bazel-skylib/docs/selects_doc.md

Skylib module containing convenience interfaces for select().

selects.config_setting_group

selects.config_setting_group(name, match_any, match_all, visibility)

Matches if all or any of its member config_settings match.

Example:

config_setting(name = "one", define_values = {"foo": "true"})
config_setting(name = "two", define_values = {"bar": "false"})
config_setting(name = "three", define_values = {"baz": "more_false"})

config_setting_group(
    name = "one_two_three",
    match_all = [":one", ":two", ":three"]
)

cc_binary(
    name = "myapp",
    srcs = ["myapp.cc"],
    deps = select({
        ":one_two_three": [":special_deps"],
        "//conditions:default": [":default_deps"]
    })

PARAMETERS

Name	Description	Default Value
name	The group's name. This is how select()s reference it.	none
match_any	A list of config_settings. This group matches if any member in the list matches. If this is set, match_all must not be set.	[]
match_all	A list of config_settings. This group matches if every member in the list matches. If this is set, match_any must be not set.	[]
visibility	Visibility of the config_setting_group.	None

selects.with_or

selects.with_or(input_dict, no_match_error)

Drop-in replacement for select() that supports ORed keys.

Example:

  ```build
  deps = selects.with_or({
      "//configs:one": [":dep1"],
      ("//configs:two", "//configs:three"): [":dep2or3"],
      "//configs:four": [":dep4"],
      "//conditions:default": [":default"]
  })
  ```

  Key labels may appear at most once anywhere in the input.

PARAMETERS

Name	Description	Default Value
input_dict	The same dictionary select() takes, except keys may take either the usual form "//foo:config1" or ("//foo:config1", "//foo:config2", ...) to signify //foo:config1 OR //foo:config2 OR ....	none
no_match_error	Optional custom error to report if no condition matches.	""

RETURNS

A native select() that expands

("//configs:two", "//configs:three"): [":dep2or3"]

to

"//configs:two": [":dep2or3"],
"//configs:three": [":dep2or3"],

selects.with_or_dict

selects.with_or_dict(input_dict)

Variation of with_or that returns the dict of the select().

Unlike select(), the contents of the dict can be inspected by Starlark macros.

PARAMETERS

Name	Description	Default Value
input_dict	Same as with_or.	none

RETURNS

A dictionary usable by a native select().