From d97eabb0bc76c942f4063b634c349cc5b10f3318 Mon Sep 17 00:00:00 2001
From: John Stumpo <stump@jstump.com>
Date: Sat, 27 Nov 2010 00:43:09 -0500
Subject: [PATCH] Generate .def files for the dependency DLLs at the end of the
 cross-build script.

---
 .gitignore              |   1 +
 win32/makedefs.py       | 122 ++++++++++++++++++++++++++++++++++++++++
 win32/makedeps-cross.sh |   5 ++
 win32/makedist.sh       |   2 +-
 4 files changed, 129 insertions(+), 1 deletion(-)
 create mode 100755 win32/makedefs.py

diff --git a/.gitignore b/.gitignore
index 4d4e7a532..e6eee0860 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,3 +30,4 @@ data/themes/*
 !data/themes/Uberlight
 win32/*
 !win32/*.sh
+!win32/*.py
diff --git a/win32/makedefs.py b/win32/makedefs.py
new file mode 100755
index 000000000..f55f324cb
--- /dev/null
+++ b/win32/makedefs.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+# Script to create .defs from a folder of MinGW implibs and a folder of DLLs.
+# Copyright (C) 2010 John Stumpo
+#
+# 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 2 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 <http://www.gnu.org/licenses/>.
+
+import os
+import struct
+import sys
+import glob
+import shlex
+import re
+import subprocess
+
+if len(sys.argv) != 4:
+    sys.stderr.write('''Usage: %s [implib-dir] [dll-dir] [identify-cmd]
+For each MinGW-style import library in implib-dir, locates the corresponding
+DLL in dll-dir and creates a .def file for it in implib-dir, which MSVC
+tools can be run on to create an MSVC-compatible implib.
+
+identify-cmd is run on each implib to discover what DLL it goes with. It is
+split into an argument list using sh-style rules, then the implib name is
+added to the end of the argument list.
+
+The .def files are named [whatever goes after -l to link to the lib].def
+''' % sys.argv[0])
+    sys.exit(1)
+
+def make_def(file):
+    f = open(file, 'rb')
+    if f.read(2) != 'MZ':
+        raise ValueError, 'Incorrect magic number in file.'
+    f.seek(60)
+    pe_header_offset = struct.unpack('<L', f.read(4))[0]
+    f.seek(pe_header_offset)
+    if f.read(4) != 'PE\0\0':
+        raise ValueError, 'Incorrect magic number in file.'
+
+    # Get sizes of tables we need.
+    f.seek(pe_header_offset + 6)
+    number_of_sections = struct.unpack('<H', f.read(2))[0]
+    f.seek(pe_header_offset + 116)
+    number_of_data_directory_entries = struct.unpack('<L', f.read(4))[0]
+    data_directory_offset = f.tell()  # it's right after the number of entries
+
+    # Where is the export table?
+    f.seek(data_directory_offset)
+    rva_of_export_table = struct.unpack('<L', f.read(4))[0]
+
+    # Get the section ranges so we can convert RVAs to file offsets.
+    f.seek(data_directory_offset + 8 * number_of_data_directory_entries)
+    sections = []
+    for i in range(number_of_sections):
+        section_descriptor_data = f.read(40)
+        name, size, va, rawsize, offset = struct.unpack('<8sLLLL', section_descriptor_data[:24])
+        sections.append({'min': va, 'max': va+rawsize, 'offset': offset})
+
+    def seek_to_rva(rva):
+        for s in sections:
+            if s['min'] <= rva and rva < s['max']:
+                f.seek(rva - s['min'] + s['offset'])
+                return
+        raise ValueError, 'Could not find section for RVA.'
+
+    # Read the relevant fields of the export directory.
+    seek_to_rva(rva_of_export_table + 12)
+    rva_of_dll_name = struct.unpack('<L', f.read(4))[0]
+    seek_to_rva(rva_of_export_table + 24)
+    number_of_names = struct.unpack('<L', f.read(4))[0]
+    seek_to_rva(rva_of_export_table + 32)
+    rva_of_name_array = struct.unpack('<L', f.read(4))[0]
+
+    def read_asciiz(rva):
+        seek_to_rva(rva)
+        value = ''
+        while True:
+            c = f.read(1)
+            if c in ('\0', ''):
+                break
+            value += c
+        return value
+
+    # Build the .def file contents with a list of all exported symbols.
+    dllname = read_asciiz(rva_of_dll_name)
+    def_contents = 'LIBRARY %s\nEXPORTS\n' % dllname
+
+    seek_to_rva(rva_of_name_array)
+    name_rvas = struct.unpack('<%sL' % number_of_names, f.read(4 * number_of_names))
+    for name_rva in name_rvas:
+        def_contents += '    %s\n' % read_asciiz(name_rva)
+
+    return def_contents
+
+
+implibs = glob.glob(os.path.join(sys.argv[1], 'lib*.a'))
+dlls = os.listdir(sys.argv[2])
+identify_cmd = shlex.split(sys.argv[3])
+
+for implib in implibs:
+    dash_l_name = re.match(r'^lib(.*?)(?:\.dll)?\.a$', os.path.basename(implib)).group(1)
+    identify_proc = subprocess.Popen(identify_cmd + [implib], stdout=subprocess.PIPE)
+    dllnames = identify_proc.stdout.readlines()
+    if identify_proc.wait() != 0 or len(dllnames) != 1:
+        print >>sys.stderr, 'Could not get a unique DLL name from %s.' % implib
+        continue
+    dllname = dllnames[0].rstrip('\n')
+
+    for dll in dlls:
+        if dll.lower() == dllname.lower():
+            def_contents = make_def(os.path.join(sys.argv[2], dll))
+            open(os.path.join(sys.argv[1], dash_l_name+'.def'), 'w').write(def_contents)
diff --git a/win32/makedeps-cross.sh b/win32/makedeps-cross.sh
index 190c59c14..e16a396af 100755
--- a/win32/makedeps-cross.sh
+++ b/win32/makedeps-cross.sh
@@ -60,6 +60,7 @@ assert_binary_on_path autoreconf
 assert_binary_on_path libtoolize
 assert_binary_on_path make
 assert_binary_on_path pkg-config
+assert_binary_on_path python
 assert_binary_on_path svn
 assert_binary_on_path tar
 assert_binary_on_path unzip
@@ -277,3 +278,7 @@ if test ! -f "$PREFIX"/build-stamps/ffmpeg; then
 fi
 
 echo "All dependencies done."
+
+echo -n "Creating .def files... "
+python makedefs.py deps/lib deps/bin "$CROSS_DLLTOOL -I"
+echo "done"
diff --git a/win32/makedist.sh b/win32/makedist.sh
index 7000c0e06..f37582bcd 100755
--- a/win32/makedist.sh
+++ b/win32/makedist.sh
@@ -4,7 +4,7 @@ mkdir -pv dist
 cp -av deps dist
 
 rm -rf dist/deps/build-stamps dist/deps/etc dist/deps/share dist/deps/lib/gettext
-rm -vf dist/deps/lib/*.def dist/deps/lib/*.la dist/deps/bin/wine-shwrap dist/deps/bin/pkg-config
+rm -vf dist/deps/lib/*.la dist/deps/bin/wine-shwrap dist/deps/bin/pkg-config
 i586-mingw32msvc-strip --strip-all dist/deps/bin/*.exe dist/deps/bin/*.dll
 ZIPFILE="fofix-win32-deppack-`date +%Y%m%d`.zip"
 rm -f "$ZIPFILE"