GCC Code Coverage Report

Line	Branch	Decision	Exec	Source
1				/*
2				** $Id: ltablib.c $
3				** Library for Table Manipulation
4				** See Copyright Notice in lua.h
5				*/
6
7				#define ltablib_c
8				#define LUA_LIB
9
10				#include "lprefix.h"
11
12
13				#include <limits.h>
14				#include <stddef.h>
15				#include <string.h>
16
17				#include "lua.h"
18
19				#include "lauxlib.h"
20				#include "lualib.h"
21
22
23				/*
24				** Operations that an object must define to mimic a table
25				** (some functions only need some of them)
26				*/
27				#define TAB_R 1 /* read */
28				#define TAB_W 2 /* write */
29				#define TAB_L 4 /* length */
30				#define TAB_RW (TAB_R | TAB_W) /* read/write */
31
32
33				#define aux_getn(L,n,w) (checktab(L, n, (w) | TAB_L), luaL_len(L, n))
34
35
36			✗	static int checkfield (lua_State *L, const char *key, int n) {
37			✗	lua_pushstring(L, key);
38			✗	return (lua_rawget(L, -n) != LUA_TNIL);
39				}
40
41
42				/*
43				** Check that 'arg' either is a table or can behave like one (that is,
44				** has a metatable with the required metamethods)
45				*/
46			✗	static void checktab (lua_State *L, int arg, int what) {
47			✗	if (lua_type(L, arg) != LUA_TTABLE) { /* is it not a table? */
48			✗	int n = 1; /* number of elements to pop */
49			✗	if (lua_getmetatable(L, arg) && /* must have metatable */
50			✗	(!(what & TAB_R) || checkfield(L, "__index", ++n)) &&
51			✗	(!(what & TAB_W) || checkfield(L, "__newindex", ++n)) &&
52			✗	(!(what & TAB_L) || checkfield(L, "__len", ++n))) {
53			✗	lua_pop(L, n); /* pop metatable and tested metamethods */
54				}
55				else
56			✗	luaL_checktype(L, arg, LUA_TTABLE); /* force an error */
57				}
58			✗	}
59
60
61			✗	static int tinsert (lua_State *L) {
62				lua_Integer pos; /* where to insert new element */
63			✗	lua_Integer e = aux_getn(L, 1, TAB_RW);
64			✗	e = luaL_intop(+, e, 1); /* first empty element */
65			✗	switch (lua_gettop(L)) {
66			✗	case 2: { /* called with only 2 arguments */
67			✗	pos = e; /* insert new element at the end */
68			✗	break;
69				}
70			✗	case 3: {
71				lua_Integer i;
72			✗	pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */
73				/* check whether 'pos' is in [1, e] */
74			✗	luaL_argcheck(L, (lua_Unsigned)pos - 1u < (lua_Unsigned)e, 2,
75				"position out of bounds");
76			✗	for (i = e; i > pos; i--) { /* move up elements */
77			✗	lua_geti(L, 1, i - 1);
78			✗	lua_seti(L, 1, i); /* t[i] = t[i - 1] */
79				}
80			✗	break;
81				}
82			✗	default: {
83			✗	return luaL_error(L, "wrong number of arguments to 'insert'");
84				}
85				}
86			✗	lua_seti(L, 1, pos); /* t[pos] = v */
87			✗	return 0;
88				}
89
90
91			✗	static int tremove (lua_State *L) {
92			✗	lua_Integer size = aux_getn(L, 1, TAB_RW);
93			✗	lua_Integer pos = luaL_optinteger(L, 2, size);
94			✗	if (pos != size) /* validate 'pos' if given */
95				/* check whether 'pos' is in [1, size + 1] */
96			✗	luaL_argcheck(L, (lua_Unsigned)pos - 1u <= (lua_Unsigned)size, 2,
97				"position out of bounds");
98			✗	lua_geti(L, 1, pos); /* result = t[pos] */
99			✗	for ( ; pos < size; pos++) {
100			✗	lua_geti(L, 1, pos + 1);
101			✗	lua_seti(L, 1, pos); /* t[pos] = t[pos + 1] */
102				}
103			✗	lua_pushnil(L);
104			✗	lua_seti(L, 1, pos); /* remove entry t[pos] */
105			✗	return 1;
106				}
107
108
109				/*
110				** Copy elements (1[f], ..., 1[e]) into (tt[t], tt[t+1], ...). Whenever
111				** possible, copy in increasing order, which is better for rehashing.
112				** "possible" means destination after original range, or smaller
113				** than origin, or copying to another table.
