X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/a4d982a7cfcc3663c03e05fc5b62ba1b4965fae1..a7689c49fe02c0c065facf736ab28b19f5997b7c:/include/wx/cpp.h?ds=sidebyside

diff --git a/include/wx/cpp.h b/include/wx/cpp.h
index 3d9941920e..9fed106a76 100644
--- a/include/wx/cpp.h
+++ b/include/wx/cpp.h
@@ -79,6 +79,28 @@
  */
 #define wxEMPTY_PARAMETER_VALUE /* Fake macro parameter value */
 
+/*
+    Helpers for defining macros that expand into a single statement.
+
+    The standatd solution is to use "do { ... } while (0)" statement but MSVC
+    generates a C4127 "condition expression is constant" warning for it so we
+    use something which is just complicated enough to not be recognized as a
+    constant but still simple enough to be optimized away.
+
+    Another solution would be to use __pragma() to temporarily disable C4127.
+
+    Notice that wxASSERT_ARG_TYPE in wx/strvargarg.h relies on these macros
+    creating some kind of a loop because it uses "break".
+ */
+#ifdef __WATCOMC__
+    #define wxFOR_ONCE(name) for(int name=0; name<1; name++)
+    #define wxSTATEMENT_MACRO_BEGIN wxFOR_ONCE(wxMAKE_UNIQUE_NAME(wxmacro)) {
+    #define wxSTATEMENT_MACRO_END }
+#else
+    #define wxSTATEMENT_MACRO_BEGIN  do {
+    #define wxSTATEMENT_MACRO_END } while ( (void)0, 0 )
+#endif
+
 /*
     Define __WXFUNCTION__ which is like standard __FUNCTION__ but defined as
     NULL for the compilers which don't support the latter.
@@ -128,8 +150,8 @@
    (With thanks to https://groups.google.com/d/topic/comp.std.c/d-6Mj5Lko_s/discussion
    and http://stackoverflow.com/questions/1872220/is-it-possible-to-iterate-over-arguments-in-variadic-macros)
 */
-#define wxCALL_FOR_EACH_NARG(...)  wxCALL_FOR_EACH_NARG_(__VA_ARGS__, wxCALL_FOR_EACH_RSEQ_N())
-#define wxCALL_FOR_EACH_NARG_(...) wxCALL_FOR_EACH_ARG_N(__VA_ARGS__)
+#define wxCALL_FOR_EACH_NARG(...)   wxCALL_FOR_EACH_NARG_((__VA_ARGS__, wxCALL_FOR_EACH_RSEQ_N()))
+#define wxCALL_FOR_EACH_NARG_(args) wxCALL_FOR_EACH_ARG_N args
 #define wxCALL_FOR_EACH_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
 #define wxCALL_FOR_EACH_RSEQ_N() 8, 7, 6, 5, 4, 3, 2, 1, 0
 
@@ -142,11 +164,11 @@
 #define wxCALL_FOR_EACH_7(what, x, ...)   what(7, x)  wxCALL_FOR_EACH_6(what,  __VA_ARGS__)
 #define wxCALL_FOR_EACH_8(what, x, ...)   what(8, x)  wxCALL_FOR_EACH_7(what,  __VA_ARGS__)
 
-#define wxCALL_FOR_EACH_(N, what, ...) \
-    wxCONCAT(wxCALL_FOR_EACH_, N)(what, __VA_ARGS__)
+#define wxCALL_FOR_EACH_(N, args) \
+    wxCONCAT(wxCALL_FOR_EACH_, N) args
 
 #define wxCALL_FOR_EACH(what, ...) \
-    wxCALL_FOR_EACH_(wxCALL_FOR_EACH_NARG(__VA_ARGS__), what, __VA_ARGS__)
+    wxCALL_FOR_EACH_(wxCALL_FOR_EACH_NARG(__VA_ARGS__), (what, __VA_ARGS__))
 
 #else
     #define wxCALL_FOR_EACH  Error_wx_CALL_FOR_EACH_requires_variadic_macros_support