During a package build we call prepare_buildenv in multiple stages of
the process. For debug packages, one of the hooks is buildenv_debugflags
which populates the debug flags to the according variables.
The issue is that the behavior of the current implementation of
buildenv_debugflags is not idempotent, so consecutive calls will append
the same flags again. In certain cases this isn't an issue, however
for context aware build frontends like cargo any change of the build
inputs leads to a fresh build. This means that any invocation of such
a build ecosystem inside the package() function will trigger a full
rebuild, which is not desired.
To fix this issue, this commit makes buildenv_debugflags idempotent
by only appending flags once to the target variables.
Signed-off-by: Levente Polyak <anthraxx@archlinux.org>
We want to use -flto=auto in Arch Linux to speed up building, but we
can't hardcode it in buildenv/lto.sh because other downstreams might
have clang < 13.0.0 which did not recognize -flto=auto as equivalent
to -flto=full.
Introducing an LTOFLAGS variable to makepkg.conf seems the way to go.
Signed-off-by: Allan McRae <allan@archlinux.org>
GCC automatically detects when it is linking LTO objects, but clang does
not. Add -flto to LDFLAGS to make this work for clang too.
Signed-off-by: Allan McRae <allan@archlinux.org>
Add the 'lto' option to enable building with link time optimization
by adding '-flto' to both CFLAGS and CXXFLAGS. The 'lto' option can
be specificed both in the PKGBUILD or by setting the default in
makepkg.conf.
Signed-off-by: Allan McRae <allan@archlinux.org>
