From 2d1b1c7daeeada3f737e62ceb2db7484cde5ff4e Mon Sep 17 00:00:00 2001 From: fanquake Date: Wed, 6 Dec 2023 12:26:02 +0000 Subject: build: remove --enable-lto This has outlived its usefulness, doesn't gel well with newer compilers & `-flto` related options, i.e thin vs full, or `=auto`, and having `-flto` as the only option means that sometimes this just needs to be worked around, i.e in oss-fuzz: https://github.com/google/oss-fuzz/blob/master/projects/bitcoin-core/build.sh. While it was convenient when `-flto` was newer, support for `-flto` is now in all compilers we use, and there's also no-longer any real need for us to treat `-flto` different to any other optimization option. Remove it, to remove build complexity, and so there's no need to port a similar option to CMake. Note that the LTO option remains in depends, because we still a way to build packages that have LTO specific patches/options. If we decide to merge this, I'll follow up downstream in oss-fuzz first, to make sure we don't break the build. --- configure.ac | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) (limited to 'configure.ac') diff --git a/configure.ac b/configure.ac index 7b286df603..19a9134bd2 100644 --- a/configure.ac +++ b/configure.ac @@ -321,11 +321,6 @@ AC_ARG_ENABLE([external-signer], [use_external_signer=$enableval], [use_external_signer=auto]) -AC_ARG_ENABLE([lto], - [AS_HELP_STRING([--enable-lto],[build using LTO (default is no)])], - [enable_lto=$enableval], - [enable_lto=no]) - AC_LANG_PUSH([C++]) dnl Check for a flag to turn compiler warnings into errors. This is helpful for checks which may @@ -377,11 +372,6 @@ if test "$enable_debug" = "yes"; then AX_CHECK_COMPILE_FLAG([-ftrapv], [DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -ftrapv"], [], [$CXXFLAG_WERROR]) fi -if test "$enable_lto" = "yes"; then - AX_CHECK_COMPILE_FLAG([-flto], [LTO_CXXFLAGS="$LTO_CXXFLAGS -flto"], [AC_MSG_ERROR([compile failed with -flto])], [$CXXFLAG_WERROR]) - AX_CHECK_LINK_FLAG([-flto], [LTO_LDFLAGS="$LTO_LDFLAGS -flto"], [AC_MSG_ERROR([link failed with -flto])], [$CXXFLAG_WERROR]) -fi - if test "$use_sanitizers" != ""; then dnl First check if the compiler accepts flags. If an incompatible pair like dnl -fsanitize=address,thread is used here, this check will fail. This will also @@ -1893,8 +1883,6 @@ AC_SUBST(GPROF_LDFLAGS) AC_SUBST(HARDENED_CXXFLAGS) AC_SUBST(HARDENED_CPPFLAGS) AC_SUBST(HARDENED_LDFLAGS) -AC_SUBST(LTO_CXXFLAGS) -AC_SUBST(LTO_LDFLAGS) AC_SUBST(PIC_FLAGS) AC_SUBST(PIE_FLAGS) AC_SUBST(SANITIZER_CXXFLAGS) @@ -2002,7 +1990,6 @@ echo " sanitizers = $use_sanitizers" echo " debug enabled = $enable_debug" echo " gprof enabled = $enable_gprof" echo " werror = $enable_werror" -echo " LTO = $enable_lto" echo echo " target os = $host_os" echo " build os = $build_os" @@ -2011,8 +1998,8 @@ echo " CC = $CC" echo " CFLAGS = $PTHREAD_CFLAGS $CFLAGS" echo " CPPFLAGS = $DEBUG_CPPFLAGS $HARDENED_CPPFLAGS $CORE_CPPFLAGS $CPPFLAGS" echo " CXX = $CXX" -echo " CXXFLAGS = $LTO_CXXFLAGS $DEBUG_CXXFLAGS $HARDENED_CXXFLAGS $WARN_CXXFLAGS $NOWARN_CXXFLAGS $ERROR_CXXFLAGS $GPROF_CXXFLAGS $CORE_CXXFLAGS $CXXFLAGS" -echo " LDFLAGS = $LTO_LDFLAGS $PTHREAD_LIBS $HARDENED_LDFLAGS $GPROF_LDFLAGS $CORE_LDFLAGS $LDFLAGS" +echo " CXXFLAGS = $DEBUG_CXXFLAGS $HARDENED_CXXFLAGS $WARN_CXXFLAGS $NOWARN_CXXFLAGS $ERROR_CXXFLAGS $GPROF_CXXFLAGS $CORE_CXXFLAGS $CXXFLAGS" +echo " LDFLAGS = $PTHREAD_LIBS $HARDENED_LDFLAGS $GPROF_LDFLAGS $CORE_LDFLAGS $LDFLAGS" echo " AR = $AR" echo " ARFLAGS = $ARFLAGS" echo -- cgit v1.2.3