build: Add a distutils-based build system for the Python bits

This is a streamlined version of the libxml2 setup.py.in that is
adapted for libxslt so that one can build the Python bindings and build
wheels easily, especially for Windows builds.

This will bundle the libxslt and libexslt DLLs, which matters more for
Python 3.8.x and later on Windows, where the dependent DLLs need to be
found at where the .pyd files are located unless one uses
os.add_dll_directory(); the libxml2 (and its dependent DLLs) should be
located with the libxml2-python package.

configure.ac

@@ -549,6 +549,7 @@
 libexslt/exsltconfig.h
 xsltproc/Makefile
 python/Makefile
+python/setup.py
 python/tests/Makefile
 tests/Makefile
 tests/xmlspec/Makefile

python/Makefile.am

@@ -13,7 +13,8 @@
 	libxml_wrap.h		\
 	libxslt_wrap.h		\
 	libxsl.py		\
-	libxslt-python-api.xml
+	libxslt-python-api.xml	\
+	setup.py.in
 
 if WITH_PYTHON
 

python/setup.py.in

+#!/usr/bin/python -u
+#
+# Setup script for libxml2 and libxslt if found
+#
+import sys, os, subprocess
+
+try:
+    import setuptools
+except ImportError:
+    pass
+
+from distutils.core import setup, Extension
+
+# Below ROOT, we expect to find include, include/libxml2, lib and bin.
+# On *nix, it is not needed (but should not harm),
+# on Windows, it is set by configure.js.
+ROOT = r'@prefix@'
+
+# If this flag is set (windows only),
+# a private copy of the dlls are included in the package.
+# If this flag is not set, the libxml2 and libxslt
+# dlls must be found somewhere in the PATH at runtime.
+WITHDLLS = 1 and sys.platform.startswith('win')
+
+def missing(file):
+    if os.access(file, os.R_OK) == 0:
+        return 1
+    return 0
+
+try:
+    HOME = os.environ['HOME']
+except:
+    HOME="C:"
+
+if sys.platform.startswith('win'):
+    libraryPrefix = 'lib'
+    platformLibs = []
+else:
+    libraryPrefix = ''
+    platformLibs = ["m","z"]
+
+# those are examined to find
+# - libxslt/xsltconfig.h
+includes_dir = [
+"/usr/include",
+"/usr/local/include",
+"/opt/include",
+os.path.join(ROOT,'include'),
+HOME
+];
+
+# those are added in the linker search path for libraries
+libdirs = [
+os.path.join(ROOT,'lib'),
+]
+
+xslt_files = ["libxslt-api.xml", "libxslt-python-api.xml",
+             "libxslt.c", "libxsl.py", "libxslt_wrap.h",
+             "generator.py"]
+
+if WITHDLLS:
+    def altImport(s):
+        s = s.replace("import libxml2mod","from libxmlmods import libxml2mod")
+        s = s.replace("import libxsltmod","from libxsltmods import libxsltmod")
+        return s
+
+if missing("libxslt-py.c") or missing("libxslt.py"):
+    if missing("generator.py") or missing(os.path.join("..", "doc", "libxslt-api.xml")):
+        print("libxslt stub generator not found, libxslt not built")
+    else:
+        try:
+            if hasattr(subprocess, 'run'):
+                subprocess.run([sys.executable,
+                                'generator.py',
+                                os.path.join('..', 'doc', 'libxslt-api.xml'),
+                                'libxslt-python-api.xml'
+                               ], check=True)
+            else:
+                subprocess.check_output([sys.executable,
+                                        'generator.py',
+                                        os.path.join('..', 'doc', 'libxslt-api.xml'),
+                                        'libxslt-python-api.xml'])
+        except:
+            print("failed to generate stubs for libxslt, aborting ...")
+            print(sys.exc_info()[0], sys.exc_info()[1])
