On 12/13/18 4:32 PM, bill.c.roberts@xxxxxxxxx wrote:
From: William Roberts <william.c.roberts@xxxxxxxxx>
Certain builds of gcc enable _FORTIFY_SOURCE which results in the error:
<command-line>:0:0: warning: "_FORTIFY_SOURCE" redefined
<command-line>:0:0: note: this is the location of the previous definition
Correct this by undefining it first and redefining it. Also, the previous
command line option was using -Wp which passing the value *AS IS* to the
pre-processor rather than to the compiler driver. The C pre-processor has
an undocumented interface subject to change per man 1 gcc. Just use the
-D option as is.
See commit ca07a2ad46be141dad90d885dd33a2ac31c6559a ("libselinux: avoid
redefining _FORTIFY_SOURCE") for why we don't specify a value for
_FORTIFY_SOURCE here. Not sure about the -Wp,-D vs -D rationale.
Signed-off-by: William Roberts <william.c.roberts@xxxxxxxxx>
---
libselinux/src/Makefile | 2 +-
libselinux/utils/Makefile | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/libselinux/src/Makefile b/libselinux/src/Makefile
index 977b5c8cfcca..ee55bd0dbff7 100644
--- a/libselinux/src/Makefile
+++ b/libselinux/src/Makefile
@@ -64,7 +64,7 @@ ifeq ($(COMPILER), gcc)
EXTRA_CFLAGS = -fipa-pure-const -Wlogical-op -Wpacked-bitfield-compat -Wsync-nand \
-Wcoverage-mismatch -Wcpp -Wformat-contains-nul -Wnormalized=nfc -Wsuggest-attribute=const \
-Wsuggest-attribute=noreturn -Wsuggest-attribute=pure -Wtrampolines -Wjump-misses-init \
- -Wno-suggest-attribute=pure -Wno-suggest-attribute=const -Wp,-D_FORTIFY_SOURCE
+ -Wno-suggest-attribute=pure -Wno-suggest-attribute=const -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
else
EXTRA_CFLAGS = -Wunused-command-line-argument
endif
diff --git a/libselinux/utils/Makefile b/libselinux/utils/Makefile
index d06ffd66893b..64ab877015c6 100644
--- a/libselinux/utils/Makefile
+++ b/libselinux/utils/Makefile
@@ -30,7 +30,7 @@ CFLAGS ?= -O -Wall -W -Wundef -Wformat-y2k -Wformat-security -Winit-self -Wmissi
-Wformat-extra-args -Wformat-zero-length -Wformat=2 -Wmultichar \
-Woverflow -Wpointer-to-int-cast -Wpragmas \
-Wno-missing-field-initializers -Wno-sign-compare \
- -Wno-format-nonliteral -Wframe-larger-than=$(MAX_STACK_SIZE) -Wp,-D_FORTIFY_SOURCE \
+ -Wno-format-nonliteral -Wframe-larger-than=$(MAX_STACK_SIZE) -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 \
-fstack-protector-all --param=ssp-buffer-size=4 -fexceptions \
-fasynchronous-unwind-tables -fdiagnostics-show-option -funit-at-a-time \
-Werror -Wno-aggregate-return -Wno-redundant-decls \
