Update Lua to 5.4.4

liblua/lmem.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.c,v 1.91.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lmem.c $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -22,79 +22,180 @@
 #include "lstate.h"
 
 
+#if defined(EMERGENCYGCTESTS)
+/*
+** First allocation will fail whenever not building initial state.
+** (This fail will trigger 'tryagain' and a full GC cycle at every
+** allocation.)
+*/
+static void *firsttry (global_State *g, void *block, size_t os, size_t ns) {
+  if (completestate(g) && ns > 0)  /* frees never fail */
+    return NULL;  /* fail */
+  else  /* normal allocation */
+    return (*g->frealloc)(g->ud, block, os, ns);
+}
+#else
+#define firsttry(g,block,os,ns)    ((*g->frealloc)(g->ud, block, os, ns))
+#endif
+
+
+
+
 
 /*
 ** About the realloc function:
-** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
+** void *frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
 ** ('osize' is the old size, 'nsize' is the new size)
 **
-** * frealloc(ud, NULL, x, s) creates a new block of size 's' (no
-** matter 'x').
+** - frealloc(ud, p, x, 0) frees the block 'p' and returns NULL.
+** Particularly, frealloc(ud, NULL, 0, 0) does nothing,
+** which is equivalent to free(NULL) in ISO C.
 **
-** * frealloc(ud, p, x, 0) frees the block 'p'
-** (in this specific case, frealloc must return NULL);
-** particularly, frealloc(ud, NULL, 0, 0) does nothing
-** (which is equivalent to free(NULL) in ISO C)
+** - frealloc(ud, NULL, x, s) creates a new block of size 's'
+** (no matter 'x'). Returns NULL if it cannot create the new block.
 **
-** frealloc returns NULL if it cannot create or reallocate the area
-** (any reallocation to an equal or smaller size cannot fail!)
+** - otherwise, frealloc(ud, b, x, y) reallocates the block 'b' from
+** size 'x' to size 'y'. Returns NULL if it cannot reallocate the
+** block to the new size.
 */
 
 
 
+
+/*
+** {==================================================================
+** Functions to allocate/deallocate arrays for the Parser
+** ===================================================================
+*/
+
+/*
+** Minimum size for arrays during parsing, to avoid overhead of
+** reallocating to size 1, then 2, and then 4. All these arrays
+** will be reallocated to exact sizes or erased when parsing ends.
+*/
 #define MINSIZEARRAY	4
 
 
-void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
-                     int limit, const char *what) {
+void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize,
+                     int size_elems, int limit, const char *what) {
   void *newblock;
-  int newsize;
-  if (*size >= limit/2) {  /* cannot double it? */
-    if (*size >= limit)  /* cannot grow even a little? */
+  int size = *psize;
+  if (nelems + 1 <= size)  /* does one extra element still fit? */
+    return block;  /* nothing to be done */
+  if (size >= limit / 2) {  /* cannot double it? */
+    if (l_unlikely(size >= limit))  /* cannot grow even a little? */
       luaG_runerror(L, "too many %s (limit is %d)", what, limit);
-    newsize = limit;  /* still have at least one free place */
+    size = limit;  /* still have at least one free place */
   }
   else {
-    newsize = (*size)*2;
-    if (newsize < MINSIZEARRAY)
-      newsize = MINSIZEARRAY;  /* minimum size */
+    size *= 2;
+    if (size < MINSIZEARRAY)
+      size = MINSIZEARRAY;  /* minimum size */
   }
-  newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
-  *size = newsize;  /* update only when everything else is OK */
+  lua_assert(nelems + 1 <= size && size <= limit);
+  /* 'limit' ensures that multiplication will not overflow */
+  newblock = luaM_saferealloc_(L, block, cast_sizet(*psize) * size_elems,
+                                         cast_sizet(size) * size_elems);
+  *psize = size;  /* update only when everything else is OK */
   return newblock;
 }
 
