After doing exactly like your code the project now compiles 
Ok, I started writing a small program to see if everything is working fine. After a few minutes I ran in some compiler errors again.
My main.mm now look like this:
1#define ALLEGRO_NO_MAGIC_MAIN
2#include <allegro5/allegro.h>
3#include <allegro5/allegro_primitives.h>
4#include <allegro5/allegro_image.h>
5#include <allegro5/allegro_native_dialog.h>
6#include <allegro5/allegro_font.h>
7#include <allegro5/allegro_ttf.h>
8#include <allegro5/allegro_audio.h>
9#include <allegro5/allegro_acodec.h>
10#include <allegro5/allegro_color.h>
11#include "stdio.h"
12
13
14ALLEGRO_DISPLAY *display = NULL;
15ALLEGRO_EVENT_QUEUE *event_queue = NULL;
16ALLEGRO_TIMER *timer = NULL;
17ALLEGRO_EVENT ev;
18ALLEGRO_TRANSFORM transform;
19
20const float FPS = 60;
21
22
23int real_main(int argc, char **argv)
24{
25
26 // init
27 if (!al_init() ) printf("al_init Failed!\n");
28
29 //if (!al_init_image_addon() ) { fprintf(stderr, "Failed to initialize al_init_image_addon!\n"); }
30 if (!al_init_primitives_addon() ) { printf("al_init_primitives_addon Failed!\n"); }
31 timer = al_create_timer(1.0 / FPS); if (!timer) { fprintf(stderr, "failed to create timer!\n"); }
32 al_init_font_addon();
33 //if (!al_init_ttf_addon() ) { fprintf(stderr, "failed to initialize the ttf addon!\n"); }
34 //if (!al_init_acodec_addon() ) { fprintf(stderr, "failed to initialize audio codecs!\n"); }
35 //if (!al_reserve_samples(8) ) { fprintf(stderr, "failed to reserve samples!\n"); }
36
37 display = al_create_display(1024, 768);
38 if (!display)
39 {
40 printf("al_create_display Failed!\n");
41 }
42
43 al_clear_to_color( al_map_rgb(0,0,0) );
44 al_flip_display();
45
46
47 event_queue = al_create_event_queue();
48
49 al_register_event_source(event_queue, al_get_display_event_source(display));
50 al_register_event_source(event_queue, al_get_timer_event_source(timer));
51
52
53 // draw something
54 al_clear_to_color( al_map_rgb(0,128,255) );
55 al_draw_filled_rectangle(0, 0, 100, 50, al_map_rgb(255,0,0) );
56 al_draw_filled_rectangle(200, 200, 300, 250, al_map_rgb(0,255,0) );
57 al_flip_display();
58
59
60 al_rest(5);
61
62
63 // clean
64 al_destroy_display(display);
65 al_destroy_timer(timer);
66 al_destroy_event_queue(event_queue);
67
68 return 0;
69
70}
71
72
73
74int main(int argc, char * argv[])
75{
76
77 /*
78 @autoreleasepool
79 {
80 return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
81 }*/
82
83 return al_run_main(argc, argv, real_main);
84
85}
See the 4 commented lines at the init section: These calls are producing a long list of compiler errors just like the one on the first post "Undefined symbols for architecture x86_64: blah blah blah referenced from:"
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