00112-2.7.13-debug-build.patch

00112 #
Patch to support building both optimized vs debug stacks DSO ABIs, sharing
the same .py and .pyc files, using "_d.so" to signify a debug build of an
extension module.

Based on Debian's patch for the same,
 http://patch-tracker.debian.org/patch/series/view/python2.6/2.6.5-2/debug-build.dpatch

(which was itself based on the upstream Windows build), but with some
changes:

  * Debian's patch to dynload_shlib.c looks for module_d.so, then module.so,
but this can potentially find a module built against the wrong DSO ABI.  We
instead search for just module_d.so in a debug build

  * We remove this change from configure.in's build of the Makefile:
  SO=$DEBUG_EXT.so
so that sysconfig.py:customize_compiler stays with shared_lib_extension='.so'
on debug builds, so that UnixCCompiler.find_library_file can find system
libraries (otherwise "make sharedlibs" fails to find system libraries,
erroneously looking e.g. for "libffi_d.so" rather than "libffi.so")

  * We change Lib/distutils/command/build_ext.py:build_ext.get_ext_filename
to add the _d there, when building an extension.  This way, "make sharedlibs"
can build ctypes, by finding the sysmtem libffi.so (rather than failing to
find "libffi_d.so"), and builds the module as _ctypes_d.so

  * Similarly, update build_ext:get_libraries handling of Py_ENABLE_SHARED by
appending "_d" to the python library's name for the debug configuration

  * We modify Modules/makesetup to add the "_d" to the generated Makefile
rules for the various Modules/*.so targets

This may introduce issues when building an extension that links directly
against another extension (e.g. users of NumPy?), but seems more robust when
searching for external libraries

  * We don't change Lib/distutils/command/build.py: build.build_purelib to
embed plat_specifier, leaving it as is, as pure python builds should be
unaffected by these differences (we'll be sharing the .py and .pyc files)

  * We introduce DEBUG_SUFFIX as well as DEBUG_EXT:
    - DEBUG_EXT is used by ELF files (names and SONAMEs); it will be "_d" for
a debug build
    - DEBUG_SUFFIX is used by filesystem paths; it will be "-debug" for a
debug build

  Both will be empty in an optimized build.  "_d" contains characters that
are valid ELF metadata, but this leads to various ugly filesystem paths (such
as the include path), and DEBUG_SUFFIX allows these paths to have more natural
names.  Changing this requires changes elsewhere in the distutils code.

  * We add DEBUG_SUFFIX to PYTHON in the Makefile, so that the two
configurations build parallel-installable binaries with different names
("python-debug" vs "python").

  * Similarly, we add DEBUG_SUFFIX within python-config and
 python$(VERSION)-config, so that the two configuration get different paths
 for these.

 See also patch 130 below

2 files changed, 14 insertions, 3 deletions

diff --git a/Python/dynload_shlib.c b/Python/dynload_shlib.c
index 17ebab1..02a94aa 100644
--- a/Python/dynload_shlib.c
+++ b/Python/dynload_shlib.c
@@ -46,11 +46,16 @@ const struct filedescr _PyImport_DynLoadFiletab[] = {
     {"module.exe", "rb", C_EXTENSION},
     {"MODULE.EXE", "rb", C_EXTENSION},
 #else
+#ifdef Py_DEBUG
+    {"_d.so", "rb", C_EXTENSION},
+    {"module_d.so", "rb", C_EXTENSION},
+#else
     {".so", "rb", C_EXTENSION},
     {"module.so", "rb", C_EXTENSION},
-#endif
-#endif
-#endif
+#endif /* Py_DEBUG */
+#endif /* __VMS */
+#endif /* defined(PYOS_OS2) && defined(PYCC_GCC) */
+#endif /* __CYGWIN__ */
     {0, 0}
 };
 
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index fdb7af2..22238ba 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1524,6 +1524,12 @@ _PySys_Init(void)
                         PyString_FromString("legacy"));
 #endif
 
+#ifdef Py_DEBUG
+    PyDict_SetItemString(sysdict, "pydebug", Py_True);
+#else
+    PyDict_SetItemString(sysdict, "pydebug", Py_False);
+#endif
+
 #undef SET_SYS_FROM_STRING
     if (PyErr_Occurred())
         return NULL;