Implement multiarch support in catkin (ros#545)

This implements multiarch support (ros#545), and supercedes
(ros#604). A two step approach uses gcc -print-multiarch and,
if failed, fallback to use dpkg-architecture to identify
an appropriate lib folder suffix to use for LD_LIBRARY_PATH
and PKG_CONFIG_PATH. builder.py and
catkin_generate_environment.cmake are modified
accordingly.

Thanks to @j-rivero for his contributions, which are hidden in
this squashed commit.

cmake/catkin_generate_environment.cmake

@@ -10,6 +10,32 @@ function(catkin_generate_environment)
     file(WRITE "${CMAKE_BINARY_DIR}/CATKIN_IGNORE" "")
   endif()
 
+  # get multiarch name
+  set(CATKIN_LIB_ENVIRONMENT_PATHS "'${CATKIN_GLOBAL_LIB_DESTINATION}'")
+  set(CATKIN_PKGCONFIG_ENVIRONMENT_PATHS "os.path.join('${CATKIN_GLOBAL_LIB_DESTINATION}', 'pkgconfig')")
+  if (UNIX AND NOT APPLE)
+    # Two step looking for multiarch support: check for gcc -print-multiarch
+    # and, if failed, try to run dpkg-architecture
+    execute_process(COMMAND gcc -print-multiarch
+                    OUTPUT_VARIABLE CATKIN_MULTIARCH
+                    OUTPUT_STRIP_TRAILING_WHITESPACE
+                    ERROR_QUIET
+    )
+    if ("${CATKIN_MULTIARCH}" STREQUAL "")
+      execute_process(COMMAND dpkg-architecture -qDEB_HOST_MULTIARCH
+                      OUTPUT_VARIABLE CATKIN_MULTIARCH
+                      OUTPUT_STRIP_TRAILING_WHITESPACE
+                      ERROR_QUIET
+      )
+    endif()
+    if (NOT "${CATKIN_MULTIARCH}" STREQUAL "")
+      set(CATKIN_LIB_ENVIRONMENT_PATHS
+        "[${CATKIN_LIB_ENVIRONMENT_PATHS}, os.path.join('${CATKIN_GLOBAL_LIB_DESTINATION}', '${CATKIN_MULTIARCH}')]")
+      set(CATKIN_PKGCONFIG_ENVIRONMENT_PATHS
+        "[${CATKIN_PKGCONFIG_ENVIRONMENT_PATHS}, os.path.join('${CATKIN_GLOBAL_LIB_DESTINATION}', '${CATKIN_MULTIARCH}', 'pkgconfig')]")
+    endif()
+  endif()
+
   # generate Python setup util
   atomic_configure_file(${catkin_EXTRAS_DIR}/templates/_setup_util.py.in
     ${CATKIN_DEVEL_PREFIX}/_setup_util.py

cmake/templates/_setup_util.py.in

@@ -52,9 +52,9 @@ IS_WINDOWS = (system == 'Windows')
 ENV_VAR_SUBFOLDERS = {
     'CMAKE_PREFIX_PATH': '',
     'CPATH': 'include',
-    'LD_LIBRARY_PATH' if not IS_DARWIN else 'DYLD_LIBRARY_PATH': '@CATKIN_GLOBAL_LIB_DESTINATION@',
+    'LD_LIBRARY_PATH' if not IS_DARWIN else 'DYLD_LIBRARY_PATH': @CATKIN_LIB_ENVIRONMENT_PATHS@,
     'PATH': '@CATKIN_GLOBAL_BIN_DESTINATION@',
-    'PKG_CONFIG_PATH': 'lib/pkgconfig',
+    'PKG_CONFIG_PATH': @CATKIN_PKGCONFIG_ENVIRONMENT_PATHS@,
     'PYTHONPATH': '@PYTHON_INSTALL_DIR@',
 }
 
@@ -68,11 +68,14 @@ def rollback_env_variables(environ, env_var_subfolders):
     lines = []
     unmodified_environ = copy.copy(environ)
     for key in sorted(env_var_subfolders.keys()):
-        subfolder = env_var_subfolders[key]
-        value = _rollback_env_variable(unmodified_environ, key, subfolder)
-        if value is not None:
-            environ[key] = value
-            lines.append(assignment(key, value))
+        subfolders = env_var_subfolders[key]
+        if not isinstance(subfolders, list):
+            subfolders = [subfolders]
+        for subfolder in subfolders:
+            value = _rollback_env_variable(unmodified_environ, key, subfolder)
+            if value is not None:
+                environ[key] = value
+                lines.append(assignment(key, value))
     if lines:
         lines.insert(0, comment('reset environment variables by unrolling modifications based on all workspaces in CMAKE_PREFIX_PATH'))
     return lines
@@ -143,19 +146,23 @@ def prepend_env_variables(environ, env_var_subfolders, workspaces):
     return lines
 
