Mailing List Archive

The recommended optimisation level for debugging is -Og, and is what tools
such as gdb prefer. In practice, it equates to -01 with a few specific
optimisations turned off.

While the use of gdb isn't necessarily very helpful for Xen, the disassembly
will have fewer structural transformations vs C, and therefore will be easier
to follow.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Wei Liu <wl@xen.org>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Juergen Gross <jgross@suse.com>

Successful CI runs:
https://gitlab.com/xen-project/people/andyhhp/xen/-/pipelines/287769787
https://cirrus-ci.com/build/5086280275984384
---
xen/Makefile | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/xen/Makefile b/xen/Makefile
index 9f3be7766d..128de93f5e 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -195,7 +195,9 @@ include/config/%.conf include/config/%.conf.cmd: $(KCONFIG_CONFIG)
$(MAKE) $(kconfig) syncconfig

ifeq ($(CONFIG_DEBUG),y)
-CFLAGS += -O1
+# Use -Og if available, -O1 otherwise
+dbg_opt_level := $(call cc-option,$(CC),-Og,-O1)
+CFLAGS += $(dbg_opt_level)
else
CFLAGS += -O2
endif
--
2.11.0