Update GentooLTO defaults

Add -fipa-pta, -fdevirtualize-at-ltrans to default flags
Make ld.gold default GentooLTO linker
Remove older ltoize versions
Rename some variables
Add new definitions

Signed-off-by: Shane Peelar <[email protected]>

metadata/news/2019-05-22-updated-defaults/2019-05-22-updated-defaults.txt

@@ -0,0 +1,40 @@
+Title: GentooLTO updated default flags
+Author: Shane Peelar <[email protected]>
+Content-Type: text/plain
+Posted: 2019-05-22
+Revision: 1
+News-Item-Format: 1.0
+
+A few weeks have passed since the introduction of GCC 9.1.0 and GentooLTO will
+now be updating the default configuration to include two new flags:
+
+* -fipa-pta
+* -fdevirtualize-at-ltrans
+
+These are two safe flags that don't change the semantics of your programs.
+Users of make.conf.lto will receive the changes transparently.  Users
+of make.conf.lto.defines will have to manually edit their config to include
+these flags. No system rebuild or lto-rebuild is required.
+
+Note that these flags will increase compilation time by some amount.
+If you encounter build failures, please make a report or email me.
+
+GentooLTO is also now using ld.gold as the default linker.
+ld.bfd is still necessary for certain packages, but gold seems
+to give less trouble than bfd in general.  A warning has been
+added to sys-config/ltoize to remind users to switch over.
+No system rebuild or lto-rebuild is required for this change.
+
+GentooLTO is also undergoing a refactor in terms of repository layout
+and documentation.  The documentation/knowledge base is being migrated
+over to the GentooLTO wiki located here:
+
+https://github.com/InBetweenNames/gentooLTO/wiki
+
+and the repository layout will change such that new and different
+configurations will be supported.  A news item will be posted
+when these changes occur so that you can update your system accordingly.
+More to come soon!
+
+All the best,
+-Shane

metadata/news/2019-05-22-updated-defaults/2019-05-22-updated-defaults.txt.asc

@@ -0,0 +1,11 @@
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sys-config/ltoize/files/make.conf.lto

@@ -76,7 +76,7 @@ source make.conf.lto.defines
 
 #Thanks to issue #49, no action necessary for preventing stripping of static libraries
 
-CFLAGS="-O3 ${GRAPHITE} ${SEMINTERPOS} ${FLTO} -fuse-linker-plugin"
+CFLAGS="-O3 ${GRAPHITE} ${DEVIRTLTO} ${IPAPTA} ${SEMINTERPOS} ${FLTO} -fuse-linker-plugin"
 
 #Your LDFLAGS should contain *ALL* of your CFLAGS for LTO to work.  It must receieve all optimization options, march, etc.
 #package.cflags takes care of this for you--no need to manually add your {C,CXX}FLAGS here.

sys-config/ltoize/files/make.conf.lto.defines

@@ -11,7 +11,7 @@
 #* Your CFLAGS should contain ${FLTO} and, depending on your gcc, -fuse-linker-plugin
 #* Newer GCCs enable -fuse-linker-plugin by default.
 #* If you want Graphite, include "${GRAPHITE}" in your CFLAGS
-#* If you want -fipa-pta, include "${IPA}" in your CFLAGS (undefined for now, issue #257)
+#* If you want -fipa-pta, include "${IPAPTA}" in your CFLAGS (undefined for now, issue #257)
 #* Anything else is up to you, such as -march, -pipe, -O{3,2,s,1}, etc...
 #* CXXFLAGS should be set to CFLAGS
 #* Optionally, set other *FLAGS for languages compiled with GCC as well (See make.conf.lto)
@@ -28,9 +28,9 @@ FLTO="-flto=${NTHREADS}"
 GRAPHITE="-fgraphite-identity -floop-nest-optimize"
 #NOTE: To use graphite, make sure you have gcc compiled with graphite support (add graphite to your USE).  Otherwise GCC will complain!
 
