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@ckirsch
Last active December 20, 2015 22:38
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This is a makefile for compiling C programs that implement shared libraries. It also serves as example for compiling regular C programs.
# This is for C but can easily be modified to work for other languages as well
CC = gcc
# Object files go into $(OBJDIR), executables go into $DISTDIR
OBJDIR = build
DISTDIR = dist
# Uncomment next line to overwrite standard malloc library
# WRAP = -Wl,--wrap=malloc -Wl,--wrap=free -Wl,--wrap=calloc -Wl,--wrap=realloc -Wl,--wrap=malloc_usable_size
# Compiler and linker flags
CFLAGS := $(SCM) -Wall -fPIC -g
LFLAGS := $(CFLAGS) -lpthread
# Gathers all header and C files located in the root directory
# in $(HFILES) and $(CFILES), respectively
HFILES := $(wildcard *.h)
CFILES := $(wildcard *.c)
# Produces in $(OFILES) the names of .o object files for all C files
OFILES := $(patsubst %.c,$(OBJDIR)/%.o,$(CFILES))
# This a rule that defines how to compile all C files that have changed
# (or their header files) since they were compiled last
$(OBJDIR)/%.o : %.c $(HFILES) $(CFILES)
$(CC) $(CFLAGS) -c $< -o $@
# Consider these targets as targets, not files
.PHONY : all libx clean
# Build everything: compile all C (changed) files and
# link the object files into an executable (app)
all: $(OFILES)
mkdir -p $(DISTDIR)
$(CC) $(LFLAGS) $(OFILES) -o $(DISTDIR)/app
# $(OBJDIR) is an order-only prerequisite:
# only compile if $(OBJDIR) does not exist yet and
# not just because $(OBJDIR) has a new time stamp
$(OFILES): | $(OBJDIR)
# Create directory for $(OBJDIR)
$(OBJDIR):
mkdir $(OBJDIR)
# Build shared library, copy library header file to $(DISTDIR)
libx: $(OFILES)
mkdir -p $(DISTDIR)
$(CC) $(LFLAGS) $(WRAP) $(OFILES) -shared -o $(DISTDIR)/libx.so
cp libx.h $(DISTDIR)
# Clean up by removing the $(OBJDIR) and $(DISTDIR) directories
clean:
rm -rf $(OBJDIR)
rm -rf $(DISTDIR)
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