Gnu cmp doesn't work with Alpha object files

[Douglas Rupp]

This is the precompiled cmp 2.8.7a for Alpha/VMS. If I force the .objects to a fixed record format instead of variable length, it works. Please fix.

These two files are identical, I just copied one to the other for this test:

$ cmpnew sem_ch4.o sem_ch4.o1
$ cmpnew --ignore-initial=64 sem_ch4.o
$ cmpnew --ignore-initial=128 sem_ch4.o sem_ch4.o1
sem_ch4.o sem_ch4.o1 differ: char 39377, line 1

[John Gillings]

Douglas,

Perhaps you've misunderstood the nature of this forum. Most of the people who read and respond to questions are NOT HP engineers, so your request to "please fix" is most unlikely to get anywhere. You will need to log a support case with HP customer support to get any reasonable chance of something being fixed.

Is this an OpenVMS question/issue? What are the file characteristics of the input files? Have you tried dumping them at the point they're claimed to be different to see what's there?

Is Gnu cmp supposed to be able to compare binary files? If it's Gnu, doesn't that mean it's maintained by the open source community?

[Douglas Rupp]

I was advised by HP Engineering that the maintainer of the VMS version of this utility reads this forum, and to post the question here.

[Steven Schweda]

> Please fix.

Please send money.

> This is the precompiled cmp 2.8.7a for
> Alpha/VMS.

_the_ ???

Which you found where? I doubt that there's
only one "cmp" out there.

You might try adding some VMS-specific stuff
to the open() in [.src]cmp.c. For example:

ALP $ gdiff -u src/cmp.c_orig src/cmp.c
--- src/cmp.c_orig 2004-04-12 02:44:35 -0500
+++ src/cmp.c 2009-12-02 00:19:39 -0600
@@ -38,6 +38,12 @@
#include
#include

+#ifdef __VMS
+# define OPEN_ARG , "ctx = stm"
+#else /* def __VMS */
+# define OPEN_ARG
+#endif /* def __VMS [else] */
+
#if defined LC_MESSAGES && ENABLE_NLS
# define hard_locale_LC_MESSAGES hard_locale (LC_MESSAGES)
#else
@@ -286,7 +292,7 @@

file_desc[f1] = (strcmp (file[f1], "-") == 0
? STDIN_FILENO
- : open (file[f1], O_RDONLY, 0));
+ : open (file[f1], O_RDONLY, 0 OPEN_ARG));
if (file_desc[f1] < 0 || fstat (file_desc[f1], stat_buf + f1) != 0)
{
if (file_desc[f1] < 0 && comparison_type == type_status)


I don't know how much trouble this would
cause in other situations, but it may help
in this one.

alp $ copy modpro.OBJ x1.obj
alp $ copy modpro.OBJ x2.obj
alp $ gcmp --ignore-initial=128 x1.obj x2.obj
x1.obj x2.obj differ: char 39409, line 1
alp $ gcmpX --ignore-initial=128 x1.obj x2.obj
alp $

[Hoff]

>I was advised by HP Engineering that the maintainer of the VMS version of this utility reads this forum, and to post the question here.

Interesting. That would appear to be be a change from longstanding past practice around the forums and around bug-reporting, if that's the case.

I'd suggest duplicating this report into the porting conference over on DECUServe; that's where the majority of the GNV discussions currently reside, and where the GNV updates and workarounds tend to get created.

If the HP maintainer(s) of this stuff _is_ monitoring this stuff? Welcome! Post up a reply or two. And please get a distributed version control system up and running, or please get the current bits moved out to SourceForge rather than the internal storage apparently in use. And with that access, we can help you with these issues.

[Steven Schweda]

> [...] GNV [...]

From the "a" (and the "7") in "2.8.7a", I
suspect that he's using my stuff rather than
the GNV stuff, but my psychic powers are too
weak to give me much confidence in that
suspicion.

[Douglas Rupp]

All respects to GNV, but I have my own ports of all Gnu utilities, except diffutils, for which I'm using Steven Schweda's port.

[Hoff]

What is your goal?

It's clear that you know how to submit patches into the GNU codebase.

And certainly many of us are frustrated around the lack of access into the GNV stuff, and the way that the GNV code has been fork-ported from the GNU codebase. Providing a DVCS or SourceForge home for the code might not work, but what we have definitely doesn't work. (The cmp tool provided within GNV V2.1-2 reports itself as 2.7 Rev 1.5; nearly eight years back.)

(That your organization doesn't have a more direct path into HP is interesting in its own regard. But I digress.)

And FWIW, the usual approach on OpenVMS involves the ANALYZE /OBJECT mechanisms; I've not seen much use of cmp or DIFFERENCE against object files on OpenVMS. It's very likely that there's an object module dump tool around, too. (There are ports of xxd around, too.) But I'd guess you're aware of this.

And possibly related to this? The C RTL handling of binary data has been brought up before, and recently too:

http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1385811

[Craig A Berry]

If the goal is just to find out whether the files are identical, wouldn't checksum do the trick?

[Douglas Rupp]

Checksum might work, but I'm constrained by the Makefile.