#!/usr/bin/make -f

# Uncomment this to turn on verbose mode.
#export DH_VERBOSE=1

# for DEB_HOST_*
include /usr/share/dpkg/architecture.mk
# for DEB_VERSION_UPSTREAM
include /usr/share/dpkg/pkg-info.mk

export DEB_BUILD_MAINT_OPTIONS = hardening=+all

# A Scheme heap block is 1024 words, so the microcode's default heap of 3072
# blocks is 12MB on a 32-bit host, and compiling imail-imap with all of Edwin
# loaded does not fit.  It cannot simply be made large: with
# HEAP_IN_LOW_MEMORY the heap has to sit below 2^26 bytes in the address
# space, so 16384 (64MB, the 64-bit default) will not even start.  10000 is
# what src/configure.ac gives its own host compiler on svm1-32, for the same
# reason, and only applies to invocations that do not pass --heap themselves.
ifeq ($(DEB_HOST_ARCH_BITS),32)
export MITSCHEME_HEAP_SIZE = 10000
endif

%:
	dh $@

override_dh_autoreconf:
	dh_autoreconf sh -- -e -x -c \
	  'for d in src doc; \
	    do (cd $$d && autoreconf -f -i) done'

# Two flavours: native code, and upstream's SVM virtual machine.  Upstream
# names its back ends its own way and its configure only auto-detects x86, so
# each name is kept here and drives --enable-native-code, the installed
# interpreter name and the alternatives symlink.  See debian/NOTES.md.

# BIN_ARCH is upstream's --enable-native-code name.  BIN_CODE_TYPE is what a
# Scheme built for that back end reports as microcode-id/compiled-code-type
# (cc_arch_name in src/microcode/utabmd.c), which is what the cross-compile
# decision below compares against.  They agree except for aarch64, whose
# --enable-native-code name carries the byte order.
ifeq ($(DEB_HOST_ARCH),amd64)
BIN_ARCH := x86-64
BIN_CODE_TYPE := x86-64
else ifeq ($(DEB_HOST_ARCH),arm64)
BIN_ARCH := aarch64le
BIN_CODE_TYPE := aarch64
else ifeq ($(DEB_HOST_ARCH),i386)
BIN_ARCH := i386
BIN_CODE_TYPE := i386
endif
export BIN_ARCH

# The SVM comes in four flavours, by word size and byte order.
SVM_ARCH := svm1-$(DEB_HOST_ARCH_BITS)$(if $(filter little,$(DEB_HOST_ARCH_ENDIAN)),le,be)
export SVM_ARCH

# Its own auxiliary directory, or it would overwrite the native build's.
SVM_AUXDIR_NAME := mit-scheme-svm
SVM_BUILDDIR := build-svm

# Ask dh_listpackages rather than working it out again: it already accounts
# for the Architecture fields and the build profiles, so debian/control stays
# the single source of truth.
DH_PACKAGES := $(shell dh_listpackages)
BUILD_NATIVE := $(if $(filter mit-scheme,$(DH_PACKAGES)),yes,no)
BUILD_SVM := $(if $(filter mit-scheme-svm,$(DH_PACKAGES)),yes,no)

# debian/control asking for a native build we have no back-end name for.
ifeq ($(BUILD_NATIVE),yes)
ifeq ($(BIN_ARCH),)
$(error debian/control builds mit-scheme on $(DEB_HOST_ARCH), but there is no \
        native back end mapped for it above)
endif
endif

CONF_FLAGS += --docdir=/usr/share/doc/mit-scheme-doc
CONF_FLAGS += --enable-html=/usr/share/doc/mit-scheme-doc/html
CONF_FLAGS += --enable-pdf=/usr/share/doc/mit-scheme-doc/pdf
CONF_FLAGS += --enable-ps=no

CONF_FLAGS += --enable-blowfish=yes
CONF_FLAGS += --enable-gdbm=yes
CONF_FLAGS += --enable-pgsql=yes

# Cross-compile whenever the Scheme we build with disagrees with the target
# about compiled-code format, or the build dies with fasl-file-bad-data when
# saving lib/runtime.com.  That is the normal case for the SVM flavour.

HOST_CODE_TYPE := $(shell mit-scheme --batch-mode --no-init-file \
	--eval '(begin (display microcode-id/compiled-code-type) (%exit 0))' \
	< /dev/null 2>/dev/null)

# Nothing to build with?  Bootstrap from a prebuilt SVM library, if the
# debian-bootstrap branch supplied one.  Compiler only; everything shipped is
# still built from source.  See debian/NOTES.md.
BOOTSTRAP_BUILDDIR := build-bootstrap
ifeq ($(HOST_CODE_TYPE),)
ifneq (,$(wildcard debian/prebuilt/$(SVM_ARCH)))
BOOTSTRAP := yes
HOST_CODE_TYPE := svm1
MIT_SCHEME_EXE := $(CURDIR)/$(BOOTSTRAP_BUILDDIR)/run-build
export MIT_SCHEME_EXE
else
BOOTSTRAP := no
endif
else
BOOTSTRAP := no
endif

# Empty when no Scheme is installed; leave the native flags alone then.
NATIVE_CONF_FLAGS :=
ifneq ($(HOST_CODE_TYPE),)
ifneq ($(HOST_CODE_TYPE),$(BIN_CODE_TYPE))
NATIVE_CONF_FLAGS += --enable-cross-compiling
endif
endif

