compilation fix for cygwin

[wxWidgets.git] / include / wx / debug.h

diff --git a/include/wx/debug.h b/include/wx/debug.h
index 85dee4be293d31cafb38f3579289c54fc8b202f7..9c92739aaa5b61f06df5ed86ab35837882349b80 100644 (file)
--- a/include/wx/debug.h
+++ b/include/wx/debug.h
@@ -13,8 +13,9 @@
 #define   _WX_DEBUG_H_
 
 #include  <assert.h>
+#include  <limits.h>            // for CHAR_BIT used below
 
-#include  "wx/wxchar.h"
+#include  "wx/wxchar.h"         // for __TFILE__ and wxChar
 
 // ----------------------------------------------------------------------------
 // Defines controlling the debugging macros
@@ -77,36 +78,38 @@
   */
   extern void WXDLLEXPORT wxOnAssert(const wxChar *szFile,
                                      int nLine,
+                                     const wxChar *szCond,
                                      const wxChar *szMsg = NULL);
 
   // call this function to break into the debugger uncodnitionally (assuming
   // the program is running under debugger, of course)
   extern void WXDLLEXPORT wxTrap();
 
-  /*
-    notice the usage of else at the end of wxASSERT macro: this ensures that
-    the following code
-
-        if ( ... )
-            wxASSERT(...);
-        else
-            ...
-
-    works like expected: if there were no "else", the one in the code above
-    would be matched with a wrong "if"
-  */
+  // helper function used to implement wxASSERT and wxASSERT_MSG
+  //
+  // note using "int" and not "bool" for cond to avoid VC++ warnings about
+  // implicit conversions when doing "wxAssert( pointer )" and also use of
+  // "!!cond" below to ensure that everything is converted to int
+  extern void WXDLLEXPORT wxAssert(int cond,
+                                   const wxChar *szFile,
+                                   int nLine,
+                                   const wxChar *szCond,
+                                   const wxChar *szMsg = NULL) ;
 
   // generic assert macro
-  #define wxASSERT(cond) if ( !(cond) ) wxOnAssert(__TFILE__, __LINE__); else
+  #define wxASSERT(cond) wxAssert(!!(cond), __TFILE__, __LINE__, _T(#cond))
 
   // assert with additional message explaining it's cause
   #define wxASSERT_MSG(cond, msg) \
-                    if ( !(cond) ) wxOnAssert(__TFILE__, __LINE__, msg); else
+    wxAssert(!!(cond), __TFILE__, __LINE__, _T(#cond), msg)
 
   // an assert helper used to avoid warning when testing constant expressions,
   // i.e. wxASSERT( sizeof(int) == 4 ) can generate a compiler warning about
   // expression being always true, but not using
   // wxASSERT( wxAssertIsEqual(sizeof(int), 4) )
+  //
+  // NB: this is made obsolete by wxCOMPILE_TIME_ASSERT() and shouldn't be
+  //     used any longer
   extern bool WXDLLEXPORT wxAssertIsEqual(int x, int y);
 #else
   #define wxTrap()
@@ -156,5 +159,54 @@ 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_