Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
This looks like a classic optimizer bug to me. For some reason, the
code generator has obviously decided it can used a cached version of
the data pointer for the if test rather than reloadingbut it
appears to make that decision only for the if test. It might be
interesting to try declaring that value as volatile and see if things
change.
Rick
On Sat, Apr 25, 2009 at 11:23 PM, Mark Miesfeld miesf...@gmail.com wrote:
Rick,
In working on the SysFileSearch bug, I tracked down what seems to be a
case where the VS 2005 compiler produces wrong code and the VS 2008
produces code that works.
It's bizarre, so it takes a bit to explain it. On Vista 64-bit, the
GetLine() function causes a memory exception here:
scan = (char *)memchr(filedata-scan, CH_NL, filedata-data);
The exception comes because it has gone past the end of the file
buffer. The check for the end of the buffer is right before, and the
whole thing looks like:
if (!(filedata-data)) { /* if out of current buffer */
if (filedata-residual) { /* may be another buffer */
ReadNextBuffer(filedata); /* try to read one */
if (!filedata-data) /* nothing more? */
return true; /* all done */
}
else
return true; /* return EOF condition */
}
/* look for a carriage return */
scan = (char *)memchr(filedata-scan, CH_NL, filedata-data);
filedata-data keeps track of where in the buffer we are and when it
is 0, we've used up the buffer.
The bizarre thing is, when I compile with Visual Studio 2005, when
filedata-data == 0, the if !(filedata-data) test passes and the
function keeps going on past the end of the buffer. Eventually,
memchr goes to compare memory it can't access.
If I compile with Visual Studio 2008, then things work as they should.
This is with the no debug build only. The debug build works fine
when compiled with either VS 2005 or VS 2008.
I sent you a text file with a lot output. It is easier to read when
the lines don't wrap.
I used this printf to show this behaviour:
printf(GetLine: size=%u scan=%p filedata-data=%u residual=%u
filedata-data == 0 ? %d\n,
filedata-size, filedata-scan, filedata-data,
filedata-residual, (filedata-data == 0));
For the build that crashes you see this:
GetLine: size=31452 scan=001E9FDC filedata-data=0 residual=0
filedata-data == 0 ? 0
GetLine: size=31452 scan=001EE48D filedata-data=4294949711
residual=0 filedata-data == 0 ? 0
You see that even though filedata-data does equal 0, (filedata-data
== 0) returns 0.
So, SysFileSearch keeps calling GetLine() until you finally reach
memory that is not accessible.
This only happens on Vista 64-bit, only on a no debug build, and only
when the compiler is VS 2005. On XP 64-bit it works fine with either
compiler. Also on 32-bit Vista it works fine with either compiler.
If there was the same problem on Vista 32 bit, i.e. it crashed with
the VS 2005 compiled version but worked with the VS 2008, then I was
thinking maybe a similar thing is happening with Mike's problem.
Still, if Mike can not reproduce his problem using the VS 2008
compiled version, then maybe it is a similar thing.
--
Mark Miesfeld
--
Crystal Reports #45; New Free Runtime and 30 Day Trial
Check out the new simplified licensign option that enables unlimited
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--
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Check out the new simplified licensign option that enables unlimited
royalty#45;free distribution of the report engine for externally facing
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Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
It's starting to look like upgrading to VS 2008 might be a winner for
this. I'm more willing to make this change than switch to the new
version of SysFile. Can the two version coexist on the same machine,
or do I need to uninstall 2005 first?
Rick
On Sat, Apr 25, 2009 at 11:23 PM, Mark Miesfeld miesf...@gmail.com wrote:
Rick,
In working on the SysFileSearch bug, I tracked down what seems to be a
case where the VS 2005 compiler produces wrong code and the VS 2008
produces code that works.
It's bizarre, so it takes a bit to explain it. On Vista 64-bit, the
GetLine() function causes a memory exception here:
scan = (char *)memchr(filedata-scan, CH_NL, filedata-data);
The exception comes because it has gone past the end of the file
buffer. The check for the end of the buffer is right before, and the
whole thing looks like:
if (!(filedata-data)) { /* if out of current buffer */
if (filedata-residual) { /* may be another buffer */
ReadNextBuffer(filedata); /* try to read one */
if (!filedata-data) /* nothing more? */
return true; /* all done */
}
else
return true; /* return EOF condition */
}
/* look for a carriage return */
scan = (char *)memchr(filedata-scan, CH_NL, filedata-data);
filedata-data keeps track of where in the buffer we are and when it
is 0, we've used up the buffer.
The bizarre thing is, when I compile with Visual Studio 2005, when
filedata-data == 0, the if !(filedata-data) test passes and the
function keeps going on past the end of the buffer. Eventually,
memchr goes to compare memory it can't access.
If I compile with Visual Studio 2008, then things work as they should.
This is with the no debug build only. The debug build works fine
when compiled with either VS 2005 or VS 2008.
I sent you a text file with a lot output. It is easier to read when
the lines don't wrap.
I used this printf to show this behaviour:
printf(GetLine: size=%u scan=%p filedata-data=%u residual=%u
filedata-data == 0 ? %d\n,
filedata-size, filedata-scan, filedata-data,
filedata-residual, (filedata-data == 0));
For the build that crashes you see this:
GetLine: size=31452 scan=001E9FDC filedata-data=0 residual=0
filedata-data == 0 ? 0
GetLine: size=31452 scan=001EE48D filedata-data=4294949711
residual=0 filedata-data == 0 ? 0
You see that even though filedata-data does equal 0, (filedata-data
== 0) returns 0.
