Mercurial > vim
view src/create_nvcmdidxs.vim @ 34309:d7cfd8fb1d75 v9.1.0089
patch 9.1.0089: qsort() comparison functions should be transitive
Commit: https://github.com/vim/vim/commit/e06e43766500ecb4cd1031fa16cf9cbebdb222c1
Author: Christian Brabandt <cb@256bit.org>
Date: Fri Feb 9 19:39:14 2024 +0100
patch 9.1.0089: qsort() comparison functions should be transitive
Problem: qsort() comparison functions should be transitive
Solution: Do not subtract values, but rather use explicit comparisons
Improve qsort() comparison functions
There has been a recent report on qsort() causing out-of-bounds read &
write in glibc for non transitive comparison functions
https://www.qualys.com/2024/01/30/qsort.txt
Even so the bug is in glibc's implementation of the qsort() algorithm,
it's bad style to just use substraction for the comparison functions,
which may cause overflow issues and as hinted at in OpenBSD's manual
page for qsort(): "It is almost always an error to use subtraction to
compute the return value of the comparison function."
So check the qsort() comparison functions and change them to be safe.
closes: #13980
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Fri, 09 Feb 2024 19:45:06 +0100 |
parents | ee1019e59bef |
children |
line wrap: on
line source
" This script generates the table nv_cmd_idx[] which contains the index in " nv_cmds[] table (normal.c) for each of the command character supported in " normal/visual mode. " This is used to speed up the command lookup in nv_cmds[]. " " Script should be run using "make nvcmdidxs", every time the nv_cmds[] table " in src/nv_cmds.h changes. " " This is written in legacy Vim script so that it can be run by a slightly " older Vim version. " Generate the table of normal/visual mode command characters and their " corresponding index. let cmd = 'create_nvcmdidxs' if has('unix') let cmd = './' .. cmd endif let nv_cmdtbl = systemlist(cmd)->map({i, ch -> {'idx': i, 'cmdchar': ch}}) " sort the table by the command character call sort(nv_cmdtbl, {a, b -> a.cmdchar - b.cmdchar}) " Compute the highest index upto which the command character can be directly " used as an index. let nv_max_linear = 0 for i in range(nv_cmdtbl->len()) if i != nv_cmdtbl[i].cmdchar let nv_max_linear = i - 1 break endif endfor " Generate a header file with the table let output =<< trim END /* * Automatically generated code by the create_nvcmdidxs.vim script. * * Table giving the index in nv_cmds[] to lookup based on * the command character. */ // nv_cmd_idx[<normal mode command character>] => nv_cmds[] index static const unsigned short nv_cmd_idx[] = { END " Add each command character in comment and the corresponding index let output += nv_cmdtbl->map({_, v -> \ printf(' /* %5d */ %3d,', v.cmdchar, v.idx)}) let output += ['};', '', \ '// The highest index for which', \ '// nv_cmds[idx].cmd_char == nv_cmd_idx[nv_cmds[idx].cmd_char]'] let output += ['static const int nv_max_linear = ' .. nv_max_linear .. ';'] call writefile(output, "nv_cmdidxs.h") quit " vim: shiftwidth=2 sts=2 expandtab