This is less error-prone.
Supply a mempcpy if the system lacks it.
* Makefile, NEWS: Mention this.
* localtime.c (tzloadbody, tzparse):
* zic.c (random_dirent, relname, doabbr):
* zdump.c (my_snprintf) [!HAVE_SNPRINTF]:
(istrftime):
Prefer mempcpy to doing it by hand.
* private.h (HAVE_MEMPCPY): New macro.
(mempcpy) [!HAVE_MEMPCPY]: New function.
---
Makefile | 1 +
NEWS | 3 +++
localtime.c | 13 +++++++------
private.h | 17 +++++++++++++++++
zdump.c | 11 +++++++----
zic.c | 36 ++++++++++++++++++++----------------
6 files changed, 55 insertions(+), 26 deletions(-)
diff --git a/Makefile b/Makefile
index 83122ecc..5b577781 100644
--- a/Makefile
+++ b/Makefile
@@ -262,6 +262,7 @@ LDLIBS=
# -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz
# localtime_rz can make zdump significantly faster, but is nonstandard.
# -DHAVE_MALLOC_ERRNO=0 if malloc etc. do not set errno on failure.
+# -DHAVE_MEMPCPY=1 if your system has mempcpy, 0 if not (default is guessed)
# -DHAVE_POSIX_DECLS=0 if your system's include files do not declare
# functions like 'link' or variables like 'tzname' required by POSIX
# -DHAVE_SETENV=0 if your system lacks the setenv function
diff --git a/NEWS b/NEWS
index 5c4786cb..0436c615 100644
--- a/NEWS
+++ b/NEWS
@@ -51,6 +51,9 @@ Unreleased, experimental changes
-DHAVE_GETRESUID=[01], and -DHAVE_GETEUID=[01] to enable or
disable these system calls' use.
+ tzcode now uses mempcpy if available, guessing its availability.
+ Compile with -DHAVE_MEMPCPY=1 or 0 to override the guess.
+
tzcode now uses strnlen to improve asymptotic performance a bit.
Compile with -DHAVE_STRNLEN=0 if your platform lacks it.
diff --git a/localtime.c b/localtime.c
index 67500312..316c7504 100644
--- a/localtime.c
+++ b/localtime.c
@@ -624,6 +624,7 @@ tzloadbody(char const *name, struct state *sp, char
tzloadflags,
}
if (!SUPPRESS_TZDIR && name[0] != '/') {
+ char *cp;
if (sizeof lsp->fullname - sizeof tzdirslash
<= strnlen(name, sizeof lsp->fullname - sizeof tzdirslash))
return ENAMETOOLONG;
@@ -631,8 +632,9 @@ tzloadbody(char const *name, struct state *sp, char
tzloadflags,
/* Create a string "TZDIR/NAME". Using sprintf here
would pull in stdio (and would fail if the
resulting string length exceeded INT_MAX!). */
- memcpy(lsp->fullname, tzdirslash, sizeof tzdirslash);
- strcpy(lsp->fullname + sizeof tzdirslash, name);
+ cp = lsp->fullname;
+ cp = mempcpy(cp, tzdirslash, sizeof tzdirslash);
+ strcpy(cp, name);
name = lsp->fullname;
}
@@ -1471,12 +1473,11 @@ tzparse(const char *name, struct state *sp, struct
state const *basep)
}
sp->charcnt = charcnt;
cp = sp->chars;
- memcpy(cp, stdname, stdlen);
- cp += stdlen;
+ cp = mempcpy(cp, stdname, stdlen);
*cp++ = '\0';
if (dstlen != 0) {
- memcpy(cp, dstname, dstlen);
- *(cp + dstlen) = '\0';
+ cp = mempcpy(cp, dstname, dstlen);
+ *cp = '\0';
}
return true;
}
diff --git a/private.h b/private.h
index 6ae0c2fd..867340fa 100644
--- a/private.h
+++ b/private.h
@@ -837,6 +837,23 @@ extern char *asctime_r(struct tm const *restrict, char
*restrict);
extern char **environ;
#endif
+#ifndef HAVE_MEMPCPY
+# if (defined mempcpy \
+ || defined __FreeBSD__ || defined __NetBSD__ || defined __linux__)
+# define HAVE_MEMPCPY 1
+# else
+# define HAVE_MEMPCPY 0
+# endif
+#endif
+#if !HAVE_MEMPCPY
+static void *
+mempcpy(char *restrict s1, char const *restrict s2, size_t n)
+{
+ char *p = memcpy(s1, s2, n);
+ return p + n;
+}
+#endif
+
#if 2 <= HAVE_TZNAME + (TZ_TIME_T || !HAVE_POSIX_DECLS)
extern char *tzname[];
#endif
diff --git a/zdump.c b/zdump.c
index 8e836e60..93fe05cb 100644
--- a/zdump.c
+++ b/zdump.c
@@ -927,6 +927,7 @@ my_snprintf(char *s, size_t size, char const *format, ...)
