platform.mk

# Platform-specific stuff
# Don't touch this unless you're changing the way targets are compiled
# You have been warned

# Platform-dependent stuff checks
CCLD := $(CC)
CGO := go tool cgo
GO := go
CAT := cat
SED := sed
LIBEXT := .so
MODEXT := $(LIBEXT)
AREXT  := .a
LIBTYPE := shared
MODTYPE := shared
ARTYPE  := static
BINEXT :=
PLATFORM = Linux
ARCH := $(word 1, $(subst -, ,$(shell $(CC) -dumpmachine)))
# Library versioning flags (platform-specific)
comma := ,
SOVER = $(if $(1),-Wl$(comma)-soname$(comma)$(3)$(call SOVER_EXT,$(1)))
# Library versioned extension (platform-specific)
SOVER_EXT = $(LIBEXT).$(1)
ifeq ($(OS),Windows_NT)
	PLATFORM := Windows
	RM := del
	LN := link
	LIBEXT := .lib
	BINEXT := .exe
else
	UNAME := $(shell uname -s)
	ifeq ($(UNAME),Darwin)
		PLATFORM := Darwin
		LIBEXT := .dylib
		MODTYPE := dynamiclib
                # OS X specific hardening since -pie doesn't work
		ifneq ($(HARDENING),no)
			BINFLAGS += -Wl,-pie
		endif
                # Version is prepended to dylib
		SOVER_EXT = .$(1)$(LIBEXT)
		SOVER = $(if $(1), -compatibility_version $(2) -current_version $(1),)
	else
		PLATFORM := POSIX
		LDFLAGS += -pthread -lm -Wl,-E
                # ELF hardening options
		ifneq ($(HARDENING),no)
			BINFLAGS += -pie
			LDFLAGS += -Wl,-z,relro,-z,now
		endif
		ifeq ($(UNAME),Linux)
		LDFLAGS += -ldl
		endif
	endif
endif

# Silent compilation
ifeq ($(V),1)
	quiet = $($1)
else
	quiet = @echo "  $1	$2"; $($1)
endif

# Make objects and depends (name)
define make_objs
$(1)_OBJ := $$($(1)_SOURCES:.c=.o)
$(1)_DEP := $$($(1)_SOURCES:.c=.d)
-include $$($(1)_DEP)
endef
define make_objrule
$(1): $(1:.o=.c)
	$$(call quiet,CC,$$<) $(2) -MMD -MP -c $$< -o $$@
endef

# Make target (name,path,ext,ldflags,dst,amalgable)
define make_target
ifeq ($(AMALG)|$(6), yes|yes)
$(1).amalg.c: $$($(1)_SOURCES)
	$(call quiet,CAT,$$@) $$($(1)_SOURCES) > $$@
# AR requires .o compiled
$(1)_OBJ := $(1).amalg.c
ifeq ($(4),-$(ARTYPE))
$(1)_OBJ := $(1).amalg.o
endif
else
$$(eval $$(call make_objs,$(1)))
endif
# Rules to generate objects with custom CFLAGS and binary/library
$$(foreach obj,$$($(1)_OBJ),$$(eval $$(call make_objrule,$$(obj),$$(BUILD_CFLAGS) $$($(1)_CFLAGS))))
$(1) := $(2)/$(1)$(3)
$(2)/$(1)$(3): $$($(1)_OBJ) $$($(1)_DEPEND)
ifeq ($(4),-$(ARTYPE))
	$(call quiet,AR,$$@) rcs $$@ $$($(1)_OBJ)
else
	$(call quiet,CCLD,$$@) $$($(1)_CFLAGS) $(BUILD_CFLAGS) $$($(1)_OBJ) $(call SOVER,$(7),$(7),$(1)) -o $$@ $(4) $$($(1)_LIBS) $(BUILD_LDFLAGS) $$($(1)_LDFLAGS)
endif
# Additional rules
$(1)-clean:
	$(RM) $$($(1)_OBJ) $$($(1)_DEP) $(2)/$(1)$(3)
ifeq ($(6), yes)
	$(RM) $(1).amalg.c $(1).amalg.o
endif
$(1)-install: $(2)/$(1)$(3)
# Modules install to special path
ifneq ($(5),$(MODULEDIR))
	$(INSTALL) -d $(DESTDIR)$(5)
endif
# Versioned library install
ifneq ($(strip $(7)),)
	$(INSTALL) $(2)/$(1)$(3) $(DESTDIR)$(5)/$(1)$(call SOVER_EXT,$(7))
	$(LN) -f $(1)$(call SOVER_EXT,$(7)) $(DESTDIR)$(5)/$(1)$(3)
else
	$(INSTALL) $(2)/$(1)$(3) $(DESTDIR)$(5)
endif
ifneq ($$(strip $$($(1)_HEADERS)),)
	$(INSTALL) -d $(DESTDIR)$(INCLUDEDIR)/$(1)
	$(INSTALL) -m 644 $$($(1)_HEADERS) $(DESTDIR)$(INCLUDEDIR)/$(1)
endif
.PHONY: $(1)-clean $(1)-install
endef

