[bazel] Move obj_transform rule to cc.bzl

Deduplicates the implementation.

Signed-off-by: James Wainwright <[email protected]>
(cherry picked from commit a329756)

Author: jwnrt

rules/opentitan.bzl

@@ -46,41 +46,6 @@ PER_DEVICE_DEPS = {
 def flatten(l):
     return [item for ll in l for item in ll]
 
-def _obj_transform_impl(ctx):
-    cc_toolchain = find_cc_toolchain(ctx)
-    outputs = []
-    for src in ctx.files.srcs:
-        binary = ctx.actions.declare_file(
-            "{}.{}".format(
-                src.basename.replace("." + src.extension, ""),
-                ctx.attr.suffix,
-            ),
-        )
-        outputs.append(binary)
-        ctx.actions.run(
-            outputs = [binary],
-            inputs = [src] + cc_toolchain.all_files.to_list(),
-            arguments = [
-                "--output-target",
-                ctx.attr.format,
-                src.path,
-                binary.path,
-            ],
-            executable = cc_toolchain.objcopy_executable,
-        )
-    return [DefaultInfo(files = depset(outputs), data_runfiles = ctx.runfiles(files = outputs))]
-
-obj_transform = rv_rule(
-    implementation = _obj_transform_impl,
-    attrs = {
-        "srcs": attr.label_list(allow_files = True),
-        "suffix": attr.string(default = "bin"),
-        "format": attr.string(default = "binary"),
-        "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
-    },
-    toolchains = ["@rules_cc//cc:toolchain_type"],
-)
-
 # A provider for device-specific archive files that hold binaries of SRAM programs.
 ArchiveInfo = provider(fields = ["archive_infos"])
 
@@ -557,7 +522,6 @@ def opentitan_binary(
     Emits rules:
       cc_binary             named: <name>.elf
       cc_binary+transition  named: <name>_elf_transition
-      obj_transform         named: <name>_bin
       elf_to_dissassembly   named: <name>_dis
       Optionally:
         gen_sim_dv_logs_db  named: <name>_logs_db
@@ -597,12 +561,6 @@ def opentitan_binary(
 
     bin_name = "{}_{}".format(name, "bin")
     targets.append(":" + bin_name)
-    obj_transform(
-        name = bin_name,
-        srcs = [native_binary_name],
-        platform = platform,
-        testonly = testonly,
-    )
 
     dis_name = "{}_{}".format(name, "dis")
     targets.append(":" + dis_name)

rules/opentitan/legacy.bzl

@@ -2,6 +2,12 @@
 # Licensed under the Apache License, Version 2.0, see LICENSE for details.
 # SPDX-License-Identifier: Apache-2.0
 
+load(
+    "@lowrisc_opentitan//rules/opentitan:transform.bzl",
+    _obj_transform = "obj_transform",
+)
+load("@lowrisc_opentitan//rules:rv.bzl", "rv_rule")
+
 def legacy_rom_targets(target, suffixes, testonly = False):
     """Create filegroups for legacy ROM rule target names.
 
@@ -27,3 +33,23 @@ def legacy_rom_targets(target, suffixes, testonly = False):
             actual = ":{}_{}".format(target, suffix),
             testonly = testonly,
         )
+
+def _obj_transform_impl(ctx):
+    outputs = [_obj_transform(ctx)]
+    return [
+        DefaultInfo(
+            files = depset(outputs),
+            data_runfiles = ctx.runfiles(files = outputs),
+        ),
+    ]
+
+obj_transform = rv_rule(
+    implementation = _obj_transform_impl,
+    attrs = {
+        "src": attr.label(allow_single_file = True),
+        "suffix": attr.string(default = "bin"),
+        "format": attr.string(default = "binary"),
+        "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
+    },
+    toolchains = ["@rules_cc//cc:toolchain_type"],
+)

rules/opentitan/transform.bzl

@@ -28,7 +28,7 @@ def obj_transform(ctx, **kwargs):
         output = "{}.{}".format(name, suffix)
 
     output = ctx.actions.declare_file(output)
-    src = get_override(ctx, "attr.src", kwargs)
+    src = get_override(ctx, "file.src", kwargs)
     out_format = get_override(ctx, "attr.format", kwargs)
 
     ctx.actions.run(

sw/device/silicon_owner/tock/kernel/BUILD

@@ -4,7 +4,8 @@
 
 load("@rules_rust//rust:defs.bzl", "rust_binary")
 load("//rules:linker.bzl", "ld_library")
-load("//rules:opentitan.bzl", "elf_to_disassembly", "obj_transform")
+load("//rules:opentitan.bzl", "elf_to_disassembly")
+load("//rules/opentitan:legacy.bzl", "obj_transform")
 load("//rules/opentitan:defs.bzl", "OPENTITAN_CPU")
 
 package(default_visibility = ["//visibility:public"])
@@ -59,6 +60,6 @@ rust_binary(
 
 obj_transform(
     name = "raw_kernel",
-    srcs = [":kernel"],
+    src = ":kernel",
     tags = ["manual"],
 )

sw/device/silicon_owner/tock/upstream_kernel/BUILD

@@ -4,8 +4,9 @@
 
 load("@rules_rust//rust:defs.bzl", "rust_binary")
 load("//rules:linker.bzl", "ld_library")
-load("//rules:opentitan.bzl", "elf_to_disassembly", "obj_transform")
+load("//rules:opentitan.bzl", "elf_to_disassembly")
 load("//rules/opentitan:defs.bzl", "OPENTITAN_CPU")
+load("//rules/opentitan:legacy.bzl", "obj_transform")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -58,6 +59,6 @@ rust_binary(
 
 obj_transform(
     name = "raw_kernel",
-    srcs = [":kernel"],
+    src = ":kernel",
     tags = ["manual"],
 )