Bug Summary

File:/home/joel/rtems-4.11-work/build/rtems/c/src/../../cpukit/posix/src/mqueueopen.c
Location:line 66, column 5
Description:Value stored to 'mode' is never read

Annotated Source Code

1/*
2 * NOTE: The structure of the routines is identical to that of POSIX
3 * Message_queues to leave the option of having unnamed message
4 * queues at a future date. They are currently not part of the
5 * POSIX standard but unnamed message_queues are. This is also
6 * the reason for the apparently unnecessary tracking of
7 * the process_shared attribute. [In addition to the fact that
8 * it would be trivial to add pshared to the mq_attr structure
9 * and have process private message queues.]
10 *
11 * This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open
12 * time.
13 *
14 * COPYRIGHT (c) 1989-2009.
15 * On-Line Applications Research Corporation (OAR).
16 *
17 * The license and distribution terms for this file may be
18 * found in the file LICENSE in this distribution or at
19 * http://www.rtems.com/license/LICENSE.
20 *
21 * $Id: mqueueopen.c,v 1.16 2009/08/06 19:26:56 joel Exp $
22 */
23
24#if HAVE_CONFIG_H1
25#include "config.h"
26#endif
27
28#include <stdarg.h>
29
30#include <pthread.h>
31#include <limits.h>
32#include <errno(*__errno_location ()).h>
33#include <fcntl.h>
34#include <mqueue.h>
35
36#include <rtems/system.h>
37#include <rtems/score/watchdog.h>
38#include <rtems/seterr.h>
39#include <rtems/posix/mqueue.h>
40#include <rtems/posix/time.h>
41
42/*
43 * 15.2.2 Open a Message Queue, P1003.1b-1993, p. 272
44 */
45mqd_t mq_open(
46 const char *name,
47 int oflag,
48 ...
49 /* mode_t mode, */
50 /* struct mq_attr attr */
51)
52{
53 va_list arg;
54 mode_t mode;
55 struct mq_attr *attr = NULL((void *)0);
56 int status;
57 Objects_Id the_mq_id;
58 POSIX_Message_queue_Control *the_mq;
59 POSIX_Message_queue_Control_fd *the_mq_fd;
60 Objects_Locations location;
61
62 _Thread_Disable_dispatch();
63
64 if ( oflag & O_CREAT0100 ) {
65 va_start(arg, oflag)__builtin_va_start(arg, oflag);
66 mode = (mode_t) va_arg( arg, unsigned int )__builtin_va_arg(arg, unsigned int);
Value stored to 'mode' is never read
67 attr = (struct mq_attr *) va_arg( arg, struct mq_attr * )__builtin_va_arg(arg, struct mq_attr *);
68 va_end(arg)__builtin_va_end(arg);
69 }
70
71 the_mq_fd = _POSIX_Message_queue_Allocate_fd();
72 if ( !the_mq_fd ) {
73 _Thread_Enable_dispatch();
74 rtems_set_errno_and_return_minus_one( ENFILE )do { (*__errno_location ()) = (23); return -1; } while(0);
75 }
76 the_mq_fd->oflag = oflag;
77
78 status = _POSIX_Message_queue_Name_to_id( name, &the_mq_id );
79
80 /*
81 * If the name to id translation worked, then the message queue exists
82 * and we can just return a pointer to the id. Otherwise we may
83 * need to check to see if this is a "message queue does not exist"
84 * or some other miscellaneous error on the name.
85 */
86 if ( status ) {
87 /*
88 * Unless provided a valid name that did not already exist
89 * and we are willing to create then it is an error.
90 */
91 if ( !( status == ENOENT2 && (oflag & O_CREAT0100) ) ) {
92 _POSIX_Message_queue_Free_fd( the_mq_fd );
93 _Thread_Enable_dispatch();
94 rtems_set_errno_and_return_minus_one_cast( status, mqd_t )do { (*__errno_location ()) = (status); return (mqd_t) -1; } while
(0);
95 }
96
97 } else { /* name -> ID translation succeeded */
98 /*
99 * Check for existence with creation.
100 */
101 if ( (oflag & (O_CREAT0100 | O_EXCL0200)) == (O_CREAT0100 | O_EXCL0200) ) {
102 _POSIX_Message_queue_Free_fd( the_mq_fd );
103 _Thread_Enable_dispatch();
104 rtems_set_errno_and_return_minus_one_cast( EEXIST, mqd_t )do { (*__errno_location ()) = (17); return (mqd_t) -1; } while
(0);
105 }
106
107 /*
108 * In this case we need to do an ID->pointer conversion to
109 * check the mode.
110 */
111 the_mq = _POSIX_Message_queue_Get( the_mq_id, &location );
112 the_mq->open_count += 1;
113 the_mq_fd->Queue = the_mq;
114 _Objects_Open_string(
115 &_POSIX_Message_queue_Information_fds,
116 &the_mq_fd->Object,
117 NULL((void *)0)
118 );
119 _Thread_Enable_dispatch();
120 _Thread_Enable_dispatch();
121 return (mqd_t)the_mq_fd->Object.id;
122
123 }
124
125 /*
126 * At this point, the message queue does not exist and everything has been
127 * checked. We should go ahead and create a message queue.
128 */
129 status = _POSIX_Message_queue_Create_support(
130 name,
131 true1, /* shared across processes */
132 attr,
133 &the_mq
134 );
135
136 /*
137 * errno was set by Create_support, so don't set it again.
138 */
139 if ( status == -1 ) {
140 _POSIX_Message_queue_Free_fd( the_mq_fd );
141 _Thread_Enable_dispatch();
142 return (mqd_t) -1;
143 }
144
145 the_mq_fd->Queue = the_mq;
146 _Objects_Open_string(
147 &_POSIX_Message_queue_Information_fds,
148 &the_mq_fd->Object,
149 NULL((void *)0)
150 );
151
152 _Thread_Enable_dispatch();
153
154 return (mqd_t) the_mq_fd->Object.id;
155}