[pseudo,17/20] makewrappers: improve error handling and robustness

diff --git a/makewrappers b/makewrappers
index c9f6ad5..326f70e 100755
--- a/makewrappers
+++ b/makewrappers
@@ -12,7 +12,6 @@  import sys
 import re
 import os.path
 import platform
-import string
 import subprocess
 from templatefile import TemplateFile
 
@@ -152,9 +151,11 @@  class Argument:
 
         # spacing between type and name, needed if type ends with a character
         # which could be part of an identifier
-        if re.match('[_a-zA-Z0-9]', self.type[-1]):
+        if self.type and re.match('[_a-zA-Z0-9]', self.type[-1]):
             self.spacer = ' '
 
+        return
+
     def decl(self, comment=False, wrap=False):
         """Produce the declaration form of this argument."""
         if self.function_pointer:
@@ -274,13 +275,13 @@  class Function:
             # ignore varargs, they never get these special treatments
             if arg.vararg:
                 pass
-            elif arg.name.endswith('dirfd'):
+            elif arg.name and arg.name.endswith('dirfd'):
                 if len(arg.name) > 5:
                     self.specific_dirfds[arg.name[:-5]] = True
                 self.dirfd = 'dirfd'
             elif arg.name == 'flags':
                 self.flags = '(flags & AT_SYMLINK_NOFOLLOW)'
-            elif arg.name.endswith('path'):
+            elif arg.name and arg.name.endswith('path'):
                 self.paths_to_munge.append(arg.name)
             elif arg.name == 'fd':
                 self.fd_arg = "fd"
@@ -304,6 +305,10 @@  class Function:
         # handle special comments, such as flags=AT_SYMLINK_NOFOLLOW
         if self.comments:
             comments = self.comments.replace('==','<equals>')
+            # Validate the comments
+            for mod in comments.split(','):
+                if '=' not in mod:
+                    raise Exception("Parse error invalid comment '%s'" % (comments))
             # Build a dictionary of key=value, key=value pairs
             modifiers = dict(mod.split("=") for mod in comments.split(','))
             # Strip all leading/trailing whitespace
@@ -535,7 +540,8 @@  additional ports to include.
         if os.path.exists(self.portfile("preports")):
             subport_proc = subprocess.Popen([self.portfile("preports"), self.name], stdout=subprocess.PIPE)
             portlist = subport_proc.communicate()[0]
-            retcode = subport_proc.poll()
+            portlist = portlist.decode("utf-8")
+            retcode = subport_proc.returncode
             if retcode:
                 raise Exception("preports script failed for port %s" % self.name)
 
@@ -546,7 +552,8 @@  additional ports to include.
         if os.path.exists(self.portfile("subports")):
             subport_proc = subprocess.Popen([self.portfile("subports"), self.name], stdout=subprocess.PIPE)
             portlist = subport_proc.communicate()[0]
-            retcode = subport_proc.poll()
+            portlist = portlist.decode("utf-8")
+            retcode = subport_proc.returncode
             if retcode:
                 raise Exception("subports script failed for port %s" % self.name)
 
@@ -622,20 +629,23 @@  def process_wrapfuncs(port):
     funcs = {}
     directory = os.path.dirname(filename)
     sys.stdout.write("%s: " % filename)
-    funclist = open(filename)
-    for line in funclist:
-        line = line.rstrip()
-        if line.startswith('#') or not line:
-            continue
-        try:
-            func = Function(port, line)
-            func.directory = directory
-            funcs[func.name] = func
-            sys.stdout.write(".")
-        except Exception as e:
-            print("Parsing failed:", e)
-            exit(1)
-    funclist.close()
+    try:
+        with open(filename, "r") as funclist:
+            for line in funclist:
+                line = line.rstrip()
+                if line.startswith('#') or not line:
+                    continue
+                try:
+                    func = Function(port, line)
+                    func.directory = directory
+                    funcs[func.name] = func
+                    sys.stdout.write(".")
+                except Exception as e:
+                    print("Parsing failed:", e)
+                    exit(1)
+    except OSError as e:
+        print("Unable to open file %s" % filename)
+        exit(1)
     print("")
     return funcs
 
@@ -645,13 +655,19 @@  def main(argv):
     sources = []
 
     for arg in argv:
+        if '=' not in arg:
+            print("Invalid argument '%s', must be of the form name=value" % arg)
+            exit(1)
         name, value = arg.split('=')
         os.environ["port_" + name] = value
 
     # error checking helpfully provided by the exception handler
-    copyright_file = open('guts/COPYRIGHT')
-    TemplateFile.copyright = copyright_file.read()
-    copyright_file.close()
+    try:
+        with open('guts/COPYRIGHT') as copyright_file:
+            TemplateFile.copyright = copyright_file.read()
+    except OSError as e:
+        print("Unable to open file guts/COPYRIGHT")
+        exit(1)
 
     for path in glob.glob('templates/*'):
         try:
@@ -665,16 +681,7 @@  def main(argv):
             print("Invalid or malformed template %s.  Aborting." % path)
             exit(1)
 
-    try:
-        port = Port('common', sources)
-
-    except KeyError:
-        print("Unknown uname -s result: '%s'." % uname_s)
-        print("Known system types are:")
-        print("%-20s %-10s %s" % ("uname -s", "port name", "description"))
-        for key in host_ports:
-            print("%-20s %-10s %s" % (key, host_ports[key],
-                                      host_descrs[host_ports[key]]))
+    port = Port('common', sources)
 
     # the per-function stuff
     print("Writing functions...")