On 9/4/12 1:49 PM, Reini Urban wrote:
On Tue, Sep 4, 2012 at 8:21 AM, Andy Dougherty<[email protected]> wrote:
On Tue, 4 Sep 2012, Nicholas Clark wrote:
On Mon, Sep 03, 2012 at 09:41:28PM -0400, James E Keenan wrote:
(These results were run at commit 5709835825; Sept 02 2012. But I've
submitted dozens of smolders with the same results in recent months.)
In my experience, it's really rare that we get consistently different
test results between all-gcc and all-g++ builds on our most heavily
tested platform.
Any thoughts as to the cause of this discrepancy?
Does this patch fix it? I haven't tested this it, but it's exactly the
sort of thing that would give rise to sign extension errors, and, if I
recall correctly, the precise rules for sign extension are slightly
different in c and c++, which would explain your discrepancy.
diff --git a/src/io/utilities.c b/src/io/utilities.c
index 08ed390..0acd4e9 100644
--- a/src/io/utilities.c
+++ b/src/io/utilities.c
@@ -551,7 +551,10 @@ io_sync_buffers_for_write(PARROT_INTERP, ARGMOD(PMC
*handle),
if (read_buffer&& !BUFFER_IS_EMPTY(read_buffer)) {
const size_t buffer_size = BUFFER_USED_SIZE(read_buffer);
Parrot_io_buffer_clear(interp, read_buffer);
- vtable->seek(interp, handle, -buffer_size, SEEK_CUR);
+ /* To avoid sign extension problems on 32-bit systems with 64-bit
+ file support, first cast the buffer_size to off_t, then change
+ the sign. */
+ vtable->seek(interp, handle, -((PIOOFF_T)buffer_size), SEEK_CUR);
}
}
Yes, I remember reading Nick's earlier analysis, but I was away for 3 weeks.
Thanks for the reminder, and Andy, yes, this was it. Confirmed and applied
as 0cc54e6972ae830e7943a15c8db1e14fc9c3cb90
The problem I reported was on the threads branch.
0cc54e6972ae830e7943a15c8db1e14fc9c3cb90 was applied to master. So the
gcc vs. g++ discrepancy persists on the threads branch (where HEAD is
5709835825a49733fd5180aaf35462e230d486ed).
All gcc: error still present
not ok 28 - write after buffered read # TODO GH #811 Write error: No
space left on device on swap fs
# Failed (TODO) test 'write after buffered read'
# at t/pmc/filehandle.t line 929.
# got: '10
# abcdefghij
# '
# expected: '10
# abcde#####klmno
# '
ok 29 - small reads and seeks
All g++:
ok 28 - write after buffered read # TODO GH #811 Write error: No space
left on device on swap fs
Thank you very much.
Jim Keenan
_______________________________________________
http://lists.parrot.org/mailman/listinfo/parrot-dev
