#!/usr/bin/env python
# encoding: utf-8
"""
wscript

The waf script to configure compilation of generated simulations.

Created by Graham Dennis on 2009-03-01.

Copyright (c) 2009-2012, Graham Dennis

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import os, sys, platform

from waflib import Task, TaskGen
from waflib.TaskGen import feature

def options(opt):
    # options provided by modules
    opt.load('compiler_cxx')

def optionAsList(var):
    if isinstance(var, str):
        return [var]
    elif isinstance(var, list):
        return var
    assert False


# This doesn't have great performance, but it's a small dataset we'll be working on
def append_to_unordered_set(dest, value):
    if value in dest:
        dest.remove(value)
    dest.append(value)

def expand_dependencies(dest, uselib, env):
    append_to_unordered_set(dest, uselib)
    if not uselib in env.uselib_dependencies: return
    expand_dependencies_of_list(dest, env.uselib_dependencies[uselib], env)

def expand_dependencies_of_list(dest, uselibs, env):
    for uselib in uselibs[:]:
        expand_dependencies(dest, uselib, env)


def configure(conf):
    env = conf.env
    
    env.uselib_dependencies = {}
    
    def _check_cxx(**KWs):
        # Don't execute when cross-compiling
        KWs['execute'] = not conf.env['is_cross_compile']
        KWs['mandatory'] = False
        KWs['ENVIRONMENT_NAME'] = conf.env['ENVIRONMENT_NAME']
        
        if 'cxxflags' in KWs:
          cxxflags = optionAsList(KWs['cxxflags'])
          
          linkflags = []
          if 'linkflags' in KWs:
            linkflags.extend(optionAsList(KWs['linkflags']))
          KWs['linkflags'] = linkflags
        
        original_uselib = []

        if 'uselib' in KWs:
            current_uselib = optionAsList(KWs['uselib'])
            original_uselib = current_uselib[:]
            expand_dependencies_of_list(current_uselib, original_uselib[:], conf.env)
            KWs['uselib'] = current_uselib
        
        result = conf.check_cxx(**KWs) not in [None, False]
        if result and 'uselib_store' in KWs:
            conf.env.append_unique('uselib', KWs['uselib_store'])
            if original_uselib:
                current_uselib_dep = conf.env.uselib_dependencies.setdefault(KWs['uselib_store'], [])
                for uselib in original_uselib:
                    if uselib == KWs['uselib_store']: continue
                    append_to_unordered_set(current_uselib_dep, uselib)
        return result
    
    def try_options(uselib_store, kwOptions, common = None):
        common = common or {}
        for kws in kwOptions:
            predicate = kws.get('predicate', True)
            if callable(predicate):
              predicate = predicate()
            if not predicate: continue
            
            allKWs = common.copy()
            allKWs.update(kws)
            if check_cxx(uselib_store=uselib_store, **allKWs):
                return True
        return False
    
    def check_cxx(**KWs):
        # Prefer a static library over a dynamic one if available
        if ('lib' not in KWs) or ('uselib_store' not in KWs) or ('_skip' in KWs):
            return _check_cxx(**KWs)
        
        lib = KWs['lib']
        del KWs['lib']
        uselib_store = KWs['uselib_store']
        KWs['_skip'] = True
        del KWs['uselib_store']
        options = [
            {'stlib': lib,   'msg': "%s (static library)" % KWs['msg'], 'errmsg': "no (will try dynamic library instead)"},
            {'lib'  : lib,   'msg': "%s (dynamic library)" % KWs['msg']},
        ]
        if not conf.env['STLIB_MARKER']:
            options = [
            # On systems like Mac OS X, it seems we can't force the linker to prefer static libraries over dynamic ones
            # Except of course by including them by listing the full path.
                {'lib': lib}
            ]
        if not 'errmsg' in KWs:
            KWs['errmsg'] = "no (it's optional anyway)"
            
        return try_options(uselib_store, options, KWs)
    
    
    def configure_compiler():
        conf.load('compiler_cxx')
        
        conf.check_cxx(
            msg = "Checking whether the compiler works",
            errmsg = "The compiler doesn't seem to work"
        )
        
        conf.check_cxx(
            msg = "Checking that we have a C++ compiler",
            fragment = """
            #include <iostream>
            int main() { return 0; }
            """,
            errmsg = "Please specify a C++ compiler."
        )

        conf.env['is_cross_compile'] = not conf.check_cxx(
            msg = "Checking whether we are cross-compiling",
            okmsg = "no",
            errmsg = "maybe, assuming we are",
            execute = True,
            mandatory = False,
        )
        
