#!/usr/bin/make -f
include /usr/share/dpkg/architecture.mk
include /usr/share/dpkg/buildflags.mk
include /usr/share/rustc/architecture.mk
export CFLAGS CXXFLAGS CPPFLAGS LDFLAGS
export DEB_HOST_RUST_TYPE DEB_HOST_GNU_TYPE
export CARGO_PROFILE_RELEASE_DEBUG=true
# stdbuf needs libstdbuf.so; upstream's GNUmakefile builds it with
# feat_external_libstdbuf and installs it into LIBSTDBUF_DIR.
export LIBSTDBUF_DIR = /usr/libexec/rust-coreutils

# who/pinky read the session list from logind rather than utmp on systemd
# systems, so build with the logind backend enabled.
export CARGOFLAGS += --features feat_systemd_logind

# libcrypto for the cksum/md5sum/sha*sum digests: much faster on CPUs without
# the SHA extensions. OPENSSL_NO_VENDOR links Debian's shared libcrypto instead
# of building the vendored openssl-src copy.
export CARGOFLAGS += --features openssl
export OPENSSL_NO_VENDOR = 1

export CARGOFLAGS += --features feat_diagnostics

# Use lld whenever it is available: it links the big multicall binary much
# faster than GNU ld. Fall back to the default linker on arches where lld is
# not installed. Always ask the linker to print its version banner (-Wl,-v)
# so the build log records which linker actually ran.
LLD := $(shell command -v ld.lld 2>/dev/null)
ifneq ($(LLD),)
export RUSTFLAGS = -C link-arg=-fuse-ld=lld -C link-arg=-Wl,-v
else
export RUSTFLAGS = -C link-arg=-Wl,-v
endif

# Fat LTO + 1 codegen unit + full debuginfo of the giant multicall crate is
# fatal on some arches: s390x hits the 150min buildd timeout, 32-bit arches OOM
# on the ~3GB address space ("rustc-LLVM ERROR: out of memory"). Set the cargo
# profile env overrides so they apply to every cargo invocation (build, test,
# install), unlike a Cargo.toml sed that only wraps one step.
ifeq ($(DEB_HOST_ARCH),s390x)
export CARGO_PROFILE_RELEASE_LTO = false
export CARGO_PROFILE_RELEASE_CODEGEN_UNITS = 16
export CARGO_PROFILE_RELEASE_DEBUG = 1
endif
ifeq ($(DEB_HOST_ARCH_BITS),32)
export CARGO_PROFILE_RELEASE_LTO = thin
export CARGO_PROFILE_RELEASE_CODEGEN_UNITS = 16
export CARGO_PROFILE_RELEASE_DEBUG = 1
endif
# PGO: instrument, train with util/build-pgo.sh, rebuild with -Cprofile-use.
# Doubles the build time and has to run the instrumented binary, hence 64-bit
# and native only. Opt out with DEB_BUILD_OPTIONS=nopgo.
PGO_ARCHS = amd64 arm64
PGO_DIR = $(CURDIR)/debian/pgo
PGO_PROFDATA = $(PGO_DIR)/coreutils.profdata

# llvm-profdata must match the LLVM rustc was built against: only it can read
# the .profraw files. Debian ships it in llvm-<N>, rustup in its sysroot.
LLVM_MAJOR := $(shell rustc --version --verbose | sed -n 's/^LLVM version: \([0-9]*\).*/\1/p')
RUST_SYSROOT := $(shell rustc --print sysroot)
LLVM_PROFDATA := $(firstword $(wildcard \
	/usr/lib/llvm-$(LLVM_MAJOR)/bin/llvm-profdata \
	$(RUST_SYSROOT)/lib/rustlib/$(DEB_HOST_RUST_TYPE)/bin/llvm-profdata))

ifeq (,$(filter nopgo,$(DEB_BUILD_OPTIONS)))
ifeq ($(DEB_BUILD_ARCH),$(DEB_HOST_ARCH))
ifneq (,$(filter $(DEB_HOST_ARCH),$(PGO_ARCHS)))
ifneq (,$(LLVM_PROFDATA))
PGO = y
endif
endif
endif
endif

ifeq ($(PGO),y)
# On both the test and install steps, so they share one set of artifacts.
PGO_RUSTFLAGS = -C profile-use=$(PGO_PROFDATA)
endif

VERSION := $(shell dpkg-parsechangelog -S Version|sed -e "s|.*~\(.*\)-.*|\1|g")
UPSTREAM_VERSION := $(shell dpkg-parsechangelog -S Version|cut -d- -f1)

