# SPDX-License-Identifier: GPL-2.0

#MAKEFLAGS += --no-print-directory


# Makefiles suck: This macro sets a default value of $(2) for the
# variable named by $(1), unless the variable has been set by
# environment or command line. This is necessary for CC and AR
# because make sets default values, so the simpler ?= approach
# won't work as expected.
define allow-override
  $(if $(or $(findstring environment,$(origin $(1))),\
            $(findstring command line,$(origin $(1)))),,\
    $(eval $(1) = $(2)))
endef

# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix.
$(call allow-override,CC,$(CROSS_COMPILE)gcc)
$(call allow-override,AR,$(CROSS_COMPILE)ar)
$(call allow-override,NM,$(CROSS_COMPILE)nm)
$(call allow-override,PKG_CONFIG,pkg-config)

EXT = -std=gnu99
INSTALL = install

# Use DESTDIR for installing into a different root directory.
# This is useful for building a package. The program will be
# installed in this directory as if it was the root directory.
# Then the build tool can move it later.
DESTDIR ?=
DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'

LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1)
ifeq ($(LP64), 1)
  libdir_relative_tmp = lib64
else
  libdir_relative_tmp = lib
endif

libdir_relative ?= $(libdir_relative_tmp)
prefix ?= /usr/local
libdir = $(prefix)/$(libdir_relative)

set_plugin_dir := 1

# Set plugin_dir to preffered global plugin location
# If we install under $HOME directory we go under
# $(HOME)/.local/lib/traceevent/plugins
#
# We dont set PLUGIN_DIR in case we install under $HOME
# directory, because by default the code looks under:
# $(HOME)/.local/lib/traceevent/plugins by default.
#
ifeq ($(plugin_dir),)
ifeq ($(prefix),$(HOME))
override plugin_dir = $(HOME)/.local/lib/traceevent/plugins
set_plugin_dir := 0
else
override plugin_dir = $(libdir)/traceevent/plugins
endif
endif

ifeq ($(set_plugin_dir),1)
PLUGIN_DIR = -DPLUGIN_DIR="$(plugin_dir)"
PLUGIN_DIR_SQ = '$(subst ','\'',$(PLUGIN_DIR))'
endif

include ../../../scripts/Makefile.include

# copy a bit from Linux kbuild

ifeq ("$(origin V)", "command line")
  VERBOSE = $(V)
endif
ifndef VERBOSE
  VERBOSE = 0
endif

ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))
srctree := $(patsubst %/,%,$(dir $(srctree)))
srctree := $(patsubst %/,%,$(dir $(srctree)))
srctree := $(patsubst %/,%,$(dir $(srctree)))
#$(info Determined 'srctree' to be $(srctree))
endif

export prefix libdir src obj

# Shell quotes
plugin_dir_SQ = $(subst ','\'',$(plugin_dir))

CONFIG_INCLUDES =
CONFIG_LIBS    =
CONFIG_FLAGS   =

OBJ            = $@
N              =

INCLUDES = -I. -I.. -I $(srctree)/tools/include $(CONFIG_INCLUDES)

# Set compile option CFLAGS
ifdef EXTRA_CFLAGS
  CFLAGS := $(EXTRA_CFLAGS)
else
  CFLAGS := -g -Wall
endif

# Append required CFLAGS
override CFLAGS += -fPIC
override CFLAGS += $(CONFIG_FLAGS) $(INCLUDES) $(PLUGIN_DIR_SQ)
override CFLAGS += $(udis86-flags) -D_GNU_SOURCE

ifeq ($(VERBOSE),1)
  Q =
else
  Q = @
endif

# Disable command line variables (CFLAGS) override from top
# level Makefile (perf), otherwise build Makefile will get
# the same command line setup.
MAKEOVERRIDES=

export srctree OUTPUT CC LD CFLAGS V

build := -f $(srctree)/tools/build/Makefile.build dir=. obj

DYNAMIC_LIST_FILE := $(OUTPUT)libtraceevent-dynamic-list

PLUGINS  = plugin_jbd2.so
PLUGINS += plugin_hrtimer.so
PLUGINS += plugin_kmem.so
PLUGINS += plugin_kvm.so
PLUGINS += plugin_mac80211.so
PLUGINS += plugin_sched_switch.so
PLUGINS += plugin_function.so
PLUGINS += plugin_xen.so
PLUGINS += plugin_scsi.so
PLUGINS += plugin_cfg80211.so