 
-def _prefix_env_variable(environ, name, paths, subfolder):
+def _prefix_env_variable(environ, name, paths, subfolders):
     '''
     Return the prefix to prepend to the environment variable NAME, adding any path in NEW_PATHS_STR without creating duplicate or empty items.
     '''
     value = environ[name] if name in environ else ''
     environ_paths = [path for path in value.split(os.pathsep) if path]
     checked_paths = []
     for path in paths:
-        if subfolder:
-            path = os.path.join(path, subfolder)
-        # exclude any path already in env and any path we already added
-        if path not in environ_paths and path not in checked_paths:
-            checked_paths.append(path)
+        if not isinstance(subfolders, list):
+            subfolders = [subfolders]
+        for subfolder in subfolders:
+            path_tmp = path
+            if subfolder:
+                path_tmp = os.path.join(path_tmp, subfolder)
+            # exclude any path already in env and any path we already added
+            if path_tmp not in environ_paths and path_tmp not in checked_paths:
+                checked_paths.append(path_tmp)
     prefix_str = os.pathsep.join(checked_paths)
     if prefix_str != '' and environ_paths:
         prefix_str += os.pathsep

python/catkin/builder.py

@@ -249,6 +249,25 @@ def isolation_print_command(cmd, path=None, add_env=None):
     )
 
 
+def get_multiarch():
+    if not sys.platform.lower().startswith('linux'):
+        return ''
+    # this function returns the suffix for lib directories on supported systems or an empty string
+    # it uses two step approach to look for multiarch: first run gcc -print-multiarch and if
+    # failed try to run dpkg-architecture
+    p = subprocess.Popen(
+        ['gcc', '-print-multiarch'],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    out, err = p.communicate()
+    if p.returncode != 0:
+        out, err = subprocess.Popen(
+            ['dpkg-architecture', '-qDEB_HOST_MULTIARCH'],
+            stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
+
+    # be sure of returning empty string or a valid multiarch tuple format
+    assert(not out.strip() or out.strip().count('-') == 2);
+    return out.strip()
+
 def get_python_install_dir():
     # this function returns the same value as the CMake variable PYTHON_INSTALL_DIR from catkin/cmake/python.cmake
     python_install_dir = 'lib'
@@ -519,9 +538,12 @@ def build_cmake_package(
         subs['ld_path'] = os.path.join(install_target, 'lib') + ":"
         pythonpath = os.path.join(install_target, get_python_install_dir())
         subs['pythonpath'] = pythonpath + ':'
-        subs['pkgcfg_path'] = os.path.join(install_target, 'lib', 'pkgconfig')
-        subs['pkgcfg_path'] += ":"
+        subs['pkgcfg_path'] = os.path.join(install_target, 'lib', 'pkgconfig') + ":"
         subs['path'] = os.path.join(install_target, 'bin') + ":"
+        arch = get_multiarch()
+        if arch:
+            subs['ld_path'] += os.path.join(install_target, 'lib', arch) + ":"
+            subs['pkgcfg_path'] += os.path.join(install_target, 'lib', arch, 'pkgconfig') + ":"
         if not os.path.exists(os.path.dirname(new_setup_path)):
             os.mkdir(os.path.dirname(new_setup_path))
         with open(new_setup_path, 'w') as file_handle:

test/unit_tests/test_setup_util.py

@@ -7,7 +7,8 @@
 
 data = configure_file(os.path.join(os.path.dirname(__file__), '..', '..', 'cmake', 'templates', '_setup_util.py.in'),
                       {
-                          'CATKIN_GLOBAL_LIB_DESTINATION': 'lib',
+                          'CATKIN_LIB_ENVIRONMENT_PATHS': "'lib'",
+                          'CATKIN_PKGCONFIG_ENVIRONMENT_PATHS': "os.path.join('lib', 'pkgconfig')",
                           'CATKIN_GLOBAL_BIN_DESTINATION': 'bin',
                           'PYTHON_INSTALL_DIR': 'pythonX.Y/packages',
                           'CMAKE_PREFIX_PATH_AS_IS': '',