# compiled-code-type says "svm1", without the size/endianness suffix.
SVM_CONF_FLAGS :=
ifneq ($(HOST_CODE_TYPE),svm1)
SVM_CONF_FLAGS += --enable-cross-compiling
endif

override_dh_auto_configure-arch:
	@test "$(BUILD_NATIVE)$(BUILD_SVM)" != nono || \
	  { echo "both flavours disabled: nothing to build" >&2; exit 1; }
ifeq ($(BOOTSTRAP),yes)
	@echo "no MIT/GNU Scheme to build with; bootstrapping one from debian/prebuilt"
	debian/bootstrap-scheme.sh $(SVM_ARCH) $(BOOTSTRAP_BUILDDIR)
endif
# -arch
ifeq ($(BUILD_NATIVE),yes)
	dh_auto_configure --sourcedirectory=src -- \
	  $(CONF_FLAGS) $(NATIVE_CONF_FLAGS) --enable-native-code=$(BIN_ARCH)
endif
ifeq ($(BUILD_SVM),yes)
	@echo "second source tree for the SVM flavour"
	rm -rf $(SVM_BUILDDIR)
	cp -a src $(SVM_BUILDDIR)
	AUXDIR_NAME=$(SVM_AUXDIR_NAME) \
	 dh_auto_configure --sourcedirectory=$(SVM_BUILDDIR) -- \
	  $(CONF_FLAGS) $(SVM_CONF_FLAGS) --enable-native-code=$(SVM_ARCH)
endif

override_dh_auto_configure-indep:
	dh_auto_configure --sourcedirectory=doc -- $(CONF_FLAGS)

# May wish to pass parameter in dh_auto_build
#  SCHEME_COMPILER=mit-scheme

override_dh_auto_build-arch:
# -arch
ifeq ($(BUILD_NATIVE),yes)
	dh_auto_build --max-parallel=1 --sourcedirectory=src
endif
ifeq ($(BUILD_SVM),yes)
	dh_auto_build --max-parallel=1 --sourcedirectory=$(SVM_BUILDDIR)
endif

override_dh_auto_build-indep:
	dh_auto_build --sourcedirectory=doc

override_dh_auto_install-arch:
# -arch
ifeq ($(BUILD_NATIVE),yes)
	dh_auto_install --max-parallel=1 --sourcedirectory=src --destdir=debian/tmp
endif
ifeq ($(BUILD_SVM),yes)
	dh_auto_install --max-parallel=1 --sourcedirectory=$(SVM_BUILDDIR) --destdir=debian/tmp-svm
endif

override_dh_auto_install-indep:
	dh_auto_install --sourcedirectory=doc -- install-html install-pdf

STAGED := $(if $(filter yes,$(BUILD_NATIVE)),debian/tmp) \
	  $(if $(filter yes,$(BUILD_SVM)),debian/tmp-svm)

execute_after_dh_auto_install-arch:
	@echo "remove symbolic link executables"
	for d in $(STAGED); do \
	  (cd $$d/usr/bin && \
	   for f in scheme bchscheme mit-scheme mit-scheme-native; do \
	     if [ -L $$f ]; then \
	       rm --verbose -f $$f; \
	     else \
	       echo skipping $$f; \
	     fi; \
	   done); \
	done
	@echo "remove .la library support files as these are not actually used by the dynamic linker"
	find $(STAGED) -name '*.la' -ls -delete

execute_after_dh_auto_install-indep:
	@echo "allow dh scripts to compress info files themselves"
	find debian/tmp \( -name '*.info.gz' -o -name '*.info-*.gz' \) -ls -exec gunzip '{}' ';'

override_dh_install:
ifeq ($(BUILD_SVM),yes)
	dh_install -pmit-scheme-svm --sourcedir=debian/tmp-svm
endif
	dh_install --remaining-packages

execute_after_dh_install-arch:
ifeq ($(BUILD_NATIVE),yes)
	@echo "All .bci files belong in -dbg, move them manually for robustness"
	mkdir -p debian/mit-scheme-dbg
	tar -C debian/mit-scheme --create --file=- --files-from=/dev/null $$(cd debian/mit-scheme && find -name '*.bci') \
	 | tar -C debian/mit-scheme-dbg -xvf -
	find debian/mit-scheme -name '*.bci' -delete
	@echo "remove empty directory"
	-rmdir debian/mit-scheme/usr/lib/$(DEB_HOST_MULTIARCH)/mit-scheme/lib
endif
ifeq ($(BUILD_SVM),yes)
	@echo "the SVM flavour has no -dbg package; drop its .bci files"
	find debian/mit-scheme-svm -name '*.bci' -delete
	-rmdir debian/mit-scheme-svm/usr/lib/$(DEB_HOST_MULTIARCH)/$(SVM_AUXDIR_NAME)/lib
endif

# Installed under the back-end-qualified name the real binary has; plain
# mit-scheme.1 comes from the alternatives as a slave link.
define install_manpage
	cd debian/$(1)/usr/share/man && \
	 mv man1/mit-scheme.1 man1/mit-scheme-$(2).1 && \
	 ln -s mit-scheme-$(2).1 man1/mit-scheme-$(2)-$(DEB_VERSION_UPSTREAM).1

endef

execute_after_dh_installman-arch:
ifeq ($(BUILD_NATIVE),yes)
	$(call install_manpage,mit-scheme,$(BIN_ARCH))
endif
ifeq ($(BUILD_SVM),yes)
	$(call install_manpage,mit-scheme-svm,$(SVM_ARCH))
endif

# Upstream changelog is over 5MB, leave a copy in the doc package but
# remove it from the binary package to reduce bloat.
# See http://dedup.debian.net/.
override_dh_installchangelogs-arch:
	dh_installchangelogs
	-rm --verbose \
	   debian/mit-scheme/usr/share/doc/mit-scheme/changelog \
	   debian/mit-scheme-dbg/usr/share/doc/mit-scheme-dbg/changelog

override_dh_auto_clean:
	-dh_auto_clean
	rm -rf $(SVM_BUILDDIR) debian/tmp-svm $(BOOTSTRAP_BUILDDIR)