Merge branch 'inline-macros' into 'main'

gmacros: Provide platform-independent G_ALWAYS_INLINE and G_NO_INLINE

See merge request GNOME/glib!2781

docs/reference/glib/glib-sections.txt

@@ -516,6 +516,10 @@ G_CONST_RETURN
 G_NORETURN
 G_NORETURN_FUNCPTR
 
+<SUBSECTION>
+G_ALWAYS_INLINE
+G_NO_INLINE
+
 <SUBSECTION>
 G_N_ELEMENTS
 </SECTION>
@@ -782,6 +786,7 @@ g_macro__has_attribute
 g_macro__has_builtin
 g_macro__has_feature
 g_macro__has_extension
+g_macro__has_attribute___always_inline__
 g_macro__has_attribute___alloc_size__
 g_macro__has_attribute___const__
 g_macro__has_attribute___deprecated__

glib/gmacros.h

@@ -212,6 +212,9 @@
  * Declaring a function as `noinline` prevents the function from being
  * considered for inlining.
  *
+ * This macro is provided for retro-compatibility and will be eventually
+ * deprecated, but %G_NO_INLINE should be used instead.
+ *
  * The attribute may be placed before the declaration or definition,
  * right before the `static` keyword.
  *
@@ -228,13 +231,10 @@
  * [GNU C documentation](https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noinline-function-attribute)
  * for more details.
  *
+ * See also: %G_NO_INLINE, %G_ALWAYS_INLINE.
+ *
  * Since: 2.58
  */
-/* Note: We can’t annotate this with GLIB_AVAILABLE_MACRO_IN_2_58 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 g_macro__has_attribute(__pure__)
 #define G_GNUC_PURE __attribute__((__pure__))
@@ -249,9 +249,11 @@
 #endif
 
 #if g_macro__has_attribute(__noinline__)
-#define G_GNUC_NO_INLINE __attribute__ ((__noinline__))
+#define G_GNUC_NO_INLINE __attribute__ ((__noinline__)) \
+  GLIB_AVAILABLE_MACRO_IN_2_58
 #else
-#define G_GNUC_NO_INLINE
+#define G_GNUC_NO_INLINE \
+  GLIB_AVAILABLE_MACRO_IN_2_58
 #endif
 
 /**
@@ -1069,6 +1071,100 @@
   GLIB_AVAILABLE_MACRO_IN_2_68
 #endif
 
+/**
+ * G_ALWAYS_INLINE:
+ *
+ * Expands to the GNU C `always_inline` or MSVC `__forceinline` function
+ * attribute depending on the compiler. It is used for declaring functions
+ * as always inlined, ignoring the compiler optimization levels.
+ *
+ * The attribute may be placed before the declaration or definition,
+ * right before the `static` keyword.
+ *
+ * |[<!-- language="C" -->
+ * G_ALWAYS_INLINE
+ * static int
+ * do_inline_this (void)
+ * {
+ *   ...
+ * }
+ * ]|
+ *
+ * See the
+ * [GNU C documentation](https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-always_005finline-function-attribute)
+ * and the
+ * [MSVC documentation](https://docs.microsoft.com/en-us/visualstudio/misc/inline-inline-forceinline)
+ *
+ * Since: 2.74
+ */
+/* Note: We can’t annotate this with GLIB_AVAILABLE_MACRO_IN_2_74 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 g_macro__has_attribute(__always_inline__)
+# if defined (__cplusplus) && __cplusplus >= 201103L
+    /* Use ISO C++11 syntax when the compiler supports it. */
+#   define G_ALWAYS_INLINE [[gnu::always_inline]]
+# else
+#   define G_ALWAYS_INLINE __attribute__ ((__always_inline__))
+# endif
+#elif defined (_MSC_VER)
+  /* Use MSVC specific syntax.  */
+# define G_ALWAYS_INLINE __forceinline
+#else
+# define G_ALWAYS_INLINE /* empty */
+#endif
+
+/**
+ * G_NO_INLINE:
+ *
+ * Expands to the GNU C or MSVC `noinline` function attribute
+ * depending on the compiler. It is used for declaring functions
+ * preventing from being considered for inlining.
+ *
+ * Note that %G_NO_INLINE supersedes the previous %G_GNUC_NO_INLINE
+ * macro, which will eventually be deprecated.
+ * %G_NO_INLINE supports more platforms.
+ *
+ * The attribute may be placed before the declaration or definition,
+ * right before the `static` keyword.
+ *
+ * |[<!-- language="C" -->
+ * G_NO_INLINE
+ * static int
+ * do_not_inline_this (void)
+ * {
+ *   ...
+ * }
+ * ]|
+ *
+ * Since: 2.74
+ */
+/* Note: We can’t annotate this with GLIB_AVAILABLE_MACRO_IN_2_74 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 g_macro__has_attribute(__noinline__)
+# if defined (__cplusplus) && __cplusplus >= 201103L
+    /* Use ISO C++11 syntax when the compiler supports it. */
+#   define G_NO_INLINE [[gnu::noinline]]
+# else
+#   define G_NO_INLINE __attribute__ ((__noinline__))
+# endif
+#elif defined (_MSC_VER) && (1200 <= _MSC_VER)
+  /* Use MSVC specific syntax.  */
+# if defined (__cplusplus) && __cplusplus >= 201103L
+    /* Use ISO C++11 syntax when the compiler supports it. */
+#   define G_NO_INLINE [[msvc::noinline]]
+# else
+#   define G_NO_INLINE __declspec (noinline)
+# endif
+#else
+# define G_NO_INLINE /* empty */
+#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/gthread-posix.c

