[PATCH] Fix build for empty with-python, but with-python-libdir

[Simon Marchi]

On 2021-10-26 02:09, Alexey Lapshin wrote:
> On 10/25/21 9:14 PM, Simon Marchi wrote:
>> [External: This email originated outside Espressif]
>>
>> On 2021-10-25 13:53, Alexey Lapshin via Gdb-patches wrote:
>>> ---
>>>   gdb/python/python.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/gdb/python/python.c b/gdb/python/python.c
>>> index c81814c557b..9e8e0149ba9 100644
>>> --- a/gdb/python/python.c
>>> +++ b/gdb/python/python.c
>>> @@ -1756,7 +1756,7 @@ gdbpy_gdb_exiting (int exit_code)
>>>   static bool
>>>   do_start_initialization ()
>>>   {
>>> -#ifdef WITH_PYTHON_PATH
>>> +#ifdef HAVE_PYTHON
>>>     /* Work around problem where python gets confused about where it is,
>>>        and then can't find its libraries, etc.
>>>        NOTE: Python assumes the following layout:
>>>
>> Hi,
>>
>> Please provide a commit message that describes the issue that you see
>> and that you try to fix.
>>
>> Simon
> 
> Hi,
> 
> The issue I faced when compile gdb with python. Configure options are 
> --with-python --with-python-libdir=$PYTHON_DIR/lib. The issue appears if 
> I do not specify path to python via --with-python option flag.
> 
> The problem which I see after the gdb build:
> python exception <type 'exceptions.ImportError'> No module named _gdb
> 
> Because _gdb is built-in module which loads in block of code under 
> "ifdef WITH_PYTHON_PATH".
> I changed it to more suitable "ifdef HAVE_PYTHON" and it works perfectly
> 

Ok, I'm not too sure how to reproduce on my side.  But looking at the
code, it sounds like we want to protect the use of python_libdir here.
So maybe we would want to check for the WITH_PYTHON_LIBDIR macro
instead?  And maybe even not define the python_libdir variable at all if
WITH_PYTHON_LIBDIR isn't defined.  Would the patch below work for you?

>From 8ff9005b53476ef86ca6fb0a8f5e4c0415452aa1 Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@polymtl.ca>
Date: Tue, 26 Oct 2021 12:30:05 -0400
Subject: [PATCH] gdb: protect use of python_libdir using WITH_PYTHON_LIBDIR

Change-Id: I5f9d4bc20f4b7ab8f8a9569c37e302feab232f16
---
 gdb/defs.h          | 2 ++
 gdb/main.c          | 2 ++
 gdb/python/python.c | 2 +-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gdb/defs.h b/gdb/defs.h
index f7e09eca9db1..48da639ebd03 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -126,9 +126,11 @@ extern std::string gdb_sysroot;
 /* * GDB datadir, used to store data files.  */
 extern std::string gdb_datadir;
 
+#if defined(WITH_PYTHON_LIBDIR)
 /* * If not empty, the possibly relocated path to python's "lib" directory
    specified with --with-python.  */
 extern std::string python_libdir;
+#endif
 
 /* * Search path for separate debug files.  */
 extern std::string debug_file_directory;
diff --git a/gdb/main.c b/gdb/main.c
index ca4ccc375dc7..19cb845538fd 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -75,9 +75,11 @@ std::string gdb_datadir;
    command line, but we don't reread system.gdbinit when that happens.  */
 static int gdb_datadir_provided = 0;
 
+#if defined(WITH_PYTHON_LIBDIR)
 /* If gdb was configured with --with-python=/path,
    the possibly relocated path to python's lib directory.  */
 std::string python_libdir;
+#endif
 
 /* Target IO streams.  */
 struct ui_file *gdb_stdtargin;
diff --git a/gdb/python/python.c b/gdb/python/python.c
index c81814c557be..489e0ce5f910 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1756,7 +1756,7 @@ gdbpy_gdb_exiting (int exit_code)
 static bool
 do_start_initialization ()
 {
-#ifdef WITH_PYTHON_PATH
+#if defined(WITH_PYTHON_LIBDIR)
   /* Work around problem where python gets confused about where it is,
      and then can't find its libraries, etc.
      NOTE: Python assumes the following layout:
-- 
2.33.1