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Diffstat (limited to 'numpy/testing/_private/extbuild.py')
| -rw-r--r-- | numpy/testing/_private/extbuild.py | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/numpy/testing/_private/extbuild.py b/numpy/testing/_private/extbuild.py new file mode 100644 index 000000000..20bf3dcea --- /dev/null +++ b/numpy/testing/_private/extbuild.py @@ -0,0 +1,251 @@ +""" +Build a c-extension module on-the-fly in tests. +See build_and_import_extensions for usage hints + +""" + +import os +import pathlib +import sys +import sysconfig +from numpy.distutils.ccompiler import new_compiler +from distutils.errors import CompileError + +__all__ = ['build_and_import_extension', 'compile_extension_module'] + + +def build_and_import_extension( + modname, functions, *, prologue="", build_dir=None, + include_dirs=[], more_init=""): + """ + Build and imports a c-extension module `modname` from a list of function + fragments `functions`. + + + Parameters + ---------- + functions : list of fragments + Each fragment is a sequence of func_name, calling convention, snippet. + prologue : string + Code to preceed the rest, usually extra ``#include`` or ``#define`` + macros. + build_dir : pathlib.Path + Where to build the module, usually a temporary directory + include_dirs : list + Extra directories to find include files when compiling + more_init : string + Code to appear in the module PyMODINIT_FUNC + + Returns + ------- + out: module + The module will have been loaded and is ready for use + + Examples + -------- + >>> functions = [("test_bytes", "METH_O", \"\"\" + if ( !PyBytesCheck(args)) { + Py_RETURN_FALSE; + } + Py_RETURN_TRUE; + \"\"\")] + >>> mod = build_and_import_extension("testme", functions) + >>> assert not mod.test_bytes(u'abc') + >>> assert mod.test_bytes(b'abc') + """ + + body = prologue + _make_methods(functions, modname) + init = """PyObject *mod = PyModule_Create(&moduledef); + """ + if not build_dir: + build_dir = pathlib.Path('.') + if more_init: + init += """#define INITERROR return NULL + """ + init += more_init + init += "\nreturn mod;" + source_string = _make_source(modname, init, body) + try: + mod_so = compile_extension_module( + modname, build_dir, include_dirs, source_string) + except CompileError as e: + # shorten the exception chain + raise RuntimeError(f"could not compile in {build_dir}:") from e + import importlib.util + spec = importlib.util.spec_from_file_location(modname, mod_so) + foo = importlib.util.module_from_spec(spec) + spec.loader.exec_module(foo) + return foo + + +def compile_extension_module( + name, builddir, include_dirs, + source_string, libraries=[], library_dirs=[]): + """ + Build an extension module and return the filename of the resulting + native code file. + + Parameters + ---------- + name : string + name of the module, possibly including dots if it is a module inside a + package. + builddir : pathlib.Path + Where to build the module, usually a temporary directory + include_dirs : list + Extra directories to find include files when compiling + libraries : list + Libraries to link into the extension module + library_dirs: list + Where to find the libraries, ``-L`` passed to the linker + """ + modname = name.split('.')[-1] + dirname = builddir / name + dirname.mkdir(exist_ok=True) + cfile = _convert_str_to_file(source_string, dirname) + include_dirs = [sysconfig.get_config_var('INCLUDEPY')] + include_dirs + + return _c_compile( + cfile, outputfilename=dirname / modname, + include_dirs=include_dirs, libraries=[], library_dirs=[], + ) + + +def _convert_str_to_file(source, dirname): + """Helper function to create a file ``source.c`` in `dirname` that contains + the string in `source`. Returns the file name + """ + filename = dirname / 'source.c' + with filename.open('w') as f: + f.write(str(source)) + return filename + + +def _make_methods(functions, modname): + """ Turns the name, signature, code in functions into complete functions + and lists them in a methods_table. Then turns the methods_table into a + ``PyMethodDef`` structure and returns the resulting code fragment ready + for compilation + """ + methods_table = [] + codes = [] + for funcname, flags, code in functions: + cfuncname = "%s_%s" % (modname, funcname) + if 'METH_KEYWORDS' in flags: + signature = '(PyObject *self, PyObject *args, PyObject *kwargs)' + else: + signature = '(PyObject *self, PyObject *args)' + methods_table.append( + "{\"%s\", (PyCFunction)%s, %s}," % (funcname, cfuncname, flags)) + func_code = """ + static PyObject* {cfuncname}{signature} + {{ + {code} + }} + """.format(cfuncname=cfuncname, signature=signature, code=code) + codes.append(func_code) + + body = "\n".join(codes) + """ + static PyMethodDef methods[] = { + %(methods)s + { NULL } + }; + static struct PyModuleDef moduledef = { + PyModuleDef_HEAD_INIT, + "%(modname)s", /* m_name */ + NULL, /* m_doc */ + -1, /* m_size */ + methods, /* m_methods */ + }; + """ % dict(methods='\n'.join(methods_table), modname=modname) + return body + + +def _make_source(name, init, body): + """ Combines the code fragments into source code ready to be compiled + """ + code = """ + #include <Python.h> + + %(body)s + + PyMODINIT_FUNC + PyInit_%(name)s(void) { + %(init)s + } + """ % dict( + name=name, init=init, body=body, + ) + return code + + +def _c_compile(cfile, outputfilename, include_dirs=[], libraries=[], + library_dirs=[]): + if sys.platform == 'win32': + compile_extra = ["/we4013"] + link_extra = ["/LIBPATH:" + os.path.join(sys.base_prefix, 'libs')] + elif sys.platform.startswith('linux'): + compile_extra = [ + "-O0", "-g", "-Werror=implicit-function-declaration", "-fPIC"] + link_extra = None + else: + compile_extra = link_extra = None + pass + if sys.platform == 'win32': + link_extra = link_extra + ['/DEBUG'] # generate .pdb file + if sys.platform == 'darwin': + # support Fink & Darwinports + for s in ('/sw/', '/opt/local/'): + if (s + 'include' not in include_dirs + and os.path.exists(s + 'include')): + include_dirs.append(s + 'include') + if s + 'lib' not in library_dirs and os.path.exists(s + 'lib'): + library_dirs.append(s + 'lib') + + outputfilename = outputfilename.with_suffix(get_so_suffix()) + saved_environ = os.environ.copy() + try: + build( + cfile, outputfilename, + compile_extra, link_extra, + include_dirs, libraries, library_dirs) + finally: + # workaround for a distutils bugs where some env vars can + # become longer and longer every time it is used + for key, value in saved_environ.items(): + if os.environ.get(key) != value: + os.environ[key] = value + return outputfilename + + +def build(cfile, outputfilename, compile_extra, link_extra, + include_dirs, libraries, library_dirs): + "cd into the directory where the cfile is, use distutils to build" + + compiler = new_compiler(force=1, verbose=2) + compiler.customize('') + objects = [] + + old = os.getcwd() + os.chdir(cfile.parent) + try: + res = compiler.compile( + [str(cfile.name)], + include_dirs=include_dirs, + extra_preargs=compile_extra + ) + objects += [str(cfile.parent / r) for r in res] + finally: + os.chdir(old) + + compiler.link_shared_object( + objects, str(outputfilename), + libraries=libraries, + extra_preargs=link_extra, + library_dirs=library_dirs) + + +def get_so_suffix(): + ret = sysconfig.get_config_var('EXT_SUFFIX') + assert ret + return ret |