使用Clang编译V8示例代码时v8::internal::Isolate::Exit()触发段错误

问题现象 #

使用GCC编译V8官方的hello-world.cc示例时程序运行正常：

$ g++ -I/path/to/v8/include hello-world.cc -o hello_world -fno-rtti -lv8_monolith -lv8_libbase -lv8_libplatform -ldl -L/path/to/v8/out.gn/x64.release.sample/obj/ -pthread -std=c++20 -DV8_COMPRESS_POINTERS -DV8_ENABLE_SANDBOX -ggdb

$ ./hello_world 
Hello, World!
3 + 4 = 7

但使用Clang编译时，程序执行完业务逻辑后，在v8::Isolate::Scope对象析构阶段触发段错误：

$ clang++ -I/path/to/v8/include hello-world.cc -o hello_world -fno-rtti -lv8_monolith -lv8_libbase -lv8_libplatform -ldl -L/path/to/v8/out.gn/x64.release.sample/obj/ -pthread -std=c++20 -DV8_COMPRESS_POINTERS -DV8_ENABLE_SANDBOX -ggdb

$ ./hello_world 
Hello, World!
3 + 4 = 7
[1]    684462 segmentation fault (core dumped)  ./hello_world

调试信息 #

栈跟踪显示段错误发生在v8::internal::Isolate::Exit()调用流程中：

#0  v8::internal::Isolate::Exit() () at ../../build/linux/debian_bullseye_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/atomic_base.h:747
#1  0x0000555555698c68 in v8::Isolate::Scope::~Scope (this=0x7fffffffd250) at /path/to/v8/include/v8-isolate.h:312
#2  0x00005555556987ff in main (argc=0x1, argv=0x7fffffffd658) at hello-world.cc:96

此时寄存器$rdi指向无效地址0x555500000001，直接导致内存解引用操作失败：

0x55555594514a <v8::internal::Isolate::Exit()+10> push   rbx
   0x55555594514b <v8::internal::Isolate::Exit()+11> sub    rsp, 0x10
   0x55555594514f <v8::internal::Isolate::Exit()+15> mov    r14, rdi
 → 0x555555945152 <v8::internal::Isolate::Exit()+18> mov    rbx, QWORD PTR [rdi+0xf380]
   0x555555945159 <v8::internal::Isolate::Exit()+25> test   rbx, rbx
   0x55555594515c <v8::internal::Isolate::Exit()+28> je     0x55555594523e <_ZN2v88internal7Isolate4ExitEv+254>
   0x555555945162 <v8::internal::Isolate::Exit()+34> mov    rax, QWORD PTR [rbx+0x8]
   0x555555945166 <v8::internal::Isolate::Exit()+38> test   rax, rax
   0x555555945169 <v8::internal::Isolate::Exit()+41> je     0x55555594517d <_ZN2v88internal7Isolate4ExitEv+61>

对比GCC编译版本，调试时$rdi指向有效内存地址0x00555559b21000。

测试环境 #

• V8版本：v12.9、HEAD版本（781c2056824）
• 编译器：Clang 18.1.8、GCC 14.2.1
• 硬件架构：x86_64
• V8 GN构建参数：

dcheck_always_on = false
is_component_build = false
is_debug = true
target_cpu = "x64"
use_custom_libcxx = false
v8_monolithic = true
v8_use_external_startup_data = false

推测这可能是V8的bug，但不确定，寻求可行的解决方案。

内容的提问来源于stack exchange，提问作者captainGeech