Remove MAX_PATH restrictions from RTS, I/O manager and various utilities

Summary:
This shims out fopen and sopen so that they use modern APIs under the hood
along with namespaced paths.

This lifts the MAX_PATH restrictions from Haskell programs and makes the new
limit ~32k.

There are only some slight caveats that have been documented.

Some utilities have not been upgraded such as lndir, since all these things are
different cabal packages I have been forced to copy the source in different places
which is less than ideal. But it's the only way to keep sdist working.

Test Plan: ./validate

Reviewers: hvr, bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #10822

Differential Revision: https://phabricator.haskell.org/D4416

1 files changed, 36 insertions, 0 deletions

diff --git a/utils/fs/fs.h b/utils/fs/fs.h
new file mode 100644
index 0000000000..ab2eded2a1
--- /dev/null
+++ b/utils/fs/fs.h
@@ -0,0 +1,36 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) Tamar Christina 2018
+ *
+ * Windows I/O routines for file opening.
+ *
+ * NOTE: Only modify this file in utils/fs/ and rerun configure. Do not edit
+ *       this file in any other directory as it will be overwritten.
+ *
+ * ---------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <stdio.h>
+
+#if !defined(FS_NAMESPACE)
+#define FS_NAMESPACE hs
+#endif
+
+/* Play some dirty tricks to get CPP to expand correctly.  */
+#define FS_FULL(ns, name) __##ns##_##name
+#define prefix FS_NAMESPACE
+#define FS_L(p, n) FS_FULL(p, n)
+#define FS(name) FS_L(prefix, name)
+
+#if defined(_WIN32)
+#include <wchar.h>
+
+int FS(swopen) (const wchar_t* filename, int oflag,
+                int shflag, int pmode);
+FILE *FS(fwopen) (const wchar_t* filename, const wchar_t* mode);
+FILE *FS(fopen) (const char* filename, const char* mode);
+#else
+
+FILE *FS(fopen) (const char* filename, const char* mode);
+#endif