output clang compile database with test build

SConstruct

@@ -2,9 +2,9 @@ import os
 import shutil
 import subprocess
 import sys
+import sysconfig
 import platform
 import numpy as np
-from sysconfig import get_paths
 
 TICI = os.path.isfile('/TICI')
 Decider('MD5-timestamp')
@@ -124,10 +124,6 @@ else:
 # change pythonpath to this
 lenv["PYTHONPATH"] = Dir("#").path
 
-#Get the path for Python.h for cython linking
-python_path = get_paths()['include']
-numpy_path = np.get_include()
-
 env = Environment(
   ENV=lenv,
   CCFLAGS=[
@@ -188,9 +184,13 @@ env = Environment(
     "#selfdrive/common",
   ],
   CYTHONCFILESUFFIX=".cpp",
-  tools=["default", "cython"]
+  COMPILATIONDB_USE_ABSPATH=True,
+  tools=["default", "cython", "compilation_db"],
 )
 
+if GetOption('test'):
+  env.CompilationDatabase('compile_commands.json')
+
 if os.environ.get('SCONS_CACHE'):
   cache_dir = '/tmp/scons_cache'
 
@@ -230,22 +230,20 @@ def abspath(x):
     # rpath works elsewhere
     return x[0].path.rsplit("/", 1)[1][:-3]
 
-#Cython build enviroment
+# Cython build enviroment
+py_include = sysconfig.get_paths()['include']
 envCython = env.Clone()
-envCython["CPPPATH"] += [python_path, numpy_path]
+envCython["CPPPATH"] += [py_include, np.get_include()]
 envCython["CCFLAGS"] += ["-Wno-#warnings", "-Wno-deprecated-declarations"]
 
-python_libs = []
+envCython["LIBS"] = []
 if arch == "Darwin":
-  envCython["LINKFLAGS"]=["-bundle", "-undefined", "dynamic_lookup"]
+  envCython["LINKFLAGS"] = ["-bundle", "-undefined", "dynamic_lookup"]
 elif arch == "aarch64":
-  envCython["LINKFLAGS"]=["-shared"]
-
-  python_libs.append(os.path.basename(python_path))
+  envCython["LINKFLAGS"] = ["-shared"]
+  envCython["LIBS"] = os.path.basename(py_include)
 else:
-  envCython["LINKFLAGS"]=["-pthread", "-shared"]
-
-envCython["LIBS"] = python_libs
+  envCython["LINKFLAGS"] = ["-pthread", "-shared"]
 
 Export('envCython')
 
@@ -306,3 +304,4 @@ if arch != "Darwin":
 
 if arch == "x86_64":
   SConscript(['tools/lib/index_log/SConscript'])
+