Makevars

# User-defined variables
# OBJECTS = rust_add.o hello.o
OBJECTS = $(patsubst %.rs,%.o,$(wildcard *.rs))

GENERATED_BINDINGS_DIR = generated_bindings
CACHE_BINDINGS_LOCATION = ../cached_bindings
ALL_R_HEADERS = $(wildcard $(R_INCLUDE_DIR)/*.h $(R_INCLUDE_DIR)/*/*.h)
NONAPI = `$(R_HOME)/bin$(R_ARCH_BIN)/Rscript --vanilla -e "cat(tools:::nonAPI, sep = '|')"`
RUSTC = rustc
R_VERSION_MAJOR_MINOR_ONLY = $(word 1,$(subst ., ,$(R_VERSION))).$(word 2,$(subst ., ,$(R_VERSION)))
RUSTC_R_VERSION_CFG = --cfg r_ver_$(subst .,_,$(R_VERSION_MAJOR_MINOR_ONLY))
UNAME = $(shell uname -s)
PLATFORM = $(UNAME)

ifeq ($(R_OSTYPE),windows)
	RUSTC_DEFAULT_FLAGS = -Cembed-bitcode=no -Cdebuginfo=2
	TARGET = --target x86_64-pc-windows-gnu
	OS_DEFINES = -DWin32 -D_Win32 
	RUSTC_LINKER = -Clinker=x86_64-w64-mingw32.static.posix-gcc.exe
	LIBGCC_EH_RECIPE = `mkdir -p libgcc_mock && touch libgcc_mock/libgcc_eh.a`
	LIBGCC_EH_FLAG = -Llibgcc_mock
	R_LIBRARY_PATH = -L"$(R_HOME)/bin$(R_ARCH)"

	PLATFORM = "windows"
else 
	RUSTC_DEFAULT_FLAGS = -Cembed-bitcode=no -Cdebuginfo=2 -Csplit-debuginfo=unpacked
	TARGET =
	OS_DEFINES =
	ifeq ($(UNAME), Darwin)
		# Mac-specific settings
		OS_DEFINES += -isysroot `xcrun -show-sdk-path`
	endif
	RUSTC_LINKER =
	LIBGCC_EH_RECIPE =
	LIBGCC_EH_FLAG =
	R_LIBRARY_PATH = -L$(R_HOME)/lib$(R_ARCH)
endif

RUSTC_FLAGS = --print native-static-libs \
	$(RUSTC_R_VERSION_CFG) \
	$(TARGET) $(RUSTC_LINKER) $(LIBGCC_EH_FLAG) $(R_LIBRARY_PATH) -lR \
	--edition=2021 \
	-Cpanic=abort \
	$(RUSTC_DEFAULT_FLAGS) -Cllvm-args=--align-all-functions=64 \
	--crate-type=cdylib \
	--emit=dep-info,obj

# PKG_LIBS += -lc -lm -lresolv -ldl -lpthread  -dynamiclib -Wl,-dylib -shared -L. -lrust_add
# PKG_LIBS += -L. -lrust_add
# PKG_LIBS += -lc -lm "-Wl,-dead_strip" "-dynamiclib" "-Wl,-dylib" "-nodefaultlibs"

R_BLOCKED_ITEMS = --blocklist-item="VECTOR_PTR|SEXPREC|DL_FUNC|TYPEOF|R_altrep_Coerce_method_t|Rf_isS4"
# TODO: use --override-abi=C-unwind if the current rustc supports it.. 
RUSTC_VERSION = `rustc --version`
ATTRIBUTE_CUSTOM = --with-attribute-custom="$(NONAPI)=\#[cfg(feature = \"nonapi\")]"
# --with-attribute-custom=".*=\#[cfg(feature = \"$(addprefix r_,$(subst .,_,$(R_VERSION_MAJOR_MINOR_ONLY)))\")]" \
# --with-attribute-custom=".*=\#[cfg(target_family = \"$(R_OSTYPE)\")]" \

BINDGEN_ARGS = \
	--raw-line "/* OS: $(R_OSTYPE) */"  \
	--raw-line "/* Platform: $(R_PLATFORM) */" \
	--raw-line "/* $(RUSTC_VERSION) */" \
	--raw-line "/* R version: $(R_VERSION) */" \
	--enable-function-attribute-detection \
	--no-layout-tests \
	--with-derive-custom="R_CMethodDef|R_CallMethodDef=Debug,Copy,Clone" \
	--opaque-type SEXPREC \
	--opaque-type DL_FUNC \
	--opaque-type CGContext \
	--builtins \
	--allowlist-item "CGContextRef|CGContext" \
	--sort-semantically --translate-enum-integer-types --merge-extern-blocks \
	--no-recursive-allowlist --rustified-non-exhaustive-enum=".*" \
	$(R_BLOCKED_ITEMS)

BINDGEN_CLANG_ARGS = -Denum_SEXPTYPE -DR_NO_REMAP -DSTRICT_R_HEADERS -DR_INTERFACE_PTRS \
	$(OS_DEFINES) \
	-Wno-visibility \
	-fparse-all-comments \
	-include Rinternals.h -include R_ext/GraphicsEngine.h -include R_ext/GraphicsDevice.h