int n;
va_list args;
char const *arg;
+ char *cp;
size_t arglen, slen;
char buf[1024];
va_start(args, format);
@@ -943,8 +944,9 @@ my_snprintf(char *s, size_t size, char const *format, ...)
arglen = n;
}
slen = arglen < size ? arglen : size - 1;
- memcpy(s, arg, slen);
- s[slen] = '\0';
+ cp = s;
+ cp = mempcpy(cp, arg, slen);
+ *cp = '\0';
n = arglen <= INT_MAX ? arglen : -1;
va_end(args);
return n;
@@ -1073,8 +1075,9 @@ istrftime(char *buf, ptrdiff_t size, char const *time_fmt,
char fbuf[100];
bool oversized = sizeof fbuf <= f_prefix_copy_size;
char *f_prefix_copy = oversized ? xmalloc(f_prefix_copy_size) : fbuf;
- memcpy(f_prefix_copy, f, f_prefix_len);
- strcpy(f_prefix_copy + f_prefix_len, "X");
+ char *cp = f_prefix_copy;
+ cp = mempcpy(cp, f, f_prefix_len);
+ strcpy(cp, "X");
formatted_len = strftime(b, s, f_prefix_copy, tm);
if (oversized)
free(f_prefix_copy);
diff --git a/zic.c b/zic.c
index 6bdb039d..e78dfd47 100644
--- a/zic.c
+++ b/zic.c
@@ -1327,10 +1327,10 @@ random_dirent(char const **name, char **namealloc)
uint_fast64_t unfair_min = - ((UINTMAX_MAX % base__6 + 1) % base__6);
if (!dst) {
- dst = xmalloc(size_sum(dirlen, prefixlen + suffixlen + 1));
- memcpy(dst, src, dirlen);
- memcpy(dst + dirlen, prefix, prefixlen);
- dst[dirlen + prefixlen + suffixlen] = '\0';
+ char *cp = dst = xmalloc(size_sum(dirlen, prefixlen + suffixlen + 1));
+ cp = mempcpy(cp, src, dirlen);
+ cp = mempcpy(cp, prefix, prefixlen);
+ cp[suffixlen] = '\0';
*name = *namealloc = dst;
}
@@ -1430,15 +1430,17 @@ relname(char const *target, char const *linkname)
if (*linkname == '/') {
/* Make F absolute too. */
size_t len = strlen(directory);
- size_t lenslash = len + (len && directory[len - 1] != '/');
+ bool needs_slash = len && directory[len - 1] != '/';
+ size_t lenslash = len + needs_slash;
size_t targetsize = strlen(target) + 1;
+ char *cp;
if (*directory != '/')
return NULL;
linksize = size_sum(lenslash, targetsize);
- f = result = xmalloc(linksize);
- memcpy(result, directory, len);
- result[len] = '/';
- memcpy(result + lenslash, target, targetsize);
+ f = cp = result = xmalloc(linksize);
+ cp = mempcpy(cp, directory, len);
+ *cp = '/';
+ memcpy(cp + needs_slash, target, targetsize);
}
for (i = 0; f[i] && f[i] == linkname[i]; i++)
if (f[i] == '/')
@@ -1448,11 +1450,13 @@ relname(char const *target, char const *linkname)
taillen = strlen(f + dir_len);
dotdotetcsize = size_sum(size_product(dotdots, 3), taillen + 1);
if (dotdotetcsize <= linksize) {
+ char *cp;
if (!result)
result = xmalloc(dotdotetcsize);
+ cp = result;
for (i = 0; i < dotdots; i++)
- memcpy(result + 3 * i, "../", 3);
- memmove(result + 3 * dotdots, f + dir_len, taillen + 1);
+ cp = mempcpy(cp, "../", 3);
+ memmove(cp, f + dir_len, taillen + 1);
}
return result;
}
@@ -2875,11 +2879,11 @@ doabbr(char *abbr, struct zone const *zp, char const
*letters,
else if (letters == disable_percent_s)
return 0;
sprintf(abbr, format, letters);
- } else if (isdst) {
- strcpy(abbr, slashp + 1);
- } else {
- memcpy(abbr, format, slashp - format);
- abbr[slashp - format] = '\0';
+ } else if (isdst)
+ strcpy(abbr, slashp + 1);
+ else {
+ char *abbrend = mempcpy(abbr, format, slashp - format);
+ *abbrend = '\0';
}
len = strlen(abbr);
if (!doquotes)
--
2.48.1
