commit fb8dba413f2bcaa61c15d1854b28112e3e91a035
parent 8ed6f00ab06dbd99ad37da1db0ad0d132865b865
Author: zeertzjq <zeertzjq@outlook.com>
Date: Thu, 19 Jun 2025 10:21:33 +0800
vim-patch:9.1.1467: too many strlen() calls (#34572)
Problem: too many strlen() calls
Solution: Change expand_env() to return string length
(John Marriott)
This commit does the following changes:
- In expand_env_esc():
- return the length of the returned dst string.
- refactor to remove some calls to STRLEN() and STRCAT()
- add check for out-of-memory condition.
- Change call sites in various source files to use the return value
closes: vim/vim#17561
https://github.com/vim/vim/commit/fff0132399082b7d012d0c1291cf0c6c99e200ff
Co-authored-by: John Marriott <basilisk@internode.on.net>
Diffstat:
5 files changed, 45 insertions(+), 31 deletions(-)
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
@@ -1449,11 +1449,10 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
// copy file name into NameBuff, expanding environment variables
char save_char = ptr[len];
ptr[len] = NUL;
- expand_env_esc(ptr, NameBuff, MAXPATHL, false, true, NULL);
+ file_to_findlen = expand_env_esc(ptr, NameBuff, MAXPATHL, false, true, NULL);
ptr[len] = save_char;
xfree(*file_to_find);
- file_to_findlen = strlen(NameBuff);
*file_to_find = xmemdupz(NameBuff, file_to_findlen);
if (options & FNAME_UNESC) {
// Change all "\ " to " ".
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
@@ -58,6 +58,7 @@
#include "nvim/os/fs_defs.h"
#include "nvim/os/input.h"
#include "nvim/os/os.h"
+#include "nvim/os/os_defs.h"
#include "nvim/os/time.h"
#include "nvim/path.h"
#include "nvim/pos_defs.h"
@@ -3275,7 +3276,7 @@ static void vim_mktempdir(void)
mode_t umask_save = umask(0077);
for (size_t i = 0; i < ARRAY_SIZE(temp_dirs); i++) {
// Expand environment variables, leave room for "/tmp/nvim.<user>/XXXXXX/999999999".
- expand_env((char *)temp_dirs[i], tmp, TEMP_FILE_PATH_MAXLEN - 64);
+ size_t tmplen = expand_env((char *)temp_dirs[i], tmp, TEMP_FILE_PATH_MAXLEN - 64);
if (!os_isdir(tmp)) {
if (strequal("$TMPDIR", temp_dirs[i])) {
if (!os_env_exists("TMPDIR", true)) {
@@ -3288,9 +3289,13 @@ static void vim_mktempdir(void)
}
// "/tmp/" exists, now try to create "/tmp/nvim.<user>/".
- add_pathsep(tmp);
- xstrlcat(tmp, "nvim.", sizeof(tmp));
- xstrlcat(tmp, user, sizeof(tmp));
+ if (!after_pathsep(tmp, tmp + tmplen)) {
+ tmplen += (size_t)vim_snprintf(tmp + tmplen, sizeof(tmp) - tmplen, PATHSEPSTR);
+ assert(tmplen < sizeof(tmp));
+ }
+ tmplen += (size_t)vim_snprintf(tmp + tmplen, sizeof(tmp) - tmplen,
+ "nvim.%s", user);
+ assert(tmplen < sizeof(tmp));
os_mkdir(tmp, 0700); // Always create, to avoid a race.
bool owned = os_file_owned(tmp);
bool isdir = os_isdir(tmp);
@@ -3301,7 +3306,10 @@ static void vim_mktempdir(void)
bool valid = isdir && owned; // TODO(justinmk): Windows ACL?
#endif
if (valid) {
- add_pathsep(tmp);
+ if (!after_pathsep(tmp, tmp + tmplen)) {
+ tmplen += (size_t)vim_snprintf(tmp + tmplen, sizeof(tmp) - tmplen, PATHSEPSTR);
+ assert(tmplen < sizeof(tmp));
+ }
} else {
if (!owned) {
ELOG("tempdir root not owned by current user (%s): %s", user, tmp);
@@ -3315,11 +3323,15 @@ static void vim_mktempdir(void)
#endif
// If our "root" tempdir is invalid or fails, proceed without "<user>/".
// Else user1 could break user2 by creating "/tmp/nvim.user2/".
- tmp[strlen(tmp) - strlen(user)] = NUL;
+ tmplen -= strlen(user);
+ tmp[tmplen] = NUL;
}
// Now try to create "/tmp/nvim.<user>/XXXXXX".
- xstrlcat(tmp, "XXXXXX", sizeof(tmp)); // mkdtemp "template", will be replaced with random alphanumeric chars.
+ // "XXXXXX" is mkdtemp "template", will be replaced with random alphanumeric chars.
