Re: [open-cobol-list] cobc linkage bug on Mint Linux ?

[Brian Tiffin]

I've got a chance to play with some various virtual GNU/Linux image
builds.  I'll try and put Mint on the list, and see if that can't help
find out what is going on.

More soon(ish).

Cheers,
Brian

On 7/18/13, Patrick <address@hidden> wrote:
> Thanks Michael
>
> I should have mentioned that I used -lpython2.7 on both Mint and Debian.
>
> Hopefully this is just a Mint problem or my mistake now.
>
>
> On 7/18/2013 5:06 AM, Michael Anderson wrote:
>> On 07/17/2013 09:28 PM, Patrick wrote:
>>> Does anyone have a fairly new install of Mint 15 to double check my
>>> findings? Can anyone run this on Ubuntu to see if it's introduced
>>> upstream?
>> On Ubuntu 12.04, it compiled fine, but I'm running Python 2.7
>>
>> $ cobc -x cobpy.cob -lpython2.7
>> $ ./cobpy
>> link cobpy with -lpython2.6
>> libcob: Cannot find module 'Py_Finalize'
>>
>> So I commented-out the call to Py_Finalize...
>>
>> $ cobc -x cobpy.cob -lpython2.7
>> $ ./cobpy
>> link cobpy with -lpython2.6
>> $
>>
>> So, it seems like 'Py_Initialize' was found by the coblib runtime?,
>> but a Call exception occurred and then Py_Finalize is not found.
>> $ ldd cobpy
>>     linux-gate.so.1 =>  (0xb7773000)
>>     libcob.so.1 => /usr/local/lib/libcob.so.1 (0xb7721000)
>>     libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb7578000)
>>     libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xb754b000)
>>     libgmp.so.10 => /usr/lib/i386-linux-gnu/libgmp.so.10 (0xb74cc000)
>>     libncurses.so.5 => /lib/i386-linux-gnu/libncurses.so.5 (0xb74aa000)
>>     libtinfo.so.5 => /lib/i386-linux-gnu/libtinfo.so.5 (0xb748b000)
>>     libdb-5.1.so => /usr/lib/i386-linux-gnu/libdb-5.1.so (0xb7303000)
>>     libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xb72fd000)
>>     /lib/ld-linux.so.2 (0xb7774000)
>>     libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb72e2000)
>>
>>
>> Maybe I'm doing something wrong. I've only been developing software in
>> the Unix env since 2008.
>> Prior to 2008, MPE/iX was my OS of choice.
>>
>> So whats going on, look at readelf.......
>> $ readelf -a /usr/lib/libpython2.7.so|grep Py_Initialize
>>
>>    941: 000a4cc0  2615 FUNC    GLOBAL DEFAULT   11 Py_InitializeEx
>>   1517: 000a5700    32 FUNC    GLOBAL DEFAULT   11 Py_Initialize
>>
>> $ readelf -a /usr/lib/libpython2.7.so|grep Py_Finalize
>>
>>   1267: 00069750   600 FUNC    GLOBAL DEFAULT   11 Py_Finalize
>>
>> So Py_Finalize is in their, what the heck? I don't know, there maybe a
>> bug in the OC "CALL" statement, but for me, there is always a work
>> around.
>>
>> Lets try it in C.
>>
>> $ more gccpy.c
>> #include <Python.h>
>>
>> int
>> main(int argc, char *argv[])
>> {
>>   Py_Initialize();
>>   PyRun_SimpleString("from time import time,ctime\n"
>>                      "print 'Today is',ctime(time())\n");
>>   Py_Finalize();
>>   return 0;
>> }
>>
>> $ cobc -x -I/usr/include/python2.7 gccpy.c -lpython2.7
>> $ ./gccpy
>> Today is Wed Jul 18 02:40:35 2013
>> $
>>
>> It works! and notice I used cobc to compile it!
>> I've had similar issues with Tcl... and I've done lots of Cobol/Tcl
>> running in production environments since 2008.
>>
>> The purpose behind embedded scripts, Python, Tcl, Guile, or similar,
>> is for me, portability, not being tied to specific compiler features.
>> Or to modify key features of your software without recompiling....
>> just change your scripts. there are pros an cons.
>>
>> Maybe a work-around, but I get better (more reliable) results using my
>> own (Cobol Friendly) C wrapper library to call the C functions that
>> were not originally designed to be called from Cobol, not calling
>> these directly from Cobol, but instead called from a library that was
>> designed to be called by Cobol.