 
+/*
+** In prototypes, the size of the array is also its number of
+** elements (to save memory). So, if it cannot shrink an array
+** to its number of elements, the only option is to raise an
+** error.
+*/
+void *luaM_shrinkvector_ (lua_State *L, void *block, int *size,
+                          int final_n, int size_elem) {
+  void *newblock;
+  size_t oldsize = cast_sizet((*size) * size_elem);
+  size_t newsize = cast_sizet(final_n * size_elem);
+  lua_assert(newsize <= oldsize);
+  newblock = luaM_saferealloc_(L, block, oldsize, newsize);
+  *size = final_n;
+  return newblock;
+}
+
+/* }================================================================== */
+
+
 l_noret luaM_toobig (lua_State *L) {
   luaG_runerror(L, "memory allocation error: block too big");
 }
 
 
+/*
+** Free memory
+*/
+void luaM_free_ (lua_State *L, void *block, size_t osize) {
+  global_State *g = G(L);
+  lua_assert((osize == 0) == (block == NULL));
+  (*g->frealloc)(g->ud, block, osize, 0);
+  g->GCdebt -= osize;
+}
+
 
 /*
-** generic allocation routine.
+** In case of allocation fail, this function will do an emergency
+** collection to free some memory and then try the allocation again.
+** The GC should not be called while state is not fully built, as the
+** collector is not yet fully initialized. Also, it should not be called
+** when 'gcstopem' is true, because then the interpreter is in the
+** middle of a collection step.
+*/
+static void *tryagain (lua_State *L, void *block,
+                       size_t osize, size_t nsize) {
+  global_State *g = G(L);
+  if (completestate(g) && !g->gcstopem) {
+    luaC_fullgc(L, 1);  /* try to free some memory... */
+    return (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
+  }
+  else return NULL;  /* cannot free any memory without a full state */
+}
+
+
+/*
+** Generic allocation routine.
 */
 void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
   void *newblock;
   global_State *g = G(L);
-  size_t realosize = (block) ? osize : 0;
-  lua_assert((realosize == 0) == (block == NULL));
-#if defined(HARDMEMTESTS)
-  if (nsize > realosize && g->gcrunning)
-    luaC_fullgc(L, 1);  /* force a GC whenever possible */
-#endif
-  newblock = (*g->frealloc)(g->ud, block, osize, nsize);
-  if (newblock == NULL && nsize > 0) {
-    lua_assert(nsize > realosize);  /* cannot fail when shrinking a block */
-    if (g->version) {  /* is state fully built? */
-      luaC_fullgc(L, 1);  /* try to free some memory... */
-      newblock = (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
-    }
-    if (newblock == NULL)
-      luaD_throw(L, LUA_ERRMEM);
+  lua_assert((osize == 0) == (block == NULL));
+  newblock = firsttry(g, block, osize, nsize);
+  if (l_unlikely(newblock == NULL && nsize > 0)) {
+    newblock = tryagain(L, block, osize, nsize);
+    if (newblock == NULL)  /* still no memory? */
+      return NULL;  /* do not update 'GCdebt' */
   }
   lua_assert((nsize == 0) == (newblock == NULL));
-  g->GCdebt = (g->GCdebt + nsize) - realosize;
+  g->GCdebt = (g->GCdebt + nsize) - osize;
   return newblock;
 }
 
+
+void *luaM_saferealloc_ (lua_State *L, void *block, size_t osize,
+                                                    size_t nsize) {
+  void *newblock = luaM_realloc_(L, block, osize, nsize);
+  if (l_unlikely(newblock == NULL && nsize > 0))  /* allocation failed? */
+    luaM_error(L);
+  return newblock;
+}
+
+
+void *luaM_malloc_ (lua_State *L, size_t size, int tag) {
+  if (size == 0)
+    return NULL;  /* that's all */
+  else {
+    global_State *g = G(L);
+    void *newblock = firsttry(g, NULL, tag, size);
+    if (l_unlikely(newblock == NULL)) {
+      newblock = tryagain(L, NULL, tag, size);
+      if (newblock == NULL)
+        luaM_error(L);
+    }
+    g->GCdebt += size;
+    return newblock;
+  }
+}