Control: tags -1 + patch
On Wed, Nov 29, 2017 at 02:33:53AM +0100, Matthias Klose wrote:
> as discussed on irc, the alternative solution should be preferred.
Ah, right. Thank you for the reminder.
In the mean time, I tried to agree on a better header name for
"X-DH-Build-For-Type: target" with Guillem and Niels, but we ultimately
failed. Thus we will end up using the debhelper extension name and do
without support from dpkg for now. Doing without dpkg means that
dh_gencontrol does not fully honour this header and we'll have to change
DEB_HOST_ARCH and friends before running it. Luckily, gcc already does
this using cross_gencontrol.
So I've split up this patch into four patches, because they kinda solve
four different subproblems. I hope this makes reviewing them easier.
#1 gcc-dhp-flags.patch
This patch is only relevant to DEB_STAGE=rtlibs. While performing a
DEB_STAGE=rtlibs build, we are in the strange situation that all binary
packages are considered architecture independent and files like
"debian/arch_binaries" and "debian/arch_binaries.all" and up being
completely empty. The foreach loops generating the -p flags for
debhelper will thus be empty and no -p flag will be generated at all.
Rather that processing no packages, this will make the various dh_*
tools process all packages. This is a bug even before debhelper became
strict, but now it became fatal.
#2 gcc-target-vars.patch
The gcc packaging has a set of make variables DEB_TARGET_* that pretty
closely mimic the dpkg-architecture variables. We need to export these
as debhelper is going to use them. Furthermore, dpkg-architecture gained
some new variables and those should be added here.
#3 gcc-target-package.patch
This patch simply adds a layer of indirection. It defines a m4 macro for
the new header in control.m4. This macro makes it easy to remove the
header if it turns out to be problematic. For instance, it could be made
empty if the release we are building for is very old or we are not
performing a cross compiler build. It also makes the next "patch"
easier.
#4 Adding the headers
I didn't implement this change as a patch, but as a sed expression:
sed -i -e '/^Package: .*`'"'"'LS$/aTARGET_PACKAGE`'"'dnl" debian/control.m4
What it does is simple enough: It looks for every package that ends in
"LS" and appends the header to that package. This is the suffix that
turns architecture dependent packages into -$arch-cross packages for
cross compilers (other than DEB_STAGE=rtlibs). This $arch is the target
architecture, so this LS suffix precisely identifies the packages that
need to be enabled.
I've tested cross compiler builds for gcc-7 and gcc-8 for a fair number
of targets now. None of the aspects changed touch native builds in any
significant way. Thus I think this patch is pretty safe.
In a distant future, this change will allow us to remove a lot of magic
like cross_shlibdeps, cross_makeshlibs and cross_clean as this tagging
will have turned into a tagging that is performed in debian/control
instead.
Helmut
--- a/debian/rules2
+++ b/debian/rules2
@@ -2396,10 +2396,12 @@
cat debian/arch_binaries debian/arch_binaries.epoch > debian/arch_binaries.all
binary-arch: debian/arch_binaries.all
+ test ! -s debian/arch_binaries.all || \
dh_compress $(foreach p,$(shell echo `cat debian/arch_binaries.all`),-p$(p)) \
-X.log.xz -X.sum.xz -X.c -X.txt -X.tag -X.map -XREADME.Bugs
ifeq ($(i586_symlinks),yes)
cd debian; \
+ test ! -s arch_binaries || \
for x in $$(find `cat arch_binaries` -type l -name 'i686-*'); do \
link=$$(echo $$x | sed 's/i686-/i586-/'); \
tgt=$$(basename $$x); \
@@ -2407,7 +2409,9 @@
rm -f $$link; cp -a $$x $$link; \
done
endif
+ test ! -s debian/arch_binaries.all || \
dh_fixperms $(foreach p,$(shell echo `cat debian/arch_binaries.all`),-p$(p))
+ test ! -s debian/arch_binaries || \
dh_gencontrol $(foreach p,$(shell echo `cat debian/arch_binaries`),-p$(p)) \
-- -v$(DEB_VERSION) $(common_substvars)
@set -e; \
@@ -2416,8 +2420,11 @@
echo dh_gencontrol $$pkgs -- -v$(DEB_EVERSION) $(common_substvars); \
dh_gencontrol $$pkgs -- -v$(DEB_EVERSION) $(common_substvars); \
fi
+ test ! -s debian/arch_binaries.all || \
dh_installdeb $(foreach p,$(shell echo `cat debian/arch_binaries.all`),-p$(p))
+ test ! -s debian/arch_binaries.all || \
dh_md5sums $(foreach p,$(shell echo `cat debian/arch_binaries.all`),-p$(p))
+ test ! -s debian/arch_binaries.all || \
dh_builddeb $(foreach p,$(shell echo `cat debian/arch_binaries.all`),-p$(p))
ifeq ($(with_check),yes)
@echo Done
--- a/debian/rules.defs
+++ b/debian/rules.defs
@@ -161,6 +161,11 @@
DEB_TARGET_GNU_TYPE := $(call vafilt,$(TARGET_VARS),DEB_HOST_GNU_TYPE)
DEB_TARGET_GNU_SYSTEM := $(call vafilt,$(TARGET_VARS),DEB_HOST_GNU_SYSTEM)
DEB_TARGET_MULTIARCH := $(call vafilt,$(TARGET_VARS),DEB_HOST_MULTIARCH)
+DEB_TARGET_ARCH_ABI := $(call vafilt,$(TARGET_VARS),DEB_HOST_ARCH_ABI)
+DEB_TARGET_ARCH_BITS := $(call vafilt,$(TARGET_VARS),DEB_HOST_ARCH_BITS)
+DEB_TARGET_ARCH_ENDIAN := $(call vafilt,$(TARGET_VARS),DEB_HOST_ARCH_ENDIAN)
+DEB_TARGET_ARCH_LIBC := $(call vafilt,$(TARGET_VARS),DEB_HOST_ARCH_LIBC)
+export DEB_TARGET_ARCH DEB_TARGET_ARCH_ABI DEB_TARGET_ARCH_BITS DEB_TARGET_ARCH_CPU DEB_TARGET_ARCH_OS DEB_TARGET_ARCH_ENDIAN DEB_TARGET_ARCH_LIBC DEB_TARGET_GNU_CPU DEB_TARGET_GNU_TYPE DEB_TARGET_GNU_SYSTEM DEB_TARGET_MULTIARCH
ifeq ($(derivative),Ubuntu)
ifeq (,$(filter $(distrelease),dapper lucid))
--- a/debian/control.m4
+++ b/debian/control.m4
@@ -33,6 +33,8 @@
define(`BUILT_USING', ifelse(add_built_using,yes,`Built-Using: ${Built-Using}
'))
+define(`TARGET_PACKAGE',`X-DH-Build-For-Type: target
+')
divert`'dnl
dnl --------------------------------------------------------------------------