        # If we have a static library marker, try to link the simulation statically for performance.
        if conf.env['STLIB_MARKER']:
            conf.env['FINAL_LINK_VAR'] = conf.env['STLIB_MARKER']
            result = conf.check_cxx(
                msg = "Checking whether we can link to only static libraries",
                errmsg = "no (will use dynamic libraries)",
                mandatory = False,
                execute = not conf.env['is_cross_compile']
            )
            if not result:
                del conf.env['FINAL_LINK_VAR']
        
        
        if conf.env['CXX_NAME'] == 'gcc':
            machine_optimisations = [
                {
                    "msg": "Trying to make compiler optimise for this machine",
                    "cxxflags": "-march=native",
                },
                {
                    "msg": "Checking for Altivec",
                    "cxxflags": ['-mpim-altivec', '-maltivec'],
                },
                {
                    "msg": "Checking for AVX",
                    "cxxflags": ["-mavx", "-msse3", "-msse2", "-msse", "-mfpmath=sse"],
                },
                {
                    "msg": "Checking for SSE3",
                    "cxxflags": ["-msse3", "-msse2", "-msse", "-mfpmath=sse"],
                },
                {
                    "msg": "Checking for SSE2",
                    "cxxflags": ["-msse2", "-msse", "-mfpmath=sse"],
                },
                {
                    "msg": "Checking for SSE",
                    "cxxflags": ["-msse", "-mfpmath=sse"]
                }
            ]
            
            try_options('optimise', machine_optimisations,
                { # This is so that the compiler will generate SIMD instructions
                  # If the linker / assembler doesn't support those instructions,
                  # Then we'll pick it up this way.
                    "fragment": "int main() { double __volatile__ a = 1.0; a *= 1.03; return 0; }"
                }
            )
            
            check_cxx(
                cxxflags='-mtune=native',
                uselib_store="optimise",
                msg = "Trying to make compiler tune for this machine"
            )
            
            optimisation_flags = [
                '-O3', '-ffast-math', '-funroll-all-loops', '-fomit-frame-pointer', '-falign-loops', '-fstrict-aliasing', '-momit-leaf-frame-pointer'
            ]
            
            for optimisation_flag in optimisation_flags:
                check_cxx(
                    cxxflags=optimisation_flag,
                    uselib_store="optimise"
                )
            
            check_cxx(
                cxxflags=['-fno-unsafe-math-optimizations', '-fno-finite-math-only'],
                uselib_store="safe_math",
                uselib='optimise',
                msg = "Checking for cautious math flags"
            )
            
            if sys.platform == 'darwin':
                env.append_unique('CXXFLAGS', ['-mmacosx-version-min=%s' % '.'.join(platform.mac_ver()[0].split('.')[:2])])
            
            check_cxx(
                cxxflags='-ftree-vectorize',
                uselib_store='vectorise',
                uselib="optimise",
                msg = "Checking for Autovectorisation"
            )
            
            check_cxx(
                cxxflags='-fopenmp',
                linkflags="-fopenmp",
                uselib_store='openmp',
                msg = "Checking for OpenMP"
            )
            
            check_cxx(
                cxxflags="-pthread",
                linkflags="-pthread",
                uselib_store="threads",
                msg = "Checking for pthreads",
            )
        elif conf.env['CXX_NAME'] == 'icc':
            compiler_optimisations = [
                {
                    "msg": "Checking for the 'go fast' compiler option",
                    "cxxflags": ['-fast', '-ffast-math', '-complex-limited-range', '-fomit-frame-pointer'],
                    "linkflags": ["-fast"],
                },
                {
                    "msg": "Checking for fallback optimisation flags",
                    "cxxflags": ['-O3', '-ipo', '-ffast-math', '-complex-limited-range', '-fomit-frame-pointer'],
                    "linkflags": ['-O3'],
                },
                {
                    "msg": "Checking safe optimisation flags",
                    "cxxflags": "-O3",
                    "linkflags": "-O3"
                }
            ]
            
            try_options('optimise', compiler_optimisations)
            
            machine_optimisations = [
                {
                    "msg": "Trying to optimise for SSE4",
                    "cxxflags": "-xS",
                },
                {
                    "msg": "Trying to optimise for SSSE3",
                    "cxxflags": "-xT",
                },
                {
                    "msg": "Trying to optimise for SSE3",
                    "cxxflags": "-xP",
                },
                {
                    "msg": "Trying to optimise for SSE2",
                    "cxxflags": "-xN",
                },
            ]
            
            try_options('optimise', machine_optimisations)
            
            check_cxx(
                cxxflags="-fma",
                uselib_store="optimise",
                msg = "Trying to fuse multiply and add instructions"
            )
            
