Overwrite variables in recursive make - makefile

Question

i am working on a chess engine and recently decided to rewrite our makefile. I have decided to go for a recursive makefile which features a set of options to compile with:
NAMING ?= 1
STATIC ?= 0
NATIVE ?= 0
DETECT ?= 1
PGO ?= 0
DEBUG ?= 0
LTO ?= 0
PEXT ?= 0
Based on the flags above, I generate the FLAGS to build my program. The main target of my makefile is called build. My makefile uses the flags above and generates all the options. Theoretically the makefile works fine if i call it like make build PGO=1 NATIVE=1 .... Now this is the behaviour I wanted to have. Furthermore I had the idea to do a recursive makefile which predefines a few of those options like:
native:
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=0 LTO=1 DETECT=1 NAMING=$(NAMING) STATIC=$(STATIC) EXE_NAME=$(EXE_NAME)
pgo:
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=1 LTO=1 DETECT=1 NAMING=$(NAMING) STATIC=$(STATIC) EXE_NAME=$(EXE_NAME)
The problem is that I am unable to overwrite those specified variables in the recursive makefile. Lets say I call make pgo, it goes into recursive make and calls
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=1 LTO=1 DETECT=1 NAMING=$(NAMING) STATIC=$(STATIC) EXE_NAME=$(EXE_NAME)
When i try to specify PGO := 0 in the makefile, it seems to have no impact on the PGO variable. It seems like I cannot overwrite it when called the way I do it. The complete makefile is the following:
_THIS := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
_ROOT := $(_THIS)/..
_SRC := $(_ROOT)/src_files
_BIN := $(_ROOT)/bin
_MAKE := $(MAKE) --no-print-directory -C $(_THIS) -e
# compiler and sources
CXX = g++
_LIBS_WL := -Wl,--whole-archive -lpthread -Wl,--no-whole-archive
_LIBS := -pthread
_CXXSRCS := $(_SRC)/*.cpp
_CSRCS := $(_SRC)/syzygy/tbprobe.c
_SRCS := $(_CSRCS) $(_CXXSRCS)
# engine name and version
NAME = Koivisto
MINOR = 11
MAJOR = 8
MAKROS = -DMINOR_VERSION=$(MINOR) -DMAJOR_VERSION=$(MAJOR)
EXE_NAME = $(NAME)_$(MAJOR).$(MINOR)
EXE_DIR = $(_ROOT)/bin
EXE = $(EXE_DIR)/$(EXE_NAME)
EVALFILE = $(_ROOT)/networks/default.net
EXE_INFO =
# compilation flags
FLAGS = -std=c++17 -Wall -Wextra -Wshadow -DEVALFILE=\"$(EVALFILE)\"
MARCH_FLAG = -march=native
PGO_PRE_FLAGS = -fprofile-generate -lgcov
PGO_POST_FLAGS = -fprofile-use -fno-peel-loops -fno-tracer
# ---------------------------------------------------------------------------------------------------------------------
# COMPILATION OPTIONS AND NAME ADJUSTMENT
# ---------------------------------------------------------------------------------------------------------------------
# options
NAMING ?= 1
STATIC ?= 0
NATIVE ?= 0
DETECT ?= 1
PGO ?= 0
DEBUG ?= 0
LTO ?= 0
PEXT ?= 0
# vector instructions
AVX512 ?= 0
AVX2 ?= $(AVX512)
AVX ?= $(AVX2)
POPCNT ?= $(AVX)
SSE42 ?= $(POPCNT)
SSE41 ?= $(SSE42)
SSE3 ?= $(SSE41)
SSE2 ?= $(SSE3)
SSE ?= $(SSE2)
# adjust the exe name as well as the FLAGS
ifeq ($(PGO),1)
EXE_INFO := $(EXE_INFO)-pgo
endif
ifeq ($(DEBUG),1)
EXE_INFO := $(EXE_INFO)-debug
else
FLAGS += -DNDEBUG -O3
endif
ifeq ($(PEXT),1)
EXE_INFO := $(EXE_INFO)-pext
FLAGS += -DUSE_PEXT -mbmi2
endif
ifeq ($(LTO),1)
FLAGS += -flto
endif
ifeq ($(STATIC),1)
FLAGS += -static -static-libgcc -static-libstdc++
endif
# toggle avx options based on the highest one
ifeq ($(AVX512),1)
FLAGS += -mavx512f -mavx512bw -mavx512dq
endif
ifeq ($(AVX2),1)
FLAGS += -mavx2
endif
ifeq ($(AVX),1)
FLAGS += -mavx
endif
ifeq ($(POPCNT),1)
FLAGS += -DUSE_POPCNT -mpopcnt
endif
ifeq ($(SSE42),1)
FLAGS += -msse4.2
endif
ifeq ($(SSE41),1)
FLAGS += -msse4.1
endif
ifeq ($(SSE3),1)
FLAGS += -msse3
endif
ifeq ($(SSE2),1)
FLAGS += -msse2
endif
ifeq ($(SSE),1)
FLAGS += -msse
endif
# set name based on highest vector extension
ifeq ($(AVX512),1)
EXE_INFO := $(EXE_INFO)-avx512
else ifeq ($(AVX2),1)
EXE_INFO := $(EXE_INFO)-avx2
else ifeq ($(AVX),1)
EXE_INFO := $(EXE_INFO)-avx
else ifeq ($(POPCNT),1)
EXE_INFO := $(EXE_INFO)-popcnt
else ifeq ($(SSE42),1)
EXE_INFO := $(EXE_INFO)-sse42
else ifeq ($(SSE41),1)
EXE_INFO := $(EXE_INFO)-sse41
else ifeq ($(SSE3),1)
EXE_INFO := $(EXE_INFO)-msse3
else ifeq ($(SSE2),1)
EXE_INFO := $(EXE_INFO)-sse2
