[Python-checkins] cpython: tracemalloc: only use unsigned types to compute hash

[victor.stinner]

http://hg.python.org/cpython/rev/f1766b7457e7
changeset:   88012:f1766b7457e7
user:        Victor Stinner <victor.stinner at gmail.com>
date:        Mon Dec 16 23:05:13 2013 +0100
summary:
  tracemalloc: only use unsigned types to compute hash

Commit to simplify the backport to python 2.7 and to make the code more
consistent.

files:
  Modules/_tracemalloc.c |  9 ++++-----
  1 files changed, 4 insertions(+), 5 deletions(-)


diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
--- a/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@ -336,8 +336,7 @@
 traceback_hash(traceback_t *traceback)
 {
     /* code based on tuplehash() of Objects/tupleobject.c */
-    Py_uhash_t x;  /* Unsigned for defined overflow behavior. */
-    Py_hash_t y;
+    Py_uhash_t x, y;  /* Unsigned for defined overflow behavior. */
     int len = traceback->nframe;
     Py_uhash_t mult = _PyHASH_MULTIPLIER;
     frame_t *frame;
@@ -345,13 +344,13 @@
     x = 0x345678UL;
     frame = traceback->frames;
     while (--len >= 0) {
-        y = PyObject_Hash(frame->filename);
-        y ^= frame->lineno;
+        y = (Py_uhash_t)PyObject_Hash(frame->filename);
+        y ^= (Py_uhash_t)frame->lineno;
         frame++;
 
         x = (x ^ y) * mult;
         /* the cast might truncate len; that doesn't change hash stability */
-        mult += (Py_hash_t)(82520UL + len + len);
+        mult += (Py_uhash_t)(82520UL + len + len);
     }
     x += 97531UL;
     return x;

-- 
Repository URL: http://hg.python.org/cpython