From 84c7d2dfeac2b1b4f7c0449744c58c3f80a8607d Mon Sep 17 00:00:00 2001 From: Jacob Garber Date: Wed, 2 Oct 2019 13:35:08 -0600 Subject: xcompile: Disable null pointer optimizations According to the C standard, accessing the NULL pointer (memory at address zero) is undefined behaviour, and so GCC is allowed to optimize it out. Of course, accessing this memory location is sometimes necessary, so this optimization can be disabled using -fno-delete-null-pointer-checks. This is already done in coreboot, but adding it to xcompile will also disable it for all the payloads. For example, coreinfo compiled with LTO libpayload crashes when this flag isn't set, presumably because the compiler is optimizing something out that it shouldn't. Change-Id: I4492277f02418ade3fe7a75304e8e0611f49ef36 Signed-off-by: Jacob Garber Reviewed-on: https://review.coreboot.org/c/coreboot/+/38289 Reviewed-by: Angel Pons Reviewed-by: Paul Menzel Tested-by: build bot (Jenkins) --- util/xcompile/xcompile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'util/xcompile') diff --git a/util/xcompile/xcompile b/util/xcompile/xcompile index 8335c347fbff..a116407b8b30 100755 --- a/util/xcompile/xcompile +++ b/util/xcompile/xcompile @@ -221,7 +221,7 @@ SUBARCH_SUPPORTED+=${TSUPP-${TARCH}} GCC_CC_${TARCH}:=${GCC} GCC_CFLAGS_${TARCH}:=${CFLAGS_GCC} # Generally available for GCC's cc1: -GCC_CFLAGS_${TARCH}+=-Wlogical-op +GCC_CFLAGS_${TARCH}+=-fno-delete-null-pointer-checks -Wlogical-op GCC_ADAFLAGS_${TARCH}:=${CFLAGS_GCC} GCC_COMPILER_RT_${TARCH}:=${CC_RT_GCC} GCC_COMPILER_RT_FLAGS_${TARCH}:=${CC_RT_EXTRA_GCC} -- cgit v1.2.3