[commit: ghc] master: Ensure text mode when calling debug functions (2b2595e)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/2b2595e03d328f8c49afe55f765635c03dc81865/ghc

>---------------------------------------------------------------

commit 2b2595e03d328f8c49afe55f765635c03dc81865
Author: Tamar Christina <tamar at zhox.com>
Date:   Mon Sep 25 20:21:39 2017 +0100

    Ensure text mode when calling debug functions
    
    Summary:
    Something seems to be changing stderr into binary mode,
    so when the `traceIO` is called, the C code that ultimately
    calls `vfprintf` is using a binary mode handle.
    
    This causes newlines not to be encoded properly.
    
    The patch ensures we're in text mode when writing the debug
    messages (% interleaving as it's not thread safe at all) and restores
    the previous mode when done.
    
    I'm slightly concerned about the performance implications of writing
    large dumps out in text mode, but I think the current behavior is not
    intended as I cannot see any of the printing code setting the mode of
    the std handles.
    
    Test Plan: ./validate
    
    Reviewers: austin, bgamari, erikd, simonmar
    
    Reviewed By: bgamari
    
    Subscribers: rwbarton, thomie
    
    GHC Trac Issues: #14188
    
    Differential Revision: https://phabricator.haskell.org/D4018


>---------------------------------------------------------------

2b2595e03d328f8c49afe55f765635c03dc81865
 rts/RtsMessages.c | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/rts/RtsMessages.c b/rts/RtsMessages.c
index 0859e50..5782c0d 100644
--- a/rts/RtsMessages.c
+++ b/rts/RtsMessages.c
@@ -21,6 +21,7 @@
 
 #if defined(HAVE_WINDOWS_H)
 #include <windows.h>
+#include <fcntl.h>
 #endif
 
 /* -----------------------------------------------------------------------------
@@ -137,7 +138,9 @@ isGUIApp(void)
 void GNU_ATTRIBUTE(__noreturn__)
 rtsFatalInternalErrorFn(const char *s, va_list ap)
 {
-#if defined (mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
+  /* Ensure we're in text mode so newlines get encoded properly.  */
+  int mode = _setmode (_fileno(stderr), _O_TEXT);
   if (isGUIApp())
   {
      char title[BUFSIZE], message[BUFSIZE];
@@ -174,6 +177,9 @@ rtsFatalInternalErrorFn(const char *s, va_list ap)
      fprintf(stderr, "    Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug\n");
      fflush(stderr);
   }
+#if defined(mingw32_HOST_OS)
+  _setmode (_fileno(stderr), mode);
+#endif
 
 #if defined(TRACING)
   if (RtsFlags.TraceFlags.tracing == TRACE_EVENTLOG) endEventLogging();
@@ -186,7 +192,9 @@ rtsFatalInternalErrorFn(const char *s, va_list ap)
 void
 rtsErrorMsgFn(const char *s, va_list ap)
 {
-#if defined (mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
+  /* Ensure we're in text mode so newlines get encoded properly.  */
+  int mode = _setmode (_fileno(stderr), _O_TEXT);
   if (isGUIApp())
   {
      char buf[BUFSIZE];
@@ -211,6 +219,9 @@ rtsErrorMsgFn(const char *s, va_list ap)
      vfprintf(stderr, s, ap);
      fprintf(stderr, "\n");
   }
+#if defined(mingw32_HOST_OS)
+  _setmode (_fileno(stderr), mode);
+#endif
 }
 
 void
@@ -218,7 +229,9 @@ rtsSysErrorMsgFn(const char *s, va_list ap)
 {
     char *syserr;
 
-#if defined (mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
+    /* Ensure we're in text mode so newlines get encoded properly.  */
+    int mode = _setmode (_fileno(stderr), _O_TEXT);
     FormatMessage(
         FORMAT_MESSAGE_ALLOCATE_BUFFER |
         FORMAT_MESSAGE_FROM_SYSTEM |
@@ -257,7 +270,7 @@ rtsSysErrorMsgFn(const char *s, va_list ap)
         }
         vfprintf(stderr, s, ap);
         if (syserr) {
-#if defined (mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
             // Win32 error messages have a terminating \n
             fprintf(stderr, ": %s", syserr);
 #else
@@ -268,15 +281,18 @@ rtsSysErrorMsgFn(const char *s, va_list ap)
         }
     }
 
-#if defined (mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
     if (syserr) LocalFree(syserr);
+    _setmode (_fileno(stderr), mode);
 #endif
 }
 
 void
 rtsDebugMsgFn(const char *s, va_list ap)
 {
-#if defined (mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
+  /* Ensure we're in text mode so newlines get encoded properly.  */
+  int mode = _setmode (_fileno(stderr), _O_TEXT);
   if (isGUIApp())
   {
      char buf[BUFSIZE];
@@ -294,4 +310,7 @@ rtsDebugMsgFn(const char *s, va_list ap)
      vfprintf(stderr, s, ap);
      fflush(stderr);
   }
+#if defined(mingw32_HOST_OS)
+  _setmode (_fileno(stderr), mode);
+#endif
 }