compatibility with cplex 12.9

[dcoudert]

Method CPXsetlogfile has been deprecated in cplex 12.8 and removed from cplex 12.9. We must instead use CPXsetlogfilename, introduced in 12.8.

[dcoudert]

This patch works with versions >= 12.8. However, we loose compatibility with versions < 12.8.

To maintain compatibility, we must be able to import CPXsetlogfile only if version < 12.8 and CPXsetlogfilename if version >= 12.8. Then, we can use CPXversionnumber to adjust usage.

I don't know how to do that.

---

New commits:

​62a1899

trac #27790: use CPXsetlogfilename

[vdelecroix]

1. merge failure

2. A possibility to make it work for both CPLEX versions, you can find out the CPLEX version from the Sage setup.py script and set a Cython constant so that you can use ​Cython conditional statements.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​61e5187

trac #27790: fix merge conflict with 8.8.beta6

[dcoudert]

Replying to vdelecroix:

1. merge failure

fixed

2. A possibility to make it work for both CPLEX versions, you can find out the CPLEX version from the Sage setup.py script and set a Cython constant so that you can use ​Cython conditional statements.

Not sure how to do that and where to put the code (setup.py, module_list.py ?).

Somehow, we want to extract line #define CPX_VERSION 12080000 from cpxconst.h, extract the number and use it for conditional compilation.

[vdelecroix]

Replying to dcoudert:

Replying to vdelecroix:

2. A possibility to make it work for both CPLEX versions, you can find out the CPLEX version from the Sage setup.py script and set a Cython constant so that you can use ​Cython conditional statements.

Not sure how to do that and where to put the code (setup.py, module_list.py ?).

It would have been easier with an optional package and a proper spkg-install... I don't know where to put it. These optional Cython modules are not very handy.

Somehow, we want to extract line #define CPX_VERSION 12080000 from cpxconst.h, extract the number and use it for conditional compilation.

I don't think that can be done directly from Cython. Here is a suggestion (similar to what is done in ​PyNormaliz)

• run a configure script (or whatever) to obtain the value of CPX_VERSION and write a line "CPX_VERSION=12080000" in a file cplex_config.py
• in the setup.py script, use the clpex_config.py to define a compile time constant and branch appropriately in the Cython code

If you find an easier way to access the CPX_VERSION macro directly from a .pyx file that would be great!

[dcoudert]

An idea to make the process transparent to users is to set the version number in module_list.py. I can get the version number like that, but I don't know how to use it with OptionalExtension.

sage: if os.path.exists(SAGE_LOCAL + '/include/cpxconst.h'):
....:     CPX_VERSION = subprocess.check_output(" grep '#define CPX_VERSION ' $SAGE_LOCAL/include/cpxconst.h | grep -o -E '[0-9]+' ", shell=True).strip()
....:     
sage: CPX_VERSION
'12080000'

[vdelecroix]

You can try the following (that works for normal extensions)

OptionalExtension(...,
   define_macros= [('CPX_VERSION', 12080000)]   # computed value
)

and the in the Cython code (with upper case)

IF CPX_VERSION >= 12080000:
    check( CPXsetlogfilename(self.env, NULL, NULL) )
ELSE:
    check( CPXsetlogfile(self.env, NULL) )

Since both versions of the code only use the self.env parameter you might want to isolate the IF/ELSE statement in a short cdef function.

[dcoudert]

This is roughly what I already tried: use define_macros, and in cplex_backend.pxd use the macro to conditionally import methods from cplex.h, but I always get

Error compiling Cython file:
------------------------------------------------------------
...
     int CPX_PARAM_SOLNPOOLGAP = 2105
     int CPX_PARAM_SOLNPOOLINTENSITY = 2107
     int CPX_MAX = -1
     int CPX_MIN = 1

IF CPX_VERSION >= 12090000:
  ^
------------------------------------------------------------

sage/numerical/backends/cplex_backend.pxd:217:3: Compile-time name 'CPX_VERSION' not defined

[vdelecroix]

try compile_time_env instead of define_macros (see ​cython thread)

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​72e1ea0

trac #27790: try to use compile time parameter

[dcoudert]

I don't understand how I can use compile_time_env.

I pushed my current trial that is not working as can be seen from the patchbot.

[vdelecroix]

line 240-241 of src/setup.py the compile_time_env variable is set up (globally). It seems that it erases any specific configuration at an Extension level.

[dcoudert]

outch... Well, either we are able to find a smart solution, or we could decide to support only cplex >= 12.8 (released Oct 2017). We already dropped support of older versions when the API introduced file cpxconst.h (#11958).

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​93ff118

trac #27790: another trial

[dcoudert]

still not working :(

[dcoudert]

I'm more and more in favor of dropping support for cplex versions < 12.8. Indeed, we have an easy solution to support versions >= 12.8, but no simple, and more important working, solution for conditional compilation enabling to support < 12.8.

[dcoudert]

another argument for dropping support of version < 12.8: the IBM academic initiative allows to get versions 12.8 and 12.9, and no prior version.

[dcoudert]

We should either wait for #28382 or rebase this ticket on it as #28382 correct the types used in this backend.