"""
Helpers to compile C.
:githublink:`%|py|5`
"""
import os
import sys
import shutil
import numpy
_header_c_float = """
void concat_float_float(float* xy, float x, float y)
{
xy[0] = x;
xy[1] = y;
}
void adot_float_float(float* res, float* vx, float* vy, int dim)
{
*res = 0;
for(; dim > 0; --dim, ++vx, ++vy)
*res += *vx * *vy;
}
void aadd_float(float* res, float* vx, float* vy, int dim)
{
for(; dim > 0; --dim, ++vx, ++vy, ++res)
*res = *vx + *vy;
}
void asub_float_float(float* res, float* vx, float* vy, int dim)
{
for(; dim > 0; --dim, ++vx, ++vy, ++res)
*res = *vx - *vy;
}
void amul_float_float(float* res, float* vx, float* vy, int dim)
{
for(; dim > 0; --dim, ++vx, ++vy, ++res)
*res = *vx * *vy;
}
void adiv_float_float(float* res, float* vx, float* vy, int dim)
{
for(; dim > 0; --dim, ++vx, ++vy, ++res)
*res = *vx / *vy;
}
void sign_float(float* res, float x)
{
*res = x >= 0 ? (float)1 : (float)0 ;
}
void atake_float_int(float* res, float * vx, int p, int dim)
{
*res = vx[p];
}
void atake_int_int(int* res, int* vx, int p, int dim)
{
*res = vx[p];
}
typedef int bool;
"""
_header_c_double = _header_c_float.replace("float", "double")
[docs]class CompilationError(Exception):
"""
Raised when a compilation error was detected.
:githublink:`%|py|74`
"""
pass
[docs]def compile_c_function(code_c, nbout, dtype=numpy.float32, add_header=True,
suffix="", additional_paths=None, tmpdir='.', fLOG=None):
"""
Compiles a C function with :epkg:`cffi`.
It takes one features vector.
:param nbout: number of expected outputs
:param code_c: code C
:param dtype: numeric type to use
:param add_header: add common function before compiling
:param suffix: avoid avoid the same compiled module name
:param additional_paths: additional paths to add to the module
:param tmpdir: see below
:param fLOG: logging function
:return: compiled function
The function assumes the first line is the signature.
If you are using Windows with Visual Studio 2017, make sure
you are using :epkg:`Python` 3.6.3+
(see `Issue 30389 <https://bugs.python.org/issue30389>`_).
Parameter *tmpdir* is used by function `compile
<http://cffi.readthedocs.io/en/latest/cdef.html?
highlight=compile#ffibuilder-compile-etc-compiling-out-of-line-modules>`_.
:githublink:`%|py|101`
"""
if sys.platform.startswith("win"):
if "VS140COMNTOOLS" not in os.environ: # pragma: no cover
raise CompilationError(
"Visual Studio is not installed.\n{0}".format(
"\n".join("{0}={1}".format(k, v) for k, v in sorted(os.environ.items()))))
sig = code_c.split("\n")[0].strip() + ";"
name = sig.split()[1]
include_paths = []
lib_paths = []
if additional_paths is None:
additional_paths = []
# ~ if len(additional_paths) == 0 and sys.platform.startswith("win") and \
# ~ 'VSSDK140Install' not in os.environ: # last condition is for the installed VisualStudio.
# ~ if fLOG:
#~ fLOG("[compile_c_function] fix PATH for VS2017 on Windows")
# ~ # Update environment variables.
# ~ adds = [r"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64",
# ~ r"C:\Program Files (x86)\Windows Kits\10\bin\10.0.15063.0\x64"]
# ~ vcvars64 = os.path.join(adds[0], 'vcvars64.bat')
#~ subprocess.run(vcvars64)