114				*/
115			✗	static int tmove (lua_State *L) {
116			✗	lua_Integer f = luaL_checkinteger(L, 2);
117			✗	lua_Integer e = luaL_checkinteger(L, 3);
118			✗	lua_Integer t = luaL_checkinteger(L, 4);
119			✗	int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */
120			✗	checktab(L, 1, TAB_R);
121			✗	checktab(L, tt, TAB_W);
122			✗	if (e >= f) { /* otherwise, nothing to move */
123				lua_Integer n, i;
124			✗	luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
125				"too many elements to move");
126			✗	n = e - f + 1; /* number of elements to move */
127			✗	luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4,
128				"destination wrap around");
129			✗	if (t > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) {
130			✗	for (i = 0; i < n; i++) {
131			✗	lua_geti(L, 1, f + i);
132			✗	lua_seti(L, tt, t + i);
133				}
134				}
135				else {
136			✗	for (i = n - 1; i >= 0; i--) {
137			✗	lua_geti(L, 1, f + i);
138			✗	lua_seti(L, tt, t + i);
139				}
140				}
141				}
142			✗	lua_pushvalue(L, tt); /* return destination table */
143			✗	return 1;
144				}
145
146
147			✗	static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
148			✗	lua_geti(L, 1, i);
149			✗	if (l_unlikely(!lua_isstring(L, -1)))
150			✗	luaL_error(L, "invalid value (%s) at index %I in table for 'concat'",
151				luaL_typename(L, -1), (LUAI_UACINT)i);
152			✗	luaL_addvalue(b);
153			✗	}
154
155
156			✗	static int tconcat (lua_State *L) {
157				luaL_Buffer b;
158			✗	lua_Integer last = aux_getn(L, 1, TAB_R);
159				size_t lsep;
160			✗	const char *sep = luaL_optlstring(L, 2, "", &lsep);
161			✗	lua_Integer i = luaL_optinteger(L, 3, 1);
162			✗	last = luaL_optinteger(L, 4, last);
163			✗	luaL_buffinit(L, &b);
164			✗	for (; i < last; i++) {
165			✗	addfield(L, &b, i);
166			✗	luaL_addlstring(&b, sep, lsep);
167				}
168			✗	if (i == last) /* add last value (if interval was not empty) */
169			✗	addfield(L, &b, i);
170			✗	luaL_pushresult(&b);
171			✗	return 1;
172				}
173
174
175				/*
176				** {======================================================
177				** Pack/unpack
178				** =======================================================
179				*/
180
181			✗	static int tpack (lua_State *L) {
182				int i;
183			✗	int n = lua_gettop(L); /* number of elements to pack */
184			✗	lua_createtable(L, n, 1); /* create result table */
185			✗	lua_insert(L, 1); /* put it at index 1 */
186			✗	for (i = n; i >= 1; i--) /* assign elements */
187			✗	lua_seti(L, 1, i);
188			✗	lua_pushinteger(L, n);
189			✗	lua_setfield(L, 1, "n"); /* t.n = number of elements */
190			✗	return 1; /* return table */
191				}
192
193
194			✗	static int tunpack (lua_State *L) {
195				lua_Unsigned n;
196			✗	lua_Integer i = luaL_optinteger(L, 2, 1);
197			✗	lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
198			✗	if (i > e) return 0; /* empty range */
199			✗	n = (lua_Unsigned)e - i; /* number of elements minus 1 (avoid overflows) */
200			✗	if (l_unlikely(n >= (unsigned int)INT_MAX ||
201				!lua_checkstack(L, (int)(++n))))
202			✗	return luaL_error(L, "too many results to unpack");
203			✗	for (; i < e; i++) { /* push arg[i..e - 1] (to avoid overflows) */
204			✗	lua_geti(L, 1, i);
205				}
206			✗	lua_geti(L, 1, e); /* push last element */
207			✗	return (int)n;
208				}
209
210				/* }====================================================== */
211
212
213
214				/*
215				** {======================================================
216				** Quicksort
217				** (based on 'Algorithms in MODULA-3', Robert Sedgewick;
218				** Addison-Wesley, 1993.)
219				** =======================================================
220				*/
221
222
223				/* type for array indices */
224				typedef unsigned int IdxT;
225
226
227				/*
228				** Produce a "random" 'unsigned int' to randomize pivot choice. This
229				** macro is used only when 'sort' detects a big imbalance in the result
230				** of a partition. (If you don't want/need this "randomness", ~0 is a
231				** good choice.)
