Exposes compile_time_env to the command line

close #2314

Cython/Build/Cythonize.py

@@ -139,6 +139,9 @@ def parse_args(args):
     parser.add_option('-X', '--directive', metavar='NAME=VALUE,...', dest='directives',
                       type=str, action='callback', callback=parse_directives, default={},
                       help='set a compiler directive')
+    parser.add_option('-E', '--compile-time-env', metavar='NAME=VALUE,...', dest='compile_time_env',
+                      type=str, action='callback', callback=Options.parse_compile_time_env, default={},
+                      help='set a compile time environment variables')
     parser.add_option('-s', '--option', metavar='NAME=VALUE', dest='options',
                       type=str, action='callback', callback=parse_options, default={},
                       help='set a cythonize option')

Cython/Compiler/CmdLine.py

@@ -47,10 +47,11 @@ Options:
   --warning-errors, -Werror      Make all warnings into errors
   --warning-extra, -Wextra       Enable extra warnings
   -X, --directive <name>=<value>[,<name=value,...] Overrides a compiler directive
+  -E, --compile-time-env name=value[,<name=value,...] Provides compile time env like DEF would do.
 """
 
 
-#The following experimental options are supported only on MacOSX:
+# The following experimental options are supported only on MacOSX:
 #  -C, --compile    Compile generated .c file to .o file
 #  --link           Link .o file to produce extension module (implies -C)
 #  -+, --cplus      Use C++ compiler for compiling and linking
@@ -174,6 +175,17 @@ def parse_command_line(args):
                 except ValueError as e:
                     sys.stderr.write("Error in compiler directive: %s\n" % e.args[0])
                     sys.exit(1)
+            elif option == "--compile-time-env" or option.startswith('-E'):
+                if option.startswith('-E') and option[2:].strip():
+                    x_args = option[2:]
+                else:
+                    x_args = pop_value()
+                try:
+                    options.compile_time_env = Options.parse_compile_time_env(
+                        x_args, current_settings=options.compile_time_env)
+                except ValueError as e:
+                    sys.stderr.write("Error in compile-time-env: %s\n" % e.args[0])
+                    sys.exit(1)
             elif option.startswith('--debug'):
                 option = option[2:].replace('-', '_')
                 from . import DebugFlags

Cython/Compiler/Options.py

@@ -423,7 +423,7 @@ def parse_directive_list(s, relaxed_bool=False, ignore_unknown=False,
         item = item.strip()
         if not item:
             continue
-        if not '=' in item:
+        if '=' not in item:
             raise ValueError('Expected "=" in option "%s"' % item)
         name, value = [s.strip() for s in item.strip().split('=', 1)]
         if name not in _directive_defaults:
@@ -441,3 +441,73 @@ def parse_directive_list(s, relaxed_bool=False, ignore_unknown=False,
             parsed_value = parse_directive_value(name, value, relaxed_bool=relaxed_bool)
             result[name] = parsed_value
     return result
+
+
+def parse_variable_value(value):
+    """
+    Parses value as an option value for the given name and returns
+    the interpreted value.
+
+    >>> parse_variable_value('True')
+    True
+    >>> parse_variable_value('true')
+    'true'
+    >>> parse_variable_value('us-ascii')
+    'us-ascii'
+    >>> parse_variable_value('str')
+    'str'
+    >>> parse_variable_value('123')
+    123
+    >>> parse_variable_value('1.23')
+    1.23
+
+    """
+    if value == "True":
+        return True
+    elif value == "False":
+        return False
+    elif value == "None":
+        return None
+    elif value.isdigit():
+        return int(value)
+    else:
+        try:
+            value = float(value)
+        except Exception:
+            # Not a float
+            pass
+        return value
+
+
+def parse_compile_time_env(s, current_settings=None):
+    """
+    Parses a comma-separated list of pragma options. Whitespace
+    is not considered.
+
+    >>> parse_compile_time_env('      ')
+    {}
+    >>> (parse_compile_time_env('boundscheck=True') ==
+    ... {'boundscheck': True})
+    True
+    >>> parse_compile_time_env('  asdf')
+    Traceback (most recent call last):
+       ...
+    ValueError: Expected "=" in option "asdf"
+    >>> parse_compile_time_env('boundscheck=hey') == {'boundscheck': 'hey'}
+    True
+    >>> parse_compile_time_env('unknown=True') == {'unknown': True}
+    True
+    """
+    if current_settings is None:
+        result = {}
+    else:
+        result = current_settings
+    for item in s.split(','):
+        item = item.strip()
+        if not item:
+            continue
+        if '=' not in item:
+            raise ValueError('Expected "=" in option "%s"' % item)
+        name, value = [s.strip() for s in item.strip().split('=', 1)]
+        result[name] = parse_variable_value(value)
+    return result