Merge branch 'mark_g_assert_as_noreturn_on_MSVC' into 'master'

Adding macros G_NORETURN and G_NORETURN_FUNCPTR

Closes #994

See merge request GNOME/glib!1078

docs/reference/glib/glib-sections.txt

@@ -469,6 +469,8 @@ G_ALIGNOF
 
 <SUBSECTION>
 G_CONST_RETURN
+G_NORETURN
+G_NORETURN_FUNCPTR
 
 <SUBSECTION>
 G_N_ELEMENTS

gio/tests/proxy.c

@@ -37,7 +37,7 @@ static const gchar *info = NULL;
 static GCancellable *cancellable = NULL;
 static gint return_value = 0;
 
-static void G_GNUC_NORETURN
+static G_NORETURN void
 usage (void)
 {
   fprintf (stderr, "Usage: proxy [-s] (uri|host:port|ip:port|path|srv/protocol/domain)\n");

gio/tests/resolver.c

@@ -40,7 +40,7 @@ static gboolean synchronous = FALSE;
 static guint connectable_count = 0;
 static GResolverRecordType record_type = 0;
 
-static void G_GNUC_NORETURN
+static G_NORETURN void
 usage (void)
 {
 	fprintf (stderr, "Usage: resolver [-s] [hostname | IP | service/protocol/domain ] ...\n");

glib/gmacros.h

@@ -423,6 +423,12 @@
  * It is used for declaring functions which never return. It enables
  * optimization of the function, and avoids possible compiler warnings.
  *
+ * Since 2.68, it is recommended that code uses %G_NORETURN instead of
+ * %G_GNUC_NORETURN, as that works on more platforms and compilers (in
+ * particular, MSVC and C++11) than %G_GNUC_NORETURN, which works with GCC and
+ * Clang only. %G_GNUC_NORETURN continues to work, so has not been deprecated
+ * yet.
+ *
  * Place the attribute after the declaration, just before the semicolon.
  *
  * |[<!-- language="C" -->
@@ -917,6 +923,76 @@
 #define G_CONST_RETURN const GLIB_DEPRECATED_MACRO_IN_2_30_FOR(const)
 #endif
 
+/**
+ * G_NORETURN:
+ *
+ * Expands to the GNU C or MSVC `noreturn` function attribute depending on
+ * the compiler. It is used for declaring functions which never return.
+ * Enables optimization of the function, and avoids possible compiler warnings.
+ *
+ * Note that %G_NORETURN supersedes the previous %G_GNUC_NORETURN macro, which
+ * will eventually be deprecated. %G_NORETURN supports more platforms.
+ *
+ * Place the attribute before the function declaration as follows:
+ *
+ * |[<!-- language="C" -->
+ * G_NORETURN void g_abort (void);
+ * ]|
+ *
+ * Since: 2.68
+ */
+/* Note: We can’t annotate this with GLIB_AVAILABLE_MACRO_IN_2_68 because it’s
+ * used within the GLib headers in function declarations which are always
+ * evaluated when a header is included. This results in warnings in third party
+ * code which includes glib.h, even if the third party code doesn’t use the new
+ * macro itself. */
+#if (3 <= __GNUC__ || (__GNUC__ == 2 && 8 <= __GNUC_MINOR__)) || (0x5110 <= __SUNPRO_C)
+  /* For compatibility with G_NORETURN_FUNCPTR on clang, use
+     __attribute__((__noreturn__)), not _Noreturn.  */
+# define G_NORETURN __attribute__ ((__noreturn__))
+#elif 1200 <= _MSC_VER
+  /* Use MSVC specific syntax.  */
+# define G_NORETURN __declspec (noreturn)
+  /* Use ISO C++11 syntax when the compiler supports it.  */
+#elif (__cplusplus >= 201103 && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) || (_MSC_VER >= 1900)
+# define G_NORETURN [[noreturn]]
+  /* Use ISO C11 syntax when the compiler supports it.  */
+#elif __STDC_VERSION__ >= 201112 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7)
+# define G_NORETURN _Noreturn
+#else
+# define G_NORETURN /* empty */
+#endif
+
+/**
+ * G_NORETURN_FUNCPTR:
+ *
+ * Expands to the GNU C or MSVC `noreturn` function attribute depending on
+ * the compiler. It is used for declaring function pointers which never return.
+ * Enables optimization of the function, and avoids possible compiler warnings.
+ *
+ * Place the attribute before the function declaration as follows:
+ *
+ * |[<!-- language="C" -->
+ * G_NORETURN_FUNCPTR void (*funcptr) (void);
+ * ]|
+ *
+ * Note that if the function is not a function pointer, you can simply use
+ * the %G_NORETURN macro as follows:
+ *
+ * |[<!-- language="C" -->
+ * G_NORETURN void g_abort (void);
+ * ]|
+ *
+ * Since: 2.68
+ */
+#if (3 <= __GNUC__ || (__GNUC__ == 2 && 8 <= __GNUC_MINOR__)) || (0x5110 <= __SUNPRO_C)
+# define G_NORETURN_FUNCPTR __attribute__ ((__noreturn__))      \
+  GLIB_AVAILABLE_MACRO_IN_2_68
+#else
+# define G_NORETURN_FUNCPTR /* empty */         \
+  GLIB_AVAILABLE_MACRO_IN_2_68
+#endif
+
 /*
  * The G_LIKELY and G_UNLIKELY macros let the programmer give hints to 
  * the compiler about the expected result of an expression. Some compilers

