'''
Preferences related to C++ compilation
Preferences
--------------------
.. document_brian_prefs:: codegen.cpp
'''
from distutils.ccompiler import get_default_compiler
from brian2.core.preferences import prefs, BrianPreference
from .codeobject import sys_info
__all__ = ['get_compiler_and_args']
# Try to get architecture information to get the best compiler setting for
# Windows
msvc_arch_flag = ''
try:
from cpuinfo import cpuinfo
res = cpuinfo.get_cpu_info()
# Note that this overwrites the arch_flag, i.e. only the best option will
# be used
if 'sse' in res['flags']:
msvc_arch_flag = '/arch:SSE'
if 'sse2' in res['flags']:
msvc_arch_flag = '/arch:SSE2'
if 'avx' in res['flags']:
msvc_arch_flag = '/arch:AVX'
if 'avx2' in res['flags']:
msvc_arch_flag = '/arch:AVX2'
except Exception:
pass # apparently it does not always work on appveyor
# Preferences
prefs.register_preferences(
'codegen.cpp',
'C++ compilation preferences',
compiler = BrianPreference(
default='',
docs='''
Compiler to use (uses default if empty)
Should be gcc or msvc.
'''
),
extra_compile_args=BrianPreference(
default=None,
validator=lambda v: True,
docs='''
Extra arguments to pass to compiler (if None, use either
``extra_compile_args_gcc`` or ``extra_compile_args_msvc``).
'''
),
extra_compile_args_gcc=BrianPreference(
default=['-w', '-O3', '-ffast-math', '-fno-finite-math-only', '-march=native'],
docs='''
Extra compile arguments to pass to GCC compiler
'''
),
extra_compile_args_msvc=BrianPreference(
default=['/Ox', '/w', msvc_arch_flag, '/MP'],
docs='''
Extra compile arguments to pass to MSVC compiler (the default
``/arch:`` flag is determined based on the processor architecture)
'''
),
extra_link_args=BrianPreference(
default=[],
docs='''
Any extra platform- and compiler-specific information to use when
linking object files together.
'''
),
include_dirs=BrianPreference(
default=[],
docs='''
Include directories to use. Note that ``$prefix/include`` will be
appended to the end automatically, where ``$prefix`` is Python's
site-specific directory prefix as returned by `sys.prefix`.
'''
),
library_dirs=BrianPreference(
default=[],
docs='''
List of directories to search for C/C++ libraries at link time.
Note that ``$prefix/lib`` will be appended to the end automatically,
where ``$prefix`` is Python's site-specific directory prefix as returned
by `sys.prefix`.
'''
),
runtime_library_dirs=BrianPreference(
default=[],
docs='''
List of directories to search for C/C++ libraries at run time.
'''
),
libraries=BrianPreference(
default=[],
docs='''
List of library names (not filenames or paths) to link against.
'''
),
headers=BrianPreference(
default=[],
docs='''
A list of strings specifying header files to use when compiling the
code. The list might look like ["<vector>","'my_header'"]. Note that
the header strings need to be in a form than can be pasted at the end
of a #include statement in the C++ code.
'''
),
define_macros=BrianPreference(
default=[],
docs='''
List of macros to define; each macro is defined using a 2-tuple,
where 'value' is either the string to define it to or None to
define it without a particular value (equivalent of "#define
FOO" in source or -DFOO on Unix C compiler command line).
'''
),
msvc_vars_location=BrianPreference(
default='',
docs='''
Location of the MSVC command line tool (or search for best by default).
'''),
msvc_architecture=BrianPreference(
default='',
docs='''
MSVC architecture name (or use system architectue by default).
Could take values such as x86, amd64, etc.
'''),
)
[docs]def get_compiler_and_args():
'''
Returns the computed compiler and compilation flags
'''
compiler = prefs['codegen.cpp.compiler']
if compiler == '':
compiler = get_default_compiler()
extra_compile_args = prefs['codegen.cpp.extra_compile_args']
if extra_compile_args is None:
if compiler in ('gcc', 'unix'):
extra_compile_args = prefs['codegen.cpp.extra_compile_args_gcc']
if compiler == 'msvc':
extra_compile_args = prefs['codegen.cpp.extra_compile_args_msvc']
return compiler, extra_compile_args
[docs]def update_for_cross_compilation(library_dirs, extra_compile_args,
extra_link_args, logger=None):
'''
Update the compiler arguments to allow cross-compilation for 32bit on a
64bit Linux system. Uses the provided ``logger`` to print an INFO message
and modifies the provided lists in-place.
Parameters
----------
library_dirs : list
List of library directories (will be modified in-place).
extra_compile_args : list
List of extra compile args (will be modified in-place).
extra_link_args : list
List of extra link args (will be modified in-place).
logger : `BrianLogger`, optional
The logger to use for the INFO message. Defaults to ``None`` (no
message).
'''
if (sys_info['system'] == 'Linux' and
sys_info['architecture'][0] == '32bit' and
sys_info['machine'] == 'x86_64'):
# We are cross-compiling to 32bit on a 64bit platform
if logger is not None:
logger.info('Cross-compiling to 32bit on a 64bit platform, a set '
'of standard compiler options will be appended for '
'this purpose (note that you need to have a 32bit '
'version of the standard library for this to work).',
'64bit_to_32bit',
once=True)
library_dirs += ['/lib32', '/usr/lib32']
extra_compile_args += ['-m32']
extra_link_args += ['-m32']