232				*/
233				#if !defined(l_randomizePivot) /* { */
234
235				#include <time.h>
236
237				/* size of 'e' measured in number of 'unsigned int's */
238				#define sof(e) (sizeof(e) / sizeof(unsigned int))
239
240				/*
241				** Use 'time' and 'clock' as sources of "randomness". Because we don't
242				** know the types 'clock_t' and 'time_t', we cannot cast them to
243				** anything without risking overflows. A safe way to use their values
244				** is to copy them to an array of a known type and use the array values.
245				*/
246			✗	static unsigned int l_randomizePivot (void) {
247			✗	clock_t c = clock();
248			✗	time_t t = time(NULL);
249				unsigned int buff[sof(c) + sof(t)];
250			✗	unsigned int i, rnd = 0;
251			✗	memcpy(buff, &c, sof(c) * sizeof(unsigned int));
252			✗	memcpy(buff + sof(c), &t, sof(t) * sizeof(unsigned int));
253			✗	for (i = 0; i < sof(buff); i++)
254			✗	rnd += buff[i];
255			✗	return rnd;
256				}
257
258				#endif /* } */
259
260
261				/* arrays larger than 'RANLIMIT' may use randomized pivots */
262				#define RANLIMIT 100u
263
264
265			✗	static void set2 (lua_State *L, IdxT i, IdxT j) {
266			✗	lua_seti(L, 1, i);
267			✗	lua_seti(L, 1, j);
268			✗	}
269
270
271				/*
272				** Return true iff value at stack index 'a' is less than the value at
273				** index 'b' (according to the order of the sort).
274				*/
275			✗	static int sort_comp (lua_State *L, int a, int b) {
276			✗	if (lua_isnil(L, 2)) /* no function? */
277			✗	return lua_compare(L, a, b, LUA_OPLT); /* a < b */
278				else { /* function */
279				int res;
280			✗	lua_pushvalue(L, 2); /* push function */
281			✗	lua_pushvalue(L, a-1); /* -1 to compensate function */
282			✗	lua_pushvalue(L, b-2); /* -2 to compensate function and 'a' */
283			✗	lua_call(L, 2, 1); /* call function */
284			✗	res = lua_toboolean(L, -1); /* get result */
285			✗	lua_pop(L, 1); /* pop result */
286			✗	return res;
287				}
288				}
289
290
291				/*
292				** Does the partition: Pivot P is at the top of the stack.
293				** precondition: a[lo] <= P == a[up-1] <= a[up],
294				** so it only needs to do the partition from lo + 1 to up - 2.
295				** Pos-condition: a[lo .. i - 1] <= a[i] == P <= a[i + 1 .. up]
296				** returns 'i'.
297				*/
298			✗	static IdxT partition (lua_State *L, IdxT lo, IdxT up) {
299			✗	IdxT i = lo; /* will be incremented before first use */
300			✗	IdxT j = up - 1; /* will be decremented before first use */
301				/* loop invariant: a[lo .. i] <= P <= a[j .. up] */
302				for (;;) {
303				/* next loop: repeat ++i while a[i] < P */
304			✗	while ((void)lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
305			✗	if (l_unlikely(i == up - 1)) /* a[i] < P but a[up - 1] == P ?? */
306			✗	luaL_error(L, "invalid order function for sorting");
307			✗	lua_pop(L, 1); /* remove a[i] */
308				}
309				/* after the loop, a[i] >= P and a[lo .. i - 1] < P */
310				/* next loop: repeat --j while P < a[j] */
311			✗	while ((void)lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
312			✗	if (l_unlikely(j < i)) /* j < i but a[j] > P ?? */
313			✗	luaL_error(L, "invalid order function for sorting");
314			✗	lua_pop(L, 1); /* remove a[j] */
315				}
316				/* after the loop, a[j] <= P and a[j + 1 .. up] >= P */
317			✗	if (j < i) { /* no elements out of place? */
318				/* a[lo .. i - 1] <= P <= a[j + 1 .. i .. up] */
319			✗	lua_pop(L, 1); /* pop a[j] */
320				/* swap pivot (a[up - 1]) with a[i] to satisfy pos-condition */
321			✗	set2(L, up - 1, i);
322			✗	return i;
323				}
324				/* otherwise, swap a[i] - a[j] to restore invariant and repeat */
325			✗	set2(L, i, j);
326				}
327				}
328
329
330				/*