PLUGINS    := $(addprefix $(OUTPUT),$(PLUGINS))
PLUGINS_IN := $(PLUGINS:.so=-in.o)

plugins: $(PLUGINS) $(DYNAMIC_LIST_FILE)

__plugin_obj = $(notdir $@)
  plugin_obj = $(__plugin_obj:-in.o=)

$(PLUGINS_IN): force
	$(Q)$(MAKE) $(build)=$(plugin_obj)

$(OUTPUT)libtraceevent-dynamic-list: $(PLUGINS)
	$(QUIET_GEN)$(call do_generate_dynamic_list_file, $(PLUGINS), $@)

$(OUTPUT)%.so: $(OUTPUT)%-in.o
	$(QUIET_LINK)$(CC) $(CFLAGS) -shared $(LDFLAGS) -nostartfiles -o $@ $^

define update_dir
  (echo $1 > $@.tmp;                           \
   if [ -r $@ ] && cmp -s $@ $@.tmp; then      \
     rm -f $@.tmp;                             \
   else                                                \
     echo '  UPDATE                 $@';       \
     mv -f $@.tmp $@;                          \
   fi);
endef

tags:	force
	$(RM) tags
	find . -name '*.[ch]' | xargs ctags --extra=+f --c-kinds=+px \
	--regex-c++='/_PE\(([^,)]*).*/TEP_ERRNO__\1/'

TAGS:	force
	$(RM) TAGS
	find . -name '*.[ch]' | xargs etags \
	--regex='/_PE(\([^,)]*\).*/TEP_ERRNO__\1/'

define do_install_mkdir
	if [ ! -d '$(DESTDIR_SQ)$1' ]; then             \
		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1'; \
	fi
endef

define do_install
	$(call do_install_mkdir,$2);                    \
	$(INSTALL) $(if $3,-m $3,) $1 '$(DESTDIR_SQ)$2'
endef

define do_install_plugins
       for plugin in $1; do                            \
         $(call do_install,$$plugin,$(plugin_dir_SQ)); \
       done
endef

define do_generate_dynamic_list_file
	symbol_type=`$(NM) -u -D $1 | awk 'NF>1 {print $$1}' | \
	xargs echo "U w W" | tr 'w ' 'W\n' | sort -u | xargs echo`;\
	if [ "$$symbol_type" = "U W" ];then				\
		(echo '{';                                              \
		$(NM) -u -D $1 | awk 'NF>1 {print "\t"$$2";"}' | sort -u;\
		echo '};';                                              \
		) > $2;                                                 \
	else                                                            \
		(echo Either missing one of [$1] or bad version of $(NM)) 1>&2;\
		fi
endef

install: $(PLUGINS)
	$(call QUIET_INSTALL, trace_plugins) \
	$(call do_install_plugins, $(PLUGINS))

clean:
	$(call QUIET_CLEAN, trace_plugins) \
		$(RM) *.o *~ $(TARGETS) *.a *.so $(VERSION_FILES) .*.d .*.cmd; \
		$(RM) $(OUTPUT)libtraceevent-dynamic-list \
		$(RM) TRACEEVENT-CFLAGS tags TAGS;

PHONY += force plugins
force:

# Declare the contents of the .PHONY variable as phony.  We keep that
# information in a variable so we can use it in if_changed and friends.
.PHONY: $(PHONY)