crt1.c revision

win32/lib/crt1.c

@@ -1,48 +1,78 @@
 // =============================================
 // crt1.c
 
-#include <stdlib.h>
 // For ExitProcess
+// windows.h header file should be included before any other library include
 #include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
 
-#define __UNKNOWN_APP    0
-#define __CONSOLE_APP    1
-#define __GUI_APP        2
-void __set_app_type(int);
-void _controlfp(unsigned a, unsigned b);
+#define _UNKNOWN_APP    0
+#define _CONSOLE_APP    1
+#define _GUI_APP        2
+
+#define _MCW_PC         0x00030000 // Precision Control
+#define _PC_24          0x00020000 // 24 bits
+#define _PC_53          0x00010000 // 53 bits
+#define _PC_64          0x00000000 // 64 bits
 
 typedef struct
 {
     int newmode;
 } _startupinfo;
 
-// prototype of __getmainargs:
-// in msvcrt v6.0 : return void
-// in msvcrt v7.0 : return int
-// using first for compatibility
-void __getmainargs(int *pargc, char ***pargv, char ***penv, int globb, _startupinfo*);
-int main(int argc, char **argv, char **env);
+// Prototype of __getmainargs:
+// in msvcrt v6.x : returns void (windows 98, 2000)
+// in msvcrt v7.x : returns int  (windows xp and above)
+// Using the last for check the result. A negative value means no success.
+// These are the test results of call to __getmainargs with the heap fully:
+// win 98, 2000 :
+//     program termination with error code 255 after call _amsg_exit(8)
+//     prints: "runtime error R6008\r\n- not enough space for arguments\r\n"
+// win xp :
+//     returns -1
+// win 7, 8 :
+//     program termination with error code -1 after call ExitProcess(-1)
+//
+// Checking the return of this function also works on windows 98 and 2000
+// because internally it sets to eax the value of the third parameter.
+// In this case is &env and at that point it is not a negative value.
 
-int _start(void)
+int __cdecl __getmainargs(int *pargc, char ***pargv, char ***penv, int globb, _startupinfo*);
+void __cdecl __set_app_type(int apptype);
+unsigned int __cdecl _controlfp(unsigned int new_value, unsigned int mask);
+
+void _start(void);
+int main(int argc, char * argv[], char * env[]);
+
+void _start(void)
 {
     __TRY__
-    int argc; char **argv; char **env;
-    _startupinfo start_info = {0};
+    int argc;
+    char **argv;
+    char **env;
+    _startupinfo start_info;
 
-    _controlfp(0x10000, 0x30000);
-    __set_app_type(__CONSOLE_APP);
+    // Sets the current application type
+    __set_app_type(_CONSOLE_APP);
 
-    argv = NULL;
-    __getmainargs(&argc, &argv, &env, 0, &start_info);
-    // check success comparing if argv now is not NULL
-    if (argv != NULL)
-    {
-        exit( main(argc, argv, env) );
-    }
-    else
+    // Set default FP precision to 53 bits (8-byte double)
+    // _MCW_PC (Precision control) is not supported on
+    // the ARM and x64 architectures
+#if defined(_X86_) && !defined(__x86_64)
+    _controlfp(_PC_53, _MCW_PC);
+#endif
+
+    start_info.newmode = 0;
+    if ( __getmainargs( &argc, &argv, &env, 0, &start_info ) < 0 )
     {
         ExitProcess(-1);
     }
+    else
+    {
+        exit( main(argc, argv, env) );
+    }
+
 }
 
 // =============================================