+        else:
+            head = open("libxsl.py", "r")
+            generated = open("libxsltclass.py", "r")
+            result = open("libxslt.py", "w")
+            for line in head.readlines():
+                if WITHDLLS:
+                    result.write(altImport(line))
+                else:
+                    result.write(line)
+            for line in generated.readlines():
+                result.write(line)
+            head.close()
+            generated.close()
+            result.close()
+
+xml_includes=""
+for dir in includes_dir:
+    if not missing(dir + "/libxml2/libxml/tree.h"):
+        xml_includes=dir + "/libxml2"
+        break;
+
+if xml_includes == "":
+    print("failed to find headers for libxml2: update includes_dir")
+    sys.exit(1)
+
+xslt_includes=""
+for dir in includes_dir:
+    if not missing(dir + "/libxslt/xsltconfig.h"):
+        xslt_includes=dir + "/libxslt"
+        break;
+
+if xslt_includes == "":
+    print("failed to find headers for libxslt: update includes_dir")
+
+if WITHDLLS:
+    # libxslt dlls (expected in ROOT/bin)
+    dlls = ['libxslt.dll','libexslt.dll']
+
+    packaged_dlls = [os.path.join(ROOT,'bin',dll) for dll in dlls]
+
+    # create __init__.py for the libxsltmods package
+    if not os.path.exists("libxsltmods"):
+        os.mkdir("libxsltmods")
+        open("libxsltmods/__init__.py","w").close()
+
+    packaged_dlls = [os.path.join(ROOT,'bin',dll) for dll in dlls]
+
+descr = "libxslt package"
+modules = [ 'libxslt']
+if WITHDLLS:
+    modules.append('libxsltmods.__init__')
+c_files = []
+includes= [xslt_includes, xml_includes]
+libs    = platformLibs
+macros  = []
+
+descr = "libxslt package"
+if not sys.platform.startswith('win'):
+    #
+    # We are gonna build 2 identical shared libs with merge initializing
+    # both libxml2mod and libxsltmod
+    #
+    c_files = c_files + ['libxslt-py.c', 'libxslt.c']
+    xslt_c_files = c_files
+else:
+    #
+    # On windows the MERGED_MODULE option is not needed
+    # (and does not work)
+    #
+    xslt_c_files = ['libxslt-py.c', 'libxslt.c', 'types.c']
+libs.insert(0, libraryPrefix + 'exslt')
+libs.insert(0, libraryPrefix + 'xslt')
+libs.insert(0, libraryPrefix + 'xml2')
+includes.append(xslt_includes)
+modules.append('libxslt')
+
+
+extens=[Extension('libxsltmod', xslt_c_files, include_dirs=includes,
+                        library_dirs=libdirs,
+                        libraries=libs, define_macros=macros)]
+
+if missing("MANIFEST"):
+
+    manifest = open("MANIFEST", "w")
+    manifest.write("setup.py\n")
+    for file in xslt_files:
+        manifest.write(file + "\n")
+    manifest.close()
+
+if WITHDLLS:
+    ext_package = "libxsltmods"
+    if sys.version >= "2.2":
+        base = "lib/site-packages/"
+    else:
+        base = ""
+    data_files = [(base+ext_package,packaged_dlls)]
+else:
+    ext_package = None
+    data_files = []
+
+setup (name = "libxslt-python",
+       # On *nix, the version number is created from setup.py.in
+       # On windows, it is set by configure.js
+       version = "@VERSION@",
+       description = descr,
+       author = "Daniel Veillard",
+       author_email = "veillard@redhat.com",
+       url = "https://gitlab.gnome.org/GNOME/libxslt",
+       licence="MIT Licence",
+       py_modules=modules,
+       ext_modules=extens,
+       ext_package=ext_package,
+       data_files=data_files,
+       install_requires=['libxml2_python>=@LIBXML_REQUIRED_VERSION@'],
+       )
+
+sys.exit(0)
+

