Filter out ANSI escape sequences when building with clang.

scripts/slave/compile.py

Index: scripts/slave/compile.py
===================================================================
--- scripts/slave/compile.py	(revision 117812)
+++ scripts/slave/compile.py	(working copy)
@@ -115,6 +115,44 @@
     env['LDPLUSPLUS'] = ldplusplus
 
 
+class CombineFilter(chromium_utils.RunCommandFilter):
+  """A RunCommandFilter that runs several RunCommandFilters in a sequence."""
+  def __init__(self, *filters):
+    chromium_utils.RunCommandFilter.__init__(self)
+    self.filters = filter(None, filters)
+
+  def FilterLine(self, a_line):
+    """Called by RunCommand for each line of output."""
+    for f in self.filters: a_line = f.FilterLine(a_line)
+    return a_line
+
+  def FilterDone(self, last_bits):
+    """Called by RunCommand when the command is done."""
+    for f in self.filters: last_bits = f.FilterDone(last_bits)
+    return last_bits
+
+
+# clang uses ANSII escape codes for colored diagnostics. Sadly, they get
+# disabled when ninja is used (https://github.com/martine/ninja/issues/174),
+# so we force clang's colors on. This filters the escape codes out so that
+# they don't show up on the buildbot output.
+# TODO(thakis): Pass escape sequences on to the master, and strip them there.
+# Then they can be converted to html on the side.
+class AnsiiEscapeSequenceStripper(chromium_utils.RunCommandFilter):
+  # http://en.wikipedia.org/wiki/ANSI_escape_code#Sequence_elements
+  # Only strip CSIs.
+  # This regex was taken from colorama.
+  ANSI_RE = re.compile('\033\[(?:\d|;)*[a-zA-Z]')
+
+  def FilterLine(self, a_line):
+    """Called by RunCommand for each line of output."""
+    return AnsiiEscapeSequenceStripper.ANSI_RE.sub('', a_line)
+
+  def FilterDone(self, last_bits):
+    """Called by RunCommand when the command is done."""
+    return AnsiiEscapeSequenceStripper.ANSI_RE.sub('', last_bits)
+
+
 # RunCommandFilter for xcodebuild
 class XcodebuildFilter(chromium_utils.RunCommandFilter):
   """xcodebuild filter"""
@@ -363,7 +401,7 @@
   # Set up the filter before changing directories so the raw build log can
   # be recorded.
   # Support a local file blocking filters (for debugging).  Also check the
-  # darwin version to make sure this is not 10.5 (easier then checking the
+  # darwin version to make sure this is not 10.5 (easier than checking the
   # Xcode version), as Xcode 3.1.x has slightly different output.
   xcodebuild_filter = None
   no_filter_path = os.path.join(os.getcwd(), 'no_xcodebuild_filter')
@@ -397,8 +435,12 @@
 
   # Run the build.
   env.print_overrides()
+
+  filter_obj = AnsiiEscapeSequenceStripper()
+  if xcodebuild_filter:
+    filter_obj = CombineFilter(filter_obj, xcodebuild_filter)
   result = chromium_utils.RunCommand(command, env=env,
-                                     filter_obj=xcodebuild_filter)
+                                     filter_obj=filter_obj)
 
   if options.compiler in ('goma', 'goma-clang', 'gomaclang'):
     # Always stop the proxy for now to allow in-place update.
@@ -643,8 +685,12 @@
       chromium_utils.RunCommand(goma_ctl_cmd + ['ensure_start'], env=env)
 
   # Run the build.
+  filter_obj = None
+  if options.compiler in ('clang', 'goma-clang'):
+    filter_obj = AnsiiEscapeSequenceStripper()
   env.print_overrides()
-  result = chromium_utils.RunCommand(command, env=env)
+  result = chromium_utils.RunCommand(command, env=env,
+                                     filter_obj=filter_obj)
 
   if options.compiler in ('goma', 'goma-clang'):
     # Always stop the proxy for now to allow in-place update.