+ tmplen += (size_t)vim_snprintf(tmp + tmplen, sizeof(tmp) - tmplen, "XXXXXX");
+ assert(tmplen < sizeof(tmp));
+ (void)tmplen;
int r = os_mkdtemp(tmp, path);
if (r != 0) {
WLOG("tempdir create failed: %s: %s", os_strerror(r), tmp);
diff --git a/src/nvim/mark.c b/src/nvim/mark.c
@@ -722,10 +722,8 @@ static void fname2fnum(xfmark_T *fm)
#else
if (fm->fname[0] == '~' && (fm->fname[1] == '/')) {
#endif
-
- expand_env("~/", NameBuff, MAXPATHL);
- int len = (int)strlen(NameBuff);
- xstrlcpy(NameBuff + len, fm->fname + 2, (size_t)(MAXPATHL - len));
+ size_t len = expand_env("~/", NameBuff, MAXPATHL);
+ xstrlcpy(NameBuff + len, fm->fname + 2, MAXPATHL - len);
} else {
xstrlcpy(NameBuff, fm->fname, MAXPATHL);
}
diff --git a/src/nvim/os/env.c b/src/nvim/os/env.c
@@ -577,9 +577,9 @@ char *expand_env_save_opt(char *src, bool one)
/// @param src Input string e.g. "$HOME/vim.hlp"
/// @param dst[out] Where to put the result
/// @param dstlen Maximum length of the result
-void expand_env(char *src, char *dst, int dstlen)
+size_t expand_env(char *src, char *dst, int dstlen)
{
- expand_env_esc(src, dst, dstlen, false, false, NULL);
+ return expand_env_esc(src, dst, dstlen, false, false, NULL);
}
/// Expand environment variable with path name and escaping.
@@ -591,8 +591,8 @@ void expand_env(char *src, char *dst, int dstlen)
/// @param esc Escape spaces in expanded variables
/// @param one `srcp` is a single filename
/// @param prefix Start again after this (can be NULL)
-void expand_env_esc(const char *restrict srcp, char *restrict dst, int dstlen, bool esc, bool one,
- char *prefix)
+size_t expand_env_esc(const char *restrict srcp, char *restrict dst, int dstlen, bool esc, bool one,
+ char *prefix)
FUNC_ATTR_NONNULL_ARG(1, 2)
{
char *tail;
@@ -600,6 +600,7 @@ void expand_env_esc(const char *restrict srcp, char *restrict dst, int dstlen, b
bool copy_char;
bool mustfree; // var was allocated, need to free it later
bool at_start = true; // at start of a name
+ char *const dst_start = dst;
int prefix_len = (prefix == NULL) ? 0 : (int)strlen(prefix);
@@ -731,23 +732,24 @@ void expand_env_esc(const char *restrict srcp, char *restrict dst, int dstlen, b
mustfree = true;
}
- if (var != NULL && *var != NUL
- && (strlen(var) + strlen(tail) + 1 < (unsigned)dstlen)) {
- STRCPY(dst, var);
- dstlen -= (int)strlen(var);
+ if (var != NULL && *var != NUL) {
int c = (int)strlen(var);
- // if var[] ends in a path separator and tail[] starts
- // with it, skip a character
- if (after_pathsep(dst, dst + c)
+ if ((size_t)c + strlen(tail) + 1 < (unsigned)dstlen) {
+ STRCPY(dst, var);
+ dstlen -= c;
+ // if var[] ends in a path separator and tail[] starts
+ // with it, skip a character
+ if (after_pathsep(dst, dst + c)
#if defined(BACKSLASH_IN_FILENAME)
- && dst[c - 1] != ':'
+ && dst[c - 1] != ':'
#endif
- && vim_ispathsep(*tail)) {
- tail++;
+ && vim_ispathsep(*tail)) {
+ tail++;
+ }
+ dst += c;
+ src = tail;
+ copy_char = false;
}
- dst += c;
- src = tail;
- copy_char = false;
}
if (mustfree) {
xfree(var);
@@ -778,6 +780,8 @@ void expand_env_esc(const char *restrict srcp, char *restrict dst, int dstlen, b
}
}
*dst = NUL;
+
+ return (size_t)(dst - dst_start);
}
/// Check if the directory "vimdir/<version>" or "vimdir/runtime" exists.
diff --git a/src/nvim/shada.c b/src/nvim/shada.c
@@ -1314,8 +1314,9 @@ static char *shada_filename(const char *file)
// because various expansions must have already be done by the shell.
// If shell is not performing them then they should be done in main.c
// where arguments are parsed, *not here*.
- expand_env((char *)file, &(NameBuff[0]), MAXPATHL);
+ size_t len = expand_env((char *)file, &(NameBuff[0]), MAXPATHL);
file = &(NameBuff[0]);
+ return xmemdupz(file, len);
}
}
return xstrdup(file);