>> That said, dynamic linking should work correctly.
>>
>> Maybe a bug in coblib, and if so, even if it gets fixed I'll still
>> prefer using a dynamic wrapper library to do these types of things.
>>
>> Example:
>> This may help with embedded Python also.
>>
>> in C:
>>
>> extern void TCLEVAL (Tcl_Interp **tclhandle, char *script, int *result)
>> {
>>     *result = Tcl_Eval(*tclhandle, script);
>> }
>>
>> Then in Cobol:
>>      Move low-values To TCL-BUFFER.
>>      String "some Tcl statement" delimited by sizeinto TCL-BUFFER.
>>      CALL "TCLEVAL" USING TCL-INTR TCL-BUFFER TCL-RESULT.
>>
>>
>> BTW: jim looks like a nice minimal Tcl library, which is a good thing
>> for packaging your software.
>> However, in development mode on Ubuntu, I just use the standard Tcllib
>> that comes with Ubuntu.
>> "sudo apt-get install tcl8.5-dev",
>>  then add any non-standard packages like pdf4tcl.
>>
>> In my C library "cobtcl" I have (Cobol Friendly) STARTTCL, STOPTCL,
>> TCLEVAL, TCLSETVAR, TCLGETVAR, and TCLEVALFILE.
>> EXAMPLE of the problem, first without cobtcl library, calling the Tcl*
>> functions directly from OpenCobol:
>>
>> $ cobc -x -free -ffunctions-all -I/usr/include/tcl8.5 -ltcl8.5
>> getlotto.cob
>> $ ./getlotto
>> libcob: Cannot find module 'Tcl_FindExecutable'
>> $
>>
>> I have successfully compiled and linked same as above, and it ran fine
>> on other Linux machines.
>> But on some machines it does not work, "can't find module" and I have
>> no idea why!
>>
>> $ ldd getlotto
>>     linux-gate.so.1 =>  (0xb77e0000)
>>     libcob.so.1 => /usr/local/lib/libcob.so.1 (0xb778e000)
>>     libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb75e5000)
>>     libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xb75b8000)
>>     libgmp.so.10 => /usr/lib/i386-linux-gnu/libgmp.so.10 (0xb7539000)
>>     libncurses.so.5 => /lib/i386-linux-gnu/libncurses.so.5 (0xb7517000)
>>     libtinfo.so.5 => /lib/i386-linux-gnu/libtinfo.so.5 (0xb74f8000)
>>     libdb-5.1.so => /usr/lib/i386-linux-gnu/libdb-5.1.so (0xb7370000)
>>     libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xb736a000)
>>     /lib/ld-linux.so.2 (0xb77e1000)
>>     libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb734f000)
>>
>> I know that Tcl_FindExecutable is in libtcl8.5.so, and -ltcl8.5 is
>> correct, but 'ldd' says that getlotto is not even looking for
>> libtcl8.5.so ..
>> and therefore coblib does not find it, can't find it.
>>
>> However, if statically linked, then it does find it.
>> Not wanting to compile the entire libtcl into my cobol program,
>> I instead write a small C wrapper, cobtcl.c, statically linking
>> cobtcl.o seems to make it work.
>> This makes sense too me, because coblib is not calling the dynamically
>> linked functions, clib is calling those.
>> coblib is only calling the statically liked functions in cobtcl.o
>>
>> So I modified getlotto.cob to call my cobtcl C functions, STARTTCL,
>> and so on... saved it as newgetlotto.cob
>>
>> $ cobc -c  -I/usr/include/tcl8.5 cobtcl.c
>> $ cobc -x -ffunctions-all -free -ltcl8.5 newgetlotto.cob cobtcl.o
>> $ ./newgetlotto
>> Most recent drawing: Lotto Texas,7,17,2013,40,8,3,12,15,25
>> $
>> $ ldd newgetlotto
>>     linux-gate.so.1 =>  (0xb7749000)
>>     libcob.so.1 => /usr/local/lib/libcob.so.1 (0xb76f7000)
>> libtcl8.5.so.0 => /usr/lib/libtcl8.5.so.0 (0xb75dd000)
>>     libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb7433000)
>>     libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0xb7407000)
>>     libgmp.so.10 => /usr/lib/i386-linux-gnu/libgmp.so.10 (0xb7388000)
>>     libncurses.so.5 => /lib/i386-linux-gnu/libncurses.so.5 (0xb7366000)
>>     libtinfo.so.5 => /lib/i386-linux-gnu/libtinfo.so.5 (0xb7347000)
>>     libdb-5.1.so => /usr/lib/i386-linux-gnu/libdb-5.1.so (0xb71be000)