# ~ # Add paths for VS2017.
# ~ includes = [r'C:\Program Files (x86)\Windows Kits\10\Include\10.0.15063.0\shared',
#~ r'C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include',
# ~ r'C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\SDK\ScopeCppSDK\SDK\include\ucrt']
# ~ libs = [r'C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\lib\amd64',
#~ r'C:\Program Files (x86)\Windows Kits\10\Lib\10.0.15063.0\um\x64',
# ~ r'C:\Program Files (x86)\Windows Kits\10\Lib\10.0.15063.0\ucrt\x64']
# ~ opaths = os.environ['PATH'].split(';')
# ~ for add in adds:
# ~ if os.path.exists(add) and add not in opaths:
#~ additional_paths.append(add)
# ~ oinc = os.environ.get('INCLUDE', '').split(';')
# ~ for inc in includes:
# ~ if os.path.exists(inc) and inc not in oinc:
#~ include_paths.append(inc)
# ~ for lib in libs:
# ~ if os.path.exists(lib):
#~ lib_paths.append(lib)
if additional_paths:
if fLOG: # pragma: no cover
for p in additional_paths:
fLOG("[compile_c_function] PATH += '{0}'".format(p))
os.environ["PATH"] += ";" + ";".join(additional_paths)
if lib_paths and sys.platform.startswith("win"): # pragma: no cover
libs = ['msvcrt.lib', 'oldnames.lib', 'kernel32.lib', 'vcruntime.lib',
'ucrt.lib']
libs = {k: False for k in libs}
for lib in lib_paths:
for name in list(libs):
if libs[name]:
continue
msv = os.path.join(lib, name)
if os.path.exists(msv):
dst = os.getcwd()
msvd = os.path.join(dst, name)
if not os.path.exists(msvd):
shutil.copy(msv, dst)
if fLOG:
fLOG("[compile_c_function] copy '{0}'".format(msv))
libs[name] = True
copied = len([k for k, v in libs.items() if v])
if copied < len(libs):
raise CompilationError('Unable to find those libraries ({0}<{1}) {2} in\n{3}'.format(
copied, len(libs), ','.join(sorted(libs)), '\n'.join(lib_paths)))
if include_paths:
if fLOG: # pragma: no cover
for p in include_paths:
fLOG("[compile_c_function] INCLUDE += '{0}'".format(p))
if 'INCLUDE' in os.environ: # pragma: no cover
os.environ["INCLUDE"] += ";" + ";".join(include_paths)
else: # pragma: no cover
os.environ["INCLUDE"] = ";".join(include_paths)
is_float = dtype == numpy.float32
header = _header_c_float if is_float else _header_c_double
code = code_c if not add_header else (header + code_c)
from cffi import FFI
ffibuilder = FFI()
try:
ffibuilder.cdef(sig)
except Exception as e: # pragma: no cover
raise CompilationError(
"Signature is wrong\n{0}\ndue to\n{1}".format(sig, e)) from e
ffibuilder.set_source("_" + name + suffix, code)
try:
ffibuilder.compile(verbose=False, tmpdir=tmpdir)
except Exception as e: # pragma: no cover
raise CompilationError(
"Compilation failed \n{0}\ndue to\n{1}".format(sig, e)) from e
mod = __import__("_{0}{1}".format(name, suffix))
fct = getattr(mod.lib, name)
def wrapper(features, output, cast_type, dtype):
"wrapper for a vector of features"
if len(features.shape) != 1:
raise TypeError( # pragma: no cover
"Only one dimension for the features not {0}.".format(
features.shape))
if output is None:
output = numpy.zeros((nbout,), dtype=dtype)
else:
if len(output.shape) != 1:
raise TypeError( # pragma: no cover
"Only one dimension for the output not {0}.".format(
output.shape))
if output.shape[0] != nbout:
raise TypeError( # pragma: no cover
"Dimension mismatch {0} != {1} (expected).".format(
output.shape, nbout))
if output.dtype != dtype:
raise TypeError( # pragma: no cover
"Type mismatch {0} != {1} (expected).".format(
output.dtype, dtype))
ptr = features.__array_interface__['data'][0]
cptr = mod.ffi.cast(cast_type, ptr)
optr = output.__array_interface__['data'][0]
cout = mod.ffi.cast(cast_type, optr)
fct(cout, cptr)
return output
def wrapper_double(features, output=None):
"wrapper for double"
return wrapper(features, output, "double*", numpy.float64)
def wrapper_float(features, output=None):
"wrapper for float"
return wrapper( # pragma: no cover
features, output, "float*", numpy.float32)
return wrapper_float if is_float else wrapper_double
