Fix for OSX (#49)

* g++ fix for pybind11 OSX

* Make compiler flag platform dependent

* Try referring to Python executable direcly

* Make CPP BDT class module local in Python bindings

* Allow different threshold and score precison in cpp backend

conifer/backends/cpp/writer.py

@@ -2,7 +2,7 @@
 import numpy as np
 from shutil import copyfile
 import copy
-from conifer.utils import _ap_include, _json_include, copydocstring
+from conifer.utils import _ap_include, _json_include, _gcc_opts, _py_executable, copydocstring
 from conifer.model import ModelBase
 from conifer.backends.common import MultiPrecisionConfig
 import logging
@@ -19,8 +19,6 @@ def _extra_validate(self):
     # TODO: proagate different precisions properly through backend
     # for now enforce that all the precisions are equal
     assert self.input_precision == self.threshold_precision, f'input & threshold precision must be equal, got: {self.input_precision} & {self.threshold_precision}'
-    assert self.threshold_precision == self.score_precision, f'threshold & score precision must be equal, got: {self.threshold_precision} & {self.score_precision}'
-
 
 class CPPModel(ModelBase):
   def __init__(self, ensembleDict, config, metadata=None):
@@ -89,7 +87,7 @@ def compile(self):
     conifer_include = f'-I{filedir}/include/'
 
     # Do the compile
-    cmd = f"g++ -O3 -shared -std=c++14 -fPIC $(python3 -m pybind11 --includes) {ap_include} {json_include} {conifer_include} bridge.cpp -o conifer_bridge_{self._stamp}.so"
+    cmd = f"g++ -O3 -shared -std=c++14 -fPIC $({_py_executable()} -m pybind11 --includes) {ap_include} {json_include} {conifer_include} {_gcc_opts()} bridge.cpp -o conifer_bridge_{self._stamp}.so"
     logger.debug(f'Compiling with command {cmd}')
     try:
       ret_val = os.system(cmd)

conifer/backends/xilinxhls/writer.py

@@ -3,7 +3,7 @@
 import warnings
 import numpy as np
 import copy
-from conifer.utils import _ap_include, copydocstring
+from conifer.utils import _ap_include, _gcc_opts, _py_executable, copydocstring
 from conifer.backends.common import BottomUpDecisionTree, MultiPrecisionConfig, read_hls_report
 from conifer.model import ModelBase
 import datetime
@@ -452,7 +452,7 @@ def compile(self):
         if ap_include is None:
             os.chdir(curr_dir)
             raise Exception("Couldn't find Xilinx ap_ headers. Source the Vivado/Vitis HLS toolchain, or set XILINX_AP_INCLUDE environment variable.")
-        cmd = f"g++ -O3 -shared -std=c++14 -fPIC $(python3 -m pybind11 --includes) {ap_include} bridge.cpp firmware/BDT.cpp firmware/{cfg.project_name}.cpp -o conifer_bridge_{self._stamp}.so"
+        cmd = f"g++ -O3 -shared -std=c++14 -fPIC $({_py_executable()} -m pybind11 --includes) {ap_include} {_gcc_opts()} bridge.cpp firmware/BDT.cpp firmware/{cfg.project_name}.cpp -o conifer_bridge_{self._stamp}.so"
         logger.debug(f'Compiling with command {cmd}')
         try:
             ret_val = os.system(cmd)

conifer/utils/__init__.py

@@ -1,2 +1,2 @@
 from .fixed_point import FixedPointConverter
-from conifer.utils.misc import _ap_include, _json_include, copydocstring
+from conifer.utils.misc import _ap_include, _json_include, _gcc_opts, _py_executable, copydocstring

conifer/utils/misc.py

@@ -1,4 +1,5 @@
 import os
+import sys
 import logging
 logger = logging.getLogger(__name__)
 
@@ -32,6 +33,21 @@ def _json_include():
     logger.warn('Could not find JSON headers. JSON_ROOT not defined')
   return ret
 
+def _gcc_opts():
+  '''
+  Get extra platform specific g++ compile options
+  '''
+  if sys.platform == 'darwin':
+     return '-undefined dynamic_lookup'
+  else:
+     return ''
+
+def _py_executable():
+  '''
+  Get the python executable 
+  '''
+  return sys.executable
+
 def copydocstring(fromfunc, sep="\n"):
   """
   Decorator: Copy the docstring of `fromfunc`