Rename ExpandArgs to NestedArgs

After discussion with @amontanez in unknown commit, we decided that NestedArgs was a more appropriate name.

BEGIN_PUBLIC
Rename ExpandArgs to NestedArgs
END_PUBLIC

PiperOrigin-RevId: 617085672
Change-Id: I1d7190cac79f8fa953d23be7d0db3b028a84cf30
diff --git a/cc/toolchains/args.bzl b/cc/toolchains/args.bzl
index e15b039..29e3a1b 100644
--- a/cc/toolchains/args.bzl
+++ b/cc/toolchains/args.bzl
@@ -25,8 +25,8 @@
     "ActionTypeSetInfo",
     "ArgsInfo",
     "ArgsListInfo",
-    "ExpandArgsInfo",
     "FeatureConstraintInfo",
+    "NestedArgsInfo",
 )
 
 visibility("public")
@@ -39,12 +39,12 @@
     files = collect_files(ctx.attr.data)
     requires = collect_provider(ctx.attr.requires_any_of, FeatureConstraintInfo)
 
-    expand = None
+    nested = None
     if ctx.attr.args:
-        # TODO: This is temporary until cc_expand_args is implemented.
-        expand = ExpandArgsInfo(
+        # TODO: This is temporary until cc_nested_args is implemented.
+        nested = NestedArgsInfo(
             label = ctx.label,
-            expand = tuple(),
+            nested = tuple(),
             iterate_over = None,
             files = files,
             requires_types = {},
@@ -55,7 +55,7 @@
         label = ctx.label,
         actions = actions,
         requires_any_of = tuple(requires),
-        expand = expand,
+        nested = nested,
         env = ctx.attr.env,
         files = files,
     )
diff --git a/cc/toolchains/cc_toolchain_info.bzl b/cc/toolchains/cc_toolchain_info.bzl
index feb1697..8c0dcd5 100644
--- a/cc/toolchains/cc_toolchain_info.bzl
+++ b/cc/toolchains/cc_toolchain_info.bzl
@@ -45,12 +45,12 @@
     },
 )
 
-ExpandArgsInfo = provider(
+NestedArgsInfo = provider(
     doc = "A provider representation of Args.add/add_all/add_joined parameters",
     # @unsorted-dict-items
     fields = {
         "label": "(Label) The label defining this provider. Place in error messages to simplify debugging",
-        "expand": "(Sequence[ExpandArgsInfo]) The nested arg expansion. Mutually exclusive with args",
+        "nested": "(Sequence[NestedArgsInfo]) The nested arg expansion. Mutually exclusive with args",
         "iterate_over": "(Optional[str]) The variable to iterate over",
         "files": "(depset[File]) The files required to use this variable",
         "requires_types": "(dict[str, str]) A mapping from variables to their expected type name (not type). This means that we can require the generic type Option, rather than an Option[T]",
@@ -65,7 +65,7 @@
         "label": "(Label) The label defining this provider. Place in error messages to simplify debugging",
         "actions": "(depset[ActionTypeInfo]) The set of actions this is associated with",
         "requires_any_of": "(Sequence[FeatureConstraintInfo]) This will be enabled if any of the listed predicates are met. Equivalent to with_features",
-        "expand": "(Optional[ExpandArgsInfo]) The args to expand. Equivalent to a flag group.",
+        "nested": "(Optional[NestedArgsInfo]) The args to expand. Equivalent to a flag group.",
         "files": "(depset[File]) Files required for the args",
         "env": "(dict[str, str]) Environment variables to apply",
     },
diff --git a/cc/toolchains/impl/legacy_converter.bzl b/cc/toolchains/impl/legacy_converter.bzl
index e4e54bb..9f9d2a9 100644
--- a/cc/toolchains/impl/legacy_converter.bzl
+++ b/cc/toolchains/impl/legacy_converter.bzl
@@ -64,11 +64,11 @@
     ]
 
     flag_sets = []
-    if args.expand != None:
+    if args.nested != None:
         flag_sets.append(legacy_flag_set(
             actions = actions,
             with_features = with_features,
-            flag_groups = [args.expand.legacy_flag_group],
+            flag_groups = [args.nested.legacy_flag_group],
         ))
 
     env_sets = []
diff --git a/tests/rule_based_toolchain/subjects.bzl b/tests/rule_based_toolchain/subjects.bzl
index f7eab87..628996e 100644
--- a/tests/rule_based_toolchain/subjects.bzl
+++ b/tests/rule_based_toolchain/subjects.bzl
@@ -23,11 +23,11 @@
     "ActionTypeSetInfo",
     "ArgsInfo",
     "ArgsListInfo",
-    "ExpandArgsInfo",
     "FeatureConstraintInfo",
     "FeatureInfo",
     "FeatureSetInfo",
     "MutuallyExclusiveCategoryInfo",
+    "NestedArgsInfo",
     "ToolInfo",
     "ToolchainConfigInfo",
 )
@@ -106,8 +106,8 @@
     ),
 )
 
-_EXPAND_ARGS_FLAGS = dict(
-    expand = None,
+_NESTED_ARGS_FLAGS = dict(
+    nested = None,
     files = _subjects.depset_file,
     iterate_over = optional_subject(_subjects.str),
     legacy_flag_group = unknown_subject,
@@ -115,18 +115,18 @@
 )
 
 # buildifier: disable=name-conventions
-_FakeExpandArgsFactory = generate_factory(
-    ExpandArgsInfo,
-    "ExpandArgsInfo",
-    _EXPAND_ARGS_FLAGS,
+_FakeNestedArgsFactory = generate_factory(
+    NestedArgsInfo,
+    "NestedArgsInfo",
+    _NESTED_ARGS_FLAGS,
 )
 
 # buildifier: disable=name-conventions
-_ExpandArgsFactory = generate_factory(
-    ExpandArgsInfo,
-    "ExpandArgsInfo",
-    _EXPAND_ARGS_FLAGS | dict(
-        expand = ProviderSequence(_FakeExpandArgsFactory),
+_NestedArgsFactory = generate_factory(
+    NestedArgsInfo,
+    "NestedArgsInfo",
+    _NESTED_ARGS_FLAGS | dict(
+        nested = ProviderSequence(_FakeNestedArgsFactory),
     ),
 )
 
@@ -139,7 +139,7 @@
         env = _subjects.dict,
         files = _subjects.depset_file,
         # Use .factory so it's not inlined.
-        expand = optional_subject(_ExpandArgsFactory.factory),
+        nested = optional_subject(_NestedArgsFactory.factory),
         requires_any_of = ProviderSequence(_FeatureConstraintFactory),
     ),
 )
@@ -220,7 +220,7 @@
 FACTORIES = [
     _ActionTypeFactory,
     _ActionTypeSetFactory,
-    _ExpandArgsFactory,
+    _NestedArgsFactory,
     _ArgsFactory,
     _ArgsListFactory,
     _MutuallyExclusiveCategoryFactory,