From d7e2a9ad8351a542a30c7fdc603adf83249f928b Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@efficios.com>
Date: Wed, 21 Feb 2024 21:23:03 -0500
Subject: [PATCH] bt2: compile `native_bt.c` with `-Wno-undef`
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As explained in the comment, work around a problem with SWIG 4.2.0.

Change-Id: Ia95fc1e4929591a0a16df48892b05f5e5df46be3
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/11849
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/11930
Reviewed-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---
 src/bindings/python/bt2/Makefile.am | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/bindings/python/bt2/Makefile.am b/src/bindings/python/bt2/Makefile.am
index 20f142e4e0..b74821ae8d 100644
--- a/src/bindings/python/bt2/Makefile.am
+++ b/src/bindings/python/bt2/Makefile.am
@@ -120,6 +120,14 @@ WARN_CFLAGS += -Wno-deprecated-declarations
 # Python 3.11 + gcc 12.2.0 gave warnings of this kind in Python.h.
 WARN_CFLAGS += -Wno-redundant-decls
 
+# SWIG 4.2.0 generates:
+#
+#   #if __cplusplus >=201103L
+#
+# ... leading to some `-Wundef` warnings when building the extension as C, where
+# `__cplusplus` is not defined.
+WARN_CFLAGS += -Wno-undef
+
 BUILD_FLAGS=CC="$(CC)" \
 		CFLAGS="$(GLIB_CFLAGS) $(AM_CFLAGS) $(CFLAGS) $(WARN_CFLAGS)" \
 		CPPFLAGS="$(AM_CPPFLAGS) $(CPPFLAGS) -I$(srcdir)/bt2" \