scripts/clean-includes: Enhance to handle header files

Enhance clean-includes to handle header files as well as .c source
files. For headers we merely remove all the redundant #include
lines, including any includes of qemu/osdep.h itself.

There is a simple mollyguard on the include file processing to
skip a few key headers like osdep.h itself, to avoid producing
bad patches if the script is run on every file in include/.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>

scripts/clean-includes

@@ -1,7 +1,8 @@
 #!/bin/sh -e
 #
 # Clean up QEMU #include lines by ensuring that qemu/osdep.h
-# is the first include listed.
+# is the first include listed in .c files, and no headers provided
+# by osdep.h itself are redundantly included in either .c or .h files.
 #
 # Copyright (c) 2015 Linaro Limited
 #
@@ -22,6 +23,11 @@
 
 # This script requires Coccinelle to be installed.
 
+# .c files will have the osdep.h included added, and redundant
+# includes removed.
+# .h files will have redundant includes (including includes of osdep.h)
+# removed.
+# Other files (including C++ and ObjectiveC) can't be handled by this script.
 
 # The following one-liner may be handy for finding files to run this on.
 # However some caution is required regarding files that might be part
@@ -73,13 +79,44 @@ EOT
 
 
 for f in "$@"; do
-  # First, use coccinelle to add qemu/osdep.h before the first existing include
+  case "$f" in
+    *.c)
+      MODE=c
+      ;;
+    *include/qemu/osdep.h | \
+    *include/qemu/compiler.h | \
+    *include/config.h | \
+    *include/standard-headers/ )
+      # Removing include lines from osdep.h itself would be counterproductive.
+      echo "SKIPPING $f (special case header)"
+      continue
+      ;;
+    *include/standard-headers/*)
+      echo "SKIPPING $f (autogenerated header)"
+      continue
+      ;;
+    *.h)
+      MODE=h
+      ;;
+    *)
+      echo "WARNING: ignoring $f (cannot handle non-C files)"
+      continue
+      ;;
+  esac
+
+  if [ "$MODE" = "c" ]; then
+    # First, use Coccinelle to add qemu/osdep.h before the first existing include
     # (this will add two lines if the file uses both "..." and <...> #includes,
     # but we will remove the extras in the next step)
     spatch  --in-place --no-show-diff --cocci-file "$COCCIFILE" "$f"
 
     # Now remove any duplicate osdep.h includes
     perl -n -i -e 'print if !/#include "qemu\/osdep.h"/ || !$n++;' "$f"
+  else
+    # Remove includes of osdep.h itself
+    perl -n -i -e 'print if !/\s*#\s*include\s*(["<][^>"]*[">])/ ||
+                            ! (grep { $_ eq $1 } qw ("qemu/osdep.h"))' "$f"
+  fi
 
   # Remove includes that osdep.h already provides
   perl -n -i -e 'print if !/\s*#\s*include\s*(["<][^>"]*[">])/ ||