|
| 1 | +"""Phase implementing variable expansion for the env attribute""" |
| 2 | + |
| 3 | +def _expand_part(ctx, attr_name, part, targets, additional_vars): |
| 4 | + """Perform `$(location)` and "Make variable" substitution for `expand_vars`. |
| 5 | +
|
| 6 | + As for why we're using the "deprecated" `ctx.expand_make_variables`: |
| 7 | +
|
| 8 | + - https://github.com/bazelbuild/bazel/issues/5859 |
| 9 | + - https://github.com/bazelbuild/bazel-skylib/pull/486 |
| 10 | +
|
| 11 | + The "deprecated" comment in the `ctx.expand_make_variables` docstring has |
| 12 | + existed from the beginning of the file's existence (2018-05-11): |
| 13 | +
|
| 14 | + - https://github.com/bazelbuild/bazel/commit/abbb9002c41bbd53588e7249756aab236f6fcb4b |
| 15 | + """ |
| 16 | + expanded = ctx.expand_location(part, targets) |
| 17 | + return ctx.expand_make_variables(attr_name, expanded, additional_vars) |
| 18 | + |
| 19 | +def expand_vars(ctx, attr_name, value, targets, additional_vars): |
| 20 | + """Perform `$(location)` and "Make variable" substitution on an attribute. |
| 21 | +
|
| 22 | + - https://bazel.build/reference/be/make-variables#use |
| 23 | +
|
| 24 | + Args: |
| 25 | + ctx: Rule context object |
| 26 | + attr_name: name of the attribute (for error messages) |
| 27 | + value: the attribute value |
| 28 | + targets: a list of `Target` values to use with `$(location)` expansion |
| 29 | + additional_vars: additional values to use with "Make variable" expansion |
| 30 | +
|
| 31 | + Returns: |
| 32 | + the result of performing `$(location)` and "Make variable" substitution |
| 33 | + on the specified attribute value |
| 34 | + """ |
| 35 | + # Splitting on `$$` ensures that escaped `$` values prevent `$(location)` |
| 36 | + # and "Make variable" substitution for those portions of `value`. |
| 37 | + return "$".join([ |
| 38 | + _expand_part(ctx, attr_name, s, targets, additional_vars) |
| 39 | + for s in value.split("$$") |
| 40 | + ]) |
| 41 | + |
| 42 | +def run_environment_info(ctx, additional_attr_names = []): |
| 43 | + """Create a RunEnvironmentInfo provider from `ctx.attr.env` values. |
| 44 | +
|
| 45 | + Implements the "values are subject to `$(location)` and "Make variable" |
| 46 | + substitution" contract for the common `env` attribute for binary and test |
| 47 | + rules: |
| 48 | +
|
| 49 | + - https://bazel.build/reference/be/common-definitions#common-attributes-binaries |
| 50 | + - https://bazel.build/reference/be/common-definitions#common-attributes-tests |
| 51 | + - https://bazel.build/reference/be/make-variables#use |
| 52 | + - https://bazel.build/rules/lib/providers/RunEnvironmentInfo |
| 53 | +
|
| 54 | + Assigns `ctx.attr.env_inherit` to `RunEnvironmentInfo.inherited_environment` |
| 55 | + if present. |
| 56 | +
|
| 57 | + Args: |
| 58 | + ctx: Rule context object |
| 59 | + additional_attr_names: list of attribute names containing targets to use |
| 60 | + when invoking `ctx.expand_location`; already includes "data", |
| 61 | + "deps", and "srcs" |
| 62 | +
|
| 63 | + Returns: |
| 64 | + a RunEnvironmentInfo object containing `ctx.attr.env` values after |
| 65 | + expanding location and Make variables |
| 66 | + """ |
| 67 | + targets = [] |
| 68 | + for attr_name in ["data"] + additional_attr_names: |
| 69 | + targets.extend(getattr(ctx.attr, attr_name, [])) |
| 70 | + |
| 71 | + return RunEnvironmentInfo( |
| 72 | + environment = { |
| 73 | + k: expand_vars(ctx, "env", v, targets, ctx.var) |
| 74 | + for k, v in ctx.attr.env.items() |
| 75 | + }, |
| 76 | + inherited_environment = getattr(ctx.attr, "env_inherit", []), |
| 77 | + ) |
| 78 | + |
| 79 | +def phase_runenvironmentinfo_provider(ctx, _): |
| 80 | + return struct( |
| 81 | + external_providers = {"RunEnvironmentInfo": run_environment_info(ctx)}, |
| 82 | + ) |
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