C++ project simple Makefile boilerplate (with Google Test)

Makefile

CXX=g++
RM=rm
Q=@
QQ=@

SRC=src
BUILD=build

SOURCES=$(wildcard $(SRC)/*.cpp)
OBJECTS:=$(patsubst $(SRC)/%.cpp,$(BUILD)/%.o,$(SOURCES))

PCH_SRC:=./include/Headers.h
PCH_OUT:=./include/Headers.h.gch

INCLUDE:=./include
INCLUDE+=./submodules/prefix/include
INCLUDE:=$(patsubst %,-I%,$(INCLUDE))

LDFLAGS:=-L./submodules/prefix/lib64
LDFLAGS+=-lgtest
LDFLAGS+=-lgmock
LDFLAGS+=-lpthread

CFLAGS+=-Wall
CFLAGS+=-Wextra
CFLAGS+=-O0
CFLAGS+=-g
CFLAGS+=-std=c++17

TARGET=main

all: $(PCH_OUT) $(TARGET)

$(TARGET): $(OBJECTS)
	$(QQ) echo "  LD      $@"
	$(Q) $(CXX) -o $@ $^ $(CFLAGS) $(LDFLAGS)

$(OBJECTS): | $(BUILD)

$(BUILD):
	$(Q) mkdir -p $(BUILD)

$(BUILD)/%.o: $(SRC)/%.cpp
	$(QQ) echo "  CXX     $@"
	$(Q) $(CXX) -c -o $@ $< $(INCLUDE) $(CFLAGS)

$(PCH_OUT): $(PCH_SRC)
	$(QQ) echo "  CXX     $@"
	$(Q) $(CXX) -c -o $@ $< $(INCLUDE) $(CFLAGS)

clean:
	$(QQ) echo "  RM      $(TARGET) $(OBJECTS)"
	$(Q) $(RM) -f $(TARGET) $(OBJECTS)

mrproper: clean
	$(QQ) echo "  RM      $(PCH_OUT)"
	$(Q) $(RM) -f $(PCH_OUT)

.PHONY: clean mrproper all