linux

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Masahiro Yamada 5aadfdeb8d kcov: test compiler capability in Kconfig and correct dependency

As Documentation/kbuild/kconfig-language.txt notes, 'select' should be
be used with care - it forces a lower limit of another symbol, ignoring
the dependency.  Currently, KCOV can select GCC_PLUGINS even if arch
does not select HAVE_GCC_PLUGINS.  This could cause the unmet direct
dependency.

Now that Kconfig can test compiler capability, let's handle this in a
more sophisticated way.

There are two ways to enable KCOV; use the compiler that natively
supports -fsanitize-coverage=trace-pc, or build the SANCOV plugin if
the compiler has ability to build GCC plugins.  Hence, the correct
dependency for KCOV is:

  depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS

You do not need to build the SANCOV plugin if the compiler already
supports -fsanitize-coverage=trace-pc.  Hence, the select should be:

  select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC

With this, GCC_PLUGIN_SANCOV is selected only when necessary, so
scripts/Makefile.gcc-plugins can be cleaner.

I also cleaned up Kconfig and scripts/Makefile.kcov as well.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>

2018-06-11 09:14:08 +09:00

.gitignore

gcc-plugins: Add the randstruct plugin

2017-06-22 16:15:45 -07:00

cyc_complexity_plugin.c

gcc-plugins: consolidate on PASS_INFO macro

2017-01-13 14:20:03 -08:00

gcc-common.h

gcc-plugins: Add include required by GCC release 8

2018-02-05 17:10:10 -08:00

gcc-generate-gimple-pass.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license