[PATCH 2/2] Do not pass -DNDEBUG to Python compilations in development mode

[Tom Tromey <tom@tromey.com>]

The Python CFLAGS include -DNDEBUG.  This was apparently done
intentionally -- setting the flags is done manually because, according
to a comment, python-config passes too many things to the compiler
(which is true).

Per PR python/20445, this patch changes configure so that -DNDEBUG is
only used by release builds.  This probably doesn't have very much
effect in practice, but I did see that some Python headers use assert,
so perhaps it will give some safety.

Tested by rebuilding and re-running gdb.python/*.exp on x86-64 Fedora 28.

ChangeLog
2018-09-16  Tom Tromey  <tom@tromey.com>

	PR python/20445:
	* configure: Rebuild.
	* configure.ac: Conditionally use -DNDEBUG for Python.
---
 gdb/ChangeLog    | 6 ++++++
 gdb/configure    | 6 +++++-
 gdb/configure.ac | 6 +++++-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/gdb/configure b/gdb/configure
index e011b77414b..2fb69a8eda6 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -10762,7 +10762,11 @@ $as_echo "#define HAVE_PYTHON 1" >>confdefs.h
   # would make the python-related objects be compiled differently from the
   # rest of GDB (e.g., -O2 and -fPIC).
   if test "${GCC}" = yes; then
-    tentative_python_cflags="-fno-strict-aliasing -DNDEBUG -fwrapv"
+    tentative_python_cflags="-fno-strict-aliasing -fwrapv"
+    # Python headers recommend -DNDEBUG, but it's unclear if that just
+    # refers to building Python itself.  In release mode, though, it
+    # doesn't hurt for the Python code in gdb to follow.
+    $development || tentative_python_cflags="tentative_python_cflags -DNDEBUG"
   fi
 
   if test "x${tentative_python_cflags}" != x; then
diff --git a/gdb/configure.ac b/gdb/configure.ac
index f658da84e32..0709b1ff720 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -965,7 +965,11 @@ if test "${have_libpython}" != no; then
   # would make the python-related objects be compiled differently from the
   # rest of GDB (e.g., -O2 and -fPIC).
   if test "${GCC}" = yes; then
-    tentative_python_cflags="-fno-strict-aliasing -DNDEBUG -fwrapv"
+    tentative_python_cflags="-fno-strict-aliasing -fwrapv"
+    # Python headers recommend -DNDEBUG, but it's unclear if that just
+    # refers to building Python itself.  In release mode, though, it
+    # doesn't hurt for the Python code in gdb to follow.
+    $development || tentative_python_cflags="tentative_python_cflags -DNDEBUG"
   fi
 
   if test "x${tentative_python_cflags}" != x; then
-- 
2.17.1