glib/gmessages.h

@@ -283,11 +283,12 @@ void g_warn_message           (const char     *domain,
                                const char     *func,
                                const char     *warnexpr) G_ANALYZER_NORETURN;
 GLIB_DEPRECATED
+G_NORETURN
 void g_assert_warning         (const char *log_domain,
 			       const char *file,
 			       const int   line,
 		               const char *pretty_function,
-		               const char *expression) G_GNUC_NORETURN;
+		               const char *expression);
 
 GLIB_AVAILABLE_IN_2_56
 void g_log_structured_standard (const gchar    *log_domain,
@@ -399,7 +400,7 @@ void g_log_structured_standard (const gchar    *log_domain,
                                        format)
 #endif
 #else   /* no varargs macros */
-static void g_error (const gchar *format, ...) G_GNUC_NORETURN G_ANALYZER_NORETURN;
+static G_NORETURN void g_error (const gchar *format, ...) G_ANALYZER_NORETURN;
 static void g_critical (const gchar *format, ...) G_ANALYZER_NORETURN;
 
 static inline void

glib/goption.c

@@ -1091,7 +1091,7 @@ g_option_context_get_help (GOptionContext *context,
   return g_string_free (string, FALSE);
 }
 
-G_GNUC_NORETURN
+G_NORETURN
 static void
 print_help (GOptionContext *context,
             gboolean        main_help,

glib/gspawn.c

@@ -1116,7 +1116,7 @@ write_all (gint fd, gconstpointer vbuf, gsize to_write)
 
 /* This function is called between fork() and exec() and hence must be
  * async-signal-safe (see signal-safety(7)). */
-G_GNUC_NORETURN
+G_NORETURN
 static void
 write_err_and_exit (gint fd, gint msg)
 {

glib/gtestutils.h

@@ -514,11 +514,12 @@ void    g_assertion_message             (const char     *domain,
                                          const char     *func,
                                          const char     *message) G_ANALYZER_NORETURN;
 GLIB_AVAILABLE_IN_ALL
+G_NORETURN
 void    g_assertion_message_expr        (const char     *domain,
                                          const char     *file,
                                          int             line,
                                          const char     *func,
-                                         const char     *expr) G_GNUC_NORETURN;
+                                         const char     *expr);
 GLIB_AVAILABLE_IN_ALL
 void    g_assertion_message_cmpstr      (const char     *domain,
                                          const char     *file,

glib/gutils.h

@@ -434,7 +434,7 @@ g_bit_storage_impl (gulong number)
 #  define g_abort() abort ()
 #else
 GLIB_AVAILABLE_IN_2_50
-void g_abort (void) G_GNUC_NORETURN G_ANALYZER_NORETURN;
+G_NORETURN void g_abort (void) G_ANALYZER_NORETURN;
 #endif
 #endif
 

msvc_recommended_pragmas.h

@@ -24,6 +24,11 @@
 #pragma warning(disable:4101) /* unreferenced local variable */
 #pragma warning(error:4150)
 
+/* G_NORETURN */
+#pragma warning(error:4646) /* function declared with __declspec(noreturn) has non-void return type */
+#pragma warning(error:4715) /* 'function': not all control paths return a value */
+#pragma warning(error:4098) /* 'void' function returning a value */
+
 #pragma warning(disable:4244)	/* No possible loss of data warnings */
 #pragma warning(disable:4305)   /* No truncation from int to char warnings */