>>     libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xb71b9000)
>>     libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb719e000)
>>     /lib/ld-linux.so.2 (0xb774a000)
>>
>> Now it works!
>>
>> more rambling's..............
>>
>> BTW: Patrick, if you want a complete copy these examples cobtcl.c,
>> just email me.. that goes for anyone.
>> The lotto program is just a dumb example that anyone can follow,
>> I use Tcl for all kinds misc functions, like access to sql data,
>> getting resources from web servers, status of files, creating PDF's,
>> and much more.
>>
>> Another example encrypt/decrypt a password.
>> These examples are AcuCobol, but the same exact source works with
>> OpenCOBOL.
>> In OpenCobol I would have used the trim function instead of "delimited
>> by size" and "delimited by space"
>> Here we Execute two pre-written Tcl functions known as 'procs',
>> EncryptData, and DecryptData.
>> So yes, you can develop all your Tcl procs, store them in one file,
>> ea. myprocs.tcl.
>> Then load all these procs into the interpreter using TCLEVALFILE after
>> calling STARTTCL.
>> Then anytime within your cobol app, you can execute a specific proc,
>> and pass parms using TCLEVAL.
>>
>> *>---------------------------------------------------------
>>  Encrypt-string.
>>      Move Spaces To Encrypted-string.
>>      Perform Set-Encryption-Key.
>>      Move LOW-VALUES TO TCL-BUFFER.
>>      Move 0 To TCL-RESULT.
>> *> =========
>> *> EncryptData takes two parms, a string, and a length.
>> *> if you were in the tclsh shell, the command would look like so:
>> *> set cipher [EncryptData mypasswd 8]
>> *> now the var 'cipher' contains the encrypted value of mypasswd
>> *> =========
>>      String "set cipher [EncryptData " Delimited By Size
>>              Cleartext-String          Delimited By " "
>>              " 8]"                     delimited by size
>>               into TCL-BUFFER.
>>
>>      CALL "TCLEVAL" USING TCL-INTR TCL-BUFFER TCL-RESULT.
>>
>>      MOVE LOW-VALUES TO TCL-VARNAME
>>      STRING "cipher" DELIMITED BY SIZE INTO TCL-VARNAME.
>>      MOVE SPACES TO TCL-BUFFER.
>>      CALL "TCLGETVAR" USING TCL-INTR TCL-VARNAME TCL-BUFFER.
>>
>>      Move Spaces To Encrypted-string.
>>      String TCL-BUFFER delimited by x"00" into Encrypted-string.
>>
>> *>---------------------------------------------------------
>>  Decrypt-String.
>>      Perform Set-Encryption-Key.
>>      Move LOW-VALUES TO TCL-BUFFER.
>>      MOVE LOW-VALUES TO TCL-VARNAME
>>      Move 0 To TCL-RESULT.
>>      Move Spaces To ClearText-String.
>>
>>      String "set CLEARTEXT [DecryptData " delimited by size
>>             Encrypted-string      delimited by " "
>>             " 8]"                 delimited by size
>>         into TCL-BUFFER.
>>
>>      CALL "TCLEVAL" USING TCL-INTR TCL-BUFFER TCL-RESULT.
>>
>>      STRING "CLEARTEXT" DELIMITED BY SIZE INTO TCL-VARNAME
>>      MOVE SPACES TO TCL-BUFFER.
>>      CALL "TCLGETVAR" USING TCL-INTR TCL-VARNAME TCL-BUFFER.
>>
>>      String TCL-BUFFER delimited by x"00" into ClearText-String.
>>
>> *>---------------------------------------------------------
>>  Set-Encryption-Key.
>>      Move LOW-VALUES TO TCL-BUFFER.
>>      MOVE LOW-VALUES TO TCL-VARNAME.
>>      Move Spaces To MY-KEY.
>>      String AUTHSESS-USER Delimited By Space
>>             AUTHSESS-FWTYPE AUTHSESS-LOG-ON-LOC AUTHSESS-HOME-LOC
>> Delimited By Size
>>             AUTHSESS-FWIP Delimited By "."
>>       Into MY-KEY.
>>      Inspect MY-KEY replacing all " " by "0".
>>
>>      String MY-KEY
>>         Delimited By Size InTo TCL-BUFFER.
>>
>>      STRING "TIWAPPKEY"
>>         Delimited By Size InTo TCL-VARNAME.
>>
>>      CALL "TCLSETVAR" USING TCL-INTR TCL-VARNAME TCL-BUFFER.
>>
>>
>>
>>
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