display "latest GM failures" link in its own line under build step

master/skia_master_scripts/skia_build_step.py

Index: master/skia_master_scripts/skia_build_step.py
diff --git a/master/skia_master_scripts/skia_build_step.py b/master/skia_master_scripts/skia_build_step.py
index 0efbccd08850ffa26c2e66587f18fb83dcbe61b6..f771e7792fb6496f33d7220d2f963be5829b3e90 100644
--- a/master/skia_master_scripts/skia_build_step.py
+++ b/master/skia_master_scripts/skia_build_step.py
@@ -16,14 +16,18 @@ class SkiaBuildStep(retcode_command.ReturnCodeCommand):
   to by BuildStep.getProperty() are scoped for the entire duration of the build.
   """
   def __init__(self, is_upload_step=False, is_rebaseline_step=False,
-               get_props_from_stdout=None, exception_on_failure=False,
-               **kwargs):
+               get_links_from_stdout=None, get_props_from_stdout=None,
+               exception_on_failure=False, **kwargs):
     """ Instantiates a new SkiaBuildStep.
 
     is_upload_step: boolean indicating whether this step should be skipped when
         the buildbot is not performing uploads.
     is_rebaseline_step: boolean indicating whether this step is required for
         rebaseline-only builds.
+    get_links_from_stdout: optional dictionary. Keys are strings indicating
+        link text to set based on the output of this step. Values are
+        strings containing regular expressions for parsing the linked URL from
+        the output of the step.
     get_props_from_stdout: optional dictionary. Keys are strings indicating
         build properties to set based on the output of this step. Values are
         strings containing regular expressions for parsing the property from
@@ -36,6 +40,7 @@ class SkiaBuildStep(retcode_command.ReturnCodeCommand):
     """
     self._is_upload_step = is_upload_step
     self._is_rebaseline_step = is_rebaseline_step
+    self._get_links_from_stdout = get_links_from_stdout
     self._get_props_from_stdout = get_props_from_stdout
     self._exception_on_failure = exception_on_failure
 
@@ -57,28 +62,41 @@ class SkiaBuildStep(retcode_command.ReturnCodeCommand):
     """ Override of BuildStep's commandComplete method which allows us to parse
     build properties from the output of this step. """
 
-    # We make a best effort to parse the properties out of stdout, whether
-    # the command succeeded or failed.  If the command succeeded, we
-    # definitely expect the property to be found in stdout--if not, raise
-    # an exception.
-    if self._get_props_from_stdout:
+    if self._get_props_from_stdout or self._get_links_from_stdout:
       log = cmd.logs['stdio']
       stdout = ''.join(log.getChunks([STDOUT], onlyText=True))

[borenet, 2014/06/06 12:10:34]

This is probably a performance killer. Seems like it wouldn't be hard to rewrite
this, as long as we don't care about properties/links with multi-line regexp.

[epoger, 2014/06/09 13:33:29]

I don't know how the chunks are split.  It would not be ideal to sometimes miss
an item because it straddled the borderline between two chunks.

       self._changed_props = {}
-      for prop, regex in self._get_props_from_stdout.iteritems():
-        matches = re.search(regex, stdout)
-        if not matches:
-          if cmd.rc == 0:
-            raise Exception('Unable to parse %s from stdout.' % prop)
-          continue
-        groups = matches.groups()
-        if len(groups) != 1:
-          if cmd.rc == 0:
-            raise Exception('Multiple matches for "%s"' % regex)
-          continue
-        prop_value = groups[0]
-        self.setProperty(prop, prop_value, ''.join(self.description))
-        self._changed_props[prop] = prop_value
+
+      # We make a best effort to parse the properties out of stdout, whether
+      # the command succeeded or failed.  If the command succeeded, we
+      # definitely expect the property to be found in stdout--if not, raise
+      # an exception.
+      if self._get_props_from_stdout:
+        for prop, regex in self._get_props_from_stdout.iteritems():
+          matches = re.search(regex, stdout)
+          if not matches:
+            if cmd.rc == 0:
+              raise Exception('Unable to parse %s from stdout.' % prop)
+            continue
+          groups = matches.groups()
+          if len(groups) != 1:
+            if cmd.rc == 0:
+              raise Exception('Multiple matches for "%s"' % regex)
+            continue
+          prop_value = groups[0]
+          self.setProperty(prop, prop_value, ''.join(self.description))
+          self._changed_props[prop] = prop_value
+
+      # If there might be URL links we want in stdout, look for them;
+      # their presence is optional, though, so we don't throw an exception
+      # if they are not found.
+      if self._get_links_from_stdout:
+        for name, regex in self._get_links_from_stdout.iteritems():
+          matches = re.search(regex, stdout)
+          if matches:
+            groups = matches.groups()
+            for url in groups:
+              self.addURL(name, url)
 
     if (cmd.rc not in (0, retcode_command.ReturnCodeCommand.RETCODE_WARNINGS)
         and self._exception_on_failure):