stella.stemenova mentioned in https://reviews.llvm.org/D93951 failures on Windows for this test.
I'm fixing the macro definitions and disabling the tests for python
versions lower than 3.7. I'll figure out that actual issue with
python3.6 after the buildbots are fine again.
Depends on D93874.
runInTerminal was using --wait-for, but it was some problems because it uses process polling looking for a single instance of the debuggee:
- it gets to know of the target late, which renders breakpoints in the main function almost impossible
- polling might fail if there are already other processes with the same name
- polling might also fail on some linux machine, as it's implemented with the ps command, and the ps command's args and output are not standard everywhere
As a better way to implement this so that it works well on Darwin and Linux, I'm using now the following process:
- lldb-vscode notices the runInTerminal, so it spawns lldb-vscode with a special flag --launch-target <target>. This flags tells lldb-vscode to wait to be attached and then it execs the target program. I'm using lldb-vscode itself to do this, because it makes finding the launcher program easier. Also no CMAKE INSTALL scripts are needed.
- Besides this, the debugger creates a temporary FIFO file where the launcher program will write its pid to. That way the debugger will be sure of which program to attach.
- Once attach happend, the debugger creates a second temporary file to notify the launcher program that it has been attached, so that it can then exec. I'm using this instead of using a signal or a similar mechanism because I don't want the launcher program to wait indefinitely to be attached in case the debugger crashed. That would pollute the process list with a lot of hanging processes. Instead, I'm setting a 20 seconds timeout (that's an overkill) and the launcher program seeks in intervals the second tepmorary file.
Some notes:
- I preferred not to use sockets because it requires a lot of code and I only need a pid. It would also require a lot of code when windows support is implemented.
- I didn't add Windows support, as I don't have a windows machine, but adding support for it should be easy, as the FIFO file can be implemented with a named pipe, which is standard on Windows and works pretty much the same way.
The existing test which didn't pass on Linux, now passes.
Differential Revision: https://reviews.llvm.org/D93951
Walter Erquinigo