Development Tools: GDB and LLDB Usage

above line to your shell's init file (e.g. `~/.bashrc` or similar). You can then open the core file in `lldb`: >bash lldb -c /cores/core.12345 < Apple's documentation archive has some other useful information https://developer.apple.com/library/archive/technotes/tn2124/_index.html#//apple_ref/doc/uid/DTS10003391-CH1-SECCOREDUMPS, but note that some of the things on this page are out of date (such as enabling core dumps with `/etc/launchd.conf`). ============================================================================== Gdb *dev-tools-gdb* USING GDB TO STEP THROUGH FUNCTIONAL TESTS Use `TEST_TAG` to run tests matching busted tags (of the form `#foo` e.g. `it("test #foo ...", ...)`): >bash GDB=1 TEST_TAG=foo make functionaltest < Then, in another terminal: >bash gdb build/bin/nvim (gdb) target remote localhost:7777 -- See `nvim_argv` in https://github.com/neovim/neovim/blob/master/test/functional/testnvim.lua. USING LLDB TO STEP THROUGH UNIT TESTS > lldb .deps/usr/bin/luajit -- .deps/usr/bin/busted --lpath="./build/?.lua" test/unit/ < USING GDB To attach to a running `nvim` process with a pid of 1234 (Tip: the pid of a running Nvim instance can be obtained by calling |getpid()|), for instance: >bash gdb -tui -p 1234 build/bin/nvim < The `gdb` interactive prompt will appear. At any time you can: - `break foo` to set a breakpoint on the `foo()` function - `n` to step over the next statement - `<Enter>` to repeat the last command - `s` to step into the next statement - `c` to continue - `finish` to step out of the current function - `p zub` to print the value of `zub` - `bt` to see a backtrace (callstack) from the current location - `CTRL-x CTRL-a` or `tui enable` to show a TUI view of the source file in the current debugging context. This can be extremely useful as it avoids the need for a gdb "frontend". - `<up>` and `<down>` to scroll the source file view GDB REVERSE DEBUGGING - `set record full insn-number-max unlimited` - `continue`

This section details how to use GDB and LLDB for debugging Nvim. It covers using LLDB to open core files on macOS, running functional tests with GDB using `TEST_TAG`, and provides instructions for attaching GDB to a running Nvim process (using its PID). It also includes common GDB commands for stepping through code, setting breakpoints, printing values, viewing backtraces, and using the GDB TUI. Additionally, it briefly mentions how to use GDB for reverse debugging.