Add toolchain definitions for autoconfigured cc_toolchain entries.

PiperOrigin-RevId: 190611069
diff --git a/tools/cpp/BUILD b/tools/cpp/BUILD
index 4412b14..57007d32 100644
--- a/tools/cpp/BUILD
+++ b/tools/cpp/BUILD
@@ -1,7 +1,52 @@
+# Copyright 2018 The Bazel Authors. All rights reserved.
+#
+# 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.
+
 package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])  # Apache 2.0
 
+# The toolchain type used to distinguish cc toolchains.
+cc_toolchain_type(name = "toolchain_type")
+
+# It is frequently necessary to constrain platforms based on the cc compiler type.
+constraint_setting(name = "cc_compiler")
+
+constraint_value(
+    name = "clang",
+    constraint_setting = ":cc_compiler",
+)
+
+constraint_value(
+    name = "gcc",
+    constraint_setting = ":cc_compiler",
+)
+
+constraint_value(
+    name = "msvc",
+    constraint_setting = ":cc_compiler",
+)
+
+constraint_value(
+    name = "mingw",
+    constraint_setting = ":cc_compiler",
+)
+
+constraint_value(
+    name = "msys",
+    constraint_setting = ":cc_compiler",
+)
+
 # TODO(lberki): Remove this once cc_toolchain_alias is in a Bazel release
 cc_toolchain_alias(name = "current_cc_toolchain")
 
@@ -67,6 +112,18 @@
     supports_param_files = 1,
 )
 
+toolchain(
+    name = "cc-toolchain-local",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:autoconfigured",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:autoconfigured",
+    ],
+    toolchain = ":cc-compiler-local",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-ppc",
     all_files = ":empty",
@@ -81,6 +138,18 @@
     supports_param_files = 1,
 )
 
+toolchain(
+    name = "cc-toolchain-ppc",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:ppc",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:ppc",
+    ],
+    toolchain = ":cc-compiler-ppc",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-armeabi-v7a",
     all_files = ":empty",
@@ -95,6 +164,18 @@
     supports_param_files = 1,
 )
 
+toolchain(
+    name = "cc-toolchain-armeabi-v7a",
+    exec_compatible_with = [
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:arm",
+        "@bazel_tools//platforms:android",
+    ],
+    toolchain = ":cc-compiler-armeabi-v7a",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-k8",
     all_files = ":empty",
@@ -109,6 +190,20 @@
     supports_param_files = 1,
 )
 
+toolchain(
+    name = "cc-toolchain-k8",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:linux",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:linux",
+    ],
+    toolchain = ":cc-compiler-k8",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-darwin",
     all_files = ":osx_wrapper",
@@ -123,6 +218,20 @@
     supports_param_files = 0,
 )
 
+toolchain(
+    name = "cc-toolchain-darwin",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:osx",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:osx",
+    ],
+    toolchain = ":cc-compiler-darwin",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-freebsd",
     all_files = ":empty",
@@ -137,6 +246,20 @@
     supports_param_files = 0,
 )
 
+toolchain(
+    name = "cc-toolchain-freebsd",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:freebsd",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:freebsd",
+    ],
+    toolchain = ":cc-compiler-freebsd",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-x64_windows",
     all_files = ":empty",
@@ -151,6 +274,20 @@
     supports_param_files = 0,
 )
 
+toolchain(
+    name = "cc-toolchain-x64_windows",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    toolchain = ":cc-compiler-x64_windows",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-x64_windows_msvc",
     all_files = ":every-file-x64_windows",
@@ -165,6 +302,21 @@
     supports_param_files = 1,
 )
 
+toolchain(
+    name = "cc-toolchain-x64_windows_msvc",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+        ":msvc",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    toolchain = ":cc-compiler-x64_windows_msvc",
+    toolchain_type = ":toolchain_type",
+)
+
 cc_toolchain(
     name = "cc-compiler-ios_x86_64",
     all_files = ":empty",
@@ -179,6 +331,18 @@
     supports_param_files = 0,
 )
 