            check_cxx(
                cxxflags = ["-fp-model", "precise"],
                uselib_store="safe_math",
                uselib="optimise",
                msg = "Checking for cautious math flags"
            )
            
            check_cxx(
                cxxflags = "-vec",
                uselib_store="vectorise",
                uselib="optimise",
                msg = "Checking for Autovectorisation"
            )
            
            check_cxx(
                cxxflags='-openmp',
                linkflags="-openmp",
                uselib_store="openmp",
                msg = "Checking for OpenMP"
            )
            
            check_cxx(
                cxxflags="-pthread",
                linkflags="-pthread",
                uselib_store="threads",
                msg = "Checking for pthreads"
            )
        
        
        check_cxx(
            cxxflags="-g",
            uselib_store="debug",
            msg = "Checking for compiler debug flags"
        )
        
        # Check for srandomdev, used for runtime initialisation of random number generators
        check_cxx(
            header_name='stdlib.h',
            function_name='srandomdev',
            defines = 'HAVE_SRANDOMDEV',
            uselib_store = 'randomisation_seeding',
            msg = "Checking for srandomdev"
        )
        
        # Check for the availability of /dev/urandom
        check_cxx(
            defines = 'HAVE_DEV_URANDOM',
            uselib_store = 'randomisation_seeding',
            fragment= '''
                extern "C" {
                #include <stdio.h>
                	int main() {
                        FILE *fp = fopen("/dev/urandom", "r");
                        return fp == NULL;
                    }
                }
            ''',
            msg = "Checking for /dev/urandom",
        )
        
        # Check for zlib, used by hdf5
        check_cxx(
            lib='z',
            function_name="deflate",
            header_name="zlib.h",
            uselib_store="zlib",
            msg = "Checking for zlib"
        )
        
        check_cxx(
            lib='hdf5',
            header_name="hdf5.h",
            function_name="H5check_version",
            uselib_store="hdf5",
            uselib="zlib" if "zlib" in conf.env['uselib'] else [],
            msg = "Checking for HDF5",
        )
        
        if 'hdf5' in conf.env['uselib']:
            check_cxx(
                lib='hdf5_hl',
                defines='HAVE_HDF5_HL',
                header_name=['hdf5.h', 'hdf5_hl.h'],
                function_name='H5DSset_scale',
                uselib_store='hdf5',
                uselib='hdf5',
                msg = "Checking for HDF5 High-level library",
            )
            
            # We need to reverse the library order because hdf5_hl depends on hdf5
            if conf.env['STLIB_hdf5']: conf.env['STLIB_hdf5'] = list(reversed(conf.env.get_flat('STLIB_hdf5').split()))
            if conf.env['SHLIB_hdf5']: conf.env['SHLIB_hdf5'] = list(reversed(conf.env.get_flat('SHLIB_hdf5').split()))
            
            check_cxx(
                header_name=['hdf5.h'],
                defines='HAVE_H5LEXISTS',
                function_name='H5Lexists',
                uselib = 'hdf5',
                uselib_store = 'hdf5',
            )
        
        check_cxx(
            lib='xmds',
            uselib_store='xmds',
            msg = "Checking for libxmds"
        )
        
        # Check for system-specific features
        if sys.platform == 'darwin':
            check_cxx(
                framework="CoreFoundation",
                uselib_store="system",
                msg = "Checking for Apple CoreFoundation framework",
            )
            check_cxx(
                framework="IOKit",
                uselib_store="system",
                uselib="system",
                msg = "Checking for Apple IOKit framework",
            )
        
        
        
        check_cxx(
            lib=["iomp", "vml"],
            header_name='mkl_vsl.h',
            function_name='vslNewStream',
            uselib_store='mkl_vsl',
            msg = "Checking for Intel's Vector Math Library"
        )
        
        # The max-inline-insns-single=1800 option works for gcc but not icc, so try a series of options to see what works
        dsfmt_optimisations = [
          {
              "cxxflags": ["-finline-functions", "--param", "max-inline-insns-single=1800"],
              "msg": "Checking aggressive dSFMT compile flags",
          },
          {
              "cxxflags": ["-finline-functions"],
              "msg": "Checking safer dSFMT compile flags",
          },
          {
              "cxxflags": [],
              "msg": "Checking dSFMT compile flags",
          },
        ];
        
        try_options('dsfmt', dsfmt_optimisations)
        
