#include <iostream>

class A
{
public:
    A() : c(0)
    {
        std::cout << "A::A()" << std::endl;
        func2();
    };
    void func2() { std::cout <<"A::func2()" << std::endl; };
private:
    int c;
};

int main(void)
{
    A a1;
    A a2;
    
    return 0;
}

GNU gdb (Ubuntu 12.1-0ubuntu1~22.04) 12.1
Copyright (C) 2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./a.out...
(gdb) b 22
Breakpoint 1 at 0x11fc: file basic.cpp, line 22.
(gdb) run
Starting program: /mnt/work/cs-note-src/src/cpp/memory/a.out
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
A::A()
A::func2()
A::A()
A::func2()

Breakpoint 1, main () at basic.cpp:22
22          return 0;
(gdb) info vtbl a1
This object does not have a virtual function table
(gdb)
This object does not have a virtual function table
(gdb) p a
$1 = {i = {0, 1045149306}, x = 1.2904777690891933e-08, d = 1.2904777690891933e-08}
(gdb) p a1
$2 = {c = 0}
(gdb) p a2
$3 = {c = 0}
(gdb) p &a1
$4 = (A *) 0x7fffffffe250
(gdb) p &a2
$5 = (A *) 0x7fffffffe254
(gdb) p typeid(a1)
could not find typeinfo symbol for 'A'
(gdb) info address A::func2
Symbol "A::func2()" is a function at address 0x5555555552da.
(gdb) info symbo A::func2
A::func2() in section .text of /mnt/work/cs-note-src/src/cpp/memory/a.out
(gdb)

0x555555557d80        0x000055555555603c
0x555555557d78        0x00007ffff7fa2fa0
0x555555557d70        0x0000555555555366
0x555555557d68        0x00005555555552ea

#include <iostream>

class A
{
public:
    A() : c(0)
    {
        std::cout << "A::A()" << std::endl;
        func2();
    };
    virtual void virtual_func1() { std::cout << "A::virtual_func1()" << std::endl;};
    void func2() { std::cout <<"A::func2()" << std::endl; };
    virtual void virtual_func3() { std::cout << "A::virtual_func3()" << std::endl;};
private:
    int c;
};

class B : public A
{
public:
    B() : a(0), b(0)
    {
        std::cout << "B::B()" << std::endl;
        func2();
    }
    B(int a, int b) : a(a), b(b)
    {
        std::cout << "B::B(int a, int b)" << std::endl;
        func2();
    }
    ~B() { std::cout << "B::~B()" << std::endl; };
    virtual void virtual_fun1() { std::cout <<"B::virtual_fun1()" << std::endl; };
    void func2() { std::cout <<"B::func2()" << std::endl; };
    virtual void virtual_func3() { std::cout << "B::virtual_func3()" << std::endl;};
private:
    int a;
    int b;
};

int main(void)

{
    A a1;
    A a2;
    B b1;
    B b2;

    return 0;

}

(gdb) b 48
Breakpoint 1 at 0x1235: file ./inheritance.cpp, line 48.
(gdb) run
Starting program: /mnt/work/cs-note-src/src/cpp/memory/inheritance
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
A::A()
A::func2()
A::A()
A::func2()
A::A()
A::func2()
B::B()
B::func2()
A::A()
A::func2()
B::B()
B::func2()

Breakpoint 1, main () at ./inheritance.cpp:48
48          return 0;
(gdb) p b1
$1 = {<A> = {_vptr.A = 0x555555557d10 <vtable for B+16>, c = 0}, a = 0, b = 0}
(gdb) p b2
$2 = {<A> = {_vptr.A = 0x555555557d10 <vtable for B+16>, c = 0}, a = 0, b = 0}
(gdb) p &b1
$3 = (B *) 0x7fffffffe210
(gdb) p &b2
$4 = (B *) 0x7fffffffe230
(gdb) p typeid(b1)
$5 = {_vptr.type_info = 0x7ffff7fa3c30 <vtable for __cxxabiv1::__si_class_type_info+16>, __name = 0x55555555607b <typeinfo name for B> "1B"}
(gdb) p typeid(b2)
$6 = {_vptr.type_info = 0x7ffff7fa3c30 <vtable for __cxxabiv1::__si_class_type_info+16>, __name = 0x55555555607b <typeinfo name for B> "1B"}
(gdb) info vtbr b1
Undefined info command: "vtbr b1".  Try "help info".
(gdb) info vtbl b1
vtable for 'B' @ 0x555555557d10 (subobject @ 0x7fffffffe210):
[0]: 0x555555555362 <A::virtual_func1()>
[1]: 0x55555555555e <B::virtual_func3()>
[2]: 0x5555555554e2 <B::virtual_fun1()>
(gdb) p &typeid(b1)
$7 = (gdb_gnu_v3_type_info *) 0x555555557d48 <typeinfo for B>
(gdb) x /16xg 0x555555557d10
0x555555557d10 <_ZTV1B+16>:     0x0000555555555362      0x000055555555555e
0x555555557d20 <_ZTV1B+32>:     0x00005555555554e2      0x0000000000000000
0x555555557d30 <_ZTV1A+8>:      0x0000555555557d60      0x0000555555555362
0x555555557d40 <_ZTV1A+24>:     0x00005555555553de      0x00007ffff7fa3c30
0x555555557d50 <_ZTI1B+8>:      0x000055555555607b      0x0000555555557d60
0x555555557d60 <_ZTI1A>:        0x00007ffff7fa2fa0      0x000055555555607e
0x555555557d70: 0x0000000000000001      0x00000000000001b6
0x555555557d80: 0x0000000000000001      0x00000000000001c5

