On Wed, Sep 08, 2021 at 08:19:57PM +0200, Matthias Kilian wrote:
> > Are you at all intersted in shaving this yak all the way so we can push
> > this fix upstream?
>
> I'll have a look. Shouldn't be too much work, since there are only
> those four function pointers and only for functions actually defined.
New diff, where I only changed the debug stuff (and introduced a
new typedef for it). The reason I didn't touch the other message
printing functions is that they call printf(3)-like functions several
times and don't do any error checking at all, and it's not clear
what to do with those functions.
Fortunately, changing vdebugBelch() / debugMsgFn, rtsDebugMsgFn()
are enough to kill the %n, and rtsDebugMsgFn() calls vfprintf(3) only
once, so it's easy to let rtsDebugMsgFn() return the result of
vfprintf(3).
If upstream is interested, the next thing would be to remove those
(unnecessary) indirections via function pointers.
Ciao,
Kili
Index: Makefile
===================================================================
RCS file: /cvs/ports/lang/ghc/Makefile,v
retrieving revision 1.188
diff -u -p -r1.188 Makefile
--- Makefile 16 Aug 2021 21:23:18 -0000 1.188
+++ Makefile 12 Sep 2021 19:40:01 -0000
@@ -19,6 +19,8 @@ DISTNAME = ghc-${GHC_VERSION}
CATEGORIES = lang devel
HOMEPAGE = https://www.haskell.org/ghc/
+REVISION = 0
+
# Version of the precompiled binaries
BIN_VER = 8.10.3.20210429
Index: patches/patch-includes_rts_Messages_h
===================================================================
RCS file: patches/patch-includes_rts_Messages_h
diff -N patches/patch-includes_rts_Messages_h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-includes_rts_Messages_h 12 Sep 2021 19:40:01 -0000
@@ -0,0 +1,34 @@
+$OpenBSD$
+
+The debug message function has to return the number of bytes written
+(like printf(3)), to allow killing a %n format specifier in one in
+one invocation of statsPrintf() in report_summary() (rts/Stats.c).
+
+Index: includes/rts/Messages.h
+--- includes/rts/Messages.h.orig
++++ includes/rts/Messages.h
+@@ -85,20 +85,21 @@ void vsysErrorBelch(const char *s, va_list ap);
+ void debugBelch(const char *s, ...)
+ GNUC3_ATTRIBUTE(format (PRINTF, 1, 2));
+
+-void vdebugBelch(const char *s, va_list ap);
++int vdebugBelch(const char *s, va_list ap);
+
+
+ /* Hooks for redirecting message generation: */
+
+ typedef void RtsMsgFunction(const char *, va_list);
++typedef int RtsMsgFunctionRetLen(const char *, va_list);
+
+ extern RtsMsgFunction *fatalInternalErrorFn;
+-extern RtsMsgFunction *debugMsgFn;
++extern RtsMsgFunctionRetLen *debugMsgFn;
+ extern RtsMsgFunction *errorMsgFn;
+
+ /* Default stdio implementation of the message hooks: */
+
+ extern RtsMsgFunction rtsFatalInternalErrorFn;
+-extern RtsMsgFunction rtsDebugMsgFn;
++extern RtsMsgFunctionRetLen rtsDebugMsgFn;
+ extern RtsMsgFunction rtsErrorMsgFn;
+ extern RtsMsgFunction rtsSysErrorMsgFn;
Index: patches/patch-rts_RtsMessages_c
===================================================================
RCS file: patches/patch-rts_RtsMessages_c
diff -N patches/patch-rts_RtsMessages_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-rts_RtsMessages_c 12 Sep 2021 19:40:01 -0000
@@ -0,0 +1,65 @@
+$OpenBSD$
+
+The debug message function has to return the number of bytes written
+(like printf(3)), to allow killing a %n format specifier in one in
+one invocation of statsPrintf() in report_summary() (rts/Stats.c).
+
+Index: rts/RtsMessages.c
+--- rts/RtsMessages.c.orig
++++ rts/RtsMessages.c
+@@ -36,7 +36,7 @@
+
+ // Default to the stdio implementation of these hooks.
