on Windows, avoid potential exception (could happen if MSVCRT isn't

[p5sagit/p5-mst-13.2.git] / win32 / win32.h

diff --git a/win32/win32.h b/win32/win32.h
index 61884ab..d9ffbfe 100644 (file)
--- a/win32/win32.h
+++ b/win32/win32.h
@@ -493,6 +493,56 @@ struct interp_intern {
     } STMT_END
 #endif
 
+#if defined(USE_FIXED_OSFHANDLE) || defined(PERL_MSVCRT_READFIX)
+#ifdef PERL_CORE
+
+/* C doesn't like repeat struct definitions */
+#ifndef _CRTIMP
+#define _CRTIMP __declspec(dllimport)
+#endif
+
+/*
+ * Control structure for lowio file handles
+ */
+typedef struct {
+    long osfhnd;    /* underlying OS file HANDLE */
+    char osfile;    /* attributes of file (e.g., open in text mode?) */
+    char pipech;    /* one char buffer for handles opened on pipes */
+    int lockinitflag;
+    CRITICAL_SECTION lock;
+} ioinfo;
+
+
+/*
+ * Array of arrays of control structures for lowio files.
+ */
+EXTERN_C _CRTIMP ioinfo* __pioinfo[];
+
+/*
+ * Definition of IOINFO_L2E, the log base 2 of the number of elements in each
+ * array of ioinfo structs.
+ */
+#define IOINFO_L2E         5
+
+/*
+ * Definition of IOINFO_ARRAY_ELTS, the number of elements in ioinfo array
+ */
+#define IOINFO_ARRAY_ELTS   (1 << IOINFO_L2E)
+
+/*
+ * Access macros for getting at an ioinfo struct and its fields from a
+ * file handle
+ */
+#define _pioinfo(i) (__pioinfo[(i) >> IOINFO_L2E] + ((i) & (IOINFO_ARRAY_ELTS - 1)))
+#define _osfhnd(i)  (_pioinfo(i)->osfhnd)
+#define _osfile(i)  (_pioinfo(i)->osfile)
+#define _pipech(i)  (_pioinfo(i)->pipech)
+
+/* since we are not doing a dup2(), this works fine */
+#define _set_osfhnd(fh, osfh) (void)(_osfhnd(fh) = (long)osfh)
+#endif
+#endif
+
 /*
  * This provides a layer of functions and macros to ensure extensions will
  * get to use the same RTL functions as the core.