userland: allow selecting targets, including directories

build-userland

@@ -30,10 +30,12 @@ allows us to build examples that rely on it.
             'targets',
             default=[],
             help='''\
-Build only the given userland programs.
-Default: build all examples that have their package dependencies met.
-For example, an OpenBLAS example can only be built if the target root filesystem
-has the OpenBLAS libraries and headers installed.
+Build only the given userland programs or all programs in the given directories.
+
+Default: build all examples that have their package dependencies met, e.g.:
+-   userland/arch/ programs only build if the target arch matches
+-   an OpenBLAS example can only be built if the target root filesystem
+    has the OpenBLAS libraries and headers installed, which you must inform with --has-package
 ''',
             nargs='*',
         )
@@ -90,7 +92,7 @@ has the OpenBLAS libraries and headers installed.
                                 '-o', out_path, LF,
                                 in_path, LF,
                             ] +
-                            extra_objs +
+                            self.sh.add_newlines(extra_objs) +
                             [
                                 '-lm', LF,
                                 '-pthread', LF,
@@ -160,9 +162,15 @@ has the OpenBLAS libraries and headers installed.
         rootdir_abs_len = len(self.env['userland_source_dir'])
         thread_limiter = threading.BoundedSemaphore(self.env['nproc'])
         self.error = False
-        for path, in_dirnames, in_filenames in os.walk(self.env['userland_source_dir']):
+        if self.env['_args_given']['targets']:
+            targets = self.env['targets']
+        else:
+            targets = [self.env['userland_source_dir']]
+        for target in targets:
+            for path, in_dirnames, in_filenames in self.sh.walk(target):
                 in_dirnames.sort()
-            dirpath_relative_root = path[rootdir_abs_len + 1:]
+                path_abs = os.path.abspath(path)
+                dirpath_relative_root = path_abs[rootdir_abs_len + 1:]
                 dirpath_relative_root_components = dirpath_relative_root.split(os.sep)
                 if (
                     len(dirpath_relative_root_components) < 2 or

common.py

@@ -1169,7 +1169,10 @@ class BuildCliFunction(LkmcCliFunction):
         self.add_argument(
             '--force-rebuild',
             default=False,
-            help="Force rebuild even if sources didn't chage",
+            help='''\
+Force rebuild even if sources didn't chage.
+TODO: not yet implemented on all scripts.
+'''
         )
         self.add_argument(
             '-j',

shell_helpers.py

@@ -310,6 +310,19 @@ class ShellHelpers:
             else:
                 os.unlink(path)
 
+    def walk(self, root):
+        '''
+        Extended walk that can take files or directories.
+        '''
+        if not os.path.exists(root):
+            raise Exception('Path does not exist: ' + root)
+        if os.path.isfile(root):
+            dirname, basename = os.path.split(root)
+            yield dirname, [], [basename]
+        else:
+            for path, dirnames, filenames in os.walk(root):
+                yield path, dirnames, filenames
+
     def wget(self, url, download_path):
         '''
         Append extra KEY=val configs into the given config file.

userland/arch/aarch64/Makefile

@@ -1 +0,0 @@
-../../Makefile

userland/arch/aarch64/params.mk

@@ -1 +0,0 @@
-COMMON_DIR = ../../..

userland/arch/x86_64/Makefile

@@ -1 +0,0 @@
-../../Makefile

userland/arch/x86_64/params.mk

@@ -1 +0,0 @@
-COMMON_DIR = ../../..