So, SysFileSearch keeps calling GetLine() until you finally reach
memory that is not accessible.
This only happens on Vista 64-bit, only on a no debug build, and only
when the compiler is VS 2005. On XP 64-bit it works fine with either
compiler. Also on 32-bit Vista it works fine with either compiler.
If there was the same problem on Vista 32 bit, i.e. it crashed with
the VS 2005 compiled version but worked with the VS 2008, then I was
thinking maybe a similar thing is happening with Mike's problem.
Still, if Mike can not reproduce his problem using the VS 2008
compiled version, then maybe it is a similar thing.
--
Mark Miesfeld
--
Crystal Reports #45; New Free Runtime and 30 Day Trial
Check out the new simplified licensign option that enables unlimited
royalty#45;free distribution of the report engine for externally facing
server and web deployment.
http://p.sf.net/sfu/businessobjects
___
Oorexx-devel mailing list
Oorexx-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/oorexx-devel
--
Crystal Reports #45; New Free Runtime and 30 Day Trial
Check out the new simplified licensign option that enables unlimited
royalty#45;free distribution of the report engine for externally facing
server and web deployment.
http://p.sf.net/sfu/businessobjects
___
Oorexx-devel mailing list
Oorexx-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/oorexx-devel
Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
On Sun, Apr 26, 2009 at 4:49 AM, Rick McGuire object.r...@gmail.com wrote: It's starting to look like upgrading to VS 2008 might be a winner for this. I'm more willing to make this change than switch to the new version of SysFile. I think upgrading to VS 2008 has less potential for letting a bug slip through to the release than switching to SysFile. I've been working with builds from both VS 2008 and VS 2005, it would just depend on which system I was on at the time -- Mark Miesfeld -- Crystal Reports #45; New Free Runtime and 30 Day Trial Check out the new simplified licensign option that enables unlimited royalty#45;free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects ___ Oorexx-devel mailing list Oorexx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/oorexx-devel
Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
On Sun, Apr 26, 2009 at 4:49 AM, Rick McGuire object.r...@gmail.com wrote: It's starting to look like upgrading to VS 2008 might be a winner for this. I'm more willing to make this change than switch to the new version of SysFile. Can the two version coexist on the same machine, or do I need to uninstall 2005 first? Here's a link that says you can and has some info on things to do / watch out for. I did'nt think you could, but I guess you can since the source is Microsoft. -- Mark Miesfeld -- Crystal Reports #45; New Free Runtime and 30 Day Trial Check out the new simplified licensign option that enables unlimited royalty#45;free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects ___ Oorexx-devel mailing list Oorexx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/oorexx-devel
Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
Did you forget to paste the link? On Sun, Apr 26, 2009 at 9:45 AM, Mark Miesfeld miesf...@gmail.com wrote: On Sun, Apr 26, 2009 at 4:49 AM, Rick McGuire object.r...@gmail.com wrote: It's starting to look like upgrading to VS 2008 might be a winner for this. I'm more willing to make this change than switch to the new version of SysFile. Can the two version coexist on the same machine, or do I need to uninstall 2005 first? Here's a link that says you can and has some info on things to do / watch out for. I did'nt think you could, but I guess you can since the source is Microsoft. -- Mark Miesfeld -- Crystal Reports #45; New Free Runtime and 30 Day Trial Check out the new simplified licensign option that enables unlimited royalty#45;free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects ___ Oorexx-devel mailing list Oorexx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/oorexx-devel -- Crystal Reports #45; New Free Runtime and 30 Day Trial Check out the new simplified licensign option that enables unlimited royalty#45;free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects ___ Oorexx-devel mailing list Oorexx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/oorexx-devel
Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
On Sun, Apr 26, 2009 at 6:58 AM, Rick McGuire object.r...@gmail.com wrote: Did you forget to paste the link? http://msdn.microsoft.com/en-us/library/ms246609.aspx Didn't have my coffee yet. grin -- Mark Miesfeld -- Crystal Reports #45; New Free Runtime and 30 Day Trial Check out the new simplified licensign option that enables unlimited royalty#45;free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects ___ Oorexx-devel mailing list Oorexx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/oorexx-devel
Re: [Oorexx-devel] Tracked down problem with: compiler, Vista, ?
On Sat, Apr 25, 2009 at 8:23 PM, Mark Miesfeld miesf...@gmail.com wrote: In working on the SysFileSearch bug, I tracked down what seems to be a case where the VS 2005 compiler produces wrong code and the VS 2008 produces code that works. Good thing I said seems to be. I was 100% wrong on this, it was not the compiler at all but the programmers. ReadFile() takes a pointer to a 32-bit value to return actual count of bytes read. In the code clean up / move to 64-bit / conversion to the new API, the variable was changed to a size_t. In ReadFile() the variable was cast as a pointer to a 32-bit variable. Well, that's no good on 64-bit Windows. grin Anyhow, sorry I blamed the compiler, it wasn't a compiler bug at all. -- Mark Miesfeld -- Crystal Reports #45; New Free Runtime and 30 Day Trial Check out the new simplified licensign option that enables unlimited royalty#45;free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects ___ Oorexx-devel mailing list Oorexx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/oorexx-devel