win32/configure.js

@@ -36,6 +36,7 @@
 var verMajorExslt;
 var verMinorExslt;
 var verMicroExslt;
+var verLibxmlReq;
 var verCvs;
 var useCvsVer = true;
 /* Libxslt features. */
@@ -48,6 +49,7 @@
 var withCrypto = true;
 var withModules = false;
 var withProfiler = true;
+var withPython = false;
 /* Win32 build options. */
 var dirSep = "\\";
 var compiler = "msvc";
@@ -108,6 +110,7 @@
 	txt += "  crypto:     Enable Crypto support (" + (withCrypto? "yes" : "no") + ")\n";
 	txt += "  modules:    Enable Module support (" + (withModules? "yes" : "no") + ")\n";
 	txt += "  profiler:   Enable Profiler support (" + (withProfiler? "yes" : "no") + ")\n";
+	txt += "  python:     Build Python bindings (" + (withPython? "yes" : "no")  + ")\n";
 	txt += "\nWin32 build options, default value given in parentheses:\n\n";
 	txt += "  compiler:   Compiler to be used [msvc|mingw] (" + compiler + ")\n";
 	txt += "  cruntime:   C-runtime compiler option (only msvc) (" + cruntime + ")\n";
@@ -169,6 +172,9 @@
 		} else if(s.search(/^LIBEXSLT_MICRO_VERSION=/) != -1) {
 			vf.WriteLine(s);
 			verMicroExslt = s.substring(s.indexOf("=") + 1, s.length);
+		} else if(s.search(/^LIBXML_REQUIRED_VERSION=/) != -1) {
+			vf.WriteLine(s);
+			verLibxmlReq = s.substring(s.indexOf("=") + 1, s.length);
 		}
 	}
 	cf.Close();
@@ -181,6 +187,7 @@
 	vf.WriteLine("WITH_CRYPTO=" + (withCrypto? "1" : "0"));
 	vf.WriteLine("WITH_MODULES=" + (withModules? "1" : "0"));
 	vf.WriteLine("WITH_PROFILER=" + (withProfiler? "1" : "0"));
+	vf.WriteLine("WITH_PYTHON=" + (withPython? "1" : "0"));
 	vf.WriteLine("DEBUG=" + (buildDebug? "1" : "0"));
 	vf.WriteLine("STATIC=" + (buildStatic? "1" : "0"));
 	vf.WriteLine("PREFIX=" + buildPrefix);
@@ -251,8 +258,8 @@
 	while (ofi.AtEndOfStream != true) {
 		ln = ofi.ReadLine();
 		s = new String(ln);
-		if (s.search(/\@LIBEXSLT_VERSION\@/) != -1) {
-			of.WriteLine(s.replace(/\@LIBEXSLT_VERSION\@/, 
+		if (s.search(/\@VERSION\@/) != -1) {
+			of.WriteLine(s.replace(/\@VERSION\@/, 
 				verMajorExslt + "." + verMinorExslt + "." + verMicroExslt));
 		} else if (s.search(/\@LIBEXSLT_VERSION_NUMBER\@/) != -1) {
 			of.WriteLine(s.replace(/\@LIBEXSLT_VERSION_NUMBER\@/, 
@@ -270,6 +277,51 @@
 	of.Close();
 }
 
