#!/usr/bin/env python3

"""
defcheck.py -- Consistency check for the .def files.
Copyright (C) 2006  Simon Budig <simon@gimp.org>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.


This is a hack to check the consistency of the .def files compared to
the respective libraries.

Invoke in the top level of the gimp source tree after compiling GIMP.
If srcdir != builddir, run it in the build directory and pass the name
of the source directory on the command-line.

Needs the tool "nm", "objdump" or "dumpbin" to work

"""

import os, sys, subprocess, shutil, glob

from os import getenv, path

def_files = (
   "libgimpbase/gimpbase.def",
   "libgimpcolor/gimpcolor.def",
   "libgimpconfig/gimpconfig.def",
   "libgimp/gimp.def",
   "libgimp/gimpui.def",
   "libgimpmath/gimpmath.def",
   "libgimpmodule/gimpmodule.def",
   "libgimpthumb/gimpthumb.def",
   "libgimpwidgets/gimpwidgets.def"
)

have_errors = 0

srcdir = None
if len(sys.argv) > 1:
   srcdir = sys.argv[1]
   if not path.exists(srcdir):
      print("Directory '%s' does not exist" % srcdir)
      sys.exit (-1)

libextension   = ".so"
command        = getenv("NM", default="nm") + " --defined-only --extern-only "
libprefix      = "lib"
platform_linux = True

if sys.platform in ['win32', 'cygwin']:
   libextension   = ".dll"
   command        = "objdump -p "
   if shutil.which("dumpbin"):
     command      = "dumpbin /EXPORTS "
     libprefix    = ""
   platform_linux = False

for df in def_files:
   directory, name = path.split (df)
   basename, extension = name.split (".")

   libname = path.join(os.getcwd(), directory, libprefix + basename + "-*" + libextension)
   matches = glob.glob(libname)
   if matches:
     libname = matches[0]
   #FIXME: This leaks to ninja stdout, which should not happen
   #print ("platform: " + sys.platform + " - extracting symbols from " + libname)

   filename = df
   if srcdir:
      filename = path.join(srcdir, df)
   try:
      defsymbols = open (filename).read ().split ()[1:]
   except IOError as message:
      print(message)
      if not srcdir:
         print("You should run this script from the toplevel source directory.")
      sys.exit (-1)

   doublesymbols = []
   for i in range (len (defsymbols)-1, 0, -1):
      if defsymbols[i] in defsymbols[:i]:
         doublesymbols.append ((defsymbols[i], i+2))

   sorterrors = ""
   sortok = True
   for i in range (len (defsymbols)-1):
      if defsymbols[i].lower() > defsymbols[i+1].lower():
         sorterrors += f"{defsymbols[i]} > {defsymbols[i+1]}\n"
         sortok = False
   sorterrors = sorterrors.split(sep='\n')

   status, nm = subprocess.getstatusoutput (command + libname)
   if status != 0:
      print("trouble reading {} - has it been compiled?".format(libname))
      print(nm)
      have_errors = -1
      continue

   nmsymbols = ""
   if platform_linux:
      nmsymbols = nm

   elif not shutil.which("dumpbin"): # Windows MSYS2
      # remove parts of objdump output we don't need: anything up to a few lines
      # after Export Table: ' Ordinal      RVA  Name'

      objnm = nm.split(sep='\n')

      found = False
      nmsymbols = ""
      for s in objnm:
         if "Ordinal   Hint Name" in s or " Ordinal      RVA  Name" in s:
            found = True
         elif found:
            s = s.strip()
            if not s:
               break
            nmsymbols += " 0 0 " + s.split()[-1] # Keep the [2::3] logic happy
         # else: skip this line

   else: # Windows MSVC

      dbin = nm.split(sep='\n')

      found = False
      nmsymbols = ""
      for s in dbin:
         if "ordinal" in s and "hint" in s and "RVA" in s:
            found = True
         elif found and s.strip() and "Summary" not in s:
            parts = s.split()
            if len(parts) >= 4:
               nmsymbols += " 0 0 " + parts[3] # Keep the [2::3] logic happy
         # else: skip this line

   nmsymbols = nmsymbols.split()[2::3]
   nmsymbols = [s for s in nmsymbols if s[0] != '_']

   missing_defs = [s for s in nmsymbols  if s not in defsymbols]
   missing_nms  = [s for s in defsymbols if s not in nmsymbols]

   if missing_defs or missing_nms or doublesymbols or not sortok:
      print()
      print("Problem found in", filename)

      if missing_defs:
         print("  the following symbols are in the library,")
         print("  but are not listed in the .def-file:")
         for s in missing_defs:
            print("     +", s)
         print()

      if missing_nms:
         print("  the following symbols are listed in the .def-file,")
         print("  but are not exported by the library.")
         for s in missing_nms:
            print("     -", s)
         print()

      if doublesymbols:
         print("  the following symbols are listed multiple times in the .def-file,")
         for s in doublesymbols:
            print("     : %s (line %d)" % s)
         print()

      if not sortok:
         print("  the .def-file is not properly sorted in the following cases")
         for s in sorterrors:
            if s != "":
               print("     * ", s)

      have_errors = -1

sys.exit (have_errors)