1 files changed, 138 insertions, 0 deletions
diff --git a/AppPkg/Applications/Python/Python-2.7.2/Parser/node.c b/AppPkg/Applications/Python/Python-2.7.2/Parser/node.c
new file mode 100644
index 0000000000..4949b7cb64
--- /dev/null
+++ b/AppPkg/Applications/Python/Python-2.7.2/Parser/node.c
@@ -0,0 +1,138 @@
+/* Parse tree node implementation */
+
+#include "Python.h"
+#include "node.h"
+#include "errcode.h"
+
+node *
+PyNode_New(int type)
+{
+    node *n = (node *) PyObject_MALLOC(1 * sizeof(node));
+    if (n == NULL)
+        return NULL;
+    n->n_type = type;
+    n->n_str = NULL;
+    n->n_lineno = 0;
+    n->n_nchildren = 0;
+    n->n_child = NULL;
+    return n;
+}
+
+/* See comments at XXXROUNDUP below.  Returns -1 on overflow. */
+static int
+fancy_roundup(int n)
+{
+    /* Round up to the closest power of 2 >= n. */
+    int result = 256;
+    assert(n > 128);
+    while (result < n) {
+        result <<= 1;
+        if (result <= 0)
+            return -1;
+    }
+    return result;
+}
+
+/* A gimmick to make massive numbers of reallocs quicker.  The result is
+ * a number >= the input.  In PyNode_AddChild, it's used like so, when
+ * we're about to add child number current_size + 1:
+ *
+ *     if XXXROUNDUP(current_size) < XXXROUNDUP(current_size + 1):
+ *         allocate space for XXXROUNDUP(current_size + 1) total children
+ *     else:
+ *         we already have enough space
+ *
+ * Since a node starts out empty, we must have
+ *
+ *     XXXROUNDUP(0) < XXXROUNDUP(1)
+ *
+ * so that we allocate space for the first child.  One-child nodes are very
+ * common (presumably that would change if we used a more abstract form
+ * of syntax tree), so to avoid wasting memory it's desirable that
+ * XXXROUNDUP(1) == 1.  That in turn forces XXXROUNDUP(0) == 0.
+ *
+ * Else for 2 <= n <= 128, we round up to the closest multiple of 4.  Why 4?
+ * Rounding up to a multiple of an exact power of 2 is very efficient, and
+ * most nodes with more than one child have <= 4 kids.
+ *
+ * Else we call fancy_roundup() to grow proportionately to n.  We've got an
+ * extreme case then (like test_longexp.py), and on many platforms doing
+ * anything less than proportional growth leads to exorbitant runtime
+ * (e.g., MacPython), or extreme fragmentation of user address space (e.g.,
+ * Win98).
+ *
+ * In a run of compileall across the 2.3a0 Lib directory, Andrew MacIntyre
+ * reported that, with this scheme, 89% of PyObject_REALLOC calls in
+ * PyNode_AddChild passed 1 for the size, and 9% passed 4.  So this usually
+ * wastes very little memory, but is very effective at sidestepping
+ * platform-realloc disasters on vulnerable platforms.
+ *
+ * Note that this would be straightforward if a node stored its current
+ * capacity.  The code is tricky to avoid that.
+ */
+#define XXXROUNDUP(n) ((n) <= 1 ? (n) :                 \
+               (n) <= 128 ? (((n) + 3) & ~3) :          \
+               fancy_roundup(n))
+
+
+int
+PyNode_AddChild(register node *n1, int type, char *str, int lineno, int col_offset)
+{
+    const int nch = n1->n_nchildren;
+    int current_capacity;
+    int required_capacity;
+    node *n;
+
+    if (nch == INT_MAX || nch < 0)
+        return E_OVERFLOW;
+
+    current_capacity = XXXROUNDUP(nch);
+    required_capacity = XXXROUNDUP(nch + 1);
+    if (current_capacity < 0 || required_capacity < 0)
+        return E_OVERFLOW;
+    if (current_capacity < required_capacity) {
+        if (required_capacity > PY_SIZE_MAX / sizeof(node)) {
+            return E_NOMEM;
+        }
+        n = n1->n_child;
+        n = (node *) PyObject_REALLOC(n,
+                                      required_capacity * sizeof(node));
+        if (n == NULL)
+            return E_NOMEM;
+        n1->n_child = n;
+    }
+
+    n = &n1->n_child[n1->n_nchildren++];
+    n->n_type = type;
+    n->n_str = str;
+    n->n_lineno = lineno;
+    n->n_col_offset = col_offset;
+    n->n_nchildren = 0;
+    n->n_child = NULL;
+    return 0;
+}
+
+/* Forward */
+static void freechildren(node *);
+
+
+void
+PyNode_Free(node *n)
+{
+    if (n != NULL) {
+        freechildren(n);
+        PyObject_FREE(n);
+    }
+}
+
+static void
+freechildren(node *n)
+{
+    int i;
+    for (i = NCH(n); --i >= 0; )
+        freechildren(CHILD(n, i));
+    if (n->n_child != NULL)
+        PyObject_FREE(n->n_child);
+    if (STR(n) != NULL)
+        PyObject_FREE(STR(n));
+}