Condition coverage, also known as MC/DC (modified condition/decision
coverage) is a coverage metric that tracks separate outcomes in
boolean expressions.
This patch adds CONFIG_CONDITION_COVERAGE option to enable MC/DC for
GCC. Clang is not supported right now.
Also, use the opportunity to convert COV_FLAGS to cov_flags-y, which
reduces amount of ifeqs in Rules.mk. Otherwise this patch had to add
another nesting level with "ifeq ($(CONFIG_CONDITION_COVERAGE),y)".
Signed-off-by: Volodymyr Babchuk <volodymyr_babc...@epam.com>
---
Changes in v4:
- Slight formatting fixes
- COV_FLAGS -> cov_flags-y
Changes in v3:
- Introduced CC_HAS_MCDC that checks if compiler supports
required feature
Changes in v2:
- Move gcc version check from .c file to Rules.mk (I can't find
an easy way to check GCC version at Kconfig level)
- Check for gcc 14, not gcc 14.1
---
xen/Kconfig | 4 ++++
xen/Kconfig.debug | 9 +++++++++
xen/Rules.mk | 14 +++++++-------
3 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/xen/Kconfig b/xen/Kconfig
index 2128f0ccfc..3a723db8ea 100644
--- a/xen/Kconfig
+++ b/xen/Kconfig
@@ -41,6 +41,10 @@ config CC_SPLIT_SECTIONS
config CC_HAS_UBSAN
def_bool $(cc-option,-fsanitize=undefined)
+# Compiler supports -fcondition-coverage aka MC/DC
+config CC_HAS_MCDC
+ def_bool $(cc-option,-fcondition-coverage)
+
# Set code alignment.
#
# Allow setting on a boolean basis, and then convert such selection to an
diff --git a/xen/Kconfig.debug b/xen/Kconfig.debug
index f7cc5ffaab..f89cbd823b 100644
--- a/xen/Kconfig.debug
+++ b/xen/Kconfig.debug
@@ -44,6 +44,15 @@ config COVERAGE
If unsure, say N here.
+config CONDITION_COVERAGE
+ bool "Condition coverage support"
+ depends on COVERAGE && CC_HAS_MCDC
+ help
+ Enable condition coverage support. Used for collecting MC/DC
+ (Modified Condition/Decision Coverage) metrics.
+
+ If unsure, say N here.
+
config DEBUG_LOCK_PROFILE
bool "Lock Profiling"
select DEBUG_LOCKS
diff --git a/xen/Rules.mk b/xen/Rules.mk
index d759cccee3..e9e049368f 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -31,6 +31,7 @@ CFLAGS-y :=
AFLAGS-y :=
nocov-y :=
noubsan-y :=
+cov-flags-y :=
SPECIAL_DATA_SECTIONS := rodata $(foreach a,1 2 4 8 16, \
$(foreach w,1 2 4, \
@@ -133,19 +134,18 @@ $(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)):
CFLAGS-y += -DINIT_SECTIONS
non-init-objects = $(filter-out %.init.o, $(obj-y) $(obj-bin-y) $(extra-y))
-ifeq ($(CONFIG_COVERAGE),y)
ifeq ($(CONFIG_CC_IS_CLANG),y)
- COV_FLAGS := -fprofile-instr-generate -fcoverage-mapping
+ cov-flags-$(CONFIG_COVERAGE) := -fprofile-instr-generate -fcoverage-mapping
else
- COV_FLAGS := -fprofile-arcs -ftest-coverage
+ cov-flags-$(CONFIG_COVERAGE) := -fprofile-arcs -ftest-coverage
+ cov-flags-$(CONFIG_CONDITION_COVERAGE) += -fcondition-coverage
endif
-# Reset COV_FLAGS in cases where an objects has another one as prerequisite
+# Reset cov-flags-y in cases where an objects has another one as prerequisite
$(nocov-y) $(filter %.init.o, $(obj-y) $(obj-bin-y) $(extra-y)): \
- COV_FLAGS :=
+ cov-flags-y :=
-$(non-init-objects): _c_flags += $(COV_FLAGS)
-endif
+$(non-init-objects): _c_flags += $(cov-flags-y)
ifeq ($(CONFIG_UBSAN),y)
# Any -fno-sanitize= options need to come after any -fsanitize= options
--
2.48.1
