X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/8b0bd21b3d4b68146272a124fcadfad02eba6599..ccdcde00d9ae27ca20ff6c3c9495918a0ec725aa:/include/wx/debug.h?ds=inline diff --git a/include/wx/debug.h b/include/wx/debug.h index 85dee4be29..436a05ab29 100644 --- a/include/wx/debug.h +++ b/include/wx/debug.h @@ -13,8 +13,9 @@ #define _WX_DEBUG_H_ #include +#include // for CHAR_BIT used below -#include "wx/wxchar.h" +#include "wx/wxchar.h" // for __TFILE__ and wxChar // ---------------------------------------------------------------------------- // Defines controlling the debugging macros @@ -156,5 +157,54 @@ WXDLLEXPORT_DATA(extern const bool) wxFalse; // to begin with...) #define wxCHECK_RET(x, msg) if (!(x)) {wxFAIL_MSG(msg); return; } +// ---------------------------------------------------------------------------- +// Compile time asserts +// +// Unlike the normal assert and related macros above which are checked during +// the program tun-time the macros below will result in a compilation error if +// the condition they check is false. This is usually used to check the +// expressions containing sizeof()s which cannot be tested with the +// preprocessor. If you can use the #if's, do use them as you can give a more +// detailed error message then. +// ---------------------------------------------------------------------------- + +/* + How this works (you don't have to understand it to be able to use the + macros): we rely on the fact that it is invalid to define a named bit field + in a struct of width 0. All the rest are just the hacks to minimize the + possibility of the compiler warnings when compiling this macro: in + particular, this is why we define a struct and not an object (which would + result in a warning about unused variable) and a named struct (otherwise we'd + get a warning about an unnamed struct not used to define an object!). + */ + +#define wxMAKE_ASSERT_NAME_HELPER(line) wxAssert_ ## line +#define wxMAKE_ASSERT_NAME(line) wxMAKE_ASSERT_NAME_HELPER(line) +#define wxMAKE_UNIQUE_ASSERT_NAME wxMAKE_ASSERT_NAME(__LINE__) +#define wxMAKE_UNIQUE_ASSERT_NAME2(text) wxMAKE_ASSERT_NAME(text) + +/* + The second argument of this macro must be a valid C++ identifier and not a + string. I.e. you should use it like this: + + wxCOMPILE_TIME_ASSERT( sizeof(int) >= 2, YourIntsAreTooSmall ); + + It may be used both within a function and in the global scope. +*/ +#define wxCOMPILE_TIME_ASSERT(expr, msg) \ + struct wxMAKE_UNIQUE_ASSERT_NAME { unsigned int msg: expr; } + +#define wxCOMPILE_TIME_ASSERT2(expr, msg, text) \ + struct wxMAKE_UNIQUE_ASSERT_NAME2(text) { unsigned int msg: expr; } + +// helpers for wxCOMPILE_TIME_ASSERT below, for private use only +#define wxMAKE_BITSIZE_MSG(type, size) type ## SmallerThan ## size ## Bits + +// a special case of compile time assert: check that the size of the given type +// is at least the given number of bits +#define wxASSERT_MIN_BITSIZE(type, size) \ + wxCOMPILE_TIME_ASSERT(sizeof(type) * CHAR_BIT >= size, \ + wxMAKE_BITSIZE_MSG(type, size)) + #endif // _WX_DEBUG_H_