else ifeq ($(SSE),1)
EXE_INFO := $(EXE_INFO)-sse
endif
# ---------------------------------------------------------------------------------------------------------------------
# HOST DETECTION AND NAME ADJUSTMENT IF NAMING IS ACTIVE
# ---------------------------------------------------------------------------------------------------------------------
ifeq ($(OS),Windows_NT)
PREFIX := windows
SUFFIX := .exe
_LIBS += $(_LIBS_WL)
else
UNAME := $(shell uname -s)
ifeq ($(UNAME),Linux)
PREFIX := linux
SUFFIX :=
_LIBS += $(_LIBS_WL)
else
ifeq ($(UNAME),Darwin)
PREFIX := darwin
SUFFIX :=
MARCH_FLAG := -mcpu=apple-a14
else
$(warning incompatible host, this might fail)
PREFIX := _
SUFFIX :=
endif
endif
endif
ifeq ($(NAMING),1)
EXE := $(EXE_DIR)/$(EXE_NAME)-$(PREFIX)$(EXE_INFO)$(SUFFIX)
endif
EXE_FULL := $(abspath $(EXE))
FLAGS += $(MARCH_FLAG)
# auto detect certain flags
ifeq ($(DETECT),1)
PROPS = $(shell echo | $(CC) $(MARCH_FLAG) -E -dM -)
ifneq ($(findstring __BMI2__, $(PROPS)),)
ifeq ($(findstring __znver1, $(PROPS)),)
ifeq ($(findstring __znver2, $(PROPS)),)
FLAGS += $(PEXTFLAGS)
endif
endif
endif
endif
# ---------------------------------------------------------------------------------------------------------------------
# RULES
# ---------------------------------------------------------------------------------------------------------------------
ifeq ($(UNAME),Darwin)
openbench:
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=0 LTO=1 DETECT=1 EVALFILE=$(EVALFILE) NAMING=0 EXE=$(EXE)
else
openbench:
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=1 LTO=1 DETECT=1 EVALFILE=$(EVALFILE) NAMING=0 EXE=$(EXE)
endif
native:
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=0 LTO=1 DETECT=1 NAMING=$(NAMING) STATIC=$(STATIC) EXE_NAME=$(EXE_NAME)
pgo:
$(_MAKE) build DEBUG=0 NATIVE=1 PGO=1 LTO=1 DETECT=1 NAMING=$(NAMING) STATIC=$(STATIC) EXE_NAME=$(EXE_NAME)
overview:
$(info NAME : $(NAME))
$(info EXE : $(EXE))
$(info FULL NAME : $(EXE_FULL))
$(info NAMING : $(NAMING))
$(info FLAGS : $(FLAGS))
$(info NATIVE : $(NATIVE))
$(info STATIC : $(STATIC))
$(info PEXT : $(PEXT))
$(info PGO : $(PGO))
$(info DEBUG : $(DEBUG))
$(info AVX512 : $(AVX512))
$(info AVX2 : $(AVX2))
$(info AVX : $(AVX))
$(info POPCNT : $(POPCNT))
$(info SSE42 : $(SSE42))
$(info SSE41 : $(SSE41))
$(info SSE3 : $(SSE3))
$(info SSE2 : $(SSE2))
$(info SSE : $(SSE))
build: updateNetwork overview
mkdir -p $(EXE_DIR)
ifeq ($(PGO),1)
$(CXX) $(PGO_PRE_FLAGS) $(FLAGS) $(_SRCS) $(MAKROS) $(_LIBS) -o $(EXE)
$(EXE_FULL) bench
$(CXX) $(PGO_POST_FLAGS) $(FLAGS) $(_SRCS) $(MAKROS) $(_LIBS) -o $(EXE)
#rm -f *.gcda
else
$(CXX) $(FLAGS) $(_SRCS) $(MAKROS) $(_LIBS) -o $(EXE)
endif
release:
#$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 AVX512=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 AVX2=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 POPCNT=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE42=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE41=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE3=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE2=1
$(_MAKE) build DEBUG=0 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE=1
#$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 AVX512=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 AVX2=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 POPCNT=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE42=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE41=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE3=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE2=1
$(_MAKE) build DEBUG=0 PEXT=1 PGO=1 LTO=1 DETECT=0 NAMING=1 STATIC=1 SSE=1
# update the network
updateNetwork:
ifeq ($(EVALFILE),$(_ROOT)/networks/default.net)
git -C .. submodule update --init
endif
Does anyone know how I can overwrite variables in recursive makefiles? I am very happy for any help!

Answer 1

From the manual:
If a variable has been set with a command argument, then ordinary
assignments in the makefile are ignored. If you want to set the
variable in the makefile even though it was set with a command
argument, you can use an override directive...
Like so:
override PGO := 0