From 0eb6aa4013051c8c0148c09d8c85ee7cbdc96f42 Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Wed, 24 Jul 2019 15:01:59 -0300 Subject: 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. --- loslib.c | 76 +++++++++++++++++++++++++++++++++++--------------------- testes/files.lua | 65 ++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 100 insertions(+), 41 deletions(-) diff --git a/loslib.c b/loslib.c index 8809e5ea..7812d29b 100644 --- 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 index c8f23d18..6e7bd9e2 100644 --- 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) -- cgit v1.2.3-55-g6feb