Update scan's Cython version and restrict it's compilation lock scope

theano/scan/scan_perform_ext.py

@@ -5,27 +5,23 @@ To update the `Scan` Cython code you must
 - run `cython scan_perform.pyx; mv scan_perform.c c_code`
 
 """
-
-
-import errno
 import logging
 import os
 import sys
-import warnings
 from importlib import reload
 
-import numpy as np
-
 import theano
 from theano.compile.compilelock import lock_ctx
 from theano.configdefaults import config
 from theano.link.c import cmodule
 
 
-_logger = logging.getLogger("theano.scan.scan_perform")
+if not config.cxx:
+    raise ImportError("No C compiler; cannot compile Cython-generated code")
 
+_logger = logging.getLogger("theano.scan.scan_perform")
 
-version = 0.297  # must match constant returned in function get_version()
+version = 0.298  # must match constant returned in function get_version()
 
 need_reload = False
 
@@ -48,9 +44,15 @@ try:
     try_import()
     need_reload = True
     if version != getattr(scan_perform, "_version", None):
-        raise ImportError()
+        raise ImportError("Scan code version mismatch")
 except ImportError:
-    with lock_ctx():
+
+    dirname = "scan_perform"
+    loc = os.path.join(config.compiledir, dirname)
+
+    os.makedirs(loc, exist_ok=True)
+
+    with lock_ctx(loc):
         # Maybe someone else already finished compiling it while we were
         # waiting for the lock?
         try:
@@ -61,87 +63,55 @@ except ImportError:
             else:
                 try_import()
                 need_reload = True
+
             if version != getattr(scan_perform, "_version", None):
                 raise ImportError()
+
         except ImportError:
-            if not config.cxx:
-                raise ImportError("no c compiler, can't compile cython code")
             _logger.info("Compiling C code for scan")
-            dirname = "scan_perform"
+
             cfile = os.path.join(theano.__path__[0], "scan", "c_code", "scan_perform.c")
+
             if not os.path.exists(cfile):
-                # This can happen in not normal case. We just
-                # disable the cython code. If we are here the user
-                # didn't disable the compiler, so print a warning.
-                warnings.warn(
-                    "The file scan_perform.c is not available. This do"
-                    "not happen normally. You are probably in a strange"
-                    "setup. This mean Theano can not use the cython code for "
-                    "scan. If you"
-                    "want to remove this warning, use the Theano flag"
-                    "'cxx=' (set to an empty string) to disable all c"
-                    "code generation."
+                raise ImportError(
+                    "The file scan_perform.c is not available, so scan "
+                    "will not use its Cython implementation."
                 )
-                raise ImportError("The file lazylinker_c.c is not available.")
-
-            with open(cfile) as f:
-                code = f.read()
-            loc = os.path.join(config.compiledir, dirname)
-            if not os.path.exists(loc):
-                try:
-                    os.mkdir(loc)
-                except OSError as e:
-                    assert e.errno == errno.EEXIST
-                    assert os.path.exists(loc)
 
             preargs = ["-fwrapv", "-O2", "-fno-strict-aliasing"]
             preargs += cmodule.GCC_compiler.compile_args()
-            # Cython 19.1 always use the old NumPy interface.  So we
-            # need to manually modify the .c file to get it compiled
-            # by Theano. As by default, we tell NumPy to don't import
-            # the old interface.
-            if False:
-                # During scan cython development, it is helpful to keep the old interface, to don't manually edit the c file each time.
-                preargs.remove("-DNPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION")
-            else:
-                numpy_ver = [int(n) for n in np.__version__.split(".")[:2]]
-                # Add add some macro to lower the number of edit
-                # needed to the c file.
-                if bool(numpy_ver >= [1, 7]):
-                    # Needed when we disable the old API, as cython
-                    # use the old interface
-                    preargs.append("-DNPY_ENSUREARRAY=NPY_ARRAY_ENSUREARRAY")
-                    preargs.append("-DNPY_ENSURECOPY=NPY_ARRAY_ENSURECOPY")
-                    preargs.append("-DNPY_ALIGNED=NPY_ARRAY_ALIGNED")
-                    preargs.append("-DNPY_WRITEABLE=NPY_ARRAY_WRITEABLE")
-                    preargs.append("-DNPY_UPDATE_ALL=NPY_ARRAY_UPDATE_ALL")
-                    preargs.append("-DNPY_C_CONTIGUOUS=NPY_ARRAY_C_CONTIGUOUS")
-                    preargs.append("-DNPY_F_CONTIGUOUS=NPY_ARRAY_F_CONTIGUOUS")
+
+            with open(cfile) as f:
+                code = f.read()
 
             cmodule.GCC_compiler.compile_str(
                 dirname, code, location=loc, preargs=preargs, hide_symbols=False
             )
             # Save version into the __init__.py file.
             init_py = os.path.join(loc, "__init__.py")
+
             with open(init_py, "w") as f:
                 f.write(f"_version = {version}\n")
+
             # If we just compiled the module for the first time, then it was
-            # imported at the same time: we need to make sure we do not
-            # reload the now outdated __init__.pyc below.
+            # imported at the same time.  We need to make sure we do not reload
+            # the now outdated __init__.pyc below.
             init_pyc = os.path.join(loc, "__init__.pyc")
+
             if os.path.isfile(init_pyc):
                 os.remove(init_pyc)
+
             try_import()
 
             try_reload()
+
             from scan_perform import scan_perform as scan_c
 
             assert scan_perform._version == scan_c.get_version()
+
             _logger.info(f"New version {scan_perform._version}")
 
-# This is caused as cython use the old NumPy C-API but we use the new one.
-# To fix it completely, we would need to modify Cython to use the new API.
-with warnings.catch_warnings():
-    warnings.filterwarnings("ignore", message="numpy.ndarray size changed")
-    from scan_perform.scan_perform import get_version, perform  # noqa: F401
+from scan_perform.scan_perform import get_version, perform  # noqa: F401, E402
+
+
 assert version == get_version()