Hi Cliff,
FYI I've just this minute merged all the latest updates to proton-c onto the branch I'm using for the JavaScript bindings and have rebuilt everything, the changes that you've done for this Jira work beautifully for me too!!! Many thanks, you're a star.

Cheers,
Frase

On 28/02/14 08:48, Cliff Jansen wrote:
Sorry for the delay.

I played a bit with emcripten  to see if there was some
misunderstanding going on, but it seems pretty clear that clang knows
exactly what is being passed in via the va_arg call and just plain
refuses to deal with a struct (at least for some architectures).

Consequently the original patch which restricts va_arg processing to
simple types seems to me the most robust and portable solution.  I
will proceed with that for 0.7.

Cliff



a bit indicates to me that clang is not somehow confused about

On Thu, Feb 27, 2014 at 9:01 AM, Fraser Adams
<fraser.ad...@blueyonder.co.uk> wrote:
Hi again Cliff,
Have you made any progress on this?
Cheers,
Frase


On 30/01/14 02:31, Cliff Jansen wrote:
Well thanks for all that.  I'll certainly take another look and report
back before committing anything.  Giving a compiler family indigestion
is certainly to be avoided.

Cliff

On Tue, Jan 28, 2014 at 11:29 AM, Fraser Adams
<fraser.ad...@blueyonder.co.uk> wrote:
Hi, me again Cliff.
I've only had time to recheck this against my test case, which is
representative of what I see for real.

Doing:

int pn_data_vfill2(const char *fmt, va_list ap)
{
      // Process the PROPERTIES constant - this seems OK
      uint64_t prop = va_arg(ap, uint64_t);
printf("prop = %llu\n", prop);

      {
          pn_bytes_t bytes = va_arg(ap, pn_bytes_t);
printf("pn_data_vfill z, bytes.size = %zu, bytes.start = %s\n",
bytes.size,
bytes.start);
      }

      // Process the char* returned by pn_string_get()
      {
          char *start = va_arg(ap, char *);
          size_t size = strlen(start);
printf("pn_data_vfill size = %zu\n", size);
printf("pn_data_vfill string = %s\n", start);
      }

      return 0;
}

E.g. the both passing and retrieving structs approach of your second
approach actually doesn't even compile for me with LLVM le32,  I get

error:
        cannot compile this aggregate va_arg expression yet
          pn_bytes_t bytes = va_arg(ap, pn_bytes_t);
                             ^~~~~~~~~~~~~~~~~~~~~~
/home/fadams/emscripten/system/include/libc/stdarg.h:15:25: note:
expanded
from
        macro 'va_arg'
#define va_arg(v,l)     __builtin_va_arg(v,l)
                          ^~~~~~~~~~~~~~~~~~~~~
1 error generated.
ERROR    root: compiler frontend failed to generate LLVM bitcode, halting
make[2]: *** [CMakeFiles/test_varargs.dir/test_varargs.o] Error 1
make[1]: *** [CMakeFiles/test_varargs.dir/all] Error 2
make: *** [all] Error 2

Though it *does* work if I do "EMCC_LLVM_TARGET=i386-pc-linux-gnu make"


So in a nutshell:
1) if I fudge the LLVM front end pure struct, put  struct retrieve
discrete
and pure discrete values all work correctly.

2) with the standard emscripten le32 LLVM front end (which is what is
recommended)
* pure struct (as above) fails to compile
* put  struct, retrieve discrete (as with the original Proton code) gives
the wrong results - that messed with my head :-)
* pure discrete values (as with your pn_string_size(msg->user_id),
pn_string_get(msg->user_id),) patch works correctly.


So I'd *really* like it if you could go down the path of your original
patch
'cause that would fix what you've been seeing and let me compile the
JavaScript stuff without needing the environment tweaked (which is an
accident waiting to happen). I hope that you are agreeable to that?

I think that it would probably be worth putting a comment in the call to
pn_data_fill and within the pn_data_vfill() 'z' case body to document
that
it's safer to pass individual entries to va_arg to avoid upsetting some
compilers - it's not entirely an *obvious* thing really :-D

Cheers,
Frase




On 27/01/14 21:21, Cliff Jansen wrote:
Thanks for the Javascript related info.

Fraser: can you test if the review board patch (with the struct "in
and out" strategy) works in your case with the unhacked llvm setup?
If that works then I'll go ahead and check it in.

If it fails, please try the first patch.  If that works, we will just
have to conclude that compilers have trouble with stucts in this case
and fall back to passing the two basic types.  That should be safe to
work in the greatest number of cases.

Many thanks.

On Mon, Jan 27, 2014 at 1:13 PM, Fraser Adams (JIRA) <j...@apache.org>
wrote:
       [

https://issues.apache.org/jira/browse/PROTON-488?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13883314#comment-13883314
]

Fraser Adams commented on PROTON-488:
-------------------------------------

Oh to be clear
either "struct in and out", or "separate size_t and char* in and out"

what I meant in my previous comment was that the separate size_t and
char* in and out is what LLVM le32 is happiest with, the structs seem
to
confuse it, I hadn't realised that you'd changed your original patch to
now
do "all 'z' encodings to be passed as a single pn_bytes_t struct and
"retrieved" as a single pn_bytes_t struct" - although this arguably
looks
neater I'd definitely prefer your first approach.

Windows 7 64-bit VS2010 qpid-proton Crash on Startup with Send / Recv
Application


---------------------------------------------------------------------------------

                   Key: PROTON-488
                   URL:
https://issues.apache.org/jira/browse/PROTON-488
               Project: Qpid Proton
            Issue Type: Bug
            Components: proton-c
      Affects Versions: 0.6
           Environment: Windows 7 64-bit VS 2010
              Reporter: Frank Quinn
              Assignee: Cliff Jansen
              Priority: Critical
           Attachments: PROTON-488-0.patch,
qpid-proton-win64-send-crash.png


Steps to recreate:
1. Grab latest 0.6 tarball
2. Start up Visual Studio x64 Win64 Command Prompt (2010) and run
"cmake
." to generate the visual studio files
3. Open Up the newly created Proton.sln in VS2010, right click on
qpid-proton and add the path to python to executable directories
4. In the configuration manager, select qpid-proton and select active
configuration to be Debug, then select "Add" to add x64 support,
copying
win32 configuration in the process.
5. Select qpid-proton properties and remove the hard coded
/machine:X86
extra command lines in Linker -> Command Line (MACHINE:X64 should
already be
in the command line above so no need to add here)
6. Right click on qpid-proton and select build
Repeat steps 3-6 for send / recv applications. When you run recv, then
run send, you'll get a crash with the (soon to be attached) trace.
Cheers,
Frank


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