-IPA="-fipa-pta"
+IPAPTA="-fipa-pta"
 
-#IPA contains -fipa* opts that are disabled by default in GCC.  These are interprocedural optimizations.  For now this is only -fipa-pta.
+#IPAPTA contains -fipa* opts that are disabled by default in GCC.  These are interprocedural optimizations.  For now this is only -fipa-pta.
 #This option increases compile times, but can potentially produce better binaries, especially with LTO.
 #Essentially, it allows the compiler to look into called function bodies when performing alias analysis
 
@@ -43,9 +43,20 @@ NOCOMMON="-fno-common"
 # This option only affects C code.  Only non-conformant C code needs -fcommon, which is enabled by default.  Clear Linux leaves this flag off by default.
 # We may enable this at some point.  For now, there's a lot of breakages to work through.
 
-FASTMATH="-fno-math-errno -fno-trapping-math"
+SAFERFASTMATH="-fno-math-errno -fno-trapping-math"
 
 #These are flags left off by default that we're planning to start using.  Clear Linux uses these in lieu of full -ffast-math optimizations
 #They DO break compliance with ISO C++, so we'll be careful about introducing these.
 #Relevant discussion: https://gcc.gnu.org/ml/gcc/2017-09/msg00079.html
 #We may end up just going full -Ofast, with exceptions done in the usual way.
+
+DEVIRTLTO="-fdevirtualize-at-ltrans"
+
+#This allows GCC to perform devirtualization across object file boundaries using LTO.  It's off by default because it
+#increases compilation time.
+
+NOPLT="-fno-plt"
+
+#This option omits the PLT from the executable, making calls go through the GOT directly.
+#It inhibits lazy binding, so this is not enabled by default.  If you use prelink, this is
+#strictly better than lazy binding.

sys-config/ltoize/files/package.cflags/ltoworkarounds.conf

@@ -52,7 +52,7 @@ games-emulation/mupen64plus-libretro *FLAGS-=-flto*
 net-p2p/cpuminer-opt *FLAGS-=-flto*
 x11-drivers/xf86-video-intel *FLAGS-=-flto*
 <app-text/mupdf-1.12.0 *FLAGS-=-flto* # Only older versions are affected
-dev-scheme/racket *FLAGS-=-flto* *FLAGS-="${IPA}" # Undefined references and multiple segfaults / violations during build.
+dev-scheme/racket *FLAGS-=-flto* *FLAGS-="${IPAPTA}" # Undefined references and multiple segfaults / violations during build.
 sys-libs/libsepol *FLAGS-=-flto*
 sys-libs/libselinux *FLAGS-=-flto*
 sys-libs/libsemanage *FLAGS-=-flto*
@@ -61,7 +61,7 @@ dev-libs/weston *FLAGS-=-flto*
 >=dev-lang/php-7.2.0 *FLAGS-=-flto* # lto-wrapper link failure / https://github.com/InBetweenNames/gentooLTO/issues/135
 sys-fs/fuse *FLAGS-=-flto* # Issue #139 and #142, it appears the symbol __fuse_read_cmd goes missing if LTO is enabled, causing linking problems on some systems.  Using gold seems to help.
 sys-fs/fuse-common *FLAGS-=-flto*
-sys-libs/glibc *FLAGS-=-flto* #Alternative: *FLAGS+=-ffat-lto-objects *FLAGS-="${IPA}" Fails in configure stage with LTO enabled, checking for builtin redirect.  With -ffat-lto-objects, and no -fipa-pta, we get further, but get multiple definition errors  Forcing past that yields undefined symbol errors.
+sys-libs/glibc *FLAGS-=-flto* #Alternative: *FLAGS+=-ffat-lto-objects *FLAGS-="${IPAPTA}" Fails in configure stage with LTO enabled, checking for builtin redirect.  With -ffat-lto-objects, and no -fipa-pta, we get further, but get multiple definition errors  Forcing past that yields undefined symbol errors.
 app-emulation/wine* *FLAGS-=-flto*
 sys-process/criu *FLAGS-=-pipe* *FLAGS-=-flto* *FLAGS-="-fuse-linker-plugin" LDFLAGS-="-Wl,--hash-style=gnu" *FLAGS-="${GRAPHITE}" # Fewer settings may be possible. Needs testing. (Dependency of LXC.)
 media-video/ffmpeg *FLAGS-=-flto* #NOTE: Depending on your CPUFLAGS this may work with LTO.  The SSE intrinsics seem to cause problems in some cases.
@@ -146,21 +146,21 @@ sys-devel/gcc LTO_ENABLE_FLAGOMATIC=yes #Build system requires special attention
 dev-lang/gnat-gpl LTO_ENABLE_FLAGOMATIC=yes
 # END: override-flagomatic workarounds
 
