[PATCH 10/12] configure: Detect kcov support and introduce CONFIG_KCOV

[Aleksandar Markovic <aleksandar.markovic@rt-rk.com>]

From: Aleksandar Markovic <amarkovic@wavecomp.com>

kcov is kernel code coverage tracing tool. It requires kernel 4.4+
compiled with certain kernel options.

This patch checks if kcov header "sys/kcov.h" is present on build
machine, and stores the result in variable CONFIG_KCOV, meant to
be used in linux-user code related to the support for three ioctls
that were introduced at the same time as the mentioned header
(their definition was a part of the first version of that header).

Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
---
 configure | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/configure b/configure
index 940bf9e..57e6eba 100755
--- a/configure
+++ b/configure
@@ -4752,6 +4752,12 @@ if compile_prog "" "" ; then
   syncfs=yes
 fi
 
+# check for kcov support (kernel must be 4.4+, compiled with certain options)
+kcov=no
+if check_include sys/kcov.h ; then
+    kcov=yes
+fi
+
 # Check we have a new enough version of sphinx-build
 has_sphinx_build() {
     # This is a bit awkward but works: create a trivial document and
@@ -6874,6 +6880,9 @@ fi
 if test "$syncfs" = "yes" ; then
   echo "CONFIG_SYNCFS=y" >> $config_host_mak
 fi
+if test "$kcov" = "yes" ; then
+  echo "CONFIG_KCOV=y" >> $config_host_mak
+fi
 if test "$inotify" = "yes" ; then
   echo "CONFIG_INOTIFY=y" >> $config_host_mak
 fi
-- 
2.7.4