1 files changed, 59 insertions, 0 deletions

diff --git a/private/crt32/misc/i386/sehsupp.c b/private/crt32/misc/i386/sehsupp.c
new file mode 100644
index 000000000..1dbce51bb
--- /dev/null
+++ b/private/crt32/misc/i386/sehsupp.c
@@ -0,0 +1,59 @@
+/***
+*sehsupp.c - helper functions for Structured Exception Handling support
+*
+*	Copyright (C) 1993, Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+*	Contains _rt_probe_read.  Helper for the SEH runtime support
+*	routines (longjmp in particular).  Much of the SEH code is written
+*	in asm, so these routines are available when probing memory in ways
+*	that must be guarded with __try/__except in case of access violation.
+*
+*Revision History:
+*	12-05-93  PML	Module created.
+*	12-22-93  GJF	Made #define WIN32_LEAN_AND_MEAN conditional.
+*	01-12-94  PML	Rewritten - still need helpers, just different ones
+*
+*******************************************************************************/
+
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
+
+#include <windows.h>
+
+/***
+*BOOL __stdcall _rt_probe_read4 - Check if a DWORD is readable
+*
+*Purpose:
+*  Internal support function called by longjmp.  Check if a DWORD is
+*  readable under a __try/__except.
+*
+*Entry:
+*  DWORD * p - Pointer to DWORD to be probed
+*
+*Exit:
+*  Success: TRUE - Able to read
+*  Failure: FALSE - Access violation while reading
+*
+******************************************************************************/
+
+BOOL __stdcall _rt_probe_read4(
+    DWORD * ptr)
+{
+    BOOL readable;
+
+    __try
+    {
+	*(volatile DWORD *)ptr;
+	readable = TRUE;
+    }
+    __except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
+		? EXCEPTION_EXECUTE_HANDLER
+		: EXCEPTION_CONTINUE_SEARCH)
+    {
+	readable = FALSE;
+    }
+
+    return readable;
+}