Patch #1464444: Add --with-system-ffi.

README

@@ -1068,6 +1068,9 @@ Modules/getpath.o.
 
 --with-tsc: Profile using the Pentium timestamping counter (TSC).
 
+--with-system-ffi:  Build the _ctypes extension module using an ffi
+	library installed on the system.
+
 
 Building for multiple architectures (using the VPATH feature)
 -------------------------------------------------------------

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 43748 .
+# From configure.in Revision: 45264 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.59 for python 2.5.
 #
@@ -863,6 +863,7 @@ Optional Packages:
   --with-suffix=.exe      set executable suffix
   --with-pydebug          build with Py_DEBUG defined
   --with-libs='lib1 ...'  link against additional libs
+  --with-system-ffi       build _ctypes module using an installed ffi library
   --with-signal-module    disable/enable signal module
   --with-dec-threads      use DEC Alpha/OSF1 thread-safe libraries
   --with(out)-threads[=DIRECTORY]
@@ -11780,6 +11781,22 @@ else
 echo "${ECHO_T}no" >&6
 fi;
 
+# Check for use of the system libffi library
+echo "$as_me:$LINENO: checking for --with-system-ffi" >&5
+echo $ECHO_N "checking for --with-system-ffi... $ECHO_C" >&6
+
+# Check whether --with-system_ffi or --without-system_ffi was given.
+if test "${with_system_ffi+set}" = set; then
+  withval="$with_system_ffi"
+
+fi;
+
+if test -z "$with_system_ffi"
+then with_system_ffi="no"
+fi
+echo "$as_me:$LINENO: result: $with_system_ffi" >&5
+echo "${ECHO_T}$with_system_ffi" >&6
+
 # Determine if signalmodule should be used.
 
 

configure.in

@@ -1604,6 +1604,16 @@ LIBS="$withval $LIBS"
 ],
 [AC_MSG_RESULT(no)])
 
+# Check for use of the system libffi library
+AC_MSG_CHECKING(for --with-system-ffi)
+AC_ARG_WITH(system_ffi,
+            AC_HELP_STRING(--with-system-ffi, build _ctypes module using an installed ffi library))
+
+if test -z "$with_system_ffi"
+then with_system_ffi="no"
+fi
+AC_MSG_RESULT($with_system_ffi)
+
 # Determine if signalmodule should be used.
 AC_SUBST(USE_SIGNAL_MODULE)
 AC_SUBST(SIGNAL_OBJS)

setup.py

@@ -973,7 +973,7 @@ class PyBuildExt(build_ext):
                 exts.append( Extension('dl', ['dlmodule.c']) )
 
         # Thomas Heller's _ctypes module
-        self.detect_ctypes()
+        self.detect_ctypes(inc_dirs, lib_dirs)
 
         # Platform-specific libraries
         if platform == 'linux2':
@@ -1269,6 +1269,7 @@ class PyBuildExt(build_ext):
         #       -lGL -lGLU -lXext -lXmu \
 
     def configure_ctypes(self, ext):
+        if not self.use_system_libffi:
             (srcdir,) = sysconfig.get_config_vars('srcdir')
             ffi_builddir = os.path.join(self.build_temp, 'libffi')
             ffi_srcdir = os.path.abspath(os.path.join(srcdir, 'Modules',
@@ -1280,8 +1281,8 @@ class PyBuildExt(build_ext):
                 mkpath(ffi_builddir)
                 config_args = []
 
-            # Pass empty CFLAGS because we'll just append the resulting CFLAGS
-            # to Python's; -g or -O2 is to be avoided.
+                # Pass empty CFLAGS because we'll just append the resulting
+                # CFLAGS to Python's; -g or -O2 is to be avoided.
                 cmd = "cd %s && env CFLAGS='' '%s/configure' %s" \
                       % (ffi_builddir, ffi_srcdir, " ".join(config_args))
 
@@ -1306,7 +1307,8 @@ class PyBuildExt(build_ext):
             ext.extra_compile_args.extend(extra_compile_args)
         return True
 
-    def detect_ctypes(self):
+    def detect_ctypes(self, inc_dirs, lib_dirs):
+        self.use_system_libffi = False
         include_dirs = []
         extra_compile_args = []
         sources = ['_ctypes/_ctypes.c',
@@ -1326,12 +1328,40 @@ class PyBuildExt(build_ext):
         ext = Extension('_ctypes',
                         include_dirs=include_dirs,
                         extra_compile_args=extra_compile_args,
+                        libraries=[],
                         sources=sources,
                         depends=depends)
         ext_test = Extension('_ctypes_test',
                              sources=['_ctypes/_ctypes_test.c'])
         self.extensions.extend([ext, ext_test])
 
+        if not '--with-system-ffi' in sysconfig.get_config_var("CONFIG_ARGS"):
+            return
+
+        ffi_inc = find_file('ffi.h', [], inc_dirs)
+        if ffi_inc is not None:
+            ffi_h = ffi_inc[0] + '/ffi.h'
+            fp = open(ffi_h)
+            while 1:
+                line = fp.readline()
+                if not line:
+                    ffi_inc = None
+                    break
+                if line.startswith('#define LIBFFI_H'):
+                    break
+        ffi_lib = None
+        if ffi_inc is not None:
+            for lib_name in ('ffi_convenience', 'ffi_pic', 'ffi'):
+                if (self.compiler.find_library_file(lib_dirs, lib_name)):
+                    ffi_lib = lib_name
+                    break
+
+        if ffi_inc and ffi_lib:
+            ext.include_dirs.extend(ffi_inc)
+            ext.libraries.append(ffi_lib)
+            self.use_system_libffi = True
+
+
 class PyBuildInstall(install):
     # Suppress the warning about installation into the lib_dynload
     # directory, which is not in sys.path when running Python during