Appropriate Makefile to replace a gcc compile/link run? - c

Question

My goal is to use a single Makefile for compiling a C app across various platforms.
I've been busily relearning C while working on a project, so as a result have not yet had the time to delve into make; instead I have a single, long gcc command in some .bat / .sh files. Needless to say that each time I change one such file, I have to make those same changes in the others. Hence, make. Conditions that need to be handled:
Builds for multiple OS & architecture, i.e. for now (at least) 32 & 64-bit for Windows & Linux, thus I need access to that info in the Makefile, and executables should go into distinct folders under /build: i.e. /win32, /win64, /lin32, /lin64 (et cetera, in future).
Required DLLs should be copied in alongside the built executable.
Separate compile & link phases (thanks #EtanReisner)
Question: Can someone show me how one would go about constructing a Makefile using the info below? And explain how each part works / why it is needed for my particular case? I have an understanding of the prerequisites approach by which Makefiles are built. Thanks in advance.
Here is my project directory tree:
+---bin
+---include
| +---enet
| +---GL
| +---libxml
| \---ncursesw
+---lib
+---src
+---fonts
\---shaders
And mingw gcc for Windows 32-bit compile:
gcc -Iinclude ./src/main.c ./src/MainCtrl.c ./src/MainView.c ./src/PerspectiveView.c ./src/LogView.c ./src/LobbyView.c ./src/TerminalView.c ./src/World.c ./src/Chunk.c ./src/CellPattern.c ./src/CellPlan.c ./src/GridPoint.c ./src/Entity.c ./src/InfluenceRadial.c ./src/AoIList.c ./src/AoI.c ./src/ChunkRenderable.c ./src/PrimitiveRenderable.c ./src/Geometry.c ./src/glew/glew.c ./src/stb/stb_image_aug.c ../curt/list_generic.c ../curt/map_generic.c ../curt/intMap.c ../curt/floatMap.c ../hedgehog/hedgehog.c ./src/Inputs.c ./src/InputResponse.c ./src/Network.c ../Disjunction/c/disjunction.c ./src/my/math/Range.c ./src/my/math/Point.c -Llib -lglfw3-32 -lopengl32 -lgdi32 -lenet-32 -lws2_32 -lwinmm -llibxml2-32 -L. -ldll32/libncursesw6 -std=c11 -m32 -w -Wall -Wpointer-arith -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wstrict-prototypes -Wlogical-op -Wcast-align -Wconversion -Wpedantic -Wfloat-equal -fopenmp -O0 -o ./build/win32/wa
And the gcc for Linux 64-bit compile:
gcc -Iinclude -I/usr/include/libxml2 ./src/main.c ./src/MainCtrl.c ./src/MainView.c ./src/PerspectiveView.c ./src/LogView.c ./src/LobbyView.c ./src/TerminalView.c ./src/World.c ./src/Chunk.c ./src/CellPattern.c ./src/CellPlan.c ./src/GridPoint.c ./src/Entity.c ./src/InfluenceRadial.c ./src/AoIList.c ./src/AoI.c ./src/ChunkRenderable.c ./src/PrimitiveRenderable.c ./src/Geometry.c ./src/glew/glew.c ./src/stb/stb_image_aug.c ../curt/list_generic.c ../curt/map_generic.c ../curt/intMap.c ../curt/floatMap.c ../hedgehog/hedgehog.c ./src/Inputs.c ./src/InputResponse.c ./src/Network.c ../disjunction/c/disjunction.c ./src/my/math/Range.c ./src/my/math/Point.c -Llib -L/usr/lib -l:libglfw.so.3 -lncurses -lGL -lxml2 -lenet -lm -std=c11 -m64 -w -Wall -Wpointer-arith -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wstrict-prototypes -Wlogical-op -Wcast-align -Wconversion -Wpedantic -Wfloat-equal -fopenmp -g -o ./wa-64.elf
(worth diffing these.)

