Use arch_genrule for arch-specific VDSO data.

Note that the select_arch macro changed in order to allow for its use within
a rule below arch_genrule. The command line settings were being manipulated in
a way that did not correctly propagate the select_arch select constraints.

PiperOrigin-RevId: 499651425

pkg/sentry/loader/vdsodata/BUILD

@@ -1,4 +1,4 @@
-load("//tools:defs.bzl", "go_add_tags", "go_embed_data", "go_library")
+load("//tools:defs.bzl", "arch_genrule", "go_embed_data", "go_library")
 
 package(licenses = ["notice"])
 
@@ -9,28 +9,17 @@ go_embed_data(
     var = "Binary",
 )
 
-[
-    # Generate multiple tagged files. Note that the contents of all files
-    # will be the same (i.e. vdso_arm64.go will contain the amd64 vdso), but
-    # the build tags will ensure only one is selected. When we generate the
-    # "Go" branch, we select all archiecture files from the relevant build.
-    # This is a hack around some limitations for "out" being a configurable
-    # attribute and selects for srcs. See also tools/go_branch.sh.
-    go_add_tags(
-        name = "vdso_%s" % arch,
-        src = ":vdso_bin",
-        out = "vdso_%s.go" % arch,
-        go_tags = [arch],
-    )
-    for arch in ("amd64", "arm64")
-]
+arch_genrule(
+    name = "vdso_arch",
+    src = ":vdso_bin",
+    template = "vdso_%s.go",
+)
 
 go_library(
     name = "vdsodata",
     srcs = [
         "vdsodata.go",
-        ":vdso_amd64",
-        ":vdso_arm64",
+        ":vdso_arch",
     ],
     marshal = False,
     stateify = False,

tools/bazeldefs/BUILD

@@ -24,21 +24,13 @@ bzl_library(
 )
 
 config_setting(
-    name = "linux_arm64_cross",
-    values = {
-        "cpu": "aarch64",
-        "host_cpu": "k8",
-    },
-    visibility = ["//visibility:private"],
+    name = "amd64",
+    values = {"cpu": "k8"},
 )
 
 config_setting(
-    name = "linux_amd64_cross",
-    values = {
-        "cpu": "k8",
-        "host_cpu": "aarch64",
-    },
-    visibility = ["//visibility:private"],
+    name = "arm64",
+    values = {"cpu": "aarch64"},
 )
 
 genrule(

tools/bazeldefs/defs.bzl

@@ -23,8 +23,8 @@ def proto_library(name, has_services = None, **kwargs):
 
 def select_arch(amd64 = "amd64", arm64 = "arm64", default = None, **kwargs):
     values = {
-        "@bazel_tools//src/conditions:linux_x86_64": amd64,
-        "@bazel_tools//src/conditions:linux_aarch64": arm64,
+        "//tools/bazeldefs:amd64": amd64,
+        "//tools/bazeldefs:arm64": arm64,
     }
     if default:
         values["//conditions:default"] = default

tools/defs.bzl

@@ -10,7 +10,7 @@ load("//tools/go_marshal:defs.bzl", "go_marshal", "marshal_deps", "marshal_test_
 load("//tools/nogo:defs.bzl", "nogo_test")
 load("//tools/bazeldefs:defs.bzl", _BuildSettingInfo = "BuildSettingInfo", _amd64_config = "amd64_config", _arch_config = "arch_config", _arm64_config = "arm64_config", _bool_flag = "bool_flag", _bpf_program = "bpf_program", _build_test = "build_test", _bzl_library = "bzl_library", _coreutil = "coreutil", _default_net_util = "default_net_util", _more_shards = "more_shards", _most_shards = "most_shards", _proto_library = "proto_library", _select_arch = "select_arch", _select_system = "select_system", _short_path = "short_path", _transition_allowlist = "transition_allowlist", _version = "version")
 load("//tools/bazeldefs:cc.bzl", _cc_binary = "cc_binary", _cc_flags_supplier = "cc_flags_supplier", _cc_grpc_library = "cc_grpc_library", _cc_library = "cc_library", _cc_proto_library = "cc_proto_library", _cc_test = "cc_test", _cc_toolchain = "cc_toolchain", _gbenchmark = "gbenchmark", _gbenchmark_internal = "gbenchmark_internal", _grpcpp = "grpcpp", _gtest = "gtest", _vdso_linker_option = "vdso_linker_option")
-load("//tools/bazeldefs:go.bzl", _gazelle = "gazelle", _go_binary = "go_binary", _go_embed_data = "go_embed_data", _go_grpc_and_proto_libraries = "go_grpc_and_proto_libraries", _go_library = "go_library", _go_path = "go_path", _go_proto_library = "go_proto_library", _go_rule = "go_rule", _go_test = "go_test", _gotsan_flag_values = "gotsan_flag_values", _gotsan_values = "gotsan_values", _select_goarch = "select_goarch", _select_goos = "select_goos")
+load("//tools/bazeldefs:go.bzl", _gazelle = "gazelle", _go_binary = "go_binary", _go_embed_data = "go_embed_data", _go_grpc_and_proto_libraries = "go_grpc_and_proto_libraries", _go_library = "go_library", _go_path = "go_path", _go_proto_library = "go_proto_library", _go_test = "go_test", _gotsan_flag_values = "gotsan_flag_values", _gotsan_values = "gotsan_values", _select_goarch = "select_goarch", _select_goos = "select_goos")
 load("//tools/bazeldefs:pkg.bzl", _pkg_deb = "pkg_deb", _pkg_tar = "pkg_tar")
 load("//tools/bazeldefs:platforms.bzl", _default_platform = "default_platform", _platform_capabilities = "platform_capabilities", _platforms = "platforms")
 load("//tools/bazeldefs:tags.bzl", "go_suffixes")
@@ -64,35 +64,6 @@ default_platform = _default_platform
 platforms = _platforms
 platform_capabilities = _platform_capabilities
 
-def _go_add_tags(ctx):
-    """ Adds tags to the given source file. """
-    output = ctx.outputs.out
-    runner = ctx.actions.declare_file(ctx.label.name + ".sh")
-    lines = ["#!/bin/bash"]
-    lines += ["echo '// +build %s' >> %s" % (tag, output.path) for tag in ctx.attr.go_tags]
-    lines.append("echo '' >> %s" % output.path)
-    lines += ["cat %s >> %s" % (f.path, output.path) for f in ctx.files.src]
-    lines.append("")
-    ctx.actions.write(runner, "\n".join(lines), is_executable = True)
-    ctx.actions.run(
-        inputs = ctx.files.src,
-        outputs = [output],
-        executable = runner,
-    )
-    return [DefaultInfo(
-        files = depset([output]),
-    )]
-
-go_add_tags = _go_rule(
-    rule,
-    implementation = _go_add_tags,
-    attrs = {
-        "go_tags": attr.string_list(doc = "Go build tags to be added.", mandatory = True),
-        "src": attr.label(doc = "Source file.", allow_single_file = True, mandatory = True),
-        "out": attr.output(doc = "Output file.", mandatory = True),
-    },
-)
-
 def go_binary(name, nogo = True, pure = False, static = False, x_defs = None, **kwargs):
     """Wraps the standard go_binary.
 

vdso/BUILD

@@ -36,10 +36,6 @@ genrule(
           # VDSO has no hooks to handle failures.
           "-fno-stack-protector " +
           vdso_linker_option +
-          select_arch(
-              amd64 = "-m64 ",
-              arm64 = "",
-          ) +
           "-shared " +
           "-nostdlib " +
           "-Wl,-soname=linux-vdso.so.1 " +