Support arch/cpu variants/features in Bazel.

Test: bp2build.sh
Change-Id: I030e570296a12d3bc5f5832a3ec94461798a7e8d

5 files changed, 175 insertions, 7 deletions

diff --git a/platforms/BUILD.bazel b/platforms/BUILD.bazel
index 0eaf477d..b1bbe5f3 100644
--- a/platforms/BUILD.bazel
+++ b/platforms/BUILD.bazel
@@ -12,7 +12,7 @@
 # These model after the arch and OS definitions in build/soong/android/arch.go.
 
 load("@soong_injection//product_config:product_variables.bzl", "product_vars")
-load("//build/bazel/platforms:product_variables/product_platform.bzl", "android_platform", "product_variable_config")
+load("//build/bazel/platforms:product_variables/product_platform.bzl", "android_platform", "android_variant_constraints", "product_variable_config")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -106,7 +106,7 @@ android_platform(
     constraint_values = [
         "//build/bazel/platforms/arch:arm",
         "//build/bazel/platforms/os:android",
-    ],
+    ] + android_variant_constraints("arm", "armv7-a-neon"),  # default to armv7-a-neon
     product = ":android_target",
 )
 
@@ -115,7 +115,7 @@ android_platform(
     constraint_values = [
         "//build/bazel/platforms/arch:arm64",
         "//build/bazel/platforms/os:android",
-    ],
+    ] + android_variant_constraints("arm64", "armv8-a"),  # default to armv8-a
     product = ":android_target",
 )
 
@@ -124,7 +124,7 @@ android_platform(
     constraint_values = [
         "//build/bazel/platforms/arch:x86",
         "//build/bazel/platforms/os:android",
-    ],
+    ] + android_variant_constraints("x86"),
     product = ":android_target",
 )
 
@@ -133,6 +133,6 @@ android_platform(
     constraint_values = [
         "//build/bazel/platforms/arch:x86_64",
         "//build/bazel/platforms/os:android",
-    ],
+    ] + android_variant_constraints("x86_64"),
     product = ":android_target",
 )
diff --git a/platforms/arch/BUILD b/platforms/arch/BUILD
index c0fdf7cd..35df294f 100644
--- a/platforms/arch/BUILD
+++ b/platforms/arch/BUILD
@@ -1,4 +1,5 @@
 # Standard cpu name constraint_setting and constraint_values
+
 licenses(["notice"])
 
 package(
diff --git a/platforms/arch/variants/BUILD b/platforms/arch/variants/BUILD
new file mode 100644
index 00000000..0b722b6b
--- /dev/null
+++ b/platforms/arch/variants/BUILD
@@ -0,0 +1,89 @@
+# Cpu/Arch Variants and features
+
+load("//build/bazel/product_variables:constants.bzl", _product_variable_constants = "constants")
+load(":constants.bzl", "constants")
+
+constraint_setting(
+    name = "arch_variant_constraint",
+)
+
+licenses(["notice"])
+
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+[
+    constraint_value(
+        name = arch_variant,
+        constraint_setting = "arch_variant_constraint",
+    )
+    for arch_variant in constants.AvailableArchVariants
+]
+
+[
+    [
+        config_setting(
+            name = variant + "-" + arch,
+            constraint_values = [
+                _product_variable_constants.ArchVariantToConstraints[arch],
+                ":" + variant,
+            ],
+        )
+        for variant in variants
+    ]
+    for arch, variants in constants.ArchToVariants.items()
+]
+
+constraint_setting(
+    name = "cpu_variant_constraint",
+)
+
+[
+    constraint_value(
+        name = cpu_variant,
+        constraint_setting = "cpu_variant_constraint",
+    )
+    for cpu_variant in constants.AvailableCpuVariants
+]
+
+[
+    [
+        config_setting(
+            name = variant + "-" + arch,
+            constraint_values = [
+                _product_variable_constants.ArchVariantToConstraints[arch],
+                ":" + variant,
+            ],
+        )
+        for variant in variants
+    ]
+    for arch, variants in constants.CpuToVariants.items()
+]
+
+[
+    (
+        constraint_setting(
+            name = "arch_feature_constraint_" + arch_feature,
+        ),
+        constraint_value(
+            name = arch_feature,
+            constraint_setting = "arch_feature_constraint_" + arch_feature,
+        ),
+    )
+    for arch_feature in constants.AvailableArchFeatures
+]
+
+[
+    [
+        config_setting(
+            name = feature + "-" + arch,
+            constraint_values = [
+                _product_variable_constants.ArchVariantToConstraints[arch],
+                ":" + feature,
+            ],
+        )
+        for feature in features
+    ]
+    for arch, features in constants.ArchToFeatures.items()
+]
diff --git a/platforms/arch/variants/constants.bzl b/platforms/arch/variants/constants.bzl
new file mode 100644
index 00000000..1e5feb94
--- /dev/null
+++ b/platforms/arch/variants/constants.bzl
@@ -0,0 +1,44 @@
+"""Constants for arch/cpu variants/features."""
+
+# Copyright (C) 2022 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+load(
+    "@soong_injection//product_config:arch_configuration.bzl",
+    _android_arch_feature_for_arch_variant = "android_arch_feature_for_arch_variants",
+    _arch_to_cpu_variants = "arch_to_cpu_variants",
+    _arch_to_features = "arch_to_features",
+    _arch_to_variants = "arch_to_variants",
+)
+
+def _flatten_string_list_dict_to_set(string_list_dict):
+    ret = {}
+    for l in string_list_dict.values():
+        for i in l:
+            ret[i] = True
+    return ret
+
+_arch_variants = _flatten_string_list_dict_to_set(_arch_to_variants)
+_cpu_variants = _flatten_string_list_dict_to_set(_arch_to_cpu_variants)
+_arch_features = _flatten_string_list_dict_to_set(_arch_to_features)
+
+constants = struct(
+    AvailableArchVariants = _arch_variants,
+    AvailableCpuVariants = _cpu_variants,
+    AvailableArchFeatures = _arch_features,
+    ArchToVariants = _arch_to_variants,
+    CpuToVariants = _arch_to_cpu_variants,
+    ArchToFeatures = _arch_to_features,
+    AndroidArchToVariantToFeatures = _android_arch_feature_for_arch_variant,
+)
diff --git a/platforms/product_variables/product_platform.bzl b/platforms/product_variables/product_platform.bzl
index 28629d01..b04ae947 100644
--- a/platforms/product_variables/product_platform.bzl
+++ b/platforms/product_variables/product_platform.bzl
@@ -1,6 +1,7 @@
 """Parallels variable.go to provide variables and create a platform based on converted config."""
 
