rectify_include_paths: warn instead of aborting on duplicate headers

We have two sendme.h files at the moment; we should fix that, but
not in this branch.

scripts/maint/rectify_include_paths.py

@@ -3,6 +3,10 @@
 import os
 import os.path
 import re
+import sys
+
+def warn(msg):
+    sys.stderr.write("WARNING: %s\n"%msg)
 
 # Find all the include files, map them to their real names.
 
@@ -11,6 +15,8 @@ def exclude(paths, dirnames):
         if p in dirnames:
             dirnames.remove(p)
 
+DUPLICATE = object()
+
 def get_include_map():
     includes = { }
 
@@ -19,7 +25,10 @@ def get_include_map():
 
         for fname in fnames:
             if fname.endswith(".h"):
-                assert fname not in includes
+                if fname in includes:
+                    warn("Multiple headers named %s"%fname)
+                    includes[fname] = DUPLICATE
+                    continue
                 include = os.path.join(dirpath, fname)
                 assert include.startswith("src/")
                 includes[fname] = include[4:]
@@ -37,7 +46,7 @@ def fix_includes(inp, out, mapping):
         if m:
             include,hdr,rest = m.groups()
             basehdr = get_base_header_name(hdr)
-            if basehdr in mapping:
+            if basehdr in mapping and mapping[basehdr] is not DUPLICATE:
                 out.write('{}{}{}\n'.format(include,mapping[basehdr],rest))
                 continue