Update lua plugin to 5.2.3

Prior to this patch the Lua plugin used version 5.1.4. This change
reduces the number of modifications in the Lua source using some new
defines and because the upstream source is now more flexible.

Unless otherwise stated, l*.[ch] files are taken unmodified from the
upstream lua-5.2.3.

fscanf.c:
file descriptors in rockbox are just ints, they are hidden behind a
void* now so liolib requires less modifications. fscanf is updated to
use void* too.

getc.c: this is a new file required for getc implementation in lauxlib.c

lauxlib.c: LoadF replaced FILE* with int, the rockbox file
descriptor int are cast to FILE* (actually void* due to typedef).
getc uses the PREFIX version. stdin is not used, as per 5.1.4.

lbaselib.c: now uses strspn in the number parsing. print uses DEBUGF now
rather than being commented out.

lbitlib.c: use the built-in version from 5.2.3 rather than Reuben
Thomas's external library. Backwards compatible and adds some new bit
operations.

ldo.c: the LUAI_THROW/TRY defines are now in the core lua code, so have
been removed from rockconf.h

liolib.c: here the implementation has changed to use the LStream from
the original source, and cast the FILE* pointers to int. This has
reduced the number of modifications from the upstream version.

llex.c: the only change from upstream is to remove the locale include.

lmathlib.c: updated from the 5.2.3 version and re-applied the changes
that were made vs 5.1.4 for random numbers and to remove unsupported
float functions.

loadlib.c: upstream version, with the 5.1.4 changes for missing
functions.

lobject.c: upstream version, with ctype.h added and sprintf changed to
snprintf.

loslib.c: upstream version with locale.h removed and 5.1.4 changes for
unsupportable functions.

lstrlib.c: sprintf changed to snprintf.

ltable.c: upstream with the hashnum function from 5.1.4 to avoid frexp
in luai_hashnum.

luaconf.h: updated to 5.2.3 version, restored relevant parts from the
original 5.1.4 configuration. The COMPAT defines that are no longer
available are not included.

lundump.c: VERSION macro conflicts with the core Rockbox equivalent.

rocklib.c: luaL_reg is no longer available, replaced by luaL_Reg
equivalent. Moved checkboolean/optboolean functions to this file and out
of core lua files. luaL_getn is no longer available, replaced by
luaL_rawlen. luaL_register is deprecated, use the newlib/setfuncs
replacements. rli_init has to be called before setting up the newlib to
avoid overwriting the rb table.

rocklib_aux.pl: use rli_checkboolean from rocklib.c.

rocklua.c: new default bits library used, update the library loading
code with idiomatic 5.2 code.

strcspn.c: no longer needed, but strspn.c is required for strspn in
lbaselib.c

Change-Id: I0c7945c755f79083afe98ec117e1e8cf13de2651
Reviewed-on: http://gerrit.rockbox.org/774
Tested: Richard Quirk <richard.quirk@gmail.com>
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>

1 files changed, 124 insertions, 50 deletions

diff --git a/apps/plugins/lua/lstring.c b/apps/plugins/lua/lstring.c
index 49113151cc..af96c89c18 100644
--- a/apps/plugins/lua/lstring.c
+++ b/apps/plugins/lua/lstring.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $
+** $Id: lstring.c,v 2.26.1.1 2013/04/12 18:48:47 roberto Exp $
 ** String table (keeps all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -18,78 +18,157 @@
 #include "lstring.h"
 
 
+/*
+** Lua will use at most ~(2^LUAI_HASHLIMIT) bytes from a string to
+** compute its hash
+*/
+#if !defined(LUAI_HASHLIMIT)
+#define LUAI_HASHLIMIT          5
+#endif
+
+
+/*
+** equality for long strings
+*/
+int luaS_eqlngstr (TString *a, TString *b) {
+  size_t len = a->tsv.len;
+  lua_assert(a->tsv.tt == LUA_TLNGSTR && b->tsv.tt == LUA_TLNGSTR);
+  return (a == b) ||  /* same instance or... */
+    ((len == b->tsv.len) &&  /* equal length and ... */
+     (memcmp(getstr(a), getstr(b), len) == 0));  /* equal contents */
+}
+
+
+/*
+** equality for strings
+*/
+int luaS_eqstr (TString *a, TString *b) {
+  return (a->tsv.tt == b->tsv.tt) &&
+         (a->tsv.tt == LUA_TSHRSTR ? eqshrstr(a, b) : luaS_eqlngstr(a, b));
+}
+
 
+unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
+  unsigned int h = seed ^ cast(unsigned int, l);
+  size_t l1;
+  size_t step = (l >> LUAI_HASHLIMIT) + 1;
+  for (l1 = l; l1 >= step; l1 -= step)
+    h = h ^ ((h<<5) + (h>>2) + cast_byte(str[l1 - 1]));
+  return h;
+}
+
+
+/*
+** resizes the string table
+*/
 void luaS_resize (lua_State *L, int newsize) {
-  GCObject **newhash;
-  stringtable *tb;
   int i;
-  if (G(L)->gcstate == GCSsweepstring)
-    return;  /* cannot resize during GC traverse */
-  newhash = luaM_newvector(L, newsize, GCObject *);
-  tb = &G(L)->strt;
-  for (i=0; i<newsize; i++) newhash[i] = NULL;
+  stringtable *tb = &G(L)->strt;
+  /* cannot resize while GC is traversing strings */
+  luaC_runtilstate(L, ~bitmask(GCSsweepstring));
+  if (newsize > tb->size) {
+    luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *);
+    for (i = tb->size; i < newsize; i++) tb->hash[i] = NULL;
+  }
   /* rehash */
   for (i=0; i<tb->size; i++) {
     GCObject *p = tb->hash[i];
+    tb->hash[i] = NULL;
     while (p) {  /* for each node in the list */
-      GCObject *next = p->gch.next;  /* save next */
-      unsigned int h = gco2ts(p)->hash;
-      int h1 = lmod(h, newsize);  /* new position */
-      lua_assert(cast_int(h%newsize) == lmod(h, newsize));
-      p->gch.next = newhash[h1];  /* chain it */
-      newhash[h1] = p;
+      GCObject *next = gch(p)->next;  /* save next */
+      unsigned int h = lmod(gco2ts(p)->hash, newsize);  /* new position */
+      gch(p)->next = tb->hash[h];  /* chain it */
+      tb->hash[h] = p;
+      resetoldbit(p);  /* see MOVE OLD rule */
       p = next;
     }
   }
-  luaM_freearray(L, tb->hash, tb->size, TString *);
+  if (newsize < tb->size) {
+    /* shrinking slice must be empty */
+    lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL);
+    luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *);
+  }
   tb->size = newsize;
-  tb->hash = newhash;
 }
 
 
-static TString *newlstr (lua_State *L, const char *str, size_t l,
-                                       unsigned int h) {
+/*
+** creates a new string object
+*/
+static TString *createstrobj (lua_State *L, const char *str, size_t l,
+                              int tag, unsigned int h, GCObject **list) {
   TString *ts;
-  stringtable *tb;
-  if (l+1 > (MAX_SIZET - sizeof(TString))/sizeof(char))
-    luaM_toobig(L);
-  ts = cast(TString *, luaM_malloc(L, (l+1)*sizeof(char)+sizeof(TString)));
+  size_t totalsize;  /* total size of TString object */
+  totalsize = sizeof(TString) + ((l + 1) * sizeof(char));
+  ts = &luaC_newobj(L, tag, totalsize, list, 0)->ts;
   ts->tsv.len = l;
   ts->tsv.hash = h;
-  ts->tsv.marked = luaC_white(G(L));
-  ts->tsv.tt = LUA_TSTRING;
-  ts->tsv.reserved = 0;
+  ts->tsv.extra = 0;
   memcpy(ts+1, str, l*sizeof(char));
   ((char *)(ts+1))[l] = '\0';  /* ending 0 */
-  tb = &G(L)->strt;
-  h = lmod(h, tb->size);
-  ts->tsv.next = tb->hash[h];  /* chain new entry */
-  tb->hash[h] = obj2gco(ts);
-  tb->nuse++;
-  if (tb->nuse > cast(lu_int32, tb->size) && tb->size <= MAX_INT/2)
-    luaS_resize(L, tb->size*2);  /* too crowded */
   return ts;
 }
 
