Implement TODO from: https://github.com/bazelbuild/bazel/blo[]fbbd6a32b95ba746f09dae1eaeaccf675cd5b3/src/main/java/com/google/devtools/build/lib/packages/Attribute.java#L1045

This allows the default value computation for latebound attributes to consider
the values of configurable attributes. This is most directly useful for user-definable Skylark defaults, which have full access to the values of all non-latebound attributes.

Without this change, this kind of scenario crashes Bazel. For example:

------------------
select_rules.bzl:
------------------
def _impl(ctx):
  ctx.file_action(
      output=ctx.outputs.out_file,
      content=ctx.attr.string_value,
  )
  return struct()


# Bug does not manifest without using this as a default.
def _derived_value(attrs, _):
  return Label("//some:dep")


selector_rule = rule(
    implementation=_impl,
    attrs={
        "string_value": attr.string(default=""),
        "out_file": attr.output(),
        "_derived": attr.label(default=_derived_value),
    },
    output_to_genfiles=True,
)


def selector_macro(name, out_file="", string_value=""):
  # This will fail with selectors.
  selector_rule(
      name="%s_skylark" % name,
      string_value=string_value,
      out_file=out_file + ".skylark",
  )

  # This does not.
  native.genrule(
      name="%s_genrule" % name,
      cmd="echo '" + string_value + "' > $@",
      outs=[out_file + ".genrule"],
  )

  native.filegroup(
      name=name,
      srcs=[":%s_genrule" % name, "%s_skylark" % name],
  )


------------------
BUILD.bzl:
------------------
config_setting(
    name = "selector",
    values = {"compilation_mode": "opt"},
)

selector_macro(
    name = "this_rule",
    string_value = """soup?  """ + select({
            ":selector": "no, thank you.",
            "//conditions:default": "yes, please!!",
        }),
    out_file = "this_rule.txt",
)

--
MOS_MIGRATED_REVID=114326474

1 files changed, 3 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/AppleToolchain.java b/src/main/java/com/google/devtools/build/lib/rules/apple/AppleToolchain.java
index 1c4b6bf509..31d223b66d 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/AppleToolchain.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/AppleToolchain.java
@@ -27,6 +27,7 @@ import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.Attribute.LateBoundLabel;
+import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleClass.Builder;
@@ -174,7 +175,8 @@ public class AppleToolchain {
         new LateBoundLabel<BuildConfiguration>(
             AppleCommandLineOptions.DEFAULT_XCODE_VERSION_CONFIG_LABEL, AppleConfiguration.class) {
           @Override
-          public Label getDefault(Rule rule, BuildConfiguration configuration) {
+          public Label getDefault(Rule rule, AttributeMap attributes,
+              BuildConfiguration configuration) {
             return configuration.getFragment(AppleConfiguration.class).getXcodeConfigLabel();
           }
         };