From 87c9e1db337767e6a19c69a907baeee57d171e45 Mon Sep 17 00:00:00 2001
From: Mark Spencer <markster@digium.com>
Date: Sat, 8 Jan 2005 19:00:46 +0000
Subject: [PATCH] Warn if flags is signed instead of unsigned (bug #3279)
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@4713 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
apps/app_queue.c | 4 +-
apps/app_voicemail.c | 2 +-
include/asterisk/channel.h | 4 +-
include/asterisk/utils.h | 81 +++++++++++++++++++++++++++++++-------
4 files changed, 72 insertions(+), 19 deletions(-)
diff --git a/apps/app_queue.c b/apps/app_queue.c
index b78f947e02..ef7115db4a 100755
--- a/apps/app_queue.c
+++ b/apps/app_queue.c
@@ -183,7 +183,7 @@ struct localuser {
int stillgoing;
int metric;
int oldstatus;
- int flags; /* flag bits */
+ unsigned int flags; /* flag bits */
time_t lastcall;
struct member *member;
struct localuser *next;
@@ -224,7 +224,7 @@ struct ast_call_queue {
char moh[80]; /* Name of musiconhold to be used */
char announce[80]; /* Announcement to play when call is answered */
char context[80]; /* Context for this queue */
- int flags; /* flag bits */
+ unsigned int flags; /* flag bits */
int strategy; /* Queueing strategy */
int announcefrequency; /* How often to announce their position */
int roundingseconds; /* How many seconds do we round to? */
diff --git a/apps/app_voicemail.c b/apps/app_voicemail.c
index b4d4c9d0fa..d33259f614 100755
--- a/apps/app_voicemail.c
+++ b/apps/app_voicemail.c
@@ -157,7 +157,7 @@ struct ast_vm_user {
char dialout[80];
char uniqueid[20]; /* Unique integer identifier */
char exit[80];
- int flags; /* VM_ flags */
+ unsigned int flags; /* VM_ flags */
int saydurationm;
struct ast_vm_user *next;
};
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 765e7ff4df..2bd38b2173 100755
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -218,7 +218,7 @@ struct ast_channel {
unsigned int pickupgroup;
/*! channel flags of AST_FLAG_ type */
- int flags;
+ unsigned int flags;
/*! For easy linking */
struct ast_channel *next;
@@ -251,7 +251,7 @@ struct ast_bridge_config {
char *end_sound;
char *start_sound;
int firstpass;
- int flags;
+ unsigned int flags;
};
struct chanmon;
diff --git a/include/asterisk/utils.h b/include/asterisk/utils.h
index 9798543ba9..ff42c13128 100755
--- a/include/asterisk/utils.h
+++ b/include/asterisk/utils.h
@@ -18,19 +18,76 @@
#include <asterisk/lock.h>
#include <limits.h>
-#define ast_test_flag(p,flag) ((p)->flags & (flag))
-
-#define ast_set_flag(p,flag) ((p)->flags |= (flag))
-
-#define ast_clear_flag(p,flag) ((p)->flags &= ~(flag))
-
-#define ast_copy_flags(dest,src,flagz) do { (dest)->flags &= ~(flagz); \
- (dest)->flags |= ((src)->flags & (flagz)); } while(0)
-
-#define ast_set2_flag(p,value,flag) ((value) ? ast_set_flag(p,flag) : ast_clear_flag(p,flag))
+/* Note:
+ It is very important to use only unsigned variables to hold
+ bit flags, as otherwise you can fall prey to the compiler's
+ sign-extension antics if you try to use the top two bits in
+ your variable.
+
+ The flag macros below use a set of compiler tricks to verify
+ that the caller is using an "unsigned int" variable to hold
+ the flags, and nothing else. If the caller uses any other
+ type of variable, a warning message similar to this:
+
+ warning: comparison of distinct pointer types lacks cast
+
+ will be generated.
+
+ The "dummy" variable below is used to make these comparisons.
+
+ Also note that at -O2 or above, this type-safety checking
+ does _not_ produce any additional object code at all.
+*/
+
+extern unsigned int __unsigned_int_flags_dummy;
+
+#define ast_test_flag(p,flag) ({ \
+ typeof ((p)->flags) __p = (p)->flags; \
+ typeof (__unsigned_int_flags_dummy) __x = 0; \
+ (void) (&__p == &__x); \
+ ((p)->flags & (flag)); \
+ })
+
+#define ast_set_flag(p,flag) do { \
+ typeof ((p)->flags) __p = (p)->flags; \
+ typeof (__unsigned_int_flags_dummy) __x = 0; \
+ (void) (&__p == &__x); \
+ ((p)->flags |= (flag)); \
+ } while(0)
+
+#define ast_clear_flag(p,flag) do { \
+ typeof ((p)->flags) __p = (p)->flags; \
+ typeof (__unsigned_int_flags_dummy) __x = 0; \
+ (void) (&__p == &__x); \
+ ((p)->flags &= ~(flag)); \
+ } while(0)
+
+#define ast_copy_flags(dest,src,flagz) do { \
+ typeof ((dest)->flags) __d = (dest)->flags; \
+ typeof ((src)->flags) __s = (src)->flags; \
+ typeof (__unsigned_int_flags_dummy) __x = 0; \
+ (void) (&__d == &__x); \
+ (void) (&__s == &__x); \
+ (dest)->flags &= ~(flagz); \
+ (dest)->flags |= ((src)->flags & (flagz)); \
+ } while (0)
+
+#define ast_set2_flag(p,value,flag) do { \
+ typeof ((p)->flags) __p = (p)->flags; \
+ typeof (__unsigned_int_flags_dummy) __x = 0; \
+ (void) (&__p == &__x); \
+ if (value) \
+ (p)->flags |= (flag); \
+ else \
+ (p)->flags &= ~(flag); \
+ } while (0)
#define AST_FLAGS_ALL UINT_MAX
+struct ast_flags {
+ unsigned int flags;
+};
+
static inline int ast_strlen_zero(const char *s)
{
return (*s == '\0');
@@ -41,10 +98,6 @@ struct ast_hostent {
char buf[1024];
};
-struct ast_flags {
- unsigned int flags;
-};
-
extern char *ast_strip(char *buf);
extern struct hostent *ast_gethostbyname(const char *host, struct ast_hostent *hp);
extern int ast_base64encode(char *dst, unsigned char *src, int srclen, int max);
--
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