git clone https://chromium.googlesource.com/chromium/tools/depot_tools

set DEPOT_TOOLS_WIN_TOOLCHAIN = 0

set GYP_MSVS_OVERRIDE_PATH =C:\Program Files (x86)\Microsoft Visual Studio19\Enterprise

set GYP_MSVS_VERSION =2019

git config --global http.proxy http://127.0.0.1:8080
git config --global https.proxy http://127.0.0.1:8080
netsh winhttp set proxy 127.0.0.1:8080
set HTTP_PROXY=http://127.0.0.1:8080
set HTTPS_PROXY=http://127.0.0.1:8080

fetch v8

cd v8

#这个切换分支的 最新稳定版- 此次编译使用的是9.4
git checkout lkgr
gclient sync

#可能要修改这两处-否则后面编译不过云
#gm.py文件修改下面的
#return os.uname()[4]
return "nt"

setup_toolchain.py文件修改下面的
#with open(environment_block_name, 'w') as f:
with open(environment_block_name, 'w',encoding='utf-8') as f:


#编译动态库- 这4条命令编译出来的lib不能用,导出符号名有问题.
python tools\dev\gm.py ia32.debug
python tools\dev\gm.py ia32.release
python tools/dev/gm.py x64.debug
python tools/dev/gm.py x64.release


#编译静态库(lib)

x64 release
python .\tools\dev\v8gen.py x64.release -- v8_monolithic=true v8_use_external_startup_data=false use_custom_libcxx=false is_component_build=false treat_warnings_as_errors=false v8_symbol_level=0 v8_enable_pointer_compression=false
ninja -C .\out.gn\x64.release v8_monolith -j 32

#x64 debug
python .\tools\dev\v8gen.py x64.debug -- enable_iterator_debugging=false v8_monolithic=true v8_enable_i18n_support=false is_debug=true v8_use_external_startup_data=false use_custom_libcxx=false is_component_build=false treat_warnings_as_errors=false v8_symbol_level=0  v8_enable_pointer_compression=false
ninja -C .\out.gn\x64.debug v8_monolith -j 32

#x86 release
python .\tools\dev\v8gen.py ia32.release -- v8_monolithic=true v8_enable_i18n_support=false v8_use_external_startup_data=false use_custom_libcxx=false is_component_build=false treat_warnings_as_errors=false v8_symbol_level=0
ninja -C .\out.gn\ia32.release v8_monolith -j 32

#x86 debug
python .\tools\dev\v8gen.py ia32.debug -- enable_iterator_debugging=false v8_monolithic=true v8_enable_i18n_support=false is_debug=true v8_use_external_startup_data=false use_custom_libcxx=false is_component_build=false treat_warnings_as_errors=false v8_symbol_level=0
ninja -C .\out.gn\ia32.debug v8_monolith -j 32


#编译动态库
#使用msvc编译
call gn gen out/ia32.debug --args="is_debug=true use_glib=false is_component_build=true v8_use_external_startup_data=false v8_static_library=false is_clang = false treat_warnings_as_errors=false v8_enable_i18n_support=false target_cpu=\"x86\""
ninja -C .\out\ia32.debug v8.dll -j 34
#ninja -C .\out\ia32.debug -j 34

#编译静态库需要修改预定义宏-以达到与VS相匹配
#修改文件build\config\BUILD.gn
#找到以下代码修改
  if (is_win) {
    if (!enable_iterator_debugging && !use_custom_libcxx) {
      # Iterator debugging is enabled by default by the compiler on debug
      # builds, and we have to tell it to turn it off.

      #defines += [ "_HAS_ITERATOR_DEBUGGING=0" ]   //修改这行
      defines += [ "_HAS_ITERATOR_DEBUGGING=1" ]
  
      #再添加这一行
      defines += [ "_ITERATOR_DEBUG_LEVEL=2" ]
    }
  } else if ((is_linux || is_chromeos) && current_cpu == "x64" &&
             enable_iterator_debugging) {
    # Enable libstdc++ debugging facilities to help catch problems early, see
    # http://crbug.com/65151 .
    # TODO(phajdan.jr): Should we enable this for all of POSIX?
    defines += [ "_GLIBCXX_DEBUG=1" ]
  }

参考:https://toyobayashi.github.io/2020/07/04/V8/