0x555555557d68       0x000055555555607e  --> typeid(a)  __name = 1A
0x555555557d60       0x00007ffff7fa2fa0  --> typeid(a) _vptr.type_info
0x555555557d58       0x0000555555557d60
0x555555557d50       0x000055555555607b  --> typeid(b)  __name = 1B
0x555555557d48       0x00007ffff7fa3c30  --> typeid(b) _vptr.type_info
0x555555557d40       0x00005555555553de  --> A::virtual_func3()
0x555555557d38       0x0000555555555362  --> A::virtual_func1()
0x555555557d30       0x0000555555557d60
0x555555557d28       0x0000000000000000
0x555555557d20       0x00005555555554e2  --> B::virtual_fun1()
0x555555557d18       0x000055555555555e  --> B::virtual_func3()
0x555555557d10       0x0000555555555362  --> A::virtual_func1()

# 启动时直接attach到一个进程
gdb -p PID

# 在gdb环境中 attach一个进程
（gdb） attach PID

display expression

gdb ./program core
bt
where
f 3

gdb -exec-run-mode non-stop your_program

gdb -record record_file_name your_program

gdb -replay record_file_name

#include <iostream>
#include <pthread.h>
#include <signal.h>

void printSigInfo(int signo, siginfo_t* info, void* context)
{
    std::cout << "Signal Info:" << std::endl;
    std::cout << "  si_signo: " << info->si_signo << " - Signal number" << std::endl;
    std::cout << "  si_code: " << info->si_code << " - Signal code" << std::endl;
    std::cout << "  si_errno: " << info->si_errno << " - Errno value associated with signal" << std::endl;
    if (info->si_code > 0 && info->si_code < NSIG) { // 可能需要针对具体情况进行检查
        std::cout << "  si_pid: " << info->si_pid << " - Sending process ID" << std::endl;
        std::cout << "  si_uid: " << info->si_uid << " - Real user ID of sending process" << std::endl;
        if (info->si_addr) {
            std::cout << "  si_addr: " << static_cast<void*>(info->si_addr) << " - Faulting address" << std::endl;
        }
    }
}

void LinuxSigHandler(int signo, siginfo_t* info, void* context)
{
    switch (signo) {
        case SIGABRT:
            std::cout << "Caught signal SIGABRT (" << signo << ")." << std::endl;
            printSigInfo (signo, info, context);
            break;
        case SIGTERM:
            std::cout << "Caught signal SIGTERM (" << signo << ")." << std::endl;
            printSigInfo (signo, info, context);
            pthread_exit(0);
            break;

        default:
            std::cout << "Caught signal " << signo << std::endl;
            break;
    }

    // 重新引发信号
    raise(signo);
}

void InitSignalHandlers(void)
{
    struct sigaction action;
    action.sa_handler = NULL;
    action.sa_sigaction = LinuxSigHandler;
    sigemptyset (&action.sa_mask);
    action.sa_flags = (typeof(action.sa_flags))(SA_RESTART | SA_SIGINFO | SA_RESETHAND);
    sigaction (SIGSEGV, &action, NULL);
    sigaction (SIGILL, &action, NULL);
    sigaction (SIGFPE, &action, NULL);
    sigaction (SIGBUS, &action, NULL);
    sigaction (SIGABRT, &action, NULL);
    sigaction (SIGTERM, &action, NULL);
    /* Ignored signals. */
    struct sigaction action_ignore;
    action_ignore.sa_handler = SIG_IGN;
    action_ignore.sa_flags = 0;
    sigemptyset (&action_ignore.sa_mask);
    sigaction (SIGPIPE, &action_ignore, NULL);
}

void main_thread()
{
    for (;;)
    {
        std::cout << "main_thread is running:" << std::endl;
        sleep(10);
    }
}

int main()
{
    InitSignalHandlers();
    try {
        main_thread();
    } catch (const std::exception& e) {
        std::cerr << "Caught exception: " << e.what() << std::endl;
    }
    catch (...) {
        std::cerr << "Caught unknown exception" << std::endl;
    }
    std::cerr << "process close" << std::endl;
    return 0;
}

g++ abi.cpp -o abi

./abi
main_thread is running:
main_thread is running:

ps -ef | grep abi
tlj       980622  976483  0 08:36 pts/0    00:00:00 ./abi
$ kill -SIGTERM 980622

./abi
main_thread is running:
main_thread is running:
Caught signal SIGTERM (15).
Signal Info:
  si_signo: 15 - Signal number
  si_code: 0 - Signal code
  si_errno: 0 - Errno value associated with signal
Caught unknown exception
FATAL: exception not rethrown
Caught signal SIGABRT (6).
Signal Info:
  si_signo: 6 - Signal number
  si_code: -6 - Signal code
  si_errno: 0 - Errno value associated with signal
Aborted (core dumped)

