Coverage Report

Created: 2023-09-15 06:20

/src/testdir/build/lua-master/source/lstring.c
Line
Count
Source (jump to first uncovered line)
1
/*
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** $Id: lstring.c $
3
** String table (keeps all strings handled by Lua)
4
** See Copyright Notice in lua.h
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*/
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7
#define lstring_c
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#define LUA_CORE
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10
#include "lprefix.h"
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12
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#include <string.h>
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15
#include "lua.h"
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#include "ldebug.h"
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#include "ldo.h"
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#include "lmem.h"
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#include "lobject.h"
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#include "lstate.h"
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#include "lstring.h"
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/*
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** Maximum size for string table.
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*/
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4.26k
#define MAXSTRTB  cast_int(luaM_limitN(MAX_INT, TString*))
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/*
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** equality for long strings
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*/
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1.06M
int luaS_eqlngstr (TString *a, TString *b) {
35
1.06M
  size_t len = a->u.lnglen;
36
1.06M
  lua_assert(a->tt == LUA_VLNGSTR && b->tt == LUA_VLNGSTR);
37
1.06M
  return (a == b) ||  /* same instance or... */
38
1.06M
    ((len == b->u.lnglen) &&  /* equal length and ... */
39
446k
     (memcmp(getlngstr(a), getlngstr(b), len) == 0));  /* equal contents */
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1.06M
}
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23.3M
unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
44
23.3M
  unsigned int h = seed ^ cast_uint(l);
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1.00G
  for (; l > 0; l--)
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984M
    h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1]));
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23.3M
  return h;
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23.3M
}
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1.12M
unsigned int luaS_hashlongstr (TString *ts) {
52
1.12M
  lua_assert(ts->tt == LUA_VLNGSTR);
53
1.12M
  if (ts->extra == 0) {  /* no hash? */
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356k
    size_t len = ts->u.lnglen;
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356k
    ts->hash = luaS_hash(getlngstr(ts), len, ts->hash);
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356k
    ts->extra = 1;  /* now it has its hash */
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356k
  }
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1.12M
  return ts->hash;
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1.12M
}
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20.1k
static void tablerehash (TString **vect, int osize, int nsize) {
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20.1k
  int i;
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2.71M
  for (i = osize; i < nsize; i++)  /* clear new elements */
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2.69M
    vect[i] = NULL;
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732k
  for (i = 0; i < osize; i++) {  /* rehash old part of the array */
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712k
    TString *p = vect[i];
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712k
    vect[i] = NULL;
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1.38M
    while (p) {  /* for each string in the list */
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671k
      TString *hnext = p->u.hnext;  /* save next */
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671k
      unsigned int h = lmod(p->hash, nsize);  /* new position */
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671k
      p->u.hnext = vect[h];  /* chain it into array */
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671k
      vect[h] = p;
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671k
      p = hnext;
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671k
    }
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712k
  }
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20.1k
}
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/*
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** Resize the string table. If allocation fails, keep the current size.
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** (This can degrade performance, but any non-zero size should work
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** correctly.)
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*/
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4.31k
void luaS_resize (lua_State *L, int nsize) {
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4.31k
  stringtable *tb = &G(L)->strt;
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4.31k
  int osize = tb->size;
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4.31k
  TString **newvect;
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4.31k
  if (nsize < osize)  /* shrinking table? */
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43
    tablerehash(tb->hash, osize, nsize);  /* depopulate shrinking part */
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4.31k
  newvect = luaM_reallocvector(L, tb->hash, osize, nsize, TString*);
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4.31k
  if (l_unlikely(newvect == NULL)) {  /* reallocation failed? */
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0
    if (nsize < osize)  /* was it shrinking table? */
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0
      tablerehash(tb->hash, nsize, osize);  /* restore to original size */
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    /* leave table as it was */
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0
  }
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4.31k
  else {  /* allocation succeeded */
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4.31k
    tb->hash = newvect;
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4.31k
    tb->size = nsize;
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4.31k
    if (nsize > osize)
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4.26k
      tablerehash(newvect, osize, nsize);  /* rehash for new size */
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4.31k
  }
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4.31k
}
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/*
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** Clear API string cache. (Entries cannot be empty, so fill them with
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** a non-collectable string.)