@@ -1490,7 +1490,8 @@ g_mutex_clear (GMutex *mutex)
     }
 }
 
-static void __attribute__((noinline))
+G_GNUC_NO_INLINE
+static void
 g_mutex_lock_slowpath (GMutex *mutex)
 {
   /* Set to contended.  If it was empty before then we
@@ -1505,7 +1506,8 @@ g_mutex_lock_slowpath (GMutex *mutex)
     }
 }
 
-static void __attribute__((noinline))
+G_GNUC_NO_INLINE
+static void
 g_mutex_unlock_slowpath (GMutex *mutex,
                          guint   prev)
 {

glib/tests/cxx.cpp

@@ -160,6 +160,30 @@ test_atomic_int_exchange (void)
 #endif
 }
 
+G_NO_INLINE
+static gboolean
+do_not_inline_this (void)
+{
+  return FALSE;
+}
+
+G_ALWAYS_INLINE
+static inline gboolean
+do_inline_this (void)
+{
+  return TRUE;
+}
+
+static void
+test_inline_no_inline_macros (void)
+{
+  g_test_message ("Test that G_NO_INLINE and G_ALWAYS_INLINE functions "
+                  "can be compiled with C++ compiler");
+
+  g_assert_false (do_not_inline_this ());
+  g_assert_true (do_inline_this ());
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -176,6 +200,7 @@ main (int argc, char *argv[])
   g_test_add_func ("/C++/atomic-int-compare-and-exchange-full", test_atomic_int_compare_and_exchange_full);
   g_test_add_func ("/C++/atomic-pointer-exchange", test_atomic_pointer_exchange);
   g_test_add_func ("/C++/atomic-int-exchange", test_atomic_int_exchange);
+  g_test_add_func ("/C++/inlined-not-inlined-functions", test_inline_no_inline_macros);
 
   return g_test_run ();
 }

gobject/gtype.h

@@ -2160,7 +2160,7 @@ type_name##_get_type (void) \
   return static_g_define_type_id; \
 } /* closes type_name##_get_type() */ \
 \
-G_GNUC_NO_INLINE \
+G_NO_INLINE \
 static GType \
 type_name##_get_type_once (void) \
 { \
@@ -2329,7 +2329,7 @@ type_name##_get_type (void) \
   return static_g_define_type_id; \
 } \
 \
-G_GNUC_NO_INLINE \
+G_NO_INLINE \
 static GType \
 type_name##_get_type_once (void) \
 { \
@@ -2366,7 +2366,7 @@ type_name##_get_type (void) \
   return static_g_define_type_id; \
 } \
 \
-G_GNUC_NO_INLINE \
+G_NO_INLINE \
 static GType \
 type_name##_get_type_once (void) \
 { \
@@ -2419,7 +2419,7 @@ type_name##_get_type (void) \
   return static_g_define_type_id; \
 } \
 \
-G_GNUC_NO_INLINE \
+G_NO_INLINE \
 static GType \
 type_name##_get_type_once (void) \
 { \