cmake: Unset CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES

As discussion in [YOCTO #14717] cmake contains a OEToolchainConfig.cmake
file to configure the toolchain correctly in cross-compile build for recipes
using cmake.

The variable CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES value updates incorrectly
during do_compile the code. Due to this getting sporadic error like below,

fatal error: stdlib.h: No such file or directory
|    75 | #include_next <stdlib.h>
|       |               ^~~~~~~~~~
| compilation terminated.
| ninja: build stopped: subcommand failed.
| WARNING: exit code 1 from a shell command.

As cmake already correctly initializes the variable from environment,
So we have to unset it in the toolchain file to avoid overwriting the
variable definition again.

(From OE-Core rev: 5599eaefee3818c865d71f5b7c3cc04fc01de848)

Signed-off-by: aszh07 <mail2szahir@gmail.com>
Signed-off-by: Zahir Hussain <zahir.basha@kpit.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 5aeada5793af53e8c93940952d4f314474dca4c2)
Signed-off-by: Steve Sakoman <steve@sakoman.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake b/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake
index d6a1e0464c..6434b27371 100644
--- a/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake
+++ b/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake
@@ -18,3 +18,6 @@ file( GLOB toolchain_config_files "${CMAKE_CURRENT_LIST_FILE}.d/*.cmake" )
 foreach(config ${toolchain_config_files})
     include(${config})
 endforeach()
+
+unset(CMAKE_C_IMPLICIT_INCLUDE_DIRECTORIES)
+unset(CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES)