| *debug.txt* Nvim | |
| VIM REFERENCE MANUAL by Bram Moolenaar | |
| Debugging Vim *debug-vim* | |
| This is for debugging Vim itself, when it doesn't work properly. | |
| For debugging Vim scripts, functions, etc. see |debug-scripts| | |
| Type |gO| to see the table of contents. | |
| ============================================================================== | |
| 1. Location of a crash, using gcc and gdb *debug-gcc* *gdb* | |
| When Vim crashes in one of the test files, and you are using gcc for | |
| compilation, here is what you can do to find out exactly where Vim crashes. | |
| This also applies when using the MingW tools. | |
| 1. Compile Vim with the "-g" option (there is a line in the src/Makefile for | |
| this, which you can uncomment). Also make sure "strip" is disabled (do not | |
| install it, or use the line "STRIP = /bin/true"). | |
| 2. Execute these commands (replace "11" with the test that fails): > | |
| cd testdir | |
| gdb ../vim | |
| run -u unix.vim -U NONE -s dotest.in test11.in | |
| 3. Check where Vim crashes, gdb should give a message for this. | |
| 4. Get a stack trace from gdb with this command: > | |
| where | |
| < You can check out different places in the stack trace with: > | |
| frame 3 | |
| < Replace "3" with one of the numbers in the stack trace. | |
| ============================================================================== | |
| 2. Locating memory leaks *debug-leaks* *valgrind* | |
| If you suspect Vim is leaking memory and you are using Linux, the valgrind | |
| tool is very useful to pinpoint memory leaks. | |
| First of all, build Vim with EXITFREE defined. Search for this in MAKEFILE | |
| and uncomment the line. | |
| Use this command to start Vim: | |
| > | |
| valgrind --log-file=valgrind.log --leak-check=full ./vim | |
| Note: Vim will run much slower. If your vimrc is big or you have several | |
| plugins you need to be patient for startup, or run with the "-u NONE" | |
| argument. | |
| There are often a few leaks from libraries, such as getpwuid() and | |
| XtVaAppCreateShell(). Those are unavoidable. The number of bytes should be | |
| very small a Kbyte or less. | |
| ============================================================================== | |
| 3. Windows Bug Reporting *debug-win32* | |
| If the Windows version of Vim crashes in a reproducible manner, you can take | |
| some steps to provide a useful bug report. | |
| 3.1 GENERIC ~ | |
| You must obtain the debugger symbols (PDB) file for your executable: gvim.pdb | |
| for gvim.exe, or vim.pdb for vim.exe. The PDB should be available from the | |
| same place that you obtained the executable. Be sure to use the PDB that | |
| matches the EXE (same date). | |
| If you built the executable yourself with the Microsoft Visual C++ compiler, | |
| then the PDB was built with the EXE. | |
| If you have Visual Studio, use that instead of the VC Toolkit and WinDbg. | |
| For other compilers, you should always use the corresponding debugger: gdb | |
| (see above |debug-gcc|) for the Cygwin and MinGW compilers. | |
| *debug-vs2005* | |
| 3.2 Debugging Vim crashes with Visual Studio 2005/Visual C++ 2005 Express ~ | |
| First launch vim.exe or gvim.exe and then launch Visual Studio. (If you don't | |
| have Visual Studio, follow the instructions at |get-ms-debuggers| to obtain a | |
| free copy of Visual C++ 2005 Express Edition.) | |
| On the Tools menu, click Attach to Process. Choose the Vim process. | |
| In Vim, reproduce the crash. A dialog will appear in Visual Studio, telling | |
| you about the unhandled exception in the Vim process. Click Break to break | |
| into the process. | |
| Visual Studio will pop up another dialog, telling you that no symbols are | |
| loaded and that the source code cannot be displayed. Click OK. | |
| Several windows will open. Right-click in the Call Stack window. Choose Load | |
| Symbols. The Find Symbols dialog will open, looking for (g)vim.pdb. Navigate | |
| to the directory where you have the PDB file and click Open. | |
| At this point, you should have a full call stack with vim function names and | |
| line numbers. Double-click one of the lines and the Find Source dialog will | |
| appear. Navigate to the directory where the Vim source is (if you have it.) | |
| If you don't know how to debug this any further, follow the instructions | |
| at ":help bug-report". Paste the call stack into the bug report. | |
| If you have a non-free version of Visual Studio, you can save a minidump via | |
| the Debug menu and send it with the bug report. A minidump is a small file | |
| (<100KB), which contains information about the state of your process. | |
| Visual C++ 2005 Express Edition cannot save minidumps and it cannot be | |
| installed as a just-in-time debugger. Use WinDbg, |debug-windbg|, if you | |
| need to save minidumps or you want a just-in-time (postmortem) debugger. | |
| *debug-windbg* | |
| 3.3 Debugging Vim crashes with WinDbg ~ | |
| See |get-ms-debuggers| to obtain a copy of WinDbg. | |
| As with the Visual Studio IDE, you can attach WinDbg to a running Vim process. | |
| You can also have your system automatically invoke WinDbg as a postmortem | |
| debugger. To set WinDbg as your postmortem debugger, run "windbg -I". | |
| To attach WinDbg to a running Vim process, launch WinDbg. On the File menu, | |
| choose Attach to a Process. Select the Vim process and click OK. | |
| At this point, choose Symbol File Path on the File menu, and add the folder | |
| containing your Vim PDB to the sympath. If you have Vim source available, | |
| use Source File Path on the File menu. You can now open source files in WinDbg | |
| and set breakpoints, if you like. Reproduce your crash. WinDbg should open the | |
| source file at the point of the crash. Using the View menu, you can examine | |
| the call stack, local variables, watch windows, and so on. | |
| If WinDbg is your postmortem debugger, you do not need to attach WinDbg to | |
| your Vim process. Simply reproduce the crash and WinDbg will launch | |
| automatically. As above, set the Symbol File Path and the Source File Path. | |
| To save a minidump, type the following at the WinDbg command line: > | |
| .dump vim.dmp | |
| < | |
| *debug-minidump* | |
| 3.4 Opening a Minidump ~ | |
| If you have a minidump file, you can open it in Visual Studio or in WinDbg. | |
| In Visual Studio 2005: on the File menu, choose Open, then Project/Solution. | |
| Navigate to the .dmp file and open it. Now press F5 to invoke the debugger. | |
| Follow the instructions in |debug-vs2005| to set the Symbol File Path. | |
| In WinDbg: choose Open Crash Dump on the File menu. Follow the instructions in | |
| |debug-windbg| to set the Symbol File Path. | |
| *get-ms-debuggers* | |
| 3.5 Obtaining Microsoft Debugging Tools ~ | |
| Visual Studio 2017 Community Edition can be downloaded for free from: | |
| https://visualstudio.microsoft.com/downloads/ | |
| ========================================================================= | |
| vim:tw=78:ts=8:noet:ft=help:norl: | |