1 files changed, 102 insertions, 0 deletions
diff --git a/meson/symbolextractor.py b/meson/symbolextractor.py
new file mode 100755
index 0000000..f2c709d
--- /dev/null
+++ b/meson/symbolextractor.py
@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+
+# Copyright 2013-2015 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This script extracts the symbols of a given shared library
+# into a file. If the symbols have not changed, the file is not
+# touched. This information is used to skip link steps if the
+# ABI has not changed.
+
+# This file is basically a reimplementation of
+# http://cgit.freedesktop.org/libreoffice/core/commit/?id=3213cd54b76bc80a6f0516aac75a48ff3b2ad67c
+
+import sys, subprocess
+import mesonlib
+import argparse
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument('--cross-host', default=None, dest='cross_host',
+                    help='cross compilation host platform')
+parser.add_argument('args', nargs='+')
+
+def dummy_syms(outfilename):
+    """Just touch it so relinking happens always."""
+    open(outfilename, 'w').close()
+
+def write_if_changed(text, outfilename):
+    try:
+        oldtext = open(outfilename, 'r').read()
+        if text == oldtext:
+            return
+    except FileNotFoundError:
+        pass
+    open(outfilename, 'w').write(text)
+
+def linux_syms(libfilename, outfilename):
+    pe = subprocess.Popen(['readelf', '-d', libfilename], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    output = pe.communicate()[0].decode()
+    if pe.returncode != 0:
+        raise RuntimeError('Readelf does not work')
+    result = [x for x in output.split('\n') if 'SONAME' in x]
+    assert(len(result) <= 1)
+    pnm = subprocess.Popen(['nm', '--dynamic', '--extern-only', '--defined-only', '--format=posix', libfilename],
+                           stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    output = pnm.communicate()[0].decode()
+    if pnm.returncode != 0:
+        raise RuntimeError('nm does not work.')
+    result += [' '.join(x.split()[0:2]) for x in output.split('\n') if len(x) > 0]
+    write_if_changed('\n'.join(result) + '\n', outfilename)
+
+def osx_syms(libfilename, outfilename):
+    pe = subprocess.Popen(['otool', '-l', libfilename], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    output = pe.communicate()[0].decode()
+    if pe.returncode != 0:
+        raise RuntimeError('Otool does not work.')
+    arr = output.split('\n')
+    for (i, val) in enumerate(arr):
+        if 'LC_ID_DYLIB' in val:
+            match = i
+            break
+    result = [arr[match+2], arr[match+5]] # Libreoffice stores all 5 lines but the others seem irrelevant.
+    pnm = subprocess.Popen(['nm', '-g', '-P', libfilename], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    output = pnm.communicate()[0].decode()
+    if pnm.returncode != 0:
+        raise RuntimeError('nm does not work.')
+    result += [' '.join(x.split()[0:2]) for x in output.split('\n') if len(x) > 0 and not x.endswith('U')]
+    write_if_changed('\n'.join(result) + '\n', outfilename)
+
+def gen_symbols(libfilename, outfilename, cross_host):
+    if cross_host is not None:
+        # In case of cross builds just always relink.
+        # In theory we could determine the correct
+        # toolset but there are more important things
+        # to do.
+        dummy_syms(outfilename)
+    elif mesonlib.is_linux():
+        linux_syms(libfilename, outfilename)
+    elif mesonlib.is_osx():
+        osx_syms(libfilename, outfilename)
+    else:
+        dummy_syms(outfilename)
+
+if __name__ == '__main__':
+    options = parser.parse_args()
+    if len(options.args) != 2:
+        print(sys.argv[0], '<shared library file> <output file>')
+        sys.exit(1)
+    libfile = options.args[0]
+    outfile = options.args[1]
+    gen_symbols(libfile, outfile, options.cross_host)