+ RtsMsgFunction *fatalInternalErrorFn = rtsFatalInternalErrorFn;
+-RtsMsgFunction *debugMsgFn = rtsDebugMsgFn;
++RtsMsgFunctionRetLen *debugMsgFn = rtsDebugMsgFn;
+ RtsMsgFunction *errorMsgFn = rtsErrorMsgFn;
+ RtsMsgFunction *sysErrorMsgFn = rtsSysErrorMsgFn;
+
+@@ -102,10 +102,10 @@ debugBelch(const char*s, ...)
+ va_end(ap);
+ }
+
+-void
++int
+ vdebugBelch(const char*s, va_list ap)
+ {
+- (*debugMsgFn)(s,ap);
++ return (*debugMsgFn)(s,ap);
+ }
+
+ /*
-----------------------------------------------------------------------------
+@@ -285,16 +285,16 @@ rtsSysErrorMsgFn(const char *s, va_list ap)
+ #endif
+ }
+
+-void
++int
+ rtsDebugMsgFn(const char *s, va_list ap)
+ {
++ int r;
+ #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];
+- int r;
+
+ r = vsnprintf(buf, BUFSIZE, s, ap);
+ if (r > 0 && r < BUFSIZE) {
+@@ -305,12 +305,13 @@ rtsDebugMsgFn(const char *s, va_list ap)
+ #endif
+ {
+ /* don't fflush(stdout); WORKAROUND bug in Linux glibc */
+- vfprintf(stderr, s, ap);
++ r = vfprintf(stderr, s, ap);
+ fflush(stderr);
+ }
+ #if defined(mingw32_HOST_OS)
+ _setmode (_fileno(stderr), mode);
+ #endif
++ return r;
+ }
+
+
Index: patches/patch-rts_Stats_c
===================================================================
RCS file: patches/patch-rts_Stats_c
diff -N patches/patch-rts_Stats_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-rts_Stats_c 12 Sep 2021 19:40:01 -0000
@@ -0,0 +1,54 @@
+$OpenBSD$
+
+Kill a use of %n format specifier.
+
+Index: rts/Stats.c
+--- rts/Stats.c.orig
++++ rts/Stats.c
+@@ -69,7 +69,7 @@ static Time *GC_coll_cpu = NULL;
+ static Time *GC_coll_elapsed = NULL;
+ static Time *GC_coll_max_pause = NULL;
+
+-static void statsPrintf( char *s, ... ) GNUC3_ATTRIBUTE(format (PRINTF, 1,
2));
++static int statsPrintf( char *s, ... ) GNUC3_ATTRIBUTE(format (PRINTF, 1, 2));
+ static void statsFlush( void );
+ static void statsClose( void );
+
+@@ -1024,8 +1024,10 @@ static void report_summary(const RTSSummaryStats* sum)
+
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ int prefix_length = 0;
+- statsPrintf("%*s" "gen[%" FMT_Word32 "%n",
+- col_width[0], "", g, &prefix_length);
++ prefix_length = statsPrintf("%*s" "gen[%" FMT_Word32,
++ col_width[0], "", g);
++ if (prefix_length < 0)
++ prefix_length = 0;
+ prefix_length -= col_width[0];
+ int suffix_length = col_width[1] + prefix_length;
+ suffix_length =
+@@ -1735,19 +1737,21 @@ void getRTSStats( RTSStats *s )
+ Dumping stuff in the stats file, or via the debug message interface
+ --------------------------------------------------------------------------
*/
+
+-void
++int
+ statsPrintf( char *s, ... )
+ {
++ int ret = 0;
+ FILE *sf = RtsFlags.GcFlags.statsFile;
+ va_list ap;
+
+ va_start(ap,s);
+ if (sf == NULL) {
+- vdebugBelch(s,ap);
++ ret = vdebugBelch(s,ap);
+ } else {
+- vfprintf(sf, s, ap);
++ ret = vfprintf(sf, s, ap);
+ }
+ va_end(ap);
++ return ret;
+ }
+
+ static void