 load("//build/bazel/product_variables:constants.bzl", "constants")
+load("//build/bazel/platforms/arch/variants:constants.bzl", _arch_constants = "constants")
 
 def _product_variables_providing_rule_impl(ctx):
     return [
@@ -76,7 +77,6 @@ def product_variable_config(name, product_config_vars):
                 constraints.append("//build/bazel/product_variables:" + constraint_var)
                 add_providing_var(providing_vars, "string", constraint_var, value)
 
-
     for (var, value) in local_vars.items():
         # TODO(b/187323817): determine how to handle remaining product
         # variables not used in product_variables
@@ -100,6 +100,9 @@ def product_variable_config(name, product_config_vars):
     )
 
     arch = local_vars.get("DeviceArch")
+    arch_variant = local_vars.get("DeviceArchVariant")
+    cpu_variant = local_vars.get("DeviceCpuVariant")
+
     os = "android"
 
     native.platform(
@@ -107,14 +110,45 @@ def product_variable_config(name, product_config_vars):
         constraint_values = constraints + [
             "//build/bazel/platforms/arch:" + arch,
             "//build/bazel/platforms/os:" + os,
-        ],
+        ] + android_variant_constraints(arch, arch_variant, cpu_variant),
     )
 
+    arch = local_vars.get("DeviceSecondaryArch")
+    arch_variant = local_vars.get("DeviceSecondaryArchVariant")
+    cpu_variant = local_vars.get("DeviceSecondaryCpuVariant")
+
+    if arch:
+        native.platform(
+            name = name + "_secondary",
+            constraint_values = constraints + [
+                "//build/bazel/platforms/arch:" + arch,
+                "//build/bazel/platforms/os:" + os,
+            ] + android_variant_constraints(arch, arch_variant, cpu_variant),
+        )
+
     product_variables_providing_rule(
         name = name + "_product_vars",
         product_vars = providing_vars,
     )
 
+def _is_variant_default(arch, variant):
+    return variant == None or variant in (arch, "generic")
+
+def android_variant_constraints(arch, arch_variant = None, cpu_variant = None):
+    additional_constraints = []
+    if not _is_variant_default(arch, arch_variant):
+        additional_constraints.append("//build/bazel/platforms/arch/variants:" + arch_variant)
+    else:
+        arch_variant = ""
+
+    features = _arch_constants.AndroidArchToVariantToFeatures[arch].get(arch_variant, [])
+    for feature in features:
+        additional_constraints.append("//build/bazel/platforms/arch/variants:" + feature)
+
+    if not _is_variant_default(arch, cpu_variant):
+        additional_constraints.append("//build/bazel/platforms/arch/variants:" + cpu_variant)
+    return additional_constraints
+
 def android_platform(name = None, constraint_values = [], product = None):
     """ android_platform creates a platform with the specified constraint_values and product constraints."""
     native.platform(