commit 0eb6aa4013051c8c0148c09d8c85ee7cbdc96f42
parent 7f5c31cdcac5388b3c48a26112dfb6d2cadb7321
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 24 Jul 2019 15:01:32 -0300
Some improvements in date/time functions
- Range in date table extended to full 32 bits.
- Easier support for times represented as floats.
- Added more tests.
Diffstat:
M | loslib.c | | | 76 | ++++++++++++++++++++++++++++++++++++++++++++++++---------------------------- |
M | testes/files.lua | | | 65 | ++++++++++++++++++++++++++++++++++++++++++++++++++++------------- |
2 files changed, 100 insertions(+), 41 deletions(-)
diff --git a/loslib.c b/loslib.c
@@ -58,18 +58,20 @@
** ===================================================================
*/
-#if !defined(l_time_t) /* { */
/*
** type to represent time_t in Lua
*/
+#if !defined(LUA_NUMTIME) /* { */
+
#define l_timet lua_Integer
#define l_pushtime(L,t) lua_pushinteger(L,(lua_Integer)(t))
+#define l_gettime(L,arg) luaL_checkinteger(L, arg)
-static time_t l_checktime (lua_State *L, int arg) {
- lua_Integer t = luaL_checkinteger(L, arg);
- luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
- return (time_t)t;
-}
+#else /* }{ */
+
+#define l_timet lua_Number
+#define l_pushtime(L,t) lua_pushnumber(L,(lua_Number)(t))
+#define l_gettime(L,arg) luaL_checknumber(L, arg)
#endif /* } */
@@ -193,11 +195,25 @@ static int os_clock (lua_State *L) {
** =======================================================
*/
-static void setfield (lua_State *L, const char *key, int value) {
- lua_pushinteger(L, value);
+/*
+** About the overflow check: an overflow cannot occurr when time
+** is represented by a lua_Integer, because either lua_Integer is
+** large enough to represent all int fields or it is not large enough
+** to represent a time that cause a field to overflow. However, if
+** times are represented as doubles and lua_Integer is int, then the
+** time 0x1.e1853b0d184f6p+55 would cause an overflow when adding 1900
+** to compute the year.
+*/
+static void setfield (lua_State *L, const char *key, int value, int delta) {
+ #if (defined(LUA_NUMTIME) && LUA_MAXINTEGER <= INT_MAX)
+ if (value > LUA_MAXINTEGER - delta)
+ luaL_error(L, "field '%s' is out-of-bound", key);
+ #endif
+ lua_pushinteger(L, (lua_Integer)value + delta);
lua_setfield(L, -2, key);
}
+
static void setboolfield (lua_State *L, const char *key, int value) {
if (value < 0) /* undefined? */
return; /* does not set field */
@@ -210,14 +226,14 @@ static void setboolfield (lua_State *L, const char *key, int value) {
** Set all fields from structure 'tm' in the table on top of the stack
*/
static void setallfields (lua_State *L, struct tm *stm) {
- setfield(L, "sec", stm->tm_sec);
- setfield(L, "min", stm->tm_min);
- setfield(L, "hour", stm->tm_hour);
- setfield(L, "day", stm->tm_mday);
- setfield(L, "month", stm->tm_mon + 1);
- setfield(L, "year", stm->tm_year + 1900);
- setfield(L, "wday", stm->tm_wday + 1);
- setfield(L, "yday", stm->tm_yday + 1);
+ setfield(L, "year", stm->tm_year, 1900);
+ setfield(L, "month", stm->tm_mon, 1);
+ setfield(L, "day", stm->tm_mday, 0);
+ setfield(L, "hour", stm->tm_hour, 0);
+ setfield(L, "min", stm->tm_min, 0);
+ setfield(L, "sec", stm->tm_sec, 0);
+ setfield(L, "yday", stm->tm_yday, 1);
+ setfield(L, "wday", stm->tm_wday, 1);
setboolfield(L, "isdst", stm->tm_isdst);
}
@@ -230,11 +246,6 @@ static int getboolfield (lua_State *L, const char *key) {
}
-/* maximum value for date fields (to avoid arithmetic overflows with 'int') */
-#if !defined(L_MAXDATEFIELD)
-#define L_MAXDATEFIELD (INT_MAX / 2)
-#endif
-
static int getfield (lua_State *L, const char *key, int d, int delta) {
int isnum;
int t = lua_getfield(L, -1, key); /* get field and its type */
@@ -247,7 +258,9 @@ static int getfield (lua_State *L, const char *key, int d, int delta) {
res = d;
}
else {
- if (!(-L_MAXDATEFIELD <= res && res <= L_MAXDATEFIELD))
+ /* unsigned avoids overflow when lua_Integer has 32 bits */
+ if (!(res >= 0 ? (lua_Unsigned)res <= (lua_Unsigned)INT_MAX + delta
+ : (lua_Integer)INT_MIN + delta <= res))
return luaL_error(L, "field '%s' is out-of-bound", key);
res -= delta;
}
@@ -275,6 +288,13 @@ static const char *checkoption (lua_State *L, const char *conv,
}
+static time_t l_checktime (lua_State *L, int arg) {
+ l_timet t = l_gettime(L, arg);
+ luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
+ return (time_t)t;
+}
+
+
/* maximum size for an individual 'strftime' item */
#define SIZETIMEFMT 250
@@ -293,7 +313,7 @@ static int os_date (lua_State *L) {
