Remove gcc injection

Removes the gcc injection code. User needs to define `distutils.cfg` file with `[compiler]\nmingw32` to use gcc.

Uses `distutils.ccompiler.get_default_compiler()` to see if `msvc` or `mingw32` is used.

Author: ahartikainen

pystan/model.py

@@ -26,20 +26,21 @@
 import warnings
 
 import distutils
-
-try:
-    # MSVC 2017 support (setuptools >= 34.4.0)
-    from setuptools import Extension
-except ImportError:
+from distutils import ccompiler
+
+if ccompiler.get_default_compiler() == 'msvc':
+    try:
+        # MSVC 2017 support (setuptools >= 34.4.0)
+        from setuptools import Extension
+    except ImportError:
+        from distutils.core import Extension
+else:
     from distutils.core import Extension
 
 import Cython
 from Cython.Build.Inline import _get_build_extension
 from Cython.Build.Dependencies import cythonize
 
-# GCC detection
-import subprocess
-
 import numpy as np
 
 import pystan.api
@@ -143,11 +144,6 @@ class StanModel:
         Indicates whether intermediate output should be piped to the console.
         This output may be useful for debugging.
     
-    compiler : string, None by default
-        Only for Windows. Choose compiler type. 
-        - for GCC use 'gcc' or 'mingw32', 
-        - for Microsoft Visual C++ use 'msvc'
-    
     kwargs : keyword arguments
         Additional arguments passed to `stanc`.
 
@@ -215,7 +211,7 @@ class StanModel:
     def __init__(self, file=None, charset='utf-8', model_name="anon_model",
                  model_code=None, stanc_ret=None, boost_lib=None,
                  eigen_lib=None, verbose=False, obfuscate_model_name=True,
-                 extra_compile_args=None, compiler=None):
+                 extra_compile_args=None):
 
         if stanc_ret is None:
             stanc_ret = pystan.api.stanc(file=file,
@@ -288,9 +284,6 @@ def __init__(self, file=None, charset='utf-8', model_name="anon_model",
             ('BOOST_DISABLE_ASSERTS', None),
         ]
 
-        # create here to allow compiler injection on Windows
-        build_extension = _get_build_extension()
-        
         # compile stan models with optimization (-O2)
         # (stanc is compiled without optimization (-O0) currently, see #33)
         if extra_compile_args is None:
@@ -300,26 +293,8 @@ def __init__(self, file=None, charset='utf-8', model_name="anon_model",
                 '-Wno-unused-function',
                 '-Wno-uninitialized',
             ]
-            if platform.platform().startswith('Win'):
-                # sanitize input
-                if compiler == 'gcc':
-                    compiler = 'mingw32'
-                # inject the compiler kw
-                if compiler is not None:
-                    build_extension.compiler = compiler
-                # inject gcc (mingw32) if found else use msvc
-                elif build_extension.compiler is None:
-                    # run subprocess without output
-                    with open(os.devnull, 'w') as DEVNULL:
-                        try:
-                            subprocess.call(["gcc", "--version"], stdout=DEVNULL)
-                        except FileNotFoundError:
-                            build_extension.compiler = "msvc"
-                        else:
-                            build_extension.compiler = "mingw32"
-                
-                if build_extension.compiler == "msvc":
-                    extra_compile_args = ['/EHsc', '-DBOOST_DATE_TIME_NO_LIB']
+            if platform.platform().startswith('Win') and ccompiler.get_default_compiler() == 'msvc':
+                extra_compile_args = ['/EHsc', '-DBOOST_DATE_TIME_NO_LIB']
 
         distutils.log.set_verbosity(verbose)
         extension = Extension(name=self.module_name,
@@ -330,7 +305,7 @@ def __init__(self, file=None, charset='utf-8', model_name="anon_model",
                               extra_compile_args=extra_compile_args)
 
         cython_include_dirs = ['.', pystan_dir]
-        
+        build_extension = _get_build_extension()
         build_extension.extensions = cythonize([extension],
                                                include_path=cython_include_dirs,
                                                quiet=not verbose)