Add "show_all_warnings" option to cythonize() to provide a simpler interface...

Add "show_all_warnings" option to cythonize() to provide a simpler interface for (temporarily) setting "Errors.LEVEL".

Cython/Build/Dependencies.py

@@ -45,6 +45,7 @@ except:
 from .. import Utils
 from ..Utils import (cached_function, cached_method, path_exists,
     safe_makedirs, copy_file_to_dir_if_newer, is_package_dir, replace_suffix)
+from ..Compiler import Errors
 from ..Compiler.Main import Context
 from ..Compiler.Options import CompilationOptions, default_options
 
@@ -882,7 +883,7 @@ def create_extension_list(patterns, exclude=None, ctx=None, aliases=None, quiet=
 
 # This is the user-exposed entry point.
 def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False, force=False, language=None,
-              exclude_failures=False, **options):
+              exclude_failures=False, show_all_warnings=False, **options):
     """
     Compile a set of source modules into C/C++ files and return a list of distutils
     Extension objects for them.
@@ -932,6 +933,9 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
                              really makes sense for compiling ``.py`` files which can also
                              be used without compilation.
 
+    :param show_all_warnings: By default, not all Cython warnings are printed.
+                              Set to true to show all warnings.
+
     :param annotate: If ``True``, will produce a HTML file for each of the ``.pyx`` or ``.py``
                      files compiled. The HTML file gives an indication
                      of how much Python interaction there is in
@@ -1058,7 +1062,7 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
                     to_compile.append((
                         priority, source, c_file, fingerprint, quiet,
                         options, not exclude_failures, module_metadata.get(m.name),
-                        full_module_name))
+                        full_module_name, show_all_warnings))
                 new_sources.append(c_file)
                 modules_by_cfile[c_file].append(m)
             else:
@@ -1101,7 +1105,7 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
             pool.terminate()
             raise
         pool.join()
-    if not nthreads:
+    else:
         for args in to_compile:
             cythonize_one(*args)
 
@@ -1206,7 +1210,8 @@ else:
 # TODO: Share context? Issue: pyx processing leaks into pxd module
 @record_results
 def cythonize_one(pyx_file, c_file, fingerprint, quiet, options=None,
-                  raise_on_failure=True, embedded_metadata=None, full_module_name=None,
+                  raise_on_failure=True, embedded_metadata=None,
+                  full_module_name=None, show_all_warnings=False,
                   progress=""):
     from ..Compiler.Main import compile_single, default_options
     from ..Compiler.Errors import CompileError, PyrexError
@@ -1242,6 +1247,10 @@ def cythonize_one(pyx_file, c_file, fingerprint, quiet, options=None,
     options.output_file = c_file
     options.embedded_metadata = embedded_metadata
 
+    old_warning_level = Errors.LEVEL
+    if show_all_warnings:
+        Errors.LEVEL = 0
+
     any_failures = 0
     try:
         result = compile_single(pyx_file, options, full_module_name=full_module_name)
@@ -1259,6 +1268,10 @@ def cythonize_one(pyx_file, c_file, fingerprint, quiet, options=None,
         import traceback
         traceback.print_exc()
         any_failures = 1
+    finally:
+        if show_all_warnings:
+            Errors.LEVEL = old_warning_level
+
     if any_failures:
         if raise_on_failure:
             raise CompileError(None, pyx_file)

tests/build/cythonize_options.srctree

+# mode: run
+
 PYTHON setup.py build_ext --inplace
 PYTHON -c "import a"
 
@@ -5,11 +7,31 @@ PYTHON -c "import a"
 
 from Cython.Build.Dependencies import cythonize
 
+import sys
 from distutils.core import setup
+from io import StringIO
+
+old_stderr = sys.stderr
+captured = sys.stderr = StringIO()
+try:
+    setup(
+      ext_modules = cythonize(
+          "*.pyx", include_path=['subdir'],
+          compiler_directives={'cdivision': True},
+          show_all_warnings=True,
+      ),
+    )
+    output = sys.stderr.getvalue()
+finally:
+    sys.stderr = old_stderr
+    sys.stderr.write(captured.getvalue())
+
+assert "Unraisable exception in function" in output, output
+
 
-setup(
-  ext_modules = cythonize("*.pyx", include_path=['subdir'], compiler_directives={'cdivision': True}),
-)
+######## subdir/x.pxd ########
+
+######## subdir/y.pxi ########
 
 ######## a.pyx ########
 
@@ -22,8 +44,6 @@ def mod_int_c(int a, int b):
 
 assert mod_int_c(-1, 10) < 0
 
-
-######## subdir/x.pxd ########
-
-######## subdir/y.pxi ########
-
+# unraisable exceptions should produce a warning
+cdef int no_exc_propagate():
+    raise TypeError()