 
-TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
+/*
+** creates a new short string, inserting it into string table
+*/
+static TString *newshrstr (lua_State *L, const char *str, size_t l,
+                                       unsigned int h) {
+  GCObject **list;  /* (pointer to) list where it will be inserted */
+  stringtable *tb = &G(L)->strt;
+  TString *s;
+  if (tb->nuse >= cast(lu_int32, tb->size) && tb->size <= MAX_INT/2)
+    luaS_resize(L, tb->size*2);  /* too crowded */
+  list = &tb->hash[lmod(h, tb->size)];
+  s = createstrobj(L, str, l, LUA_TSHRSTR, h, list);
+  tb->nuse++;
+  return s;
+}
+
+
+/*
+** checks whether short string exists and reuses it or creates a new one
+*/
+static TString *internshrstr (lua_State *L, const char *str, size_t l) {
   GCObject *o;
-  unsigned int h = cast(unsigned int, l);  /* seed */
-  size_t step = (l>>5)+1;  /* if string is too long, don't hash all its chars */
-  size_t l1;
-  for (l1=l; l1>=step; l1-=step)  /* compute hash */
-    h = h ^ ((h<<5)+(h>>2)+cast(unsigned char, str[l1-1]));
-  for (o = G(L)->strt.hash[lmod(h, G(L)->strt.size)];
+  global_State *g = G(L);
+  unsigned int h = luaS_hash(str, l, g->seed);
+  for (o = g->strt.hash[lmod(h, g->strt.size)];
        o != NULL;
-       o = o->gch.next) {
+       o = gch(o)->next) {
     TString *ts = rawgco2ts(o);
-    if (ts->tsv.len == l && (memcmp(str, getstr(ts), l) == 0)) {
-      /* string may be dead */
-      if (isdead(G(L), o)) changewhite(o);
+    if (h == ts->tsv.hash &&
+        l == ts->tsv.len &&
+        (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
+      if (isdead(G(L), o))  /* string is dead (but was not collected yet)? */
+        changewhite(o);  /* resurrect it */
       return ts;
     }
   }
-  return newlstr(L, str, l, h);  /* not found */
+  return newshrstr(L, str, l, h);  /* not found; create a new string */
+}
+
+
+/*
+** new string (with explicit length)
+*/
+TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
+  if (l <= LUAI_MAXSHORTLEN)  /* short string? */
+    return internshrstr(L, str, l);
+  else {
+    if (l + 1 > (MAX_SIZET - sizeof(TString))/sizeof(char))
+      luaM_toobig(L);
+    return createstrobj(L, str, l, LUA_TLNGSTR, G(L)->seed, NULL);
+  }
+}
+
+
+/*
+** new zero-terminated string
+*/
+TString *luaS_new (lua_State *L, const char *str) {
+  return luaS_newlstr(L, str, strlen(str));
 }
 
 
@@ -97,15 +176,10 @@ Udata *luaS_newudata (lua_State *L, size_t s, Table *e) {
   Udata *u;
   if (s > MAX_SIZET - sizeof(Udata))
     luaM_toobig(L);
-  u = cast(Udata *, luaM_malloc(L, s + sizeof(Udata)));
-  u->uv.marked = luaC_white(G(L));  /* is not finalized */
-  u->uv.tt = LUA_TUSERDATA;
+  u = &luaC_newobj(L, LUA_TUSERDATA, sizeof(Udata) + s, NULL, 0)->u;
   u->uv.len = s;
   u->uv.metatable = NULL;
   u->uv.env = e;
-  /* chain it on udata list (after main thread) */
-  u->uv.next = G(L)->mainthread->next;
-  G(L)->mainthread->next = obj2gco(u);
   return u;
 }