rcar-gen3: kernel-module-gles: WORKAROUND to build with GCC 8.1

Current GFX source code will get compilation error with GCC 8.1,
because it is defined in makefile to use -Wall to enable all
Warnings check.
-Wcast-function-type, -Wsizeof-pointer-div and -Wstringop-truncation
are new command-line options have been added for the C and C++
compilers in GCC 8.

This commit applies a W/A patch to silence -Wcast-function-type,
-Wsizeof-pointer-div and -Wstringop-truncation errors.

Signed-off-by: Thuy Tran <thuy.tran.xh@renesas.com>
Signed-off-by: Takamitsu Honda <takamitsu.honda.pv@renesas.com>

2 files changed, 63 insertions, 0 deletions

diff --git a/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles.bb b/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles.bb
index f43a791..844b41f 100644
--- a/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles.bb
+++ b/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles.bb
@@ -18,6 +18,9 @@ SRC_URI_r8a77990 = 'file://GSX_KM_E3.tar.bz2'
 
 S = "${WORKDIR}/rogue_km"
 
+# W/A fix build errors with GCC 8.1
+SRC_URI_append = " file://0001-Silenced-Wcast-function-type-Wsizeof-pointer-div-and.patch"
+
 KBUILD_DIR_r8a7795 = "${S}/build/linux/r8a7795_linux"
 KBUILD_DIR_r8a7796 = "${S}/build/linux/r8a7796_linux"
 KBUILD_DIR_r8a77965 = "${S}/build/linux/r8a77965_linux"
diff --git a/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles/0001-Silenced-Wcast-function-type-Wsizeof-pointer-div-and.patch b/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles/0001-Silenced-Wcast-function-type-Wsizeof-pointer-div-and.patch
new file mode 100644
index 0000000..fd91158
--- /dev/null
+++ b/meta-rcar-gen3/recipes-kernel/kernel-module-gles/kernel-module-gles/0001-Silenced-Wcast-function-type-Wsizeof-pointer-div-and.patch
@@ -0,0 +1,60 @@
+From 1bc7c0daece11b36abebc48b9113193056289fe6 Mon Sep 17 00:00:00 2001
+From: Thuy Tran <thuy.tran.xh@renesas.com>
+Date: Tue, 17 Jul 2018 15:01:56 +0700
+Subject: [PATCH] Silenced -Wcast-function-type, -Wsizeof-pointer-div and
+ -Wstringop-truncation options of GCC 8.1
+
+Current GFX source code will get compilation error with GCC 8.1,
+because it is defined in makefile to use -Wall to enable all Warnings
+check.
+-Wcast-function-type, -Wsizeof-pointer-div and -Wstringop-truncation
+are new Warnings from GCC 8.
+
+=====================================================================
+* Error generated by -Wcast-function-type
+
+    rogue_km/binary_r8a7796_linux_release/target_aarch64/kbuild/services/server/env/linux/module_common.c:43:
+    kernel-source/include/linux/timer.h: In function 'timer_setup':
+    error: cast between incompatible function types from 'void (*)(struct timer_list *)' to 'void (*)(long unsigned int)' [-Werror=cast-function-type]
+  __setup_timer(timer, (TIMER_FUNC_TYPE)callback,
+                       ^
+/ssd/thuy/FS2.6/M1/build_m3ulcb_mmp/tmp/work-shared/m3ulcb/kernel-source/include/linux/timer.h:144:25: note: in definition of macro '__setup_timer'
+   (_timer)->function = (_fn);    \
+                         ^~~
+======================================================================
+* Error generated by -Wsizeof-pointer-div
+
+    rogue_km/binary_r8a7796_linux_release/target_aarch64/kbuild/services/server/env/linux/km_apphint.c:229:48: error: division 'sizeof (void *) / sizeof (void)' does not compute the number of array elements [-Werror=sizeof-pointer-div]
+ #define APPHINT_HELP_ARRAY_SIZE(a) (sizeof((a))/(sizeof((a[0]))))
+                                                ^
+    rogue_km/binary_r8a7796_linux_release/target_aarch64/kbuild/services/server/env/linux/km_apphint.c:233:49: note: in expansion of macro 'APPHINT_HELP_ARRAY_SIZE'
+  {APPHINT_ID_ ## a, APPHINT_DATA_TYPE_ ## b, e, APPHINT_HELP_ARRAY_SIZE(e) },
+                                                 ^~~~~~~~~~~~~~~~~~~~~~~
+======================================================================
+* Error generated by -Wstringop-truncation
+
+    rogue_km/binary_r8a7796_linux_release/target_aarch64/kbuild/services/server/devices/rgx/rgxfwutils.c:1294:2: error: 'strncat' output truncated before terminating nul copying 7 bytes from a string of the same length [-Werror=stringop-truncation]
+  strncat(sCCBCtlName, sAppend, APPEND_STR_SIZE);
+  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Signed-off-by: Thuy Tran <thuy.tran.xh@renesas.com>
+---
+ build/linux/buildvars.mk | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/build/linux/buildvars.mk b/build/linux/buildvars.mk
+index a871d37..ddf12eb 100644
+--- a/build/linux/buildvars.mk
++++ b/build/linux/buildvars.mk
+@@ -51,7 +51,7 @@
+ 
+ # These flags are used for kernel, User C and User C++
+ #
+-COMMON_FLAGS := -W -Wall
++COMMON_FLAGS := -W -Wall -Wno-cast-function-type -Wno-sizeof-pointer-div -Wno-stringop-truncation
+ 
+ # Enable 64-bit file & memory handling on 32-bit systems.
+ #
+-- 
+2.7.4
+