[PATCH v2 16/21] kcov: imply GCC_PLUGINS and GCC_PLUGIN_SANCOV instead of select'ing them

From: Masahiro Yamada
Date: Tue Mar 27 2018 - 01:34:09 EST


As Documentation/kbuild/kconfig-language.txt notes, 'select' should be
used with care - it forces a lower limit of another symbol, ignoring
the dependency. In this case, KCOV can select GCC_PLUGINS even if
'depends on HAVE_GCC_PLUGINS' is unmet.

'imply' is modest enough to observe the dependency, and this makes
sense. If you enable KCOV, you will probably want to enable
GCC_PLUGIN_SANCOV, but it should not break the dependency.

I also remove unneeded code, I just happened to notice.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
- Drop depends on GCC_VERSION

---

Changes in v2: None

lib/Kconfig.debug | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5be22e4..8243c9d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -743,8 +743,8 @@ config KCOV
bool "Code coverage for fuzzing"
depends on ARCH_HAS_KCOV
select DEBUG_FS
- select GCC_PLUGINS if !COMPILE_TEST
- select GCC_PLUGIN_SANCOV if !COMPILE_TEST
+ imply GCC_PLUGINS
+ imply GCC_PLUGIN_SANCOV
help
KCOV exposes kernel code coverage information in a form suitable
for coverage-guided fuzzing (randomized testing).
@@ -758,7 +758,6 @@ config KCOV
config KCOV_ENABLE_COMPARISONS
bool "Enable comparison operands collection by KCOV"
depends on KCOV
- default n
help
KCOV also exposes operands of every comparison in the instrumented
code along with operand sizes and PCs of the comparison instructions.
@@ -768,7 +767,7 @@ config KCOV_ENABLE_COMPARISONS
config KCOV_INSTRUMENT_ALL
bool "Instrument all code by default"
depends on KCOV
- default y if KCOV
+ default y
help
If you are doing generic system call fuzzing (like e.g. syzkaller),
then you will want to instrument the whole kernel and you should
--
2.7.4