# Build a multicall binary instead of multiple binaries
# to reduce the storage footprint
export MULTICALL = y

# Vendoring setup.
# The crates are NOT part of the upstream tarball (which is the pristine
# GitHub tag): they are vendored into debian/rust-vendor by the 'vendor'
# target below and shipped in the .debian.tar. This is what the Ubuntu
# package does, so the two stay mergeable.
export CARGO_VENDOR_DIR = debian/rust-vendor
export CARGO_HOME = $(CURDIR)/debian/cargo_home

# Configure dh_quilt_patch for applying vendor patches.
# This allows debian/rust-vendor/ to be patched without dpkg-source issues.
export QUILT_PATCH_DIR = debian/patches/rust-vendor
export QUILT_PC = debian/rust-vendor/.pc

%:
	dh $@ --buildsystem cargo

override_dh_auto_configure:
	# The translations live in a separate upstream repository and are shipped
	# as a component tarball; without them the package would silently build
	# without any localisation.
	@if [ ! -d l10n/src ]; then \
		echo "Error: l10n translations not found! Run 'uscan' to download the l10n tarball." >&2; \
		exit 1; \
	fi
	# The tldr examples embedded in the manpages (see improve-man.diff) come
	# from the tldr-pages release shipped in debian/, since the upstream
	# tarball does not contain it and the build has no network access.
	cp debian/tldr.zip docs/tldr.zip
	dh_auto_configure
	# Debian's dh-cargo hardcodes "prepare-debian debian/cargo_registry
	# --link-from-system" in its configure step, while Ubuntu's honours
	# CARGO_VENDOR_DIR. Point cargo back at our vendor directory afterwards
	# so the build uses the same crates on both distributions.
	DEB_CARGO_CRATE=coreutils_$(VERSION) /usr/share/cargo/bin/cargo prepare-debian $(CARGO_VENDOR_DIR)
	# dh-cargo-vendored-sources only exists in Ubuntu's dh-cargo; it checks
	# XS-Vendored-Sources-Rust against the vendor directory. Run it when it
	# is there so the Ubuntu build behaves exactly as before.
	[ ! -x /usr/share/cargo/bin/dh-cargo-vendored-sources ] || /usr/share/cargo/bin/dh-cargo-vendored-sources
	dh_quilt_patch

.PHONY: vendor

# Maintainer-side target: regenerate debian/rust-vendor. Needs
# cargo-vendor-filterer, which is not packaged in Debian:
#   cargo install cargo-vendor-filterer
# Run it after every new upstream import, then commit the result.
vendor:
	rm -rf $(CARGO_VENDOR_DIR)
	# Deliberately don't use the wrapper, as it expects the configure step
	# to have occurred already.
	# If you have to modify the path here, don't forget to change the
	# README.source doc as well.
	# PATH/HOME are kept so that a cargo-vendor-filterer installed with
	# 'cargo install' is found and can reach the registry cache; everything
	# else (CARGO_HOME, CARGO_VENDOR_DIR, ...) is deliberately cleared.
	env -i PATH="$$PATH" HOME="$$HOME" cargo-vendor-filterer --all-features --tier 2 --platform '*-*-linux-gnu' --platform '*-*-linux-gnueabi' $(CARGO_VENDOR_DIR)
	# Blank the checksum lists. Two reasons: it lets us patch the crates, and
	# dpkg-source drops VCS files (.gitmodules & co) from the .debian.tar, so a
	# crate shipping one would otherwise fail with "failed to calculate
	# checksum". Rewritten with json, not sed: cargo-vendor-filterer has since
	# added a "$comment" key and a line-anchored regexp silently skips those.
	@$(CURDIR)/debian/blank-vendor-checksums.py $(CARGO_VENDOR_DIR)
	# cargo-vendor-filterer keeps the crates' pre-publish Cargo.toml.orig;
	# cargo never reads it and lintian flags it as debian-adds-patch-failure-file.
	find $(CARGO_VENDOR_DIR) -name Cargo.toml.orig -delete
	# Cleanup temp files
	rm -rf $(CARGO_HOME)
	# Update include-binaries
	rm -f debian/source/include-binaries
	dpkg-source --include-binaries -b .
	# Update XS-Vendored-Sources-Rust field. Ubuntu generates it with
	# dh-cargo-vendored-sources; that helper is not in Debian's dh-cargo, so
	# read the crate names out of the vendor directory instead.
	python3 debian/update-vendored-sources-field.py
	# Commit changes
	git add -f $(CARGO_VENDOR_DIR)
	git commit -m "Update vendored rust crates" || true
	git add debian/source/
	git commit -m "Update debian/source/include-binaries" || true
	git add debian/control
	git commit debian/control -m "Update XS-Vendored-Sources-Rust field" || true

