x3afea780c809 reason= CopyAddDescriptor ]
[TraceMaps: InitialMap map= 0x3afea780c861 SFI= 24_Worker ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c441 to= 0x3afea780c8b9 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780c969 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780c911 SFI= 25_ ]
[TraceMaps: Transition from= 0x3afea78032d9 to= 0x3afea780c9c1 name= system ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780ca71 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780ca19 SFI= 26_ ]
[TraceMaps: Transition from= 0x3afea780c9c1 to= 0x3afea780cac9 name= chdir ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780cb79 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780cb21 SFI= 27_ ]
[TraceMaps: Transition from= 0x3afea780cac9 to= 0x3afea780cbd1 name= setenv ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780cc81 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780cc29 SFI= 28_ ]
[TraceMaps: Transition from= 0x3afea780cbd1 to= 0x3afea780ccd9 name= unsetenv ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780cd89 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780cd31 SFI= 29_ ]
[TraceMaps: Transition from= 0x3afea780ccd9 to= 0x3afea780cde1 name= umask ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780ce91 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780ce39 SFI= 30_ ]
[TraceMaps: Transition from= 0x3afea780cde1 to= 0x3afea780cee9 name= mkdirp ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780cf99 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780cf41 SFI= 31_ ]
[TraceMaps: Transition from= 0x3afea780cee9 to= 0x3afea780cff1 name= rmdir ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780c8b9 to= 0x3afea780d049 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780d049 to= 0x3afea780d0a1 reason= CopyAddDescriptor ]
[TraceMaps: InitialMap map= 0x3afea780d0f9 SFI= 1_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b0a9 to= 0x3afea780d151 reason= ForceSetPrototype ]
[TraceMaps: Transition from= 0x3afea780b159 to= 0x3afea780d1a9 name= print ]
[TraceMaps: Transition from= 0x3afea780d1a9 to= 0x3afea780d201 name= printErr ]
[TraceMaps: Transition from= 0x3afea780d201 to= 0x3afea780d259 name= write ]
[TraceMaps: Transition from= 0x3afea780d259 to= 0x3afea780d2b1 name= read ]
[TraceMaps: Transition from= 0x3afea780d2b1 to= 0x3afea780d309 name= readbuffer ]
[TraceMaps: Transition from= 0x3afea780d309 to= 0x3afea780d361 name= readline ]
[TraceMaps: Transition from= 0x3afea780d361 to= 0x3afea780d3b9 name= load ]
[TraceMaps: Transition from= 0x3afea780d3b9 to= 0x3afea780d411 name= quit ]
[TraceMaps: Transition from= 0x3afea780d411 to= 0x3afea780d469 name= version ]
[TraceMaps: Transition from= 0x3afea780d469 to= 0x3afea780d4c1 name= <Symbol.toStringTag> ]
[TraceMaps: Transition from= 0x3afea780d4c1 to= 0x3afea780d519 name= Realm ]
[TraceMaps: Transition from= 0x3afea780d519 to= 0x3afea780d571 name= performance ]
[TraceMaps: Transition from= 0x3afea780d571 to= 0x3afea780d5c9 name= Worker ]
[TraceMaps: Transition from= 0x3afea780d5c9 to= 0x3afea780d621 name= os ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780aff9 to= 0x3afea780d679 reason= ForceSetPrototype ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780d151 to= 0x3afea780d6d1 reason= ForceSetPrototype ]
[TraceMaps: ReplaceDescriptors from= 0x3afea7805279 to= 0x3afea780d729 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78078f9 to= 0x3afea780d781 reason= GenAll_RootModification2 ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780d781 to= 0x3afea780d7d9 reason= GenAll_RootModification2 ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780d7d9 to= 0x3afea780d831 reason= GenAll_RootModification2 ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780d831 to= 0x3afea780d889 reason= GenAll_RootModification2 ]
[TraceMaps: ReplaceDescriptors from= 0x3afea7802db1 to= 0x3afea780d8e1 reason= CopyAddDescriptor ]
[TraceMaps: InitialMap map= 0x3afea780d991 SFI= 34_WebAssembly ]
[TraceMaps: Transition from= 0x3afea780d991 to= 0x3afea780d9e9 name= <Symbol.toStringTag> ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780da99 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780da41 SFI= 35_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780daf1 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780d9e9 to= 0x3afea780db49 name= compile ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780dbf9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780dba1 SFI= 36_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780dc51 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780db49 to= 0x3afea780dca9 name= validate ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780dd59 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780dd01 SFI= 37_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780ddb1 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780dca9 to= 0x3afea780de09 name= instantiate ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780deb9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780de61 SFI= 38_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780df11 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780de09 to= 0x3afea780df69 name= Module ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780de61 to= 0x3afea780e019 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780dfc1 SFI= 38_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780e0c9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e071 SFI= 39_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780e121 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780df11 to= 0x3afea780e179 name= imports ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780e229 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e1d1 SFI= 40_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780e281 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780e179 to= 0x3afea780e2d9 name= exports ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780e389 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e331 SFI= 41_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780e3e1 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780e2d9 to= 0x3afea780e439 name= customSections ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e019 to= 0x3afea780e491 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e491 to= 0x3afea780e4e9 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780e599 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e541 SFI= 42_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780e5f1 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780df69 to= 0x3afea780e649 name= Instance ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e541 to= 0x3afea780e6f9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e6a1 SFI= 42_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e6f9 to= 0x3afea780e751 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e751 to= 0x3afea780e7a9 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780e859 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e801 SFI= 43_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780e8b1 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780e649 to= 0x3afea780e909 name= Table ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e801 to= 0x3afea780e9b9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780e961 SFI= 43_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780e9b9 to= 0x3afea780ea11 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780eac1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780ea69 SFI= 44_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780ea11 to= 0x3afea780eb19 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780ebc9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780eb71 SFI= 45_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780ec21 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780eb19 to= 0x3afea780ec79 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780ed29 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780ecd1 SFI= 46_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780ed81 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780ec79 to= 0x3afea780edd9 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780ee89 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780ee31 SFI= 47_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780eee1 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780edd9 to= 0x3afea780ef39 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780ef39 to= 0x3afea780ef91 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780f041 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780efe9 SFI= 48_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780f099 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: Transition from= 0x3afea780e909 to= 0x3afea780f0f1 name= Memory ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780efe9 to= 0x3afea780f1a1 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780f149 SFI= 48_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780f1a1 to= 0x3afea780f1f9 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780f2a9 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780f251 SFI= 49_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea78029e9 to= 0x3afea780f301 reason= GenAll_AttributesMismatchProtoMap ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780f1f9 to= 0x3afea780f359 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780b051 to= 0x3afea780f409 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780f3b1 SFI= 50_ ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780f359 to= 0x3afea780f461 reason= CopyAddDescriptor ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780f461 to= 0x3afea780f4b9 reason= CopyAddDescriptor ]
[TraceMaps: Transition from= 0x3afea780f0f1 to= 0x3afea780f511 name= CompileError ]
[TraceMaps: Transition from= 0x3afea780f511 to= 0x3afea780f569 name= LinkError ]
[TraceMaps: Transition from= 0x3afea780f569 to= 0x3afea780f5c1 name= RuntimeError ]
FUNCTION "Person" = function Person
VARIABLE (0x555555637460) (mode = CONST) "p"
[TraceMaps: Normalize from= 0x3afea780b051 to= 0x3afea780f6c9 reason= NormalizeAsPrototype ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780f6c9 to= 0x3afea780f721 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780f671 SFI= 52_Person ]
[TraceMaps: Transition from= 0x3afea780f671 to= 0x3afea780f779 name= name ]
[TraceMaps: Transition from= 0x3afea780f779 to= 0x3afea780f7d1 name= age ]
Process 26464 exited with status = 0 (0x00000000)
上面的log是全部的transitions maps,筛选出有用的如下:
[TraceMap: InitialMap map= 0x3afea78032d9 SFI= 0_Object ]
...
FUNCTION "Person" = function Person
VARIABLE (0x555555637460) (mode = CONST) "p"
[TraceMaps: Normalize from= 0x3afea780b051 to= 0x3afea780f6c9 reason= NormalizeAsPrototype ]
[TraceMaps: ReplaceDescriptors from= 0x3afea780f6c9 to= 0x3afea780f721 reason= CopyAsPrototype ]
[TraceMaps: InitialMap map= 0x3afea780f671 SFI= 52_Person ]
[TraceMaps: Transition from= 0x3afea780f671 to= 0x3afea780f779 name= name ]
[TraceMaps: Transition from= 0x3afea780f779 to= 0x3afea780f7d1 name= age ]
forked from https://github.com/v8/v8
V8 is Google's open source JavaScript engine.
V8 implements ECMAScript as specified in ECMA-262.
V8 is written in C++ and is used in Google Chrome, the open source browser from Google.
V8 can run standalone, or can be embedded into any C++ application.
V8 Project page: https://github.com/v8/v8/wiki
Checkout depot tools, and run
fetch v8
This will checkout V8 into the directory v8 and fetch all of its dependencies.
To stay up to date, run
git pull origin
gclient sync
For fetching all branches, add the following into your remote
configuration in .git/config:
fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
fetch = +refs/tags/*:refs/tags/*
Please follow the instructions mentioned on the V8 wiki.