[RFC] Help python find its files

[RFC] Help python find its files

[Doug Evans]

Hi.

We had problems with python not being able to find its files.
This may be specific to installations where gdb and python
are installed in different places.

2010-02-08  Doug Evans  <dje@google.com>

	* configure.ac (--with-python): Define WITH_PYTHON_PATH if
	--with-python arg is a path.
	* config.in: Regenerated.
	* configure: Regenerated.
	* python/python.c (_initialize_python): If configured
	--with-python=/path, pass a fake argv[0] to Py_SetProgramName so
	python can find its files.

Index: configure.ac
===================================================================
RCS file: /cvs/src/src/gdb/configure.ac,v
retrieving revision 1.114
diff -u -p -r1.114 configure.ac
--- configure.ac	25 Jan 2010 13:22:02 -0000	1.114
+++ configure.ac	8 Feb 2010 19:08:11 -0000
@@ -652,6 +657,13 @@ else
       AC_DEFINE(HAVE_LIBPYTHON2_4, 1, [Define if Python 2.4 is being used.])
     fi
   fi
+  if test ${have_libpython} = yes; then
+    case "${with_python}" in
+    /*)
+      AC_DEFINE_UNQUOTED(WITH_PYTHON_PATH, "${with_python}", [Define if --with-python contains a path.])
+      ;;
+    esac
+  fi
   if test ${have_libpython} = no; then
     case "${with_python}" in
     yes)
Index: python/python.c
===================================================================
RCS file: /cvs/src/src/gdb/python/python.c,v
retrieving revision 1.25
diff -u -p -r1.25 python.c
--- python/python.c	18 Jan 2010 10:50:44 -0000	1.25
+++ python/python.c	8 Feb 2010 19:08:11 -0000
@@ -631,6 +631,12 @@ Enables or disables auto-loading of Pyth
 			   &show_python_list);
 
 #ifdef HAVE_PYTHON
+#ifdef WITH_PYTHON_PATH
+  /* Work around problem where python gets confused about where it is,
+     and then can't find its libraries, etc.
+     Lie and pretend argv[0] is in WITH_PYTHON_PATH.  */
+  Py_SetProgramName(WITH_PYTHON_PATH "/bin/python");
+#endif
   Py_Initialize ();
   PyEval_InitThreads ();
 

Re: [RFC] Help python find its files

[Daniel Jacobowitz]

On Mon, Feb 08, 2010 at 11:29:42AM -0800, Doug Evans wrote:
> Hi.
> 
> We had problems with python not being able to find its files.
> This may be specific to installations where gdb and python
> are installed in different places.
> 
> 2010-02-08  Doug Evans  <dje@google.com>
> 
> 	* configure.ac (--with-python): Define WITH_PYTHON_PATH if
> 	--with-python arg is a path.
> 	* config.in: Regenerated.
> 	* configure: Regenerated.
> 	* python/python.c (_initialize_python): If configured
> 	--with-python=/path, pass a fake argv[0] to Py_SetProgramName so
> 	python can find its files.

I suspect this patch will break relocatability.  --with-python is a
path on the build system (for -I and -L), not a path on the host
system.


-- 
Daniel Jacobowitz
CodeSourcery

Re: [RFC] Help python find its files

[Doug Evans]

On Mon, Feb 8, 2010 at 11:56 AM, Daniel Jacobowitz <dan@codesourcery.com> wrote:
> On Mon, Feb 08, 2010 at 11:29:42AM -0800, Doug Evans wrote:
>> Hi.
>>
>> We had problems with python not being able to find its files.
>> This may be specific to installations where gdb and python
>> are installed in different places.
>>
>> 2010-02-08  Doug Evans  <dje@google.com>
>>
>>       * configure.ac (--with-python): Define WITH_PYTHON_PATH if
>>       --with-python arg is a path.
>>       * config.in: Regenerated.
>>       * configure: Regenerated.
>>       * python/python.c (_initialize_python): If configured
>>       --with-python=/path, pass a fake argv[0] to Py_SetProgramName so
>>       python can find its files.
>
> I suspect this patch will break relocatability.  --with-python is a
> path on the build system (for -I and -L), not a path on the host
> system.

Amazing, or depressing, how I forget such things.

Re: [RFC] Help python find its files

[Daniel Jacobowitz]

On Mon, Feb 08, 2010 at 12:04:44PM -0800, Doug Evans wrote:
> Amazing, or depressing, how I forget such things.

It's not the typical scenario :-) You could always add another option.
Actually, I'm not sure relocatability really works... it would depend
on what Python did.  I know that for my builds, I have a local patch
to override the Python default paths.  But the place I override them
to only has Python modules in it, not the Python libraries or headers.

-- 
Daniel Jacobowitz
CodeSourcery

Re: [RFC] Help python find its files

[Tom Tromey]

>>>>> "Doug" == Doug Evans <dje@google.com> writes:

Doug> +  Py_SetProgramName(WITH_PYTHON_PATH "/bin/python");

Missing a space before "(".

Tom