Patch from MJW for ssize_t

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30479 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

configure.in

@@ -3477,6 +3477,9 @@ AC_TYPE_SIZE_T
 dnl   defines uid_t and gid_t if not already defined
 AC_TYPE_UID_T
 
+dnl sets HAVE_SSIZE_T if ssize_t is defined
+AC_CHECK_TYPES(ssize_t)
+
 dnl check what exactly size_t is on this machine - this is necessary to avoid
 dnl ambiguous overloads in several places, notably wx/string.h and wx/array.h
 AC_LANG_SAVE

include/wx/defs.h

@@ -886,6 +886,19 @@ inline void *wxUIntToPtr(wxUIntPtr p)
 #endif
 
 
+/* Make sure ssize_t is defined (a signed type the same size as size_t) */
+/* HAVE_SSIZE_T should be defined for compiliers that already have it */
+#ifndef HAVE_SSIZE_T
+    #if SIZEOF_SIZE_T == 4
+        typedef wxInt32 ssize_t;
+    #elif SIZEOF_SIZE_T == 8
+        typedef wxInt64 ssize_t
+    #else
+        #error "error defining ssize_t, size_t is not 4 or 8 bytes"
+    #endif
+#endif
+
+
 /*  base floating point types */
 /*  wxFloat32: 32 bit IEEE float ( 1 sign, 8 exponent bits, 23 fraction bits */
 /*  wxFloat64: 64 bit IEEE float ( 1 sign, 11 exponent bits, 52 fraction bits */

setup.h.in

@@ -39,6 +39,9 @@
 /* Define to `unsigned' if <sys/types.h> doesn't define.  */
 #undef size_t
 
+/* Define if ssize_t type is available.  */
+#undef HAVE_SSIZE_T
+
 /* Define if you have the ANSI C header files.  */
 #undef STDC_HEADERS
 

setup.h_vms

@@ -53,6 +53,9 @@
 /* Define to `unsigned' if <sys/types.h> doesn't define.  */
 #undef size_t
 
+/* Define if ssize_t type is available.  */
+#undef HAVE_SSIZE_T
+
 /* Define if you have the ANSI C header files.  */
 #define STDC_HEADERS
 

src/common/file.cpp

@@ -144,14 +144,6 @@
     #include "wx/msw/private.h"
 #endif
 
-#if !defined __UNIX__ && !defined __DJGPP__
-    #ifdef __WXWINCE__
-        typedef int ssize_t;
-    #else
-        typedef ptrdiff_t ssize_t;
-    #endif
-#endif
-wxCOMPILE_TIME_ASSERT(sizeof(ssize_t) == sizeof(size_t), ssize_t_wrong_size);
 
 // ============================================================================
 // implementation of wxFile