Caught unknown exception

ulimit -c unlimited
echo "/var/crash/core-%e-%p-%t" > /proc/sys/kernel/core_pattern

root@ubuntu:/mnt/work/cs-note-src/src/cpp/debug# gdb ./abi core_abi_2262_1712044154
GNU gdb (Ubuntu 12.1-0ubuntu1~22.04) 12.1
Copyright (C) 2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./abi...
[New LWP 2262]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `./abi'.
Program terminated with signal SIGABRT, Aborted.
#0  __pthread_kill_implementation (no_tid=0, signo=6, threadid=139802159551424) at ./nptl/pthread_kill.c:44
44      ./nptl/pthread_kill.c: No such file or directory.
(gdb)
(gdb) bt
#0  __pthread_kill_implementation (no_tid=0, signo=6, threadid=139802159551424) at ./nptl/pthread_kill.c:44
#1  __pthread_kill_internal (signo=6, threadid=139802159551424) at ./nptl/pthread_kill.c:78
#2  __GI___pthread_kill (threadid=139802159551424, signo=signo@entry=6) at ./nptl/pthread_kill.c:89
#3  0x00007f263a21b476 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#4  0x00007f263a2017f3 in __GI_abort () at ./stdlib/abort.c:79
#5  0x00007f263a2623dc in __libc_message (action=do_abort, fmt=0x7f263a3b479c "%s", fmt=0x7f263a3b479c "%s", action=do_abort)
    at ../sysdeps/posix/libc_fatal.c:155
#6  0x00007f263a2626f0 in __GI___libc_fatal (message=<optimized out>) at ../sysdeps/posix/libc_fatal.c:164
#7  0x00007f263a2763f6 in unwind_cleanup (reason=<optimized out>, exc=<optimized out>) at ./nptl/unwind.c:114
#8  0x0000562cea54094f in main () at new_abi.cpp:85
(gdb)

root@ubuntu:/mnt/work/cs-note-src/src/cpp/debug# ./abi
main_thread is running:
Caught signal SIGTERM (15).
Signal Info:
  si_signo: 15 - Signal number
  si_code: 0 - Signal code
  si_errno: 0 - Errno value associated with signal

#include <iostream>
#include <string>
#include <memory>

using namespace std;

class A
{
public:
    A (int a) : a(a) { cout << "A::A(): " << a << endl; }
    virtual ~A() { cout << "A::~A(): " << a << endl; }
    void disp() { cout <<"A disp" << endl; }
private:
    int a;
};

class B : public A
{
public:
    B (int a, const string &b) : A(a), b(b) { cout << "B::B(): " << b << endl; }
    ~B() { cout << "B::~B(): " << b << endl; }
    void disp() { cout <<"B disp" << endl; }
private:
    int a;
    string b;
};

void f1()
{
    cout << "f1() Start " << endl;
    B b1(1, "stack object");
    A *P = new B(2, "heap object");
    shared_ptr<A> p2 = make_shared<B>(3, "shared ptr object");  
    throw 100;
    cout << "f1() End " << endl;
}

void f2()
{
    cout << "f2() Start " << endl;
    f1();
    cout << "f2() End " << endl;
}

void f3()
{
    cout << "f3() Start " << endl;
    try {
        f2();
    }
    catch (int i) {
        cout << "Caught Exception: " << i << endl;
    }
    cout << "f3() End" << endl;
}

int main()
{
    f3();
    return 0;
}

f3() Start
f2() Start
f1() Start
A::A(): 1
B::B(): stack object
A::A(): 2
B::B(): heap object
A::A(): 3
B::B(): shared ptr object
B::~B(): shared ptr object
A::~A(): 3
B::~B(): stack object
A::~A(): 1
Caught Exception: 100
f3() End

// https://github.com/lattera/glibc/blob/master/nptl/unwind.c
static void
unwind_cleanup (_Unwind_Reason_Code reason, struct _Unwind_Exception *exc)
{
  /* When we get here a C++ catch block didn't rethrow the object.  We
     cannot handle this case and therefore abort.  */
  __libc_fatal ("FATAL: exception not rethrown\n");
}

int main()
{
    InitSignalHandlers();
    try {
        main_thread();
    } catch (const std::exception& e) {
        std::cerr << "Caught exception: " << e.what() << std::endl;
    }
	catch (abi::_forced_unwind&) {
		std::cerr << "Caught forced_unwid error and retrow it" << std::endl;
		throw;
	}
    catch (...) {
        std::cerr << "Caught unknown exception" << std::endl;
    }
    std::cerr << "process close" << std::endl;
    return 0;
}

main_thread is running:
main_thread is running:
Caught signal SIGTERM (15).
Signal Info:
  si_signo: 15 - Signal number
  si_code: 0 - Signal code
  si_errno: 0 - Errno value associated with signal
Caught forced_unwid error and retrow it

int ioctl(int fd, unsigned long op, ...);  /* glibc, BSD */