# Make targets (name,path,amalgable yes|no,abiver)
make_bin = $(call make_target,$(1),$(2),$(BINEXT),$(BINFLAGS),$(BINDIR),$(3))
make_sbin = $(call make_target,$(1),$(2),$(BINEXT),$(BINFLAGS),$(SBINDIR),$(3))
make_lib = $(call make_target,$(1),$(2),$(LIBEXT),-$(LIBTYPE),$(LIBDIR),$(3),$(4))
make_module = $(call make_target,$(1),$(2),$(LIBEXT),-$(LIBTYPE),$(MODULEDIR),$(3))
make_shared = $(call make_target,$(1),$(2),$(MODEXT),-$(MODTYPE),$(LIBDIR),$(3))
make_static = $(call make_target,$(1),$(2),$(AREXT),-$(ARTYPE),$(LIBDIR),$(3))

# Find library (pkg-config)
define find_lib
	$(call find_alt,$(1),$(1),$(2))
endef

# Find library alternative (pkg-config)
define find_alt
	ifeq ($$(strip $$($(1)_LIBS)),)
		ifneq ($(strip $(3)),)
			$(1)_VER := $(shell pkg-config --atleast-version=$(3) $(2) && echo $(3))
		endif
		ifeq ($(strip $(3)),$$($(1)_VER))
			$(1)_CFLAGS := $(shell pkg-config --cflags $(2) --silence-errors)
			$(1)_LIBS := $(shell pkg-config --libs $(2)  --silence-errors)
		endif
	endif
	ifeq ($$(strip $$($(1)_LIBS)),)
		HAS_$(1) := no
	else
		HAS_$(1) := yes
	endif
endef

# Find binary
define find_bin
	ifeq ($$(strip $$($(1)_BIN)),)
		$(1)_BIN := $(shell which $(1))
	endif
	ifeq ($$(strip $$($(1)_BIN)),)
		HAS_$(1) := no
	else
		HAS_$(1) := yes
		$(1) := $$($(1)_BIN)
	endif
endef

# Find version
define find_ver
	ifeq ($(shell test $(2) -ge $(3); echo $$?),0)
		HAS_$(1) := yes
	else
		HAS_$(1) := no
	endif
endef

# Find Go package
define find_gopkg
	HAS_$(1) := $(shell go list $(2) > /dev/null 2>&1 && echo yes || echo no)
endef

define find_soname

# N/A on Windows
ifeq ($(PLATFORM),Windows)
	$(1)_SONAME = $(1).dll
endif

# Use otool -D on OS X
ifeq ($(PLATFORM),Darwin)
	$(1)_SONAME = $$(shell otool -D $$$$(pkg-config --variable=libdir $(1))/$(1)$(LIBEXT) | sed -ne 's,.*/\($(1)\.[0-9]*.$(LIBEXT)\),\1,p')
endif

# Use objdump -p on Linux and BSDs
ifeq ($(PLATFORM),POSIX)
ifeq ($(UNAME),OpenBSD)
	$(1)_SONAME = $$(shell basename $$$$(readlink -f $$$$(pkg-config --variable=libdir $(1))/$(1)$(LIBEXT)) | cut -f 1-3 -d .)
else
	$(1)_SONAME = $$(shell objdump -p $$$$(pkg-config --variable=libdir $(1))/$(1)$(LIBEXT) | sed -ne 's/[[:space:]]*SONAME[[:space:]]*\($(1)\.so\.[0-4]*\)/\1/p')
endif
endif

endef # find_soname

# Use this on OpenBSD
#