From 2ef960b14579c085215bdf882325688924cc70e9 Mon Sep 17 00:00:00 2001 From: "Alexander E. Patrakov" Date: Fri, 9 May 2014 23:48:55 +0600 Subject: [PATCH] build-sys: Eliminate _FORTIFY_SOURCE warnings The warnings were produced because the command-line flag redefined the value of _FORTIFY_SOURCE coming from the specs on some distributions, including Gentoo. So, undefine this macro before defining it. --- configure.ac | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/configure.ac b/configure.ac index e75973f6..76490f46 100644 --- a/configure.ac +++ b/configure.ac @@ -177,14 +177,20 @@ AX_APPEND_COMPILE_FLAGS( [-Wall -W -Wextra -pipe -Wno-long-long -Wno-overlength-strings -Wunsafe-loop-optimizations -Wundef -Wformat=2 -Wlogical-op -Wsign-compare -Wformat-security -Wmissing-include-dirs -Wformat-nonliteral -Wold-style-definition -Wpointer-arith -Winit-self -Wdeclaration-after-statement -Wfloat-equal -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wmissing-declarations -Wmissing-noreturn -Wshadow -Wendif-labels -Wcast-align -Wstrict-aliasing -Wwrite-strings -Wno-unused-parameter -ffast-math -fno-common -fdiagnostics-show-option], [], [-pedantic -Werror]) -# Only enable fastpath asserts when doing a debug build, e.g. from bootstrap.sh. -AS_CASE([" $CFLAGS "], [*" -O0 "*], [], [AX_APPEND_FLAG(["-DFASTPATH"], [CPPFLAGS])]) - -# Only set _FORTIFY_SOURCE when optimizations are enabled. If optimizations -# are disabled, _FORTIFY_SOURCE doesn't do anything, and causes tons of -# warnings during compiling on some distributions (at least Fedora). -AS_CASE([" $CFLAGS "], [*" -O0 "*], [], [AX_APPEND_FLAG(["-D_FORTIFY_SOURCE=2"], [CPPFLAGS])]) - +AS_CASE([" $CFLAGS "], [*" -O0 "*], [], [ + # Don't append the flag if it already exists. + # Only enable fastpath asserts when doing a debug build, e.g. from bootstrap.sh. + AX_APPEND_FLAG([-DFASTPATH], [CPPFLAGS]) + + # Cannot use AX_APPEND_FLAG here, as it assumes no space inside the added flags. + # Cannot append flags with AX_APPEND_FLAG one by one, as this would destroy all fortifications + # if CPPFLAGS already contain -D_FORTIFY_SOURCE=2. + + # Warnings to be aware of that appear with -D_FORTIFY_SOURCE=2 but without -U_FORTIFY_SOURCE: + # On Fedora 20 with -O0: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp] + # On Gentoo with -O2: "_FORTIFY_SOURCE" redefined [enabled by default] + AS_VAR_APPEND([CPPFLAGS],[" -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2"]) +]) #### Linker flags #### -- 2.39.2