331				** Choose an element in the middle (2nd-3th quarters) of [lo,up]
332				** "randomized" by 'rnd'
333				*/
334			✗	static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) {
335			✗	IdxT r4 = (up - lo) / 4; /* range/4 */
336			✗	IdxT p = rnd % (r4 * 2) + (lo + r4);
337				lua_assert(lo + r4 <= p && p <= up - r4);
338			✗	return p;
339				}
340
341
342				/*
343				** Quicksort algorithm (recursive function)
344				*/
345			✗	static void auxsort (lua_State *L, IdxT lo, IdxT up,
346				unsigned int rnd) {
347			✗	while (lo < up) { /* loop for tail recursion */
348				IdxT p; /* Pivot index */
349				IdxT n; /* to be used later */
350				/* sort elements 'lo', 'p', and 'up' */
351			✗	lua_geti(L, 1, lo);
352			✗	lua_geti(L, 1, up);
353			✗	if (sort_comp(L, -1, -2)) /* a[up] < a[lo]? */
354			✗	set2(L, lo, up); /* swap a[lo] - a[up] */
355				else
356			✗	lua_pop(L, 2); /* remove both values */
357			✗	if (up - lo == 1) /* only 2 elements? */
358			✗	return; /* already sorted */
359			✗	if (up - lo < RANLIMIT || rnd == 0) /* small interval or no randomize? */
360			✗	p = (lo + up)/2; /* middle element is a good pivot */
361				else /* for larger intervals, it is worth a random pivot */
362			✗	p = choosePivot(lo, up, rnd);
363			✗	lua_geti(L, 1, p);
364			✗	lua_geti(L, 1, lo);
365			✗	if (sort_comp(L, -2, -1)) /* a[p] < a[lo]? */
366			✗	set2(L, p, lo); /* swap a[p] - a[lo] */
367				else {
368			✗	lua_pop(L, 1); /* remove a[lo] */
369			✗	lua_geti(L, 1, up);
370			✗	if (sort_comp(L, -1, -2)) /* a[up] < a[p]? */
371			✗	set2(L, p, up); /* swap a[up] - a[p] */
372				else
373			✗	lua_pop(L, 2);
374				}
375			✗	if (up - lo == 2) /* only 3 elements? */
376			✗	return; /* already sorted */
377			✗	lua_geti(L, 1, p); /* get middle element (Pivot) */
378			✗	lua_pushvalue(L, -1); /* push Pivot */
379			✗	lua_geti(L, 1, up - 1); /* push a[up - 1] */
380			✗	set2(L, p, up - 1); /* swap Pivot (a[p]) with a[up - 1] */
381			✗	p = partition(L, lo, up);
382				/* a[lo .. p - 1] <= a[p] == P <= a[p + 1 .. up] */
383			✗	if (p - lo < up - p) { /* lower interval is smaller? */
384			✗	auxsort(L, lo, p - 1, rnd); /* call recursively for lower interval */
385			✗	n = p - lo; /* size of smaller interval */
386			✗	lo = p + 1; /* tail call for [p + 1 .. up] (upper interval) */
387				}
388				else {
389			✗	auxsort(L, p + 1, up, rnd); /* call recursively for upper interval */
390			✗	n = up - p; /* size of smaller interval */
391			✗	up = p - 1; /* tail call for [lo .. p - 1] (lower interval) */
392				}
393			✗	if ((up - lo) / 128 > n) /* partition too imbalanced? */
394			✗	rnd = l_randomizePivot(); /* try a new randomization */
395				} /* tail call auxsort(L, lo, up, rnd) */
396				}
397
398
399			✗	static int sort (lua_State *L) {
400			✗	lua_Integer n = aux_getn(L, 1, TAB_RW);
401			✗	if (n > 1) { /* non-trivial interval? */
402			✗	luaL_argcheck(L, n < INT_MAX, 1, "array too big");
403			✗	if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
404			✗	luaL_checktype(L, 2, LUA_TFUNCTION); /* must be a function */
405			✗	lua_settop(L, 2); /* make sure there are two arguments */
406			✗	auxsort(L, 1, (IdxT)n, 0);
407				}
408			✗	return 0;
409				}
410
411				/* }====================================================== */
412
413
414				static const luaL_Reg tab_funcs[] = {
415				{"concat", tconcat},
416				{"insert", tinsert},
417				{"pack", tpack},
418				{"unpack", tunpack},
419				{"remove", tremove},
420				{"move", tmove},
421				{"sort", sort},
422				{NULL, NULL}
423				};
424
425
426			✗	LUAMOD_API int luaopen_table (lua_State *L) {
427			✗	luaL_newlib(L, tab_funcs);
428			✗	return 1;
429				}
430
431