+/* Configures Python bindings. Otherwise identical to the above */
+function configureLibxsltPy()
+{
+	var pyOptsFileIn = baseDir + "\\python\\setup.py.in";
+	var pyOptsFile = baseDir + "\\python\\setup.py";
+	var fso, ofi, of, ln, s;
+	fso = new ActiveXObject("Scripting.FileSystemObject");
+	ofi = fso.OpenTextFile(pyOptsFileIn, 1);
+	of = fso.CreateTextFile(pyOptsFile, true);
+	while (ofi.AtEndOfStream != true) {
+		ln = ofi.ReadLine();
+		s = new String(ln);
+		if (s.search(/\@VERSION\@/) != -1) {
+			of.WriteLine(s.replace(/\@VERSION\@/, 
+				verMajorXslt + "." + verMinorXslt + "." + verMicroXslt));
+		} else if (s.search(/\@prefix\@/) != -1) {
+			of.WriteLine(s.replace(/\@prefix\@/, buildPrefix));
+		} else if (s.search(/\@LIBXSLT_VERSION_NUMBER\@/) != -1) {
+			of.WriteLine(s.replace(/\@LIBXSLT_VERSION_NUMBER\@/, 
+				verMajorXslt*10000 + verMinorXslt*100 + verMicroXslt*1));
+		} else if (s.search(/\@LIBXSLT_VERSION_EXTRA\@/) != -1) {
+			of.WriteLine(s.replace(/\@LIBXSLT_VERSION_EXTRA\@/, verCvs));
+		} else if (s.search(/\@WITH_TRIO\@/) != -1) {
+			of.WriteLine(s.replace(/\@WITH_TRIO\@/, withTrio? "1" : "0"));
+		} else if (s.search(/\@WITH_XSLT_DEBUG\@/) != -1) {
+			of.WriteLine(s.replace(/\@WITH_XSLT_DEBUG\@/, withXsltDebug? "1" : "0"));
+		} else if (s.search(/\@WITH_MEM_DEBUG\@/) != -1) {
+			of.WriteLine(s.replace(/\@WITH_MEM_DEBUG\@/, withMemDebug? "1" : "0"));
+		} else if (s.search(/\@WITH_DEBUGGER\@/) != -1) {
+			of.WriteLine(s.replace(/\@WITH_DEBUGGER\@/, withDebugger? "1" : "0"));
+		} else if (s.search(/\@WITH_MODULES\@/) != -1) {
+			of.WriteLine(s.replace(/\@WITH_MODULES\@/, withModules? "1" : "0"));
+		} else if (s.search(/\@WITH_PROFILER\@/) != -1) {
+			of.WriteLine(s.replace(/\@WITH_PROFILER\@/, withProfiler? "1" : "0"));
+		} else if (s.search(/\@LIBXSLT_DEFAULT_PLUGINS_PATH\@/) != -1) {
+			of.WriteLine(s.replace(/\@LIBXSLT_DEFAULT_PLUGINS_PATH\@/, "NULL"));
+		} else if (s.search(/\@LIBXML_REQUIRED_VERSION\@/) != -1) {
+			of.WriteLine(s.replace(/\@LIBXML_REQUIRED_VERSION\@/, verLibxmlReq));
+		} else
+			of.WriteLine(ln);
+	}
+	ofi.Close();
+	of.Close();
+}
+
 /* Creates the readme file for the binary distribution of 'bname', for the
    version 'ver' in the file 'file'. This one is called from the Makefile when
    generating a binary distribution. The parameters are passed by make. */
@@ -336,6 +388,8 @@
 			withModules = strToBool(arg.substring(opt.length + 1, arg.length));
 		else if (opt == "profiler")
 			withProfiler = strToBool(arg.substring(opt.length + 1, arg.length));
+		else if (opt == "python")
+			withPython = strToBool(arg.substring(opt.length + 1, arg.length));
 		else if (opt == "compiler")
 			compiler = arg.substring(opt.length + 1, arg.length);
  		else if (opt == "cruntime")
@@ -432,6 +486,15 @@
 	WScript.Quit(error);
 }
 
+if (withPython == true) {
+	configureLibxsltPy();
+	if (error != 0) {
+		WScript.Echo("Configuration failed, aborting.");
+		WScript.Quit(error);
+	}
+
+}
+
 // Configure libexslt.
 configureExslt();
 if (error != 0) {
@@ -469,6 +532,7 @@
 txtOut += "            Crypto: " + boolToStr(withCrypto) + "\n";
 txtOut += "           Modules: " + boolToStr(withModules) + "\n";
 txtOut += "          Profiler: " + boolToStr(withProfiler) + "\n";
+txtOut += "   Python bindings: " + boolToStr(withPython) + "\n";
 txtOut += "\n";
 txtOut += "Win32 build configuration\n";
 txtOut += "-------------------------\n";