From: Stefan Behnel <stefan_ml@behnel.de>
Date: Mon, 29 Apr 2013 17:28:46 +0000 (+0200)
Subject: fix negative-index warning on empty slices
X-Git-Tag: 0.19.1~34
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6075a3c6cd3441e2b37de543f0f6327e6d65abb3;p=platform%2Fupstream%2Fpython-cython.git

fix negative-index warning on empty slices
---

diff --git a/Cython/Compiler/ExprNodes.py b/Cython/Compiler/ExprNodes.py
index d8f153b..42d067c 100755
--- a/Cython/Compiler/ExprNodes.py
+++ b/Cython/Compiler/ExprNodes.py
@@ -106,14 +106,14 @@ def check_negative_indices(*nodes):
     Used to find (potential) bugs inside of "wraparound=False" sections.
     """
     for node in nodes:
-        if not isinstance(node.constant_result, (int, float, long)):
+        if (node is None
+                or not isinstance(node.constant_result, (int, float, long))):
             continue
-        if node.constant_result >= 0:
-            continue
-        warning(node.pos,
-                "the result of using negative indices inside of "
-                "code sections marked as 'wraparound=False' is "
-                "undefined", level=1)
+        if node.constant_result < 0:
+            warning(node.pos,
+                    "the result of using negative indices inside of "
+                    "code sections marked as 'wraparound=False' is "
+                    "undefined", level=1)
 
 
 class ExprNode(Node):
diff --git a/tests/errors/wraparound_warnings.pyx b/tests/errors/wraparound_warnings.pyx
index 5d88bed..f8a166d 100644
--- a/tests/errors/wraparound_warnings.pyx
+++ b/tests/errors/wraparound_warnings.pyx
@@ -7,13 +7,18 @@ s = "abc"
 l = [1, 2, 3]
 
 def normal_wraparound(int i, bytes B not None, list L not None):
+    a = s[:]
     a = s[1:2]
     a = s[-2:-1]
     a = "abc"[-2:-1]
     a = "abc"[-2:i]
     a = B[-2:-1]
+    a = B[:-1]
+    a = B[-2:]
 
     b = l[1:2]
+    b = l[:2]
+    b = l[1:]
     b = l[-2:-1]
     b = [1, 2, 3][-2:-1]
     b = [1, 2, 3][-2:i]
@@ -21,27 +26,35 @@ def normal_wraparound(int i, bytes B not None, list L not None):
 
 @cython.wraparound(False)
 def no_wraparound(int i, bytes B not None, list L not None):
+    a = s[:]
     a = s[1:2]
     a = s[-2:-1]
-    a = "abc"[-2:-1]
+    a = "abc"[-2:-1]  # evaluated at compile time
     a = "abc"[-2:i]
+    a = B[:]
     a = B[-2:-1]
+    a = B[:-1]
+    a = B[-2:]
 
     b = l[1:2]
+    b = l[:2]
+    b = l[1:]
     b = l[-2:-1]
     b = [1, 2, 3][-2:i]
     b = L[-2:-1]
 
 
 _ERRORS = """
-25:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-25:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-27:15: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-28:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-28:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
 31:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
 31:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-32:19: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-33:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
-33:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+33:15: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+35:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+35:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+36:12: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+37:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+42:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+42:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+43:19: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+44:11: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
+44:14: the result of using negative indices inside of code sections marked as 'wraparound=False' is undefined
 """