https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93024
Bug ID: 93024
Summary: Python Pretty Printers get disabled on executable
reload by GDB
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: gcc at mailinator dot com
Target Milestone: ---
Version:
```
$ gcc --version
gcc (GCC) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gdb --version
GNU gdb (GDB) 8.3.1
Copyright (C) 2019 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.
```
Description:
When the executable changes, `run` will automatically reload the symbol, but
the pretty printer are not reloaded.
GDB session:
```
$ cat <<'eof' >a.cpp
> #include <iostream>
> #include <vector>
> int main() {
> std::vector<int> a{1};
> std::cout<<"";
> }
> eof
$ g++ -g a.cpp -o a
$ gdb -q a
Reading symbols from a...
(gdb) b 5
Breakpoint 1 at 0x1236: file a.cpp, line 5.
(gdb) r
Starting program: /tmp/a
Breakpoint 1, main () at a.cpp:5
5 std::cout<<"";
(gdb) p a
$1 = std::vector of length 1, capacity 1 = {1}
(gdb)
[1]+ Stopped gdb -q a
(failed reverse-i-search)`g+++': ^C+ -g a.cpp -o a
$ g++ -g a.cpp -o a
$ fg %1
(gdb) r
The program being debugged has been started already.
Start it from the beginning? (y or n) y
`/tmp/a' has changed; re-reading symbols.
Starting program: /tmp/a
Breakpoint 1, main () at a.cpp:5
5 std::cout<<"";
(gdb) p a
$3 = {<std::_Vector_base<int, std::allocator<int> >> = {
_M_impl = {<std::allocator<int>> = {<__gnu_cxx::new_allocator<int>> = {<No
data fields>}, <No data fields>}, <std::_Vector_base<int, std::allocator<int>
>::_Vector_impl_data> = {_M_start = 0x55555556aeb0,
_M_finish = 0x55555556aeb4, _M_end_of_storage = 0x55555556aeb4}, <No
data fields>}}, <No data fields>}
```
You can see that the last `p a` command doesn't use the pretty printer.
--------------
Currently, `file a` will work (if used for each recompilation), and `py
register_libstdcxx_printers(None)` will work (only need to call once regardless
of the number of recompilation)
