Fix grcc compilation with python3 by adding local subdirs to __path__

As the directory structure in the repository is different then the one
after the package gets installed we need to add those subdirectories to
the __path__ otherwise python3 is not able to load the modules using the
relative import syntax and grcc compilation and some unit tests fail.

Mofiy __path__ only when the CMAKE_BINARY_DIR environment variable is
present.

Revert "grgsm_livemon: Set cell_allocation to [0]"

This reverts commit 013d4c258c6ad31c2581f0caa4eee3aa609fd9de.

Change-Id: I223fd6181e8e36027039301186b671712a597ff8

apps/grgsm_livemon.grc

@@ -360,7 +360,7 @@ blocks:
   parameters:
     affinity: ''
     alias: ''
-    cell_allocation: '[0]'
+    cell_allocation: '[arfcn.downlink2arfcn(fc)]'
     comment: ''
     maxoutbuf: '0'
     minoutbuf: '0'

apps/grgsm_livemon_headless.grc

@@ -315,7 +315,7 @@ blocks:
   parameters:
     affinity: ''
     alias: ''
-    cell_allocation: '[0]'
+    cell_allocation: '[arfcn.downlink2arfcn(fc)]'
     comment: ''
     maxoutbuf: '0'
     minoutbuf: '0'

cmake/Modules/GrccCompile.cmake

@@ -39,6 +39,7 @@ macro(GRCC_COMPILE file_name)
         OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${file_name}
         COMMAND "${CMAKE_COMMAND}"
         -E env PYTHONPATH="${PYTHONPATH}" GRC_BLOCKS_PATH=${CMAKE_SOURCE_DIR}/grc
+        CMAKE_BINARY_DIR=${CMAKE_BINARY_DIR}
         ${GRCC} -o ${CMAKE_CURRENT_BINARY_DIR}
         ${CMAKE_CURRENT_SOURCE_DIR}/${file_name}.grc
         COMMAND "${CMAKE_COMMAND}" -E rename ${CMAKE_CURRENT_BINARY_DIR}/${file_name}.py ${CMAKE_CURRENT_BINARY_DIR}/${file_name}

python/CMakeLists.txt

@@ -47,7 +47,8 @@ GR_PYTHON_INSTALL(
 include(GrTest)
 
 set(GR_TEST_TARGET_DEPS gr-gsm)
-set(GR_TEST_PYTHON_DIRS ${CMAKE_BINARY_DIR}/swig:${CMAKE_BINARY_DIR}/python/misc_utils:${CMAKE_BINARY_DIR}/python/receiver:${CMAKE_BINARY_DIR}/python/demapping:${CMAKE_BINARY_DIR}/python/transmitter)
+set(GR_TEST_PYTHON_DIRS ${CMAKE_BINARY_DIR}/swig:${CMAKE_BINARY_DIR}/python/misc_utils)
+set(GR_TEST_ENVIRONS "CMAKE_BINARY_DIR=${CMAKE_BINARY_DIR}")
 GR_ADD_TEST(qa_arfcn ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_arfcn.py)
 GR_ADD_TEST(qa_decryption ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_decryption.py)
 GR_ADD_TEST(qa_burst_printer ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_burst_printer.py)

python/__init__.py

@@ -23,6 +23,25 @@ This is the GNU Radio GSM module. Place your Python package
 description here (python/__init__.py).
 '''
 
+import os
+
+if "CMAKE_BINARY_DIR" in os.environ:
+    dirname, filename = os.path.split(os.path.abspath(__file__))
+
+    # As the directory structure in the repository is different then the one after the package
+    # gets installed we need to add those subdirectories to the __path__ otherwise python3 is
+    # not able to load the modules using the relative import syntax and grcc compilation and
+    # some unit tests fail.
+    __path__ += [
+        # Load the local (not yet installed) grgsm_swig from the ../swig subdirectory.
+        os.path.join(os.environ.get("CMAKE_BINARY_DIR"), "swig"),
+
+        # Load the local (not yet installed) python modules from the local subdirectories
+        os.path.join(dirname, "misc_utils"),
+        os.path.join(dirname, "receiver"),
+        os.path.join(dirname, "demapping"),
+        os.path.join(dirname, "transmitter"),
+        os.path.join(dirname, "trx")]
 
 # import swig generated symbols into the gsm namespace
 from .grgsm_swig import *