update for HEAD-2003021201

[reactos.git] / lib / crtdll / stdlib / alloca.c

diff --git a/lib/crtdll/stdlib/alloca.c b/lib/crtdll/stdlib/alloca.c
new file mode 100644 (file)
index 0000000..cfbcc91
--- /dev/null
+++ b/lib/crtdll/stdlib/alloca.c
@@ -0,0 +1,68 @@
+#include <windows.h>
+#include <msvcrt/stdlib.h>
+
+
+#undef alloca
+void *alloca(size_t s)
+{
+       register unsigned int as = s;
+
+// alloca(0) should not return the stack pointer
+       if ( s == 0 )
+               return NULL;
+
+       
+       if ( (s & 0xfffffffc)  != 0 )
+               as += 4;
+               
+       as &= 0xfffffffc;
+       
+       __asm__ __volatile__(
+       "mov %0, %%edx          \n"
+//     "popl %%ebp             \n"
+       "leave                  \n"
+       "popl  %%ecx            \n"
+        "subl  %%edx, %%esp    \n"
+        "movl  %%esp, %%eax    \n"
+        "addl  $20, %%eax        \n"//4 bytes + 16 bytes = arguments
+        "push  %%ecx           \n"
+        "ret                   \n"
+        :
+        :"g" ( as)
+        );
+        
+       
+        return NULL;
+}
+
+void *_alloca(size_t s)
+{
+       register unsigned int as = s;
+
+// alloca(0) should not return the stack pointer
+       if ( s == 0 )
+               return NULL;
+
+       
+       if ( (s & 0xfffffffc)  != 0 )
+               as += 4;
+               
+       as &= 0xfffffffc;
+       
+       __asm__ __volatile__(
+       "mov %0, %%edx          \n"
+//     "popl %%ebp             \n"
+       "leave                  \n"
+       "popl  %%ecx            \n"
+        "subl  %%edx, %%esp    \n"
+        "movl  %%esp, %%eax    \n"
+        "addl  $20, %%eax        \n"//4 bytes + 16 bytes = arguments
+        "push  %%ecx           \n"
+        "ret                   \n"
+        :
+        :"g" ( as)
+        );
+        
+       
+        return NULL;
+}