在C语言中，如何添加第三方库并使用Makefile从我现有的代码库中调用

Question

I am new to IOT and cloud.

For IOT project, we are trying to send on the fly data to cloud for Analytics. We are using only c, cpp code in my target board. Debian OS.

Every one second, 2 seconds, 3 seconds different types of data will come.

In my target board, I want to use 3rd party libraries( https_client ) to send data to the cloud. I need to hit the service(URL) in the cloud with data (using only GET method).

For this, I downloaded https_client code and trying to integrate into my code base.

In the below 1st make file is original Makefile, 2nd one is only 3rd party s/w Makefile, the 3rd one is modified original Makefile to integrate 3rd party library.

In my target board, we don't have much space, so what is best light weight approach to send data to the cloud? My cloud will support only https and WSS. Is my approach is correct? Any other easy way is available?

In the modified Makefile I am getting below error.

make: *** No rule to make target
`https_client-master/https_client-master/main.c', needed by `all'.
Stop.

My changes in Makefile is not the standard way. Can anyone review my modified Makefile and correct me.

Waiting for your valuable suggestion.

#---------------------------------------------------------------------------
-
--
#1.  Below is the original make file of my existing code base
#---------------------------------------------------------------------------
---
SOURCES=./SRC/MMC/Main.cpp \
    ./SRC/MMC/ModbusMasterController.cpp \
    ./SRC/DM/DeviceManager.cpp \
    .......
    ./Wrapper/MtrWrapper.cpp 


OBJECTS=$(SOURCES:.cpp=.o)
EXECUTABLE=BusMaster
CFLAGS = -c -w -I/usr/include/libxml2 -I./INC/Common -I./INC/ADM -I./INC/MMC 
-I./INC/DM  -I./INC/CM  -I./INC/MMT -I./INC/MPI -I./INC/MMT/DataProc -
I./INC/MMT/CmdProc -I./INC/MMT/CmdProc/Fileoperations -I./INC/SH -
I./INC/FT_MBUS -I./INC/Timer -I./Wrapper -I./INC/DC -Wall

LDFLAGS = -Bdynamic -lSharedMemory -lMessageQueue -luspepc -lxml2 -
lmbusmaster -lrt

CC=g++


all: $(SOURCES) $(EXECUTABLE)

$(EXECUTABLE): $(OBJECTS)
$(CC) $(OBJECTS) -o $@ $(LDFLAGS) 

.cpp.o:
$(CC) $(CFLAGS) $< -o $@

clean: 
rm -rf $(OBJECTS) $(EXECUTABLE)

#----------------------------------------original make end------------------
 -
-------------------

#----------------------------------------2. Below is the 3rd pary Library 
Makefile I want to add--------------------------------------
#CROSS = arm-linux-gnueabihf-

MAKE = make

CC = $(CROSS)gcc
LD = $(CROSS)ld
STRIP = $(CROSS)strip

ROOT_DIR = $(CURDIR)
MBEDTLS = $(ROOT_DIR)/mbedtls

CFLAGS = -fPIC -DHAVE_CONFIG_H -D_U_="__attribute__((unused))" -O2
LDFLAGS =

INCLUDES = -I$(MBEDTLS)/include
LIBS = $(MBEDTLS)/library/libmbedx509.a $(MBEDTLS)/library/libmbedtls.a 
$(MBEDTLS)/library/libmbedcrypto.a

SOURCES = main.c https.c

OBJS = $(SOURCES:.c=.o)

.SUFFIXES:.c .o

all: https_client

mbedtls_make:
@for dir in $(MBEDTLS); do \
    $(MAKE) -C $$dir ; \
    if [ $$? != 0 ]; then exit 1; fi; \
done

https_client: mbedtls_make $(OBJS)
@echo Linking: $@ ....
$(CC) -o $@ $(OBJS) $(LDFLAGS) $(LIBS)
$(STRIP) -s $@

.c.o:
@echo Compiling: $< ....
$(CC) -c $(CFLAGS) $(INCLUDES) -o $@ $<

clean: mbedtls_clean
rm -f https_client *.o

mbedtls_clean:
 @for dir in $(MBEDTLS); do \
    $(MAKE) -C $$dir clean; \
    if [ $$? != 0 ]; then exit 1; fi; \
 done
#----------------------------------------3rd pary Library Makefile end------
  -
-------------------------------

