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, 4 insertions, 2 deletions

diff --git a/rts/RtsFlags.c b/rts/RtsFlags.c
index b674e9b685..abb980039d 100644
--- a/rts/RtsFlags.c
+++ b/rts/RtsFlags.c
@@ -31,6 +31,8 @@
 #include <sys/types.h>
 #endif
 
+#include <fs_rts.h>
+
 // Flag Structure
 RTS_FLAGS RtsFlags;
 
@@ -1697,7 +1699,7 @@ openStatsFile (char *filename,           // filename, or NULL
         f = NULL; /* NULL means use debugBelch */
     } else {
         if (*filename != '\0') {  /* stats file specified */
-            f = fopen(filename,"w");
+            f = __rts_fopen (filename,"w");
         } else {
             if (filename_fmt == NULL) {
                 errorBelch("Invalid stats filename format (NULL)\n");
@@ -1707,7 +1709,7 @@ openStatsFile (char *filename,           // filename, or NULL
             char stats_filename[STATS_FILENAME_MAXLEN];
             snprintf(stats_filename, STATS_FILENAME_MAXLEN, filename_fmt,
                 prog_name);
-            f = fopen(stats_filename,"w");
+            f = __rts_fopen (stats_filename,"w");
         }
         if (f == NULL) {
             errorBelch("Can't open stats file %s\n", filename);