2022.11.18 macos c++ gcc, debug to find which line caused the "segment fault"

gist: https://gist.github.com/JaosnHsieh/69ae210db4f43f133a08724882d6adc9

main.cpp

```
#include <iostream>
#include <vector>
using namespace std;

int main(){
  vector<vector<int>> v;
  v[2][2];
  return 0;
}
```


Steps 


```
1. gcc -lstdc++ -std="c++11" ./main.cpp -o main -g  
##compile with -g for debug

2. lldb --file ./main. 
## use lldb instead of gdb ( tried gdb and found no way to get it right )

3. (in lldb repl)
  1. r
  2. bt

after "bt", we can see which lines caused the error


```

messages from lldb , we can see main.cpp:7:3 listed
```
lldb --file ./main
(lldb) target create "./main"
Current executable set to '/Users/jh/git/cpp-test/main' (x86_64).
(lldb) 
Current executable set to '/Users/jh/git/cpp-test/main' (x86_64).
(lldb) r
Process 67186 launched: '/Users/jh/git/cpp-test/main' (x86_64)
Process 67186 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x30)
    frame #0: 0x0000000100003430 main`std::__1::vector<int, std::__1::allocator<int> >::operator[](this=0x0000000000000030 size=0, __n=2) at vector:1572:18
   1569 vector<_Tp, _Allocator>::operator[](size_type __n) _NOEXCEPT
   1570 {
   1571     _LIBCPP_ASSERT(__n < size(), "vector[] index out of bounds");
-> 1572     return this->__begin_[__n];
   1573 }
   1574
   1575 template <class _Tp, class _Allocator>
Target 1: (main) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x30)
  * frame #0: 0x0000000100003430 main`std::__1::vector<int, std::__1::allocator<int> >::operator[](this=0x0000000000000030 size=0, __n=2) at vector:1572:18
    frame #1: 0x00000001000033c3 main`main at main.cpp:7:3
    frame #2: 0x00007ff812929310 dyld`start + 2432
```

from:

https://stackoverflow.com/a/63943980/6414615

https://stackoverflow.com/a/2876374/6414615



tools version 

```
gcc -v
Apple clang version 14.0.0 (clang-1400.0.29.102)
Target: x86_64-apple-darwin22.1.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
```

```
 lldb --version
lldb-1400.0.30.3
Apple Swift version 5.7 (swiftlang-5.7.0.127.4 clang-1400.0.29.50)
```

```
macos 13.0.1
```


gist: https://gist.github.com/JaosnHsieh/69ae210db4f43f133a08724882d6adc9