#----------------------------------------3. Modified original Makefile to 
add 
3rd party library----------------

SOURCES=./SRC/MMC/Main.cpp \
    ./SRC/MMC/ModbusMasterController.cpp \
    ./SRC/DM/DeviceManager.cpp \
    .......
    ./Wrapper/MtrWrapper.cpp 

 SOURCES2=./https_client-master/https_client-master/main.c \
    ./https_client-master/https_client-master/https.c

OBJECTS=$(SOURCES1:.cpp=.o)
OBJS=$(SOURCES2:.c=.o)
.SUFFIXES:.c .o
ROOT_DIR = $(CURDIR)
MBEDTLS = $(ROOT_DIR)/https_client-master/https_client-master/mbedtls
EXECUTABLE1=BusMaster
EXECUTABLE2=https_client
CFLAGS = -c -w -I/usr/include/libxml2 -I./INC/Common -I./INC/ADM -I./INC/MMC 
-I./INC/DM  -I./INC/CM  -I./INC/MMT -I./INC/MPI -I./INC/MMT/DataProc -
I./INC/MMT/CmdProc -I./INC/MMT/CmdProc/Fileoperations -I./INC/SH -
I./INC/FT_MBUS -I./INC/Timer -I./Wrapper -I./INC/DC -Wall
CFLAGS2 = -fPIC -DHAVE_CONFIG_H -D_U_="__attribute__((unused))" -O2
INCLUDES = -I$(MBEDTLS)/include
LIBS = $(MBEDTLS)/library/libmbedx509.a $(MBEDTLS)/library/libmbedtls.a 
$(MBEDTLS)/library/libmbedcrypto.a
LDFLAGS = -Bdynamic -lSharedMemory -lMessageQueue -luspepc -lxml2 -
lmbusmaster -lrt
LDFLAGS2 =
STRIP = strip

CC1=g++
CC2=gcc



 all: $(SOURCES1) $(EXECUTABLE1) $(SOURCES2) $(EXECUTABLE2)
 #$(SOURCES2)
 $(EXECUTABLE1): $(OBJECTS)
 @echo EXECUTABLE1:
 $(CC1) $(OBJECTS) -o $@ $(LDFLAGS)

 mbedtls_make:
 @echo mbedtls_make: ....
 @for dir in $(MBEDTLS); do \
    $(MAKE) -C $$dir ; \
    if [ $$? != 0 ]; then exit 1; fi; \
 done

 $(EXECUTABLE2): mbedtls_make $(OBJS)
 @echo Linking: $@ ....
 $(CC1) -o $@ $(OBJS) $(LDFLAGS2) $(LIBS)
 $(STRIP) -s $@

 .c.o:
 @echo Compiling c: $< ....
 $(CC2) -c $(CFLAGS2) $(INCLUDES) -o $@ $<

 .cpp.o:
 @echo Compiling cpp: $< ....
 $(CC1) $(CFLAGS) $< -o $@

 clean: mbedtls_clean
 rm -rf $(OBJECTS) $(EXECUTABLE1)
 rm -f https_client *.o
 mbedtls_clean:
 @for dir in $(MBEDTLS); do \
    $(MAKE) -C $$dir clean; \
    if [ $$? != 0 ]; then exit 1; fi; \
 done


 #------------------------------------------Modified original Makefile end--
 -
 ---------------------------------

Answer 1

I don't think you should have 2 lists of sources. Below is snippet of how MBEDTLS is included in Makefile.

https://github.com/acornblue/AZURE_LAB

#####################################################
# Projects/Multi/Applications/Azure_Sns_DM/Makefile
#####################################################
C_SOURCE = \
...
Middlewares/Third_Parties/mbedtls/library/aes.c \
Middlewares/Third_Parties/mbedtls/library/aesni.c \
...
-DUSE_MBED_TLS \
-DMBEDTLS_CONFIG_FILE='<mbedtls_config.h>'
...
-IMiddlewares/Third_Parties/mbedTLS/include \