Add conditional support for noreturn functions.

This adds support for tagging functions with the noreturn attribute.
If DO_CRASH is enabled then ast_do_crash never returns.  If AST_DEVMODE
and DO_CRASH are enabled then failed assertions never return.  This can
resolve a large number of false positives with static analyzers.

ASTERISK-26220 #close

Change-Id: Icfb61e5fe54574eced4c3e88b317244f467ec753

6 files changed, 92 insertions, 9 deletions

diff --git a/configure b/configure
index 6d3faf204..fab78d018 100755
--- a/configure
+++ b/configure
@@ -14150,7 +14150,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14196,7 +14196,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14220,7 +14220,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14265,7 +14265,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14289,7 +14289,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -18026,6 +18026,74 @@ CFLAGS="$saved_CFLAGS"
 
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for compiler 'attribute noreturn' support" >&5
+$as_echo_n "checking for compiler 'attribute noreturn' support... " >&6; }
+saved_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -Wall -Wno-unused -Werror"
+
+
+if test "xnoreturn" = "x"
+then
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+ void __attribute__((noreturn)) *test(void *muffin, ...) {return (void *) 0;}
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_ATTRIBUTE_noreturn 1
+_ACEOF
+
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+ void __attribute__((noreturn)) *test(void *muffin, ...) ;
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_ATTRIBUTE_noreturn 1
+_ACEOF
+
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+
+CFLAGS="$saved_CFLAGS"
+
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -fsanitize=address support" >&5
 $as_echo_n "checking for -fsanitize=address support... " >&6; }
 saved_sanitize_CFLAGS="${CFLAGS}"
diff --git a/configure.ac b/configure.ac
index dedfd8a2e..3331f78fe 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1076,6 +1076,7 @@ AST_GCC_ATTRIBUTE(warn_unused_result)
 AST_GCC_ATTRIBUTE(may_alias)
 AST_GCC_ATTRIBUTE(constructor)
 AST_GCC_ATTRIBUTE(destructor)
+AST_GCC_ATTRIBUTE(noreturn,noreturn)
 
 AC_MSG_CHECKING(for -fsanitize=address support)
 saved_sanitize_CFLAGS="${CFLAGS}"
diff --git a/include/asterisk/autoconfig.h.in b/include/asterisk/autoconfig.h.in
index 51f0f1462..9d2a84c02 100644
--- a/include/asterisk/autoconfig.h.in
+++ b/include/asterisk/autoconfig.h.in
@@ -102,6 +102,9 @@
 /* Define to 1 if your GCC C compiler supports the 'may_alias' attribute. */
 #undef HAVE_ATTRIBUTE_may_alias
 
+/* Define to 1 if your GCC C compiler supports the 'noreturn' attribute. */
+#undef HAVE_ATTRIBUTE_noreturn
+
 /* Define to 1 if your GCC C compiler supports the 'pure' attribute. */
 #undef HAVE_ATTRIBUTE_pure
 
diff --git a/include/asterisk/compiler.h b/include/asterisk/compiler.h
index 77b5de40e..6ceaa5f77 100644
--- a/include/asterisk/compiler.h
+++ b/include/asterisk/compiler.h
@@ -77,6 +77,12 @@
 #define attribute_may_alias
 #endif
 
+#ifdef HAVE_ATTRIBUTE_noreturn
+#define attribute_noreturn __attribute__((noreturn))
+#else
+#define attribute_noreturn
+#endif
+
 /* Some older version of GNU gcc (3.3.5 on OpenBSD 4.3 for example) dont like 'NULL' as sentinel */
 #define SENTINEL ((char *)NULL)
 
diff --git a/include/asterisk/utils.h b/include/asterisk/utils.h
index c7a473732..c311e9cd5 100644
--- a/include/asterisk/utils.h
+++ b/include/asterisk/utils.h
@@ -843,9 +843,14 @@ struct ast_http_digest {
  */
 int ast_parse_digest(const char *digest, struct ast_http_digest *d, int request, int pedantic);
 
+#ifdef DO_CRASH
+#define DO_CRASH_NORETURN attribute_noreturn
+#else
+#define DO_CRASH_NORETURN
+#endif
 
 #ifdef AST_DEVMODE
-void __ast_assert_failed(int condition, const char *condition_str, const char *file, int line, const char *function);
+void DO_CRASH_NORETURN __ast_assert_failed(int condition, const char *condition_str, const char *file, int line, const char *function);
 #define ast_assert(a) _ast_assert(a, # a, __FILE__, __LINE__, __PRETTY_FUNCTION__)
 static void force_inline _ast_assert(int condition, const char *condition_str, const char *file, int line, const char *function)
 {
@@ -864,7 +869,7 @@ static void force_inline _ast_assert(int condition, const char *condition_str, c
  *
  * \return Nothing
  */
-void ast_do_crash(void);
+void DO_CRASH_NORETURN ast_do_crash(void);
 
 #include "asterisk/strings.h"
 
diff --git a/main/utils.c b/main/utils.c
index 09839752b..46edf43ea 100644
--- a/main/utils.c
+++ b/main/utils.c
@@ -2420,7 +2420,7 @@ char *ast_utils_which(const char *binary, char *fullpath, size_t fullpath_size)
 	return NULL;
 }
 
-void ast_do_crash(void)
+void DO_CRASH_NORETURN ast_do_crash(void)
 {
 #if defined(DO_CRASH)
 	abort();
@@ -2433,7 +2433,7 @@ void ast_do_crash(void)
 }
 
 #if defined(AST_DEVMODE)
-void __ast_assert_failed(int condition, const char *condition_str, const char *file, int line, const char *function)
+void DO_CRASH_NORETURN __ast_assert_failed(int condition, const char *condition_str, const char *file, int line, const char *function)
 {
 	/*
 	 * Attempt to put it into the logger, but hope that at least