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CONFIG_GCOV_FORMAT_AUTODETECT compiles either gcc_3_4.c or gcc_4_7.c according to your GCC version. We can achieve the equivalent behavior by setting reasonable dependency with the knowledge of the compiler version. If GCC older than 4.7 is used, GCOV_FORMAT_3_4 is the default, but users are still allowed to select GCOV_FORMAT_4_7 in case the newer format is back-ported. On the other hand, If GCC 4.7 or newer is used, there is no reason to use GCOV_FORMAT_3_4, so it should be hidden. If you downgrade the compiler to GCC 4.7 or older, oldconfig/syncconfig will display a prompt for the choice because GCOV_FORMAT_3_4 becomes visible as a new symbol. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org>
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menu "GCOV-based kernel profiling"
config GCOV_KERNEL bool "Enable gcov-based kernel profiling" depends on DEBUG_FS select CONSTRUCTORS if !UML default n ---help--- This option enables gcov-based code profiling (e.g. for code coverage measurements).
If unsure, say N.
Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data
for the entire kernel. To enable profiling for specific files or
directories, add a line similar to the following to the respective
Makefile:
For a single file (e.g. main.o):
GCOV_PROFILE_main.o := y
For all files in one directory:
GCOV_PROFILE := y
To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL
is specified, use:
GCOV_PROFILE_main.o := n
and:
GCOV_PROFILE := n
Note that the debugfs filesystem has to be mounted to access
profiling data.
config ARCH_HAS_GCOV_PROFILE_ALL def_bool n
config GCOV_PROFILE_ALL bool "Profile entire Kernel" depends on !COMPILE_TEST depends on GCOV_KERNEL depends on ARCH_HAS_GCOV_PROFILE_ALL default n ---help--- This options activates profiling for the entire kernel.
If unsure, say N.
Note that a kernel compiled with profiling flags will be significantly
larger and run slower. Also be sure to exclude files from profiling
which are not linked to the kernel image to prevent linker errors.
choice prompt "Specify GCOV format" depends on GCOV_KERNEL ---help--- The gcov format is usually determined by the GCC version, and the default is chosen according to your GCC version. However, there are exceptions where format changes are integrated in lower-version GCCs. In such a case, change this option to adjust the format used in the kernel accordingly.
config GCOV_FORMAT_3_4 bool "GCC 3.4 format" depends on CC_IS_GCC && GCC_VERSION < 40700 ---help--- Select this option to use the format defined by GCC 3.4.
config GCOV_FORMAT_4_7 bool "GCC 4.7 format" ---help--- Select this option to use the format defined by GCC 4.7.
endchoice
endmenu