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*/
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117k
void luaS_clearcache (global_State *g) {
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117k
  int i, j;
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6.32M
  for (i = 0; i < STRCACHE_N; i++)
113
18.6M
    for (j = 0; j < STRCACHE_M; j++) {
114
12.4M
      if (iswhite(g->strcache[i][j]))  /* will entry be collected? */
115
67.4k
        g->strcache[i][j] = g->memerrmsg;  /* replace it with something fixed */
116
12.4M
    }
117
117k
}
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/*
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** Initialize the string table and the string cache
122
*/
123
15.8k
void luaS_init (lua_State *L) {
124
15.8k
  global_State *g = G(L);
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15.8k
  int i, j;
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15.8k
  stringtable *tb = &G(L)->strt;
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15.8k
  tb->hash = luaM_newvector(L, MINSTRTABSIZE, TString*);
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15.8k
  tablerehash(tb->hash, 0, MINSTRTABSIZE);  /* clear array */
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15.8k
  tb->size = MINSTRTABSIZE;
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  /* pre-create memory-error message */
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15.8k
  g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
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15.8k
  luaC_fix(L, obj2gco(g->memerrmsg));  /* it should never be collected */
133
854k
  for (i = 0; i < STRCACHE_N; i++)  /* fill cache with valid strings */
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2.51M
    for (j = 0; j < STRCACHE_M; j++)
135
1.67M
      g->strcache[i][j] = g->memerrmsg;
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15.8k
}
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/*
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** creates a new string object
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*/
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2.50M
static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) {
144
2.50M
  TString *ts;
145
2.50M
  GCObject *o;
146
2.50M
  size_t totalsize;  /* total size of TString object */
147
2.50M
  totalsize = sizelstring(l);
148
2.50M
  o = luaC_newobj(L, tag, totalsize);
149
2.50M
  ts = gco2ts(o);
150
2.50M
  ts->hash = h;
151
2.50M
  ts->extra = 0;
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2.50M
  getstr(ts)[l] = '\0';  /* ending 0 */
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2.50M
  return ts;
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2.50M
}
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752k
TString *luaS_createlngstrobj (lua_State *L, size_t l) {
158
752k
  TString *ts = createstrobj(L, l, LUA_VLNGSTR, G(L)->seed);
159
752k
  ts->u.lnglen = l;
160
752k
  ts->shrlen = 0xFF;  /* signals that it is a long string */
161
752k
  return ts;
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752k
}
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164
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1.75M
void luaS_remove (lua_State *L, TString *ts) {
166
1.75M
  stringtable *tb = &G(L)->strt;
167
1.75M
  TString **p = &tb->hash[lmod(ts->hash, tb->size)];
168
1.88M
  while (*p != ts)  /* find previous element */
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130k
    p = &(*p)->u.hnext;
170
1.75M
  *p = (*p)->u.hnext;  /* remove element from its list */
171
1.75M
  tb->nuse--;
172
1.75M
}
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4.26k
static void growstrtab (lua_State *L, stringtable *tb) {
176
4.26k
  if (l_unlikely(tb->nuse == MAX_INT)) {  /* too many strings? */
177
0
    luaC_fullgc(L, 1);  /* try to free some... */
178
0
    if (tb->nuse == MAX_INT)  /* still too many? */
179
0
      luaM_error(L);  /* cannot even create a message... */
180
0
  }
181
4.26k
  if (tb->size <= MAXSTRTB / 2)  /* can grow string table? */
182
4.26k
    luaS_resize(L, tb->size * 2);
183
4.26k
}
184
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/*
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** Checks whether short string exists and reuses it or creates a new one.
