Rules
action_listener
View rule sourceopen_in_newaction_listener rule doesn’t produce any output itself.
Instead, it allows tool developers to insert
extra_action s into the build system,
by providing a mapping from action to extra_action.
This rule’s arguments map action mnemonics to
extra_action rules.
By specifying the option --experimental_action_listener=<label>,
the build will use the specified action_listener to insert
extra_action s into the build graph.
Example
Arguments
Attributesname
Name; required
A unique name for this target.
extra_actions
List of labels; required
A list of extra_action targets
this action_listener should add to the build graph.
E.g. [ "//my/tools:analyzer" ].
mnemonics
List of strings; required
A list of action mnemonics this action_listener should listen
for, e.g. [ "Javac" ].
Mnemonics are not a public interface.
There’s no guarantee that the mnemonics and their actions don’t change.
extra_action
View rule sourceopen_in_newextra_action rule doesn’t produce any meaningful output
when specified as a regular build target. Instead, it allows tool developers
to insert additional actions into the build graph that shadow existing actions.
See action_listener for details
on how to enable extra_action s.
The extra_action s run as a command-line. The command-line tool gets
access to a file containing a protocol buffer as $(EXTRA_ACTION_FILE)
with detailed information on the original action it is shadowing.
It also has access to all the input files the original action has access to.
See extra_actions_base.proto
for details on the data stored inside the protocol buffer. Each proto file
contains an ExtraActionInfo message.
Just like all other actions, extra actions are sandboxed, and should be designed to handle that.
Arguments
Attributesname
Name; required
A unique name for this target.
You may refer to this rule by label in the extra_actions argument
of action_listener rules.
cmd
String; required
The command to run.
Like genrule cmd attribute with the following
differences:
- No heuristic label expansion. Only labels using $(location …) are expanded.
-
An additional pass is applied to the string to replace all
occurrences of the outputs created from the
out_templatesattribute. All occurrences of$(output out_template)are replaced with the path to the file denoted bylabel. E.g. out_template$(ACTION_ID).analysiscan be matched with$(output $(ACTION_ID).analysis). In effect, this is the same substitution as$(location)but with a different scope.
out_templates
List of strings; default is []
A list of templates for files generated by the extra_action command.
The template can use the following variables:
- $(ACTION_ID), an id uniquely identifying this
extra_action. Used to generate a unique output file.
requires_action_output
Boolean; default is False
Indicates this extra_action requires the output of the
original action to be present as input to this extra_action.
When true (default false), the extra_action can assume that the
original action outputs are available as part of its inputs.
tools
List of labels; default is []
A list of tool dependencies for this rule.
See the definition of dependencies for more
information.
The build system ensures these prerequisites are built before running the
extra_action command; they are built using the
exec configuration,
since they must run as a tool during the build itself. The path of an individual
tools target //x:y can be obtained using
$(location //x:y).
All tools and their data dependencies are consolidated into a single tree
within which the command can use relative paths. The working directory will
be the root of that unified tree.