- move ast_strdupa from channel.h to utils.h

- attempt to log an error message if the __builtin_alloca inside of ast_strdupa
  fails.
- document the fact that it is known and intended behavior for ast_strdupa to
  cause Asterisk to crash if the alloca fails
- use __builtin_expect when checking for allocation failure in all of the
  allocation wrappers

New Janitor Project!  Anywhere that we check for a successful allocation after
a call to ast_strdupa is unnecessary and should be removed.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@8356 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 6121481..449b38e 100644 (file)
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -1174,17 +1174,6 @@ static inline int ast_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds,
 #endif
 }
 
-#if !defined(ast_strdupa) && defined(__GNUC__)
-# define ast_strdupa(s)                                                                        \
-  (__extension__                                                                               \
-    ({                                                                                                 \
-      __const char *__old = (s);                                               \
-      size_t __len = strlen (__old) + 1;                               \
-      char *__new = (char *) __builtin_alloca (__len); \
-      (char *) memcpy (__new, __old, __len);                   \
-    }))
-#endif
-
 #ifdef DO_CRASH
 #define CRASH do { fprintf(stderr, "!! Forcing immediate crash a-la abort !!\n"); *((int *)0) = 0; } while(0)
 #else

diff --git a/include/asterisk/utils.h b/include/asterisk/utils.h
index 9c09fe8..070a6af 100644 (file)
--- a/include/asterisk/utils.h
+++ b/include/asterisk/utils.h
@@ -261,7 +261,7 @@ void *_ast_malloc(size_t len, const char *file, int lineno, const char *func),
 
        p = malloc(len);
 
-       if (!p)
+       if (__builtin_expect(!p, 0))
                ast_log(LOG_ERROR, "Memory Allocation Failure - '%d' bytes in function %s at line %d of %s\n", (int)len, func, lineno, file);
 
        return p;
@@ -286,7 +286,7 @@ void *_ast_calloc(size_t num, size_t len, const char *file, int lineno, const ch
 
        p = calloc(num, len);
 
-       if (!p)
+       if (__builtin_expect(!p, 0))
                ast_log(LOG_ERROR, "Memory Allocation Failure - '%d' bytes in function %s at line %d of %s\n", (int)len, func, lineno, file);
 
        return p;
@@ -311,7 +311,7 @@ void *_ast_realloc(void *p, size_t len, const char *file, int lineno, const char
 
        newp = realloc(p, len);
 
-       if (!newp)
+       if (__builtin_expect(!newp, 0))
                ast_log(LOG_ERROR, "Memory Allocation Failure - '%d' bytes in function %s at line %d of %s\n", (int)len, func, lineno, file);
 
        return newp;
@@ -341,7 +341,7 @@ char *_ast_strdup(const char *str, const char *file, int lineno, const char *fun
        if (str) {
                newstr = strdup(str);
 
-               if (!newstr)
+               if (__builtin_expect(!newstr, 0))
                        ast_log(LOG_ERROR, "Memory Allocation Failure - Could not duplicate '%s' in function %s at line %d of %s\n", str, func, lineno, file);
        }
 
@@ -372,7 +372,7 @@ char *_ast_strndup(const char *str, size_t len, const char *file, int lineno, co
        if (str) {
                newstr = strndup(str, len);
 
-               if (!newstr)
+               if (__builtin_expect(!newstr, 0))
                        ast_log(LOG_ERROR, "Memory Allocation Failure - Could not duplicate '%d' bytes of '%s' in function %s at line %d of %s\n", (int)len, str, func, lineno, file);
        }
 
@@ -380,4 +380,30 @@ char *_ast_strndup(const char *str, size_t len, const char *file, int lineno, co
 }
 )
 
+#if !defined(ast_strdupa) && defined(__GNUC__)
+/*!
+  \brief duplicate a string in memory from the stack
+  \param s The string to duplicate
+
+  This macro will duplicate the given string.  It returns a pointer to the stack
+  allocatted memory for the new string.
+
+  \note If this function fails to allocate memory on the stack, we do not make
+  any effort to prevent Asterisk from crashing.  We will attempt to log an
+  error message, but Asterisk will crash shortly after.
+*/
+#define ast_strdupa(s)                                                    \
+       (__extension__                                                    \
+       ({                                                                \
+               const char *__old = (s);                                  \
+               size_t __len = strlen(__old) + 1;                         \
+               char *__new = __builtin_alloca(__len);                    \
+               if (__builtin_expect(!__new, 0))                          \
+                       ast_log(LOG_ERROR, "Stack Allocation Error in"    \
+                               "function '%s' at line '%d' of '%s'!\n",  \
+                               __PRETTY_FUNCTION__, __LINE__, __FILE__); \
+               (char *) memcpy (__new, __old, __len);                    \
+       }))
+#endif
+
 #endif /* _ASTERISK_UTILS_H */