Answer 1

Trial and error led tothe following... work in progress, but the basics are there. Features:
No need to manually list source / object files (all relevant sources expected to be in src)
Separate compile & link phases using shared logic for .c/.o file lists
OS & architecture autodetection (WIP), with manual override for arch (
e.g. make BITS=32)
Clean that works for both Win & *nixes
Copies in .DLLs on compile (WIP to supply a list of DLLs to copy in)
Thanks to Yanick Rochon, Samuel and Trevor Robinson for their answers, and to those who wrote the GNU Makefile examples.
CC = gcc
#Directories
HDRDIR = include
SRCDIR = ./src
OBJDIR = ./obj
BINDIR = ./bin
LIBDIR = lib
#File lists
HDRS := $(wildcard $(HDRDIR)/*.h)
SRCS := $(wildcard $(SRCDIR)/*.c)
OBJS := $(SRCS:$(SRCDIR)/%.c=$(OBJDIR)/%.o)
#Autodetect OS / architecture
OS =
BITS = 32
#ifeq ($(shell echo "check_quotes"),"check_quotes")
ifeq ($(OS),Windows_NT)
OS := win
EXT := .exe
rm := del /q
cp := copy /y
ifeq ($(PROCESSOR_ARCHITECTURE),AMD64)
CFLAGS += -D AMD64
endif
ifeq ($(PROCESSOR_ARCHITECTURE),x86)
CFLAGS += -D IA32
endif
else
UNAME_S := $(shell uname -s)
ifeq ($(UNAME_S),Linux)
OS := lin
EXT := .elf
rm := rm -f
cp := cp
CCFLAGS += -D LINUX
BITS = $(shell getconf LONG_BIT)
endif
ifeq ($(UNAME_S),Darwin)
OS := osx
EXT :=
rm := rm -f
cp := cp
CCFLAGS += -D OSX
BITS = $(shell getconf LONG_BIT)
endif
UNAME_P := $(shell uname -p)
ifeq ($(UNAME_P),x86_64)
CCFLAGS += -D AMD64
endif
ifneq ($(filter %86,$(UNAME_P)),)
CCFLAGS += -D IA32
endif
ifneq ($(filter arm%,$(UNAME_P)),)
CCFLAGS += -D ARM
endif
endif
#Define flags for compile & link
CFLAGS = -I$(HDRDIR) -std=c11 -m64 -fopenmp -Wall -Werror -Wmissing-prototypes -Wpointer-arith -Wcast-qual -Wstrict-prototypes -Wlogical-op -Wcast-align -Wconversion -Wpedantic -Wfloat-equal -w -O0 -DGLEW_STATIC
LFLAGS = -L$(LIBDIR)
#Do we want verbose linker messages?
LVERBOSE := false
LLIBS =
ifeq ($(OS),win)
LLIBS += -lglfw3-$(BITS) -lglew32s -lglew32 -lopengl32 -lgdi32 -lwinmm
endif
ifeq ($(OS),lin)
LLIBS += -lglew32s -lglew32 -lGL -lm
endif
ifeq ($(LVERBOSE),true)
LFLAGS += -Wl,--verbose
endif
TARGET = program$(EXT)
#Rules
$(BINDIR)/$(TARGET): $(OBJS)
#$(CC) -o ./$# $(OBJS) $(LFLAGS) $(LLIBS)
#echo Linking complete.
#$(cp) $(LIBDIR)\glfw3.dll $(BINDIR)
#echo DLLs accompanying executable.
$(OBJS): $(OBJDIR)/%.o : $(SRCDIR)/%.c
#$(CC) $(CFLAGS) -c $< -o ./$#
#echo Compiled $<.
.PHONEY: clean
clean:
ifeq ($(OS),win)
#$(rm) $(subst /,\\,$(OBJS))
#$(rm) $(subst /,\\,$(BINDIR)/*.*)
else
#$(rm) $(OBJS)
#$(rm) $(BINDIR)/*
endif
#echo Cleanup complete.
#$(subst /,\\, $(SOMETHING)) replaces all (make-native) forward slashes with backslashes, for Windows.