Print instructions on how to promote subsubprojects.

mesonbuild/interpreter.py

@@ -2196,6 +2196,7 @@ to directly access options of other subprojects.''')
                         # we won't actually read all the build files.
                         return fallback_dep
                 if not dep:
+                    self.print_nested_info(name)
                     assert(exception is not None)
                     raise exception
 
@@ -2209,6 +2210,28 @@ to directly access options of other subprojects.''')
     def func_disabler(self, node, args, kwargs):
         return Disabler()
 
+    def print_nested_info(self, dependency_name):
+        message_templ = '''\nDependency %s not found but it is available in a sub-subproject.
+To use it in the current project, promote it by going in the project source
+root and issuing %s.
+
+'''
+        sprojs = mesonlib.detect_subprojects('subprojects', self.source_root)
+        if dependency_name not in sprojs:
+            return
+        found = sprojs[dependency_name]
+        if len(found) > 1:
+            suffix = 'one of the following commands'
+        else:
+            suffix = 'the following command'
+        message = message_templ % (dependency_name, suffix)
+        cmds = []
+        command_templ = 'meson wrap promote '
+        for l in found:
+            cmds.append(command_templ + l[len(self.source_root)+1:])
+        final_message = message + '\n'.join(cmds)
+        print(final_message)
+
     def get_subproject_infos(self, kwargs):
         fbinfo = kwargs['fallback']
         check_stringlist(fbinfo)

mesonbuild/mesonlib.py

@@ -881,6 +881,35 @@ def windows_proof_rmtree(f):
     # Try one last time and throw if it fails.
     shutil.rmtree(f)
 
+def unholder_array(entries):
+    result = []
+    entries = flatten(entries)
+    for e in entries:
+        if hasattr(e, 'held_object'):
+            e = e.held_object
+        result.append(e)
+    return result
+
+
+def detect_subprojects(spdir_name, current_dir='', result=None):
+    if result is None:
+        result = {}
+    spdir = os.path.join(current_dir, spdir_name)
+    if not os.path.exists(spdir):
+        return result
+    for trial in glob(os.path.join(spdir, '*')):
+        basename = os.path.split(trial)[1]
+        if trial == 'packagecache':
+            continue
+        if not os.path.isdir(trial):
+            continue
+        if basename in result:
+            result[basename].append(trial)
+        else:
+            result[basename] = [trial]
+        detect_subprojects(spdir_name, trial, result)
+    return result
+
 class OrderedSet(collections.MutableSet):
     """A set that preserves the order in which items are added, by first
     insertion.

mesonbuild/wrap/wraptool.py

@@ -21,6 +21,8 @@ from glob import glob
 
 from .wrap import API_ROOT, open_wrapdburl
 
+from .. import mesonlib
+
 help_templ = '''This program allows you to manage your Wrap dependencies
 using the online wrap database http://wrapdb.mesonbuild.com.
 
@@ -149,29 +151,10 @@ def do_promotion(from_path, spdir_name):
         sys.exit('Output dir %s already exists. Will not overwrite.' % outputdir)
     shutil.copytree(from_path, outputdir, ignore=shutil.ignore_patterns('subprojects'))
 
-def detect_subprojects(spdir_name, current_dir='', result=None):
-    if result is None:
-        result = {}
-    spdir = os.path.join(current_dir, spdir_name)
-    if not os.path.exists(spdir):
-        return result
-    for trial in glob(os.path.join(spdir, '*')):
-        basename = os.path.split(trial)[1]
-        if trial == 'packagecache':
-            continue
-        if not os.path.isdir(trial):
-            continue
-        if basename in result:
-            result[basename].append(trial)
-        else:
-            result[basename] = [trial]
-        detect_subprojects(spdir_name, trial, result)
-    return result
-
 def promote(argument):
     path_segment, subproject_name = os.path.split(argument)
     spdir_name = 'subprojects'
-    sprojs = detect_subprojects(spdir_name)
+    sprojs = mesonlib.detect_subprojects(spdir_name)
     if subproject_name not in sprojs:
         sys.exit('Subproject %s not found in directory tree.' % subproject_name)
     matches = sprojs[subproject_name]