override_dh_auto_build:
	dh_auto_build
ifeq ($(PGO),y)
	# Step 1: the instrumented binary, built with *exactly* the command that
	# builds the shipped one. A profile only applies to a matching build: with
	# a different feature set the symbols differ, -Cprofile-use finds no data
	# and PGO silently does nothing. Hence not the script's own step 1, which
	# builds "--features unix" (see d/p/pgo-use-prebuilt-binary.patch).
	CARGO_TARGET_DIR=$(PGO_DIR)/instrumented \
	RUSTFLAGS="$(RUSTFLAGS) -C profile-generate=$(PGO_DIR)/profiles --cfg pgo_training" \
	CARGO_HOME=$(CURDIR)/debian/cargo_home \
		make SELINUX_ENABLED=1 PROFILE=release MULTICALL=$(MULTICALL) build-coreutils
	# Steps 2-4: corpus, training workloads, merge. The optimized build is the
	# package's own, via PGO_RUSTFLAGS.
	util/build-pgo.sh --train-only \
		--target-dir $(PGO_DIR) \
		--instrumented-binary $(PGO_DIR)/instrumented/release/coreutils \
		--llvm-profdata $(LLVM_PROFDATA)
	test -f $(PGO_PROFDATA)
	# Several GB, and nothing downstream needs it.
	rm -rf $(PGO_DIR)/instrumented
else
	@echo "PGO disabled on $(DEB_HOST_ARCH) (or by DEB_BUILD_OPTIONS=nopgo)"
endif

override_dh_auto_test:
ifeq ($(DEB_HOST_ARCH),s390x)
	# The release test build (every util + every test) is what actually hits
	# the buildd inactivity timeout on s390x. Tests are non-gating here (||true)
	# anyway, so skip them and rely on the other arches for coverage.
	@echo "Skipping the test suite on s390x to stay under the buildd timeout"
else
	# for now, don't fail the build if tests are failing
	RUSTFLAGS="$(RUSTFLAGS) $(PGO_RUSTFLAGS)" CARGO_HOME=$(CURDIR)/debian/cargo_home make PROFILE=release MULTICALL=$(MULTICALL) test||true
endif

override_dh_auto_install:
# The vendor directory is prepared once in override_dh_auto_configure.
# LTO/debuginfo/codegen are handled globally via CARGO_PROFILE_RELEASE_* env
# overrides at the top of this file, so no Cargo.toml editing is needed here.
	RUSTFLAGS="$(RUSTFLAGS) $(PGO_RUSTFLAGS)" CARGO_HOME=$(CURDIR)/debian/cargo_home DESTDIR=$(CURDIR)/debian/tmp/ make SELINUX_ENABLED=1 PROFILE=release MULTICALL=$(MULTICALL) install
# Create the symlink early to be able to generate the manpages
	cd debian/tmp/usr/share/zsh/site-functions && mkdir rust-coreutils && chmod -x _* && mv _* rust-coreutils
	cd debian/tmp/usr/share/bash-completion/completions/ && chmod -x rust-*
	cd debian/tmp/usr/share/fish/vendor_completions.d/ && chmod -x *.fish
	cd debian/tmp/usr/bin && mv rust-coreutils coreutils && rm rust-*
#	cd debian/tmp/usr/share/fish/vendor_completions.d && for f in *fish; do mv $$f rust-$$f; done
	dh_link

override_dh_missing:
	dh_missing --fail-missing

override_dh_fixperms:
	dh_fixperms
	# A shared library is not executable.
	chmod 0644 debian/rust-coreutils/usr/libexec/rust-coreutils/libstdbuf.so

override_dh_dwz:
	# Don't do anything. fails because of the
	# https://github.com/rust-lang/rust/issues/66118

execute_after_dh_auto_configure:
	# Log the toolchain and linker up front, on every arch, so the build log
	# always records which linker was used - even if a later step times out
	# before any link runs. The leading '-' keeps the build going on the rare
	# arch where ld.lld is absent (we fall back to the default linker there).
	rustc --version --verbose
	-ld.lld --version
	-ld --version | head -n1

override_dh_clean:
	dh_quilt_unpatch
	rm -rf $(PGO_DIR)
	rm -f Cargo.toml.orig docs/tldr.zip
	dh_clean --exclude=Cargo.toml.orig --exclude=config.guess

override_dh_update_autotools_config:
	# don't do anything - impact vendoring otherwise