188
*/
189
22.9M
static TString *internshrstr (lua_State *L, const char *str, size_t l) {
190
22.9M
  TString *ts;
191
22.9M
  global_State *g = G(L);
192
22.9M
  stringtable *tb = &g->strt;
193
22.9M
  unsigned int h = luaS_hash(str, l, g->seed);
194
22.9M
  TString **list = &tb->hash[lmod(h, tb->size)];
195
22.9M
  lua_assert(str != NULL);  /* otherwise 'memcmp'/'memcpy' are undefined */
196
30.0M
  for (ts = *list; ts != NULL; ts = ts->u.hnext) {
197
28.3M
    if (l == ts->shrlen && (memcmp(str, getshrstr(ts), l * sizeof(char)) == 0)) {
198
      /* found! */
199
21.2M
      if (isdead(g, ts))  /* dead (but not collected yet)? */
200
774
        changewhite(ts);  /* resurrect it */
201
21.2M
      return ts;
202
21.2M
    }
203
28.3M
  }
204
  /* else must create a new string */
205
1.75M
  if (tb->nuse >= tb->size) {  /* need to grow string table? */
206
4.26k
    growstrtab(L, tb);
207
4.26k
    list = &tb->hash[lmod(h, tb->size)];  /* rehash with new size */
208
4.26k
  }
209
1.75M
  ts = createstrobj(L, l, LUA_VSHRSTR, h);
210
1.75M
  ts->shrlen = cast_byte(l);
211
1.75M
  memcpy(getshrstr(ts), str, l * sizeof(char));
212
1.75M
  ts->u.hnext = *list;
213
1.75M
  *list = ts;
214
1.75M
  tb->nuse++;
215
1.75M
  return ts;
216
22.9M
}
217
218
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/*
220
** new string (with explicit length)
221
*/
222
23.7M
TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
223
23.7M
  if (l <= LUAI_MAXSHORTLEN)  /* short string? */
224
22.9M
    return internshrstr(L, str, l);
225
746k
  else {
226
746k
    TString *ts;
227
746k
    if (l_unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char)))
228
0
      luaM_toobig(L);
229
746k
    ts = luaS_createlngstrobj(L, l);
230
746k
    memcpy(getlngstr(ts), str, l * sizeof(char));
231
746k
    return ts;
232
746k
  }
233
23.7M
}
234
235
236
/*
237
** Create or reuse a zero-terminated string, first checking in the
238
** cache (using the string address as a key). The cache can contain
239
** only zero-terminated strings, so it is safe to use 'strcmp' to
240
** check hits.
241
*/
242
1.86M
TString *luaS_new (lua_State *L, const char *str) {
243
1.86M
  unsigned int i = point2uint(str) % STRCACHE_N;  /* hash */
244
1.86M
  int j;
245
1.86M
  TString **p = G(L)->strcache[i];
246
4.72M
  for (j = 0; j < STRCACHE_M; j++) {
247
3.33M
    if (strcmp(str, getstr(p[j])) == 0)  /* hit? */
248
478k
      return p[j];  /* that is it */
249
3.33M
  }
250
  /* normal route */
251
2.76M
  for (j = STRCACHE_M - 1; j > 0; j--)
252
1.38M
    p[j] = p[j - 1];  /* move out last element */
253
  /* new element is first in the list */
254
1.38M
  p[0] = luaS_newlstr(L, str, strlen(str));
255
1.38M
  return p[0];
256
1.86M
}
257
258
259
64.0k
Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue) {
260
64.0k
  Udata *u;
261
64.0k
  int i;
262
64.0k
  GCObject *o;
263
64.0k
  if (l_unlikely(s > MAX_SIZE - udatamemoffset(nuvalue)))
264
0
    luaM_toobig(L);
265
64.0k
  o = luaC_newobj(L, LUA_VUSERDATA, sizeudata(nuvalue, s));
266
64.0k
  u = gco2u(o);
267
64.0k
  u->len = s;
268
64.0k
  u->nuvalue = nuvalue;
269
64.0k
  u->metatable = NULL;
270
64.0k
  for (i = 0; i < nuvalue; i++)
271
64.0k
    setnilvalue(&u->uv[i].uv);
272
64.0k
  return u;
273
64.0k
}
274