Replace CompileArgsfile#input_args with cmd_form to materialize dependent Artifacts

Summary: Replace the usage of `CompileArgsfile#input_args` `CompileArgsfile#cmd_form` to materialize dependent `Artifact`s of the subtargets `[argsfiles]` and `[xcode-argsfiles]` to save memory and simplify. `CompileArgsfile#cmd_form` stores all the dependent `Artifact`s of `CompileArgsfile#file`, so `CompileArgsfile#input_args` is redundant.This results in less retained memory usage in analysis (based off `buck2 profile analysis --recursive --mode heap-summary-retained  $TARGET`) because `CompileArgsfile` is smaller.

Reviewed By: christycylee

Differential Revision: D75712066

fbshipit-source-id: 42a787ea3632624c39a3845560f66e4adcd8ed0a

Author: skrueger

prelude/apple/swift/swift_compilation.bzl

@@ -842,7 +842,6 @@ def _compile_with_argsfile(
     argsfile = CompileArgsfile(
         file = argsfile,
         cmd_form = argsfile_cmd_form,
-        input_args = [shared_flags],
         args = shell_quoted_args,
         args_without_file_prefix_args = shared_flags,
     )

prelude/cxx/argsfiles.bzl

@@ -13,8 +13,6 @@ CompileArgsfile = record(
     file = field(Artifact),
     # This argsfile as a command form that would use the argsfile (includes dependent inputs).
     cmd_form = field(cmd_args),
-    # Input args necessary for the argsfile to reference.
-    input_args = field(list[cmd_args]),
     # Args as written to the argsfile (with shell quoting applied).
     args = field(cmd_args),
     # Args aggregated for the argsfile excluding file prefix args (excludes shell quoting).
@@ -35,7 +33,11 @@ def get_argsfiles_output(ctx: AnalysisContext, argsfile_by_ext: dict[str, Compil
     for _, argsfile in argsfile_by_ext.items():
         argsfiles.append(argsfile.file)
         argsfile_names.append(cmd_args(argsfile.file, ignore_artifacts = True))
-        dependent_outputs.extend(argsfile.input_args)
+
+        # To materialize the dependent `Artifact`s of `CompileArgsfile#file`,
+        # `CompileArgsfile#cmd_form` is returned in `DefaultInfo#other_outputs`,
+        # because it tracks the dependents through the `cmd_args` API.
+        dependent_outputs.append(argsfile.cmd_form)
 
     argsfiles_summary = ctx.actions.write(summary_name, cmd_args(argsfile_names))
 

prelude/cxx/compile.bzl

@@ -1129,7 +1129,6 @@ def _mk_argsfiles(
     return CompileArgsfile(
         file = argsfile,
         cmd_form = cmd_form,
-        input_args = input_args,
         args = args,
         args_without_file_prefix_args = args_without_file_prefix_args,
     )
@@ -1186,15 +1185,13 @@ def _mk_header_units_argsfile(
     # TODO(nml): Tag args with headers_tag.tag_artifacts() once -MD -MF reports correct
     # usage of PCMs.
     args.add(preprocessor.set.project_as_args("header_units_args"))
-    input_args = [args]
     file_args = cmd_args(args, quote = "shell")
     argsfile, _ = ctx.actions.write(file_name, file_args, allow_args = True)
-    cmd_form = cmd_args(argsfile, format = "@{}", hidden = input_args)
+    cmd_form = cmd_args(argsfile, format = "@{}", hidden = file_args)
 
     return CompileArgsfile(
         file = argsfile,
         cmd_form = cmd_form,
-        input_args = input_args,
         args = file_args,
         args_without_file_prefix_args = args,
     )