[pypy-svn] pypy fast-forward: warnings.warn can still display the source line even when

[amauryfa]

Author: Amaury Forgeot d'Arc <amauryfa at gmail.com>
Branch: fast-forward
Changeset: r40386:9c14c6964756
Date: 2011-01-04 16:46 +0100
http://bitbucket.org/pypy/pypy/changeset/9c14c6964756/

Log:	warnings.warn can still display the source line even when
	showarning() is missing

diff --git a/pypy/module/_warnings/test/test_warnings.py b/pypy/module/_warnings/test/test_warnings.py
--- a/pypy/module/_warnings/test/test_warnings.py
+++ b/pypy/module/_warnings/test/test_warnings.py
@@ -43,5 +43,20 @@
             assert len(w) == 0
         warnings.defaultaction = 'default'
 
+    def test_show_source_line(self):
+        import warnings
+        import sys, StringIO
+        from test.warning_tests import inner
+        # With showarning() missing, make sure that output is okay.
+        del warnings.showwarning
 
+        stderr = sys.stderr
+        try:
+            sys.stderr = StringIO.StringIO()
+            inner('test message')
+            result = sys.stderr.getvalue()
+        finally:
+            sys.stderr = stderr
 
+        assert result.count('\n') == 2
+        assert '  warnings.warn(message, ' in result

diff --git a/pypy/module/_warnings/interp_warnings.py b/pypy/module/_warnings/interp_warnings.py
--- a/pypy/module/_warnings/interp_warnings.py
+++ b/pypy/module/_warnings/interp_warnings.py
@@ -211,15 +211,31 @@
     space.call_method(w_stderr, "write", space.wrap(message))
 
     # Print "  source_line\n"
-    if w_sourceline:
-        line = space.str_w(w_sourceline)
-        message = "\n"
-        for i in range(len(line)):
-            c = line[i]
-            if c not in ' \t\014':
-                message = "  %s\n" % (line[i:],)
-                break
-        space.call_method(w_stderr, "write", space.wrap(message))
+    if not w_sourceline:
+        try:
+            # sourceline = linecache.getline(filename, lineno).strip()
+            w_builtins = space.getbuiltinmodule('__builtin__')
+            w_linecachemodule = space.call_method(w_builtins, '__import__',
+                                                  space.wrap("linecache"))
+            w_sourceline = space.call_method(w_linecachemodule, "getline",
+                                             w_filename, space.wrap(lineno))
+            w_sourceline = space.call_method(w_sourceline, "strip")
+        except OperationError:
+            w_sourceline = None
+
+    if not w_sourceline:
+        return
+    line = space.str_w(w_sourceline)
+    if not line:
+        return
+
+    message = "\n"
+    for i in range(len(line)):
+        c = line[i]
+        if c not in ' \t\014':
+            message = "  %s\n" % (line[i:],)
+            break
+    space.call_method(w_stderr, "write", space.wrap(message))
 
 def do_warn(space, w_message, w_category, stacklevel):
     context_w = setup_context(space, stacklevel)