Bug 1630350 - apply mach try filter to try syntax selector r=jmaher,gbrown

Changes:

Applies the `filter_tasks_by_blacklist` method to try syntax pushes as well.

  - moved `TARGET_TASK_BLACKLIST`and `filter_tasks_by_blacklist` method to live in `taskcluster/taskgraph/target_tasks.py`.
  - removed existing filters against `ccov, windows10-aarch64` and `android-hw` filters against try syntax pushes.
  - update imports for `fuzzy` and `chooser` selectors to refer to the new location of `filter_tasks_by_blacklist` method.

The reason for moving the logic (again) from `tools/tryselect` to `taskcluster/` is due to the placement of `try_option_syntax` and `target_tasks` files and both of those files handle the processing of `mach try syntax` pushes.

Differential Revision: https://phabricator.services.mozilla.com/D71698

taskcluster/taskgraph/target_tasks.py

@@ -6,12 +6,29 @@
 
 from __future__ import absolute_import, print_function, unicode_literals
 
+from re import search
+
 from taskgraph import try_option_syntax
 from taskgraph.parameters import Parameters
 from taskgraph.util.attributes import match_run_on_projects, match_run_on_hg_branches
 
 _target_task_methods = {}
 
+# Some tasks show up in the target task set, but are possibly special cases,
+# uncommon tasks, or tasks running against limited hardware set that they
+# should only be selectable with --full.
+TARGET_TASK_BLACKLIST = [
+    r'-ccov/',
+    r'windows10-aarch64/opt',
+    r'win64-aarch64-laptop',
+    r'windows10-64-ref-hw-2017',
+    r'android-hw',
+    r'android-geckoview-docs',
+    r'linux1804-32',   # hide linux32 tests - bug 1599197
+    r'linux-',  # hide all linux32 tasks by default - bug 1599197
+    r'linux.*web-platform-tests.*-fis-',  # hide wpt linux fission tests - bug 1610879
+]
+
 
 def _target_task(name):
     def wrap(func):
@@ -58,6 +75,23 @@ def filter_on_platforms(task, platforms):
     return (platform in platforms)
 
 
+def filter_tasks_by_blacklist(task, optional_filters=None):
+    """Filters tasks based on blacklist rules.
+
+    Args:
+        task (str): String representing the task name.
+
+    Returns:
+        (Boolean): True if task does not match any known filters.
+        False otherwise.
+    """
+    if optional_filters:
+        for item in optional_filters:
+            TARGET_TASK_BLACKLIST.append(item)
+
+    return not any(search(pattern, task) for pattern in TARGET_TASK_BLACKLIST)
+
+
 def filter_release_tasks(task, parameters):
     platform = task.attributes.get('build_platform')
     if platform in (
@@ -111,7 +145,7 @@ def _try_option_syntax(full_task_graph, parameters, graph_config):
     parameters['message'] and, for context, the full task graph."""
     options = try_option_syntax.TryOptionSyntax(parameters, full_task_graph, graph_config)
     target_tasks_labels = [t.label for t in full_task_graph.tasks.itervalues()
-                           if options.task_matches(t)]
+                           if options.task_matches(t) and filter_tasks_by_blacklist(t.label)]
 
     attributes = {
         k: getattr(options, k) for k in [