c - Generate library with makefile : No rule to make target

Question

CC= gcc
CFLAGS= -Wall -g
INCLUDES= -I/usr/local/include/
LFLAGS= -L/usr/local/lib64
LDFLAGS=
LIBS= -L. -lrabbitmq
SRCS= amqp_connection.c amqp_consumer.c amqp_deconnection.c amqp_producer.c amqp_utils.c
OBJS= $(SRCS:.c=.o)
EXEC=amqp_test

.PHONY: all
all: $(EXEC)
    @echo "$(MAKE) : Tout est généré"

$(EXEC): $(OBJS)
    $(CC) $(CFLAGS) -o $(EXEC) $(OBJS) $(LDFLAGS) $(INCLUDES) $(LFLAGS) $(LIBS)

.PHONY: clean
clean:
    $(RM) *~ *.o $(EXEC)

I want to generate a library not an executable

Can you help me please ? I launched "make" and the result is :

make: *** No rule to make target amqp_connection.o', needed by amqp_test'. Stop. amqp_test is the name of the file which contain the main().

The sources are :

amqp_connection / amqp_consumer /amqp_deconnection / amqp_producer

question from:https://stackoverflow.com/questions/65849491/generate-library-with-makefile-no-rule-to-make-target

Answer 1

This is an example file using some common practices. Here, I'm redefining the source directory and the object directory, and defining an implicit rule to build the objects given a source in a different directory.

CC := gcc
CFLAGS := -Wall -g
SRCDIR := src
OBJDIR := obj
INCLUDES := -I/usr/local/include/
LFLAGS := -L/usr/local/lib64
LDFLAGS :=
LIBS := -L. -lrabbitmq
SRCS_RAW := amqp_connection.c amqp_consumer.c amqp_deconnection.c amqp_producer.c amqp_utils.c

SRCS := $(addprefix $(SRCDIR)/,$(SRCS_RAW))
OBJS := $(addprefix $(OBJDIR)/,$(SRCS_RAW:.c=.o))
EXEC := amqp_test

$(info DEBUG: SRCS=$(SRCS))
$(info DEBUG: OBJS=$(OBJS))
$(info DEBUG: EXEC=$(EXEC))

.PHONY: all
all: $(EXEC)
    @echo "$(MAKE) : Tout est généré"

$(EXEC): $(OBJS)
    $(CC) $(CFLAGS) -o $(EXEC) $(OBJS) $(LDFLAGS) $(INCLUDES) $(LFLAGS) $(LIBS)

#rule to create object directory if it doesnt exist
$(OBJDIR):
    mkdir $(OBJDIR)

#define implicit rule to build objects in their own directory
#(note -- order only dependency on object directory)
$(OBJS): $(OBJDIR)/%.o: $(SRCDIR)/%.c | $(OBJDIR)
    $(CC) $(CFLAGS) $(INCLUDES) -c $< -o $@

.PHONY: clean
clean:
    $(RM) *~  $(EXEC)
    $(RM) -r $(OBJDIR)