ALL_R_BINDINGS = $(patsubst $(R_INCLUDE_DIR)/%.h,$(GENERATED_BINDINGS_DIR)/%.rs,$(ALL_R_HEADERS))

ALL_CACHED_BINDINGS = $(patsubst $(GENERATED_BINDINGS_DIR)/%.rs,$(CACHE_BINDINGS_LOCATION)/%-$(PLATFORM)-$(R_VERSION_MAJOR_MINOR_ONLY).rs,$(ALL_R_BINDINGS))

# TODO: unless `rust_analyzer_dummy` is added here, it won't do anything
all: DEBUG LIBGCC_EH_RECIPE_SETUP $(ALL_R_BINDINGS) $(ALL_CACHED_BINDINGS) BINDINGS_CRATE $(OBJECTS) $(SHLIB)

DEBUG:
# $(ECHO) $(.VARIABLES)
# $(foreach var,$(.VARIABLES),$(info $(var) = $($(var))))
# $(ECHO) SDK `xcrun --show-sdk-path`
# $(ECHO) $(NONAPI)
# $(ECHO) $(ATTRIBUTE_CUSTOM)

LIBGCC_EH_RECIPE_SETUP:
	$(LIBGCC_EH_RECIPE)

$(GENERATED_BINDINGS_DIR)/R.rs: BINDGEN_EXTRA = --blocklist-item __STDC_WANT_IEC_60559_FUNCS_EXT__
$(GENERATED_BINDINGS_DIR)/R_ext/Constants.rs: BINDGEN_EXTRA = --blocklist-item M_PI
# Applic.h includes what's in R_ext/Utils.h, so we block them
$(GENERATED_BINDINGS_DIR)/R_ext/Applic.rs: BINDGEN_EXTRA = --blocklist-item findInterval
# Lapack.h includes what's in R_ext/BLAS.h, so we block them
$(GENERATED_BINDINGS_DIR)/R_ext/Lapack.rs: BINDGEN_EXTRA = --blocklist-item zdrot_
# Rinternals.h includes what's in R_ext/Rallocators.h, so we block them (and Rembedded)
$(GENERATED_BINDINGS_DIR)/Rinternals.rs: BINDGEN_EXTRA = --blocklist-item "R_allocator|R_allocator_t|R_RunExitFinalizers"
$(GENERATED_BINDINGS_DIR)/R_ext/RStartup.rs: BINDGEN_EXTRA = --blocklist-item "setup_Rmainloop"
# Rmath includes what's in R_ext/Random.h, so we block them
$(GENERATED_BINDINGS_DIR)/Rmath.rs: BINDGEN_EXTRA = --blocklist-item "__STDC_WANT_IEC_60559_FUNCS_EXT__|norm_rand|unif_rand|R_unif_index|exp_rand"
# Rallocators have items blocked by Rinternals, so we allow them explicitly here.
$(GENERATED_BINDINGS_DIR)/R_ext/Rallocators.rs: BINDGEN_EXTRA = --allowlist-item "R_allocator|R_allocator_t"
# Varaible length arguments are messing up bindgen. Maybe it can be done by custom bindings.
$(GENERATED_BINDINGS_DIR)/R_ext/Print.rs: BINDGEN_EXTRA = --blocklist-item "Rvprintf|REvprintf"

$(GENERATED_BINDINGS_DIR)/%.rs: $(R_INCLUDE_DIR)/%.h
	$(ECHO) "Generating $@ from $<"
	@mkdir -p $(dir $@)
	bindgen "$<" -o "$@" $(BINDGEN_ARGS) $(BINDGEN_EXTRA) --allowlist-file "$<" -- -I$(R_INCLUDE_DIR)  $(BINDGEN_CLANG_ARGS)

$(CACHE_BINDINGS_LOCATION)/%-$(PLATFORM)-$(R_VERSION_MAJOR_MINOR_ONLY).rs: $(GENERATED_BINDINGS_DIR)/%.rs
	$(ECHO) "Updating cache for $< -> $@"
	@mkdir -p $(dir $@)
	@cp -f $< $@

BINDINGS_CRATE: $(ALL_R_BINDINGS)
	$(RUSTC) --print native-static-libs \
	$(TARGET) $(RUSTC_LINKER) $(LIBGCC_EH_FLAG) $(R_LIBRARY_PATH) \
	--edition=2021 \
	-Cpanic=abort \
	$(RUSTC_DEFAULT_FLAGS) \
	-Cllvm-args=--align-all-functions=64 \
	-l dylib=R --crate-type=lib bindings.rs

%.o: %.rs BINDINGS_CRATE
	$(ECHO) "Compiling $< to $@"
	$(RUSTC) $(RUSTC_FLAGS) -L. -lbindings -lR $<

# rust_analyzer_dummy: ALL_R_BINDINGS
# 	mkdir -p dummy/bindings
# 	cp -r bindings/ dummy/bindings