Give better message when source files are missing

If source files are missing from the system which are in the plist
file we should write out the missing file paths too.

libcodechecker/libhandlers/store.py

@@ -187,21 +187,32 @@ def assemble_zip(inputs, zip_file, client):
     # but different path.
     file_to_hash = {}
     file_to_mtime = {}
+    missing_source_files = set()
 
     def collect_file_hashes_from_plist(plist_file):
+        """
+        Collects file content hashes and last modification times of files which
+        can be found in the given plist file.
+
+        :returns List of file paths which are in the processed plist file but
+        missing from the user's disk.
+        """
+        missing_files = []
         try:
             files, _ = plist_parser.parse_plist(plist_file)
 
             for f in files:
                 if not os.path.isfile(f):
-                    return False
+                    missing_files.append(f)
+                    missing_source_files.add(f)
+                    continue
 
                 content_hash = util.get_file_content_hash(f)
                 hash_to_file[content_hash] = f
                 file_to_hash[f] = content_hash
                 file_to_mtime[f] = util.get_last_mod_time(f)
 
-            return True
+            return missing_files
         except Exception as ex:
             LOG.error('Parsing the plist failed: ' + str(ex))
 
@@ -223,15 +234,16 @@ def collect_file_hashes_from_plist(plist_file):
         for f in files:
             plist_file = os.path.join(input_path, f)
             if f.endswith(".plist"):
-                if collect_file_hashes_from_plist(plist_file):
+                missing_files = collect_file_hashes_from_plist(plist_file)
+                if not missing_files:
                     LOG.debug(
                         "Copying file '{0}' to ZIP assembly dir..."
                         .format(plist_file))
                     plist_report_files.append(os.path.join(input_path, f))
                 else:
-                    LOG.warning("Skipping '{0}' because it contains "
-                                "a missing source file."
-                                .format(plist_file))
+                    LOG.warning("Skipping '%s' because it refers "
+                                "the following missing source files: %s",
+                                plist_file, missing_files)
             elif f == 'metadata.json':
                 plist_report_files.append(os.path.join(input_path, f))
 
@@ -278,6 +290,10 @@ def collect_file_hashes_from_plist(plist_file):
 
     LOG.debug("[ZIP] Mass store zip written at '{0}'".format(zip_file))
 
+    if missing_source_files:
+        LOG.warning("Missing source files: \n%s", '\n'.join(
+            map(lambda f_: " - " + f_, missing_source_files)))
+
 
 def main(args):
     """