1 files changed, 26 insertions, 19 deletions

diff --git a/numpy/linalg/lapack_lite/clapack_scrub.py b/numpy/linalg/lapack_lite/clapack_scrub.py
index 738fad7fe..fffd70910 100644
--- a/numpy/linalg/lapack_lite/clapack_scrub.py
+++ b/numpy/linalg/lapack_lite/clapack_scrub.py
@@ -1,12 +1,17 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python2.7
+# WARNING! This a Python 2 script. Read README.rst for rationale.
 import os
 import re
 import sys
-from io import StringIO
 
 from plex import Scanner, Str, Lexicon, Opt, Bol, State, AnyChar, TEXT, IGNORE
 from plex.traditional import re as Re
 
+try:
+    from io import BytesIO as UStringIO  # Python 2
+except ImportError:
+    from io import StringIO as UStringIO  # Python 3
+
 
 class MyScanner(Scanner):
     def __init__(self, info, name='<default>'):
@@ -22,8 +27,8 @@ def sep_seq(sequence, sep):
     return pat
 
 def runScanner(data, scanner_class, lexicon=None):
-    info = StringIO(data)
-    outfo = StringIO()
+    info = UStringIO(data)
+    outfo = UStringIO()
     if lexicon is not None:
         scanner = scanner_class(lexicon, info)
     else:
@@ -190,7 +195,7 @@ def cleanComments(source):
             return SourceLines
 
     state = SourceLines
-    for line in StringIO(source):
+    for line in UStringIO(source):
         state = state(line)
     comments.flushTo(lines)
     return lines.getValue()
@@ -218,20 +223,23 @@ def removeHeader(source):
         return OutOfHeader
 
     state = LookingForHeader
-    for line in StringIO(source):
+    for line in UStringIO(source):
         state = state(line)
     return lines.getValue()
 
 def removeSubroutinePrototypes(source):
-    expression = re.compile(
-        r'/\* Subroutine \*/^\s*(?:(?:inline|static)\s+){0,2}(?!else|typedef|return)\w+\s+\*?\s*(\w+)\s*\([^0]+\)\s*;?'
-    )
-    lines = LineQueue()
-    for line in StringIO(source):
-        if not expression.match(line):
-            lines.add(line)
-
-    return lines.getValue()
+    # This function has never worked as advertised by its name:
+    # - "/* Subroutine */" declarations may span multiple lines and
+    #   cannot be matched by a line by line approach.
+    # - The caret in the initial regex would prevent any match, even
+    #   of single line "/* Subroutine */" declarations.
+    #
+    # While we could "fix" this function to do what the name implies
+    # it should do, we have no hint of what it should really do.
+    #
+    # Therefore we keep the existing (non-)functionaity, documenting
+    # this function as doing nothing at all.
+    return source
 
 def removeBuiltinFunctions(source):
     lines = LineQueue()
@@ -249,7 +257,7 @@ def removeBuiltinFunctions(source):
             return InBuiltInFunctions
 
     state = LookingForBuiltinFunctions
-    for line in StringIO(source):
+    for line in UStringIO(source):
         state = state(line)
     return lines.getValue()
 
@@ -299,6 +307,5 @@ if __name__ == '__main__':
 
     source = scrub_source(source, nsteps, verbose=True)
 
-    writefo = open(outfilename, 'w')
-    writefo.write(source)
-    writefo.close()
+    with open(outfilename, 'w') as writefo:
+        writefo.write(source)