        # Find CBLAS
        cblas_options = [
            {# Intel MKL
                'defines': 'CBLAS_MKL',
                'lib': ['mkl_intel_lp64', 'mkl_intel_thread', 'mkl_core'],
                'uselib': 'openmp',
                'header_name': 'mkl.h',
                'msg': "Checking for Intel's Math Kernel Library",
            },
            {# Apple Accelerate
                'defines': 'CBLAS_VECLIB',
                'framework_name': 'Accelerate',
                'msg': "Checking for Apple's Accelerate framework",
                'predicate': sys.platform == 'darwin'
            },
            {# ATLAS CBLAS
                'defines': 'CBLAS_ATLAS',
                'lib': 'cblas',
                'fragment': '''
                    extern "C" {
                    #include <cblas.h>
                    	int main() {
                    	    void *p=(void*)(cblas_dgemm);
                    	    return 0;
                        }
                    }
                ''',
                'msg': "Checking for ATLAS's CBLAS."
            },
            {# GSL CBLAS
                'defines': 'CBLAS_GSL',
                'lib': 'gslcblas',
                'header_name': 'gsl/gsl_cblas.h',
                'msg': "Checking for GSL's CBLAS",
            }
        ]
        cblas_common = {
            'function_name': 'cblas_dgemm',
        }
        
        try_options('cblas', cblas_options, cblas_common)
        
        check_cxx(
            lib='gsl',
            uselib='cblas',
            uselib_store='gsl',
            header_name='gsl/gsl_sf.h',
            function_name='gsl_sf_bessel_jl',
            msg="Checking for GSL"
        )
        
        check_cxx(
            lib='fftw3',
            header_name='fftw3.h',
            function_name='fftw_execute',
            uselib_store='fftw3',
            msg = "Checking for FFTW3",
            errmsg = "Couldn't find FFTW3.  Please install."
        )
        
        check_cxx(
            lib='fftw3f',
            header_name='fftw3.h',
            function_name='fftwf_execute',
            uselib_store='fftw3f',
            msg = "Checking for single-precision FFTW3"
        )
        
        if 'fftw3' in conf.env['uselib']:
            check_cxx(
                lib='fftw3_threads',
                header_name='fftw3.h',
                function_name='fftw_init_threads',
                uselib_store='fftw3_threads',
                uselib=['fftw3', 'threads'],
                msg = "Checking for threading support in FFTW3",
            )
            check_cxx(
                lib='fftw3_omp',
                header_name='fftw3.h',
                function_name='fftw_init_threads',
                uselib_store='fftw3_omp',
                uselib=['fftw3', 'openmp'],
                msg = "Checking for OpenMP support in FFTW3",
            )
        if 'fftw3f' in conf.env['uselib']:
            check_cxx(
                lib='fftw3f_threads',
                header_name='fftw3.h',
                function_name='fftwf_init_threads',
                uselib_store='fftw3f_threads',
                uselib=['fftw3f', 'threads'],
                msg = "Checking for threading support in single-precision FFTW3",
            )
            check_cxx(
                lib='fftw3f_omp',
                header_name='fftw3.h',
                function_name='fftwf_init_threads',
                uselib_store='fftw3f_omp',
                uselib=['fftw3f', 'openmp'],
                msg = "Checking for OpenMP support in single-precision FFTW3",
            )
        
        # Destroy all those unnecessary #define's generated by waf.
        # Any we actually want will be attached to a uselib var.
        del conf.env["DEFINES"]
    
    print
    print "Configuring for single-process scripts..."
    conf.setenv('default', env)
    conf.env['ENVIRONMENT_NAME'] = 'default'
    configure_compiler()
    
    # Stuff for MPI variant
    print
    print "Configuring for MPI scripts..."
    conf.setenv('mpi', env)
    conf.env['ENVIRONMENT_NAME'] = 'mpi'
    if conf.find_program('mpic++', var='MPICXX', mandatory = False):
        
        conf.env['CXX'] = conf.env['MPICXX']
        conf.env['LINK_CXX'] = conf.env['MPICXX']
        
        configure_compiler()
        
        if 'fftw3' in conf.env['uselib']:
            check_cxx(
                lib='fftw3_mpi',
                header_name='fftw3.h fftw3-mpi.h',
                function_name='fftw_mpi_init',
                uselib_store='fftw3_mpi',
                uselib='fftw3',
                msg = "Checking for FFTW3 with MPI"
            )
        if 'fftw3f' in conf.env['uselib']:
            check_cxx(
                lib='fftw3f_mpi',
                header_name='fftw3.h fftw3-mpi.h',
                function_name='fftwf_mpi_init',
                uselib_store='fftw3f_mpi',
                uselib='fftw3f',
                msg = "Checking for single-precision FFTW3 with MPI"
            )
        
        del conf.env["DEFINES"]
    else:
        print "MPI not found. No scripts using MPI can be compiled on this system."
        conf.setenv('default', env)
        del conf.all_envs['mpi']
    