-#sys-devel/gcc BOOT_CFLAGS="${CFLAGS}"
+#>=sys-devel/gcc-9 *FLAGS-=-flto* BOOT_CFLAGS='"${CFLAGS}"'
 
 # BEGIN: -fipa-pta workarounds
-www-client/firefox *FLAGS-="${IPA}" #ICE on -fipa-pta
-www-client/torbrowser *FLAGS-="${IPA}" #ICE on -fipa-pta
-=sys-apps/gawk-4.1.4 *FLAGS-="${IPA}" # during IPA pass: pta lto1: internal compiler error: Segmentation fault
-dev-qt/qtwebkit *FLAGS-="${IPA}"
-media-sound/mpc *FLAGS-="${IPA}" # hangs on exit with -fipa-pta
-dev-lang/R *FLAGS-="${IPA}" # during IPA pass: pta lto1: internal compiler error: Segmentation fault
-sys-devel/gcc *FLAGS-="${IPA}"
-dev-lang/gnat-gpl *FLAGS-="${IPA}"
-dev-lisp/sbcl *FLAGS-="${IPA}" #ICE on -fipa-pta
-x11-wm/bspwm *FLAGS-="${IPA}" # needed for version 0.9.7 on 17.0 profile running the testing branch everywhere with GCC 8.3.0
-media-libs/libwebp *FLAGS-=-fipa-pta # no compilation issues, but -fipa-pta causes webp images to be displayed incorrectly
-dev-qt/qtgui *FLAGS-=-fipa-pta # Same problem as above
+www-client/firefox *FLAGS-="${IPAPTA}" #ICE on -fipa-pta
+www-client/torbrowser *FLAGS-="${IPAPTA}" #ICE on -fipa-pta
+=sys-apps/gawk-4.1.4 *FLAGS-="${IPAPTA}" # during IPAPTA pass: pta lto1: internal compiler error: Segmentation fault
+dev-qt/qtwebkit *FLAGS-="${IPAPTA}"
+media-sound/mpc *FLAGS-="${IPAPTA}" # hangs on exit with -fipa-pta
+dev-lang/R *FLAGS-="${IPAPTA}" # during IPAPTA pass: pta lto1: internal compiler error: Segmentation fault
+sys-devel/gcc *FLAGS-="${IPAPTA}"
+dev-lang/gnat-gpl *FLAGS-="${IPAPTA}"
+dev-lisp/sbcl *FLAGS-="${IPAPTA}" #ICE on -fipa-pta
+x11-wm/bspwm *FLAGS-="${IPAPTA}" # needed for version 0.9.7 on 17.0 profile running the testing branch everywhere with GCC 8.3.0
+media-libs/libwebp *FLAGS-="${IPAPTA}" # no compilation issues, but -fipa-pta causes webp images to be displayed incorrectly
+dev-qt/qtgui *FLAGS-="${IPAPTA}" # Same problem as above
 # END: -fipa-pta workarounds
 
 # BEGIN: TLS dialect workarounds