Re: Help me wrap PahoMQTT
- Posted by ghaberek (admin) Apr 22, 2019
- 2928 views
What I do to get structure alignments reliably, is construct simple C programs to output everything for me.
Makefile
CFLAGS = -Ieclipse/paho.mqtt.c/src
all : test64.exe test32.exe
@test64.exe
@echo.
@test32.exe
test64.exe : test.c
gcc -m64 -DBITS=64 -o $@ $< $(CFLAGS)
test32.exe : test.c
gcc -m32 -DBITS=32 -o $@ $< $(CFLAGS)
test.c
#include <stdio.h>
#include <stddef.h>
#include "MQTTClient.h"
#if ( BITS == 64 )
#define ARCH_TYPE() printf( "-- 64-bit ------------------------------------\n" )
#else
#define ARCH_TYPE() printf( "-- 32-bit ------------------------------------\n" )
#endif
#define OFFSETOF( st, mb ) printf( "%-40s = %2d,\n", #st "__" #mb, offsetof(st,mb) )
#define SIZEOF( st ) printf( "SIZEOF_%-33s = %2d,\n", #st, sizeof(st) )
int main( int argc, char* argv[] )
{
ARCH_TYPE();
OFFSETOF( MQTTClient_willOptions, struct_id );
OFFSETOF( MQTTClient_willOptions, struct_version );
OFFSETOF( MQTTClient_willOptions, topicName );
OFFSETOF( MQTTClient_willOptions, message );
OFFSETOF( MQTTClient_willOptions, retained );
OFFSETOF( MQTTClient_willOptions, qos );
OFFSETOF( MQTTClient_willOptions, payload.len );
OFFSETOF( MQTTClient_willOptions, payload.data );
SIZEOF( MQTTClient_willOptions );
return 0;
}
Output
C:\>mingw32-make -- 64-bit ------------------------------------ MQTTClient_willOptions__struct_id = 0, MQTTClient_willOptions__struct_version = 4, MQTTClient_willOptions__topicName = 8, MQTTClient_willOptions__message = 16, MQTTClient_willOptions__retained = 24, MQTTClient_willOptions__qos = 28, MQTTClient_willOptions__payload.len = 32, MQTTClient_willOptions__payload.data = 40, SIZEOF_MQTTClient_willOptions = 48, -- 32-bit ------------------------------------ MQTTClient_willOptions__struct_id = 0, MQTTClient_willOptions__struct_version = 4, MQTTClient_willOptions__topicName = 8, MQTTClient_willOptions__message = 12, MQTTClient_willOptions__retained = 16, MQTTClient_willOptions__qos = 20, MQTTClient_willOptions__payload.len = 24, MQTTClient_willOptions__payload.data = 28, SIZEOF_MQTTClient_willOptions = 32,
Now I can copy/paste that output and format in my wrapper as I showed above.
-Greg