stm = l_localtime(&t, &tmr);
if (stm == NULL) /* invalid date? */
return luaL_error(L,
- "time result cannot be represented in this installation");
+ "date result cannot be represented in this installation");
if (strcmp(s, "*t") == 0) {
lua_createtable(L, 0, 9); /* 9 = number of fields */
setallfields(L, stm);
@@ -329,12 +349,12 @@ static int os_time (lua_State *L) {
struct tm ts;
luaL_checktype(L, 1, LUA_TTABLE);
lua_settop(L, 1); /* make sure table is at the top */
- ts.tm_sec = getfield(L, "sec", 0, 0);
- ts.tm_min = getfield(L, "min", 0, 0);
- ts.tm_hour = getfield(L, "hour", 12, 0);
- ts.tm_mday = getfield(L, "day", -1, 0);
- ts.tm_mon = getfield(L, "month", -1, 1);
ts.tm_year = getfield(L, "year", -1, 1900);
+ ts.tm_mon = getfield(L, "month", -1, 1);
+ ts.tm_mday = getfield(L, "day", -1, 0);
+ ts.tm_hour = getfield(L, "hour", 12, 0);
+ ts.tm_min = getfield(L, "min", 0, 0);
+ ts.tm_sec = getfield(L, "sec", 0, 0);
ts.tm_isdst = getboolfield(L, "isdst");
t = mktime(&ts);
setallfields(L, &ts); /* update fields with normalized values */
diff --git a/testes/files.lua b/testes/files.lua
@@ -775,11 +775,24 @@ assert(os.date(string.rep("%d", 1000), t) ==
string.rep(os.date("%d", t), 1000))
assert(os.date(string.rep("%", 200)) == string.rep("%", 100))
-local t = os.time()
-D = os.date("*t", t)
-load(os.date([[assert(D.year==%Y and D.month==%m and D.day==%d and
- D.hour==%H and D.min==%M and D.sec==%S and
- D.wday==%w+1 and D.yday==%j)]], t))()
+local function checkDateTable (t)
+ _G.D = os.date("*t", t)
+ assert(os.time(D) == t)
+ load(os.date([[assert(D.year==%Y and D.month==%m and D.day==%d and
+ D.hour==%H and D.min==%M and D.sec==%S and
+ D.wday==%w+1 and D.yday==%j)]], t))()
+ _G.D = nil
+end
+
+checkDateTable(os.time())
+if not _port then
+ -- assume that time_t can represent these values
+ checkDateTable(0)
+ checkDateTable(1)
+ checkDateTable(1000)
+ checkDateTable(0x7fffffff)
+ checkDateTable(0x80000000)
+end
checkerr("invalid conversion specifier", os.date, "%")
checkerr("invalid conversion specifier", os.date, "%9")
@@ -793,11 +806,24 @@ checkerr("not an integer", os.time, {year=1000, month=1, day=1, hour=1.5})
checkerr("missing", os.time, {hour = 12}) -- missing date
+
+if string.packsize("i") == 4 then -- 4-byte ints
+ checkerr("field 'year' is out-of-bound", os.time,
+ {year = -(1 << 31) + 1899, month = 1, day = 1})
+end
+
if not _port then
-- test Posix-specific modifiers
assert(type(os.date("%Ex")) == 'string')
assert(type(os.date("%Oy")) == 'string')
+ -- test large dates (assume at least 4-byte ints and time_t)
+ local t0 = os.time{year = 1970, month = 1, day = 0}
+ local t1 = os.time{year = 1970, month = 1, day = 0, sec = (1 << 31) - 1}
+ assert(t1 - t0 == (1 << 31) - 1)
+ t0 = os.time{year = 1970, month = 1, day = 1}
+ t1 = os.time{year = 1970, month = 1, day = 1, sec = -(1 << 31)}
+ assert(t1 - t0 == -(1 << 31))
-- test out-of-range dates (at least for Unix)
if maxint >= 2^62 then -- cannot do these tests in Small Lua
@@ -812,25 +838,37 @@ if not _port then
-- time_t has 8 bytes; an int year cannot represent a huge time
print(" 8-byte time_t")
checkerr("cannot be represented", os.date, "%Y", 2^60)
- -- it should have no problems with year 4000
- assert(tonumber(os.time{year=4000, month=1, day=1}))
+
+ -- this is the maximum year
+ assert(tonumber(os.time
+ {year=(1 << 31) + 1899, month=12, day=31, hour=23, min=59, sec=59}))
+
+ -- this is too much
+ checkerr("represented", os.time,
+ {year=(1 << 31) + 1899, month=12, day=31, hour=23, min=59, sec=60})
end
+
+ -- internal 'int' fields cannot hold these values
+ checkerr("field 'day' is out-of-bound", os.time,
+ {year = 0, month = 1, day = 2^32})
+
+ checkerr("field 'month' is out-of-bound", os.time,
+ {year = 0, month = -((1 << 31) + 1), day = 1})
+
+ checkerr("field 'year' is out-of-bound", os.time,
+ {year = (1 << 31) + 1900, month = 1, day = 1})
+
else -- 8-byte ints
-- assume time_t has 8 bytes too
print(" 8-byte time_t")
assert(tonumber(os.date("%Y", 2^60)))
+
-- but still cannot represent a huge year
checkerr("cannot be represented", os.time, {year=2^60, month=1, day=1})
end
end
end
-
-D = os.date("!*t", t)
-load(os.date([[!assert(D.year==%Y and D.month==%m and D.day==%d and
- D.hour==%H and D.min==%M and D.sec==%S and
- D.wday==%w+1 and D.yday==%j)]], t))()
-
do
local D = os.date("*t")
local t = os.time(D)
@@ -844,6 +882,7 @@ do
assert(t == t1) -- if isdst is absent uses correct default
end
+local D = os.date("*t")
t = os.time(D)
D.year = D.year-1;
local t1 = os.time(D)