remove usage of deprecated "U" file open mode flag which is enabled anyway

Cython/Build/Dependencies.py

@@ -399,7 +399,7 @@ def parse_dependencies(source_filename):
     # Actual parsing is way to slow, so we use regular expressions.
     # The only catch is that we must strip comments and string
     # literals ahead of time.
-    fh = Utils.open_source_file(source_filename, "rU", error_handling='ignore')
+    fh = Utils.open_source_file(source_filename, error_handling='ignore')
     try:
         source = fh.read()
     finally:

Cython/Compiler/Main.py

@@ -336,8 +336,7 @@ class Context(object):
         # Parse the given source file and return a parse tree.
         num_errors = Errors.num_errors
         try:
-            f = Utils.open_source_file(source_filename, "rU")
-            try:
+            with Utils.open_source_file(source_filename) as f:
                 from . import Parsing
                 s = PyrexScanner(f, source_desc, source_encoding = f.encoding,
                                  scope = scope, context = self)
@@ -349,8 +348,6 @@ class Context(object):
                         raise RuntimeError(
                             "Formal grammer can only be used with compiled Cython with an available pgen.")
                     ConcreteSyntaxTree.p_module(source_filename)
-            finally:
-                f.close()
         except UnicodeDecodeError, e:
             #import traceback
             #traceback.print_exc()
@@ -360,11 +357,8 @@ class Context(object):
             position = e.args[2]
             encoding = e.args[0]
 
-            f = open(source_filename, "rb")
-            try:
+            with open(source_filename, "rb") as f:
                 byte_data = f.read()
-            finally:
-                f.close()
 
             # FIXME: make this at least a little less inefficient
             for idx, c in enumerate(byte_data):

Cython/Compiler/Parsing.py

@@ -1768,13 +1768,10 @@ def p_include_statement(s, ctx):
         include_file_path = s.context.find_include_file(include_file_name, pos)
         if include_file_path:
             s.included_files.append(include_file_name)
-            f = Utils.open_source_file(include_file_path, mode="rU")
-            source_desc = FileSourceDescriptor(include_file_path)
-            s2 = PyrexScanner(f, source_desc, s, source_encoding=f.encoding, parse_comments=s.parse_comments)
-            try:
+            with Utils.open_source_file(include_file_path) as f:
+                source_desc = FileSourceDescriptor(include_file_path)
+                s2 = PyrexScanner(f, source_desc, s, source_encoding=f.encoding, parse_comments=s.parse_comments)
                 tree = p_statement_list(s2, ctx)
-            finally:
-                f.close()
             return tree
         else:
             return None

Cython/Compiler/Scanning.py

@@ -199,15 +199,10 @@ class FileSourceDescriptor(SourceDescriptor):
                 return lines
         except KeyError:
             pass
-        f = Utils.open_source_file(
-            self.filename, encoding=encoding,
-            error_handling=error_handling,
-            # newline normalisation is costly before Py2.6
-            require_normalised_newlines=False)
-        try:
+
+        with Utils.open_source_file(self.filename, encoding=encoding, error_handling=error_handling) as f:
             lines = list(f)
-        finally:
-            f.close()
+
         if key in self._lines:
             self._lines[key] = lines
         else:

Cython/Utils.py

@@ -244,16 +244,13 @@ def skip_bom(f):
 
 
 def open_source_file(source_filename, mode="r",
-                     encoding=None, error_handling=None,
-                     require_normalised_newlines=True):
+                     encoding=None, error_handling=None):
     if encoding is None:
         # Most of the time the coding is unspecified, so be optimistic that
         # it's UTF-8.
         f = open_source_file(source_filename, encoding="UTF-8", mode=mode, error_handling='ignore')
         encoding = detect_opened_file_encoding(f)
-        if (encoding == "UTF-8"
-                and error_handling == 'ignore'
-                and require_normalised_newlines):
+        if encoding == "UTF-8" and error_handling == 'ignore':
             f.seek(0)
             skip_bom(f)
             return f
@@ -266,8 +263,7 @@ def open_source_file(source_filename, mode="r",
             if source_filename.startswith(loader.archive):
                 return open_source_from_loader(
                     loader, source_filename,
-                    encoding, error_handling,
-                    require_normalised_newlines)
+                    encoding, error_handling)
         except (NameError, AttributeError):
             pass
 
@@ -279,8 +275,7 @@ def open_source_file(source_filename, mode="r",
 
 def open_source_from_loader(loader,
                             source_filename,
-                            encoding=None, error_handling=None,
-                            require_normalised_newlines=True):
+                            encoding=None, error_handling=None):
     nrmpath = os.path.normpath(source_filename)
     arcname = nrmpath[len(loader.archive)+1:]
     data = loader.get_data(arcname)