[PATCH v2 1/2] gdb: make Python conftest compatible with Python limited C API

[Matthieu Longo <matthieu.longo@arm.com>]

The current test to check the support of '--dynamic-list' linker flag
uses PyRun_SimpleString (), which is part of the unstable API. As it is
now, the test will systematically fail due to the undefined symbol
rather than testing the import of ctypes.
This patch replaces PyRun_SimpleString () by an equivalent code relying
on the limited C API, and compatible with Python 3.4.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23830
---
 gdb/configure    | 13 ++++++++++---
 gdb/configure.ac | 13 ++++++++++---
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/gdb/configure b/gdb/configure
index db63481b1c6..b7a2079d206 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -31034,11 +31034,18 @@ else
 int
 main ()
 {
-int err;
+
+          const char *code = "import ctypes\n";
           Py_Initialize ();
-          err = PyRun_SimpleString ("import ctypes\n");
+          PyObject *main_module = PyImport_AddModule ("__main__");
+          PyObject *global_dict = PyModule_GetDict (main_module);
+          PyObject *local_dict = PyDict_New ();
+          PyObject *py_code = Py_CompileString (code, "test", Py_single_input);
+          if (py_code == NULL)
+            return 1;
+          PyObject *res = PyEval_EvalCode (py_code, global_dict, local_dict);
           Py_Finalize ();
-          return err == 0 ? 0 : 1;
+          return res ? 0 : 1;
   ;
   return 0;
 }
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 52924106bca..a88b6ebffe5 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1761,11 +1761,18 @@ if test "${gdb_native}" = yes; then
      AC_RUN_IFELSE(
        [AC_LANG_PROGRAM(
          [#include "Python.h"],
-         [int err;
+         [
+          const char *code = "import ctypes\n";
           Py_Initialize ();
-          err = PyRun_SimpleString ("import ctypes\n");
+          PyObject *main_module = PyImport_AddModule ("__main__");
+          PyObject *global_dict = PyModule_GetDict (main_module);
+          PyObject *local_dict = PyDict_New ();
+          PyObject *py_code = Py_CompileString (code, "test", Py_single_input);
+          if (py_code == NULL)
+            return 1;
+          PyObject *res = PyEval_EvalCode (py_code, global_dict, local_dict);
           Py_Finalize ();
-          return err == 0 ? 0 : 1;])],
+          return res ? 0 : 1;])],
        [dynamic_list=true], [], [true])
      LIBS="$old_LIBS"
      CFLAGS="$old_CFLAGS"
-- 
2.51.0