+++ /dev/null
-/* Parse tree node implementation */\r
-\r
-#include "Python.h"\r
-#include "node.h"\r
-#include "errcode.h"\r
-\r
-node *\r
-PyNode_New(int type)\r
-{\r
- node *n = (node *) PyObject_MALLOC(1 * sizeof(node));\r
- if (n == NULL)\r
- return NULL;\r
- n->n_type = type;\r
- n->n_str = NULL;\r
- n->n_lineno = 0;\r
- n->n_nchildren = 0;\r
- n->n_child = NULL;\r
- return n;\r
-}\r
-\r
-/* See comments at XXXROUNDUP below. Returns -1 on overflow. */\r
-static int\r
-fancy_roundup(int n)\r
-{\r
- /* Round up to the closest power of 2 >= n. */\r
- int result = 256;\r
- assert(n > 128);\r
- while (result < n) {\r
- result <<= 1;\r
- if (result <= 0)\r
- return -1;\r
- }\r
- return result;\r
-}\r
-\r
-/* A gimmick to make massive numbers of reallocs quicker. The result is\r
- * a number >= the input. In PyNode_AddChild, it's used like so, when\r
- * we're about to add child number current_size + 1:\r
- *\r
- * if XXXROUNDUP(current_size) < XXXROUNDUP(current_size + 1):\r
- * allocate space for XXXROUNDUP(current_size + 1) total children\r
- * else:\r
- * we already have enough space\r
- *\r
- * Since a node starts out empty, we must have\r
- *\r
- * XXXROUNDUP(0) < XXXROUNDUP(1)\r
- *\r
- * so that we allocate space for the first child. One-child nodes are very\r
- * common (presumably that would change if we used a more abstract form\r
- * of syntax tree), so to avoid wasting memory it's desirable that\r
- * XXXROUNDUP(1) == 1. That in turn forces XXXROUNDUP(0) == 0.\r
- *\r
- * Else for 2 <= n <= 128, we round up to the closest multiple of 4. Why 4?\r
- * Rounding up to a multiple of an exact power of 2 is very efficient, and\r
- * most nodes with more than one child have <= 4 kids.\r
- *\r
- * Else we call fancy_roundup() to grow proportionately to n. We've got an\r
- * extreme case then (like test_longexp.py), and on many platforms doing\r
- * anything less than proportional growth leads to exorbitant runtime\r
- * (e.g., MacPython), or extreme fragmentation of user address space (e.g.,\r
- * Win98).\r
- *\r
- * In a run of compileall across the 2.3a0 Lib directory, Andrew MacIntyre\r
- * reported that, with this scheme, 89% of PyObject_REALLOC calls in\r
- * PyNode_AddChild passed 1 for the size, and 9% passed 4. So this usually\r
- * wastes very little memory, but is very effective at sidestepping\r
- * platform-realloc disasters on vulnerable platforms.\r
- *\r
- * Note that this would be straightforward if a node stored its current\r
- * capacity. The code is tricky to avoid that.\r
- */\r
-#define XXXROUNDUP(n) ((n) <= 1 ? (n) : \\r
- (n) <= 128 ? (((n) + 3) & ~3) : \\r
- fancy_roundup(n))\r
-\r
-\r
-int\r
-PyNode_AddChild(register node *n1, int type, char *str, int lineno, int col_offset)\r
-{\r
- const int nch = n1->n_nchildren;\r
- int current_capacity;\r
- int required_capacity;\r
- node *n;\r
-\r
- if (nch == INT_MAX || nch < 0)\r
- return E_OVERFLOW;\r
-\r
- current_capacity = XXXROUNDUP(nch);\r
- required_capacity = XXXROUNDUP(nch + 1);\r
- if (current_capacity < 0 || required_capacity < 0)\r
- return E_OVERFLOW;\r
- if (current_capacity < required_capacity) {\r
- if (required_capacity > PY_SIZE_MAX / sizeof(node)) {\r
- return E_NOMEM;\r
- }\r
- n = n1->n_child;\r
- n = (node *) PyObject_REALLOC(n,\r
- required_capacity * sizeof(node));\r
- if (n == NULL)\r
- return E_NOMEM;\r
- n1->n_child = n;\r
- }\r
-\r
- n = &n1->n_child[n1->n_nchildren++];\r
- n->n_type = type;\r
- n->n_str = str;\r
- n->n_lineno = lineno;\r
- n->n_col_offset = col_offset;\r
- n->n_nchildren = 0;\r
- n->n_child = NULL;\r
- return 0;\r
-}\r
-\r
-/* Forward */\r
-static void freechildren(node *);\r
-\r
-\r
-void\r
-PyNode_Free(node *n)\r
-{\r
- if (n != NULL) {\r
- freechildren(n);\r
- PyObject_FREE(n);\r
- }\r
-}\r
-\r
-static void\r
-freechildren(node *n)\r
-{\r
- int i;\r
- for (i = NCH(n); --i >= 0; )\r
- freechildren(CHILD(n, i));\r
- if (n->n_child != NULL)\r
- PyObject_FREE(n->n_child);\r
- if (STR(n) != NULL)\r
- PyObject_FREE(STR(n));\r
-}\r
projects / mirror_edk2.git / blobdiff