+toolchain(
+    name = "cc-toolchain-ios_x86_64",
+    exec_compatible_with = [
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:ios",
+    ],
+    toolchain = ":cc-compiler-ios_x86_64",
+    toolchain_type = ":toolchain_type",
+)
+
 filegroup(
     name = "every-file-x64_windows",
     srcs = [
@@ -228,18 +392,3 @@
     name = "crosstool_lib",
     srcs = ["crosstool_lib.bzl"],
 )
-
-cc_toolchain_type(name = "toolchain_type")
-
-# A dummy toolchain is necessary to satisfy toolchain resolution until platforms
-# are used in c++ by default.
-# TODO(b/64754003): Remove once platforms are used in c++ by default.
-toolchain(
-    name = "dummy_cc_toolchain",
-    toolchain = "dummy_cc_toolchain_impl",
-    toolchain_type = ":toolchain_type",
-)
-
-load(":dummy_toolchain.bzl", "dummy_toolchain")
-
-dummy_toolchain(name = "dummy_cc_toolchain_impl")
diff --git a/tools/cpp/BUILD.static b/tools/cpp/BUILD.static
deleted file mode 100644
index 6175a5a..0000000
--- a/tools/cpp/BUILD.static
+++ /dev/null
@@ -1,146 +0,0 @@
-package(default_visibility = ["//visibility:public"])
-
-cc_library(
-    name = "malloc",
-)
-
-cc_library(
-    name = "stl",
-)
-
-filegroup(
-    name = "empty",
-    srcs = [],
-)
-
-# Hardcoded toolchain, legacy behaviour.
-cc_toolchain_suite(
-    name = "toolchain",
-    toolchains = {
-        "armeabi-v7a|compiler": ":cc-compiler-armeabi-v7a",
-        "freebsd|compiler": ":cc-compiler-freebsd",
-        "x64_windows|msvc-cl": ":cc-compiler-x64_windows",
-        "x64_windows|msys-gcc": ":cc-compiler-x64_windows_msys",
-        "x64_windows|mingw-gcc": ":cc-compiler-x64_windows_mingw",
-        "ios_x86_64|compiler": ":cc-compiler-ios_x86_64",
-    },
-)
-
-cc_toolchain(
-    name = "cc-compiler-armeabi-v7a",
-    all_files = ":empty",
-    compiler_files = ":empty",
-    cpu = "local",
-    dwp_files = ":empty",
-    dynamic_runtime_libs = [":empty"],
-    linker_files = ":empty",
-    objcopy_files = ":empty",
-    static_runtime_libs = [":empty"],
-    strip_files = ":empty",
-    supports_param_files = 1,
-)
-
-cc_toolchain(
-    name = "cc-compiler-freebsd",
-    all_files = ":empty",
-    compiler_files = ":empty",
-    cpu = "local",
-    dwp_files = ":empty",
-    dynamic_runtime_libs = [":empty"],
-    linker_files = ":empty",
-    objcopy_files = ":empty",
-    static_runtime_libs = [":empty"],
-    strip_files = ":empty",
-    supports_param_files = 0,
-)
-
-cc_toolchain(
-    name = "cc-compiler-x64_windows_msys",
-    all_files = ":empty",
-    compiler_files = ":empty",
-    cpu = "local",
-    dwp_files = ":empty",
-    dynamic_runtime_libs = [":empty"],
-    linker_files = ":empty",
-    objcopy_files = ":empty",
-    static_runtime_libs = [":empty"],
-    strip_files = ":empty",
-    supports_param_files = 1,
-)
-
-cc_toolchain(
-    name = "cc-compiler-x64_windows_mingw",
-    all_files = ":empty",
-    compiler_files = ":empty",
-    cpu = "x64_windows",
-    dwp_files = ":empty",
-    dynamic_runtime_libs = [":empty"],
-    linker_files = ":empty",
-    objcopy_files = ":empty",
-    static_runtime_libs = [":empty"],
-    strip_files = ":empty",
-    supports_param_files = 1,
-)
-
-cc_toolchain(
-    name = "cc-compiler-x64_windows",
-    all_files = ":every-file-x64_windows",
-    compiler_files = ":compile-x64_windows",
-    cpu = "x64_windows",
-    dwp_files = ":empty",
-    dynamic_runtime_libs = [":empty"],
-    linker_files = ":empty",
-    objcopy_files = ":empty",
-    static_runtime_libs = [":empty"],
-    strip_files = ":empty",
-    supports_param_files = 1,
-)
-
-cc_toolchain(
-    name = "cc-compiler-ios_x86_64",
-    all_files = ":empty",
-    compiler_files = ":empty",
-    cpu = "local",
-    dwp_files = ":empty",
-    dynamic_runtime_libs = [":empty"],
-    linker_files = ":empty",
-    objcopy_files = ":empty",
-    static_runtime_libs = [":empty"],
-    strip_files = ":empty",
-    supports_param_files = 0,
-)
-
-filegroup(
-    name = "every-file-x64_windows",
-    srcs = [
-        ":compile-x64_windows",
-    ],
-)
-
-filegroup(
-    name = "compile-x64_windows",
-    srcs = glob([
-        "wrapper/bin/msvc_*",
-        "wrapper/bin/pydir/msvc*",
-    ]),
-)
-
-filegroup(
-    name = "link_dynamic_library",
-    srcs = ["link_dynamic_library.sh"],
-)
-
-cc_toolchain_type(name = "toolchain_type")
-
-# A dummy toolchain is necessary to satisfy toolchain resolution until platforms
-# are used in c++ by default.
-# TODO(b/64754003): Remove once platforms are used in c++ by default.
-toolchain(
-    name = "dummy_cc_toolchain",
-    toolchain = "dummy_cc_toolchain_impl",
-    toolchain_type = ":toolchain_type",
-)
-
-load(":dummy_toolchain.bzl", "dummy_toolchain")
-
-dummy_toolchain(name = "dummy_cc_toolchain_impl")
diff --git a/tools/cpp/BUILD.static.freebsd b/tools/cpp/BUILD.static.freebsd
new file mode 100644
index 0000000..4ec5691
--- /dev/null
+++ b/tools/cpp/BUILD.static.freebsd
@@ -0,0 +1,128 @@
+# Copyright 2018 The Bazel Authors. All rights reserved.
+#
+# 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.
+
+# This becomes the BUILD file for @local_config_cc// under FreeBSD.
+
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "malloc",
+)
+
+cc_library(
+    name = "stl",
+)
+
+filegroup(
+    name = "empty",
+    srcs = [],
+)
+
+# Hardcoded toolchain, legacy behaviour.
+cc_toolchain_suite(
+    name = "toolchain",
+    toolchains = {
+        "armeabi-v7a|compiler": ":cc-compiler-armeabi-v7a",
+        "freebsd|compiler": ":cc-compiler-freebsd",
+        "ios_x86_64|compiler": ":cc-compiler-ios_x86_64",
+    },
+)
+
+cc_toolchain(
+    name = "cc-compiler-freebsd",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 0,
+)
+
+toolchain(
+    name = "cc-toolchain-freebsd",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:freebsd",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:freebsd",
+    ],
+    toolchain = ":cc-compiler-freebsd",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+cc_toolchain(
+    name = "cc-compiler-armeabi-v7a",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 0,
+)
+
+toolchain(
+    name = "cc-toolchain-armeabi-v7a",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:arm",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:arm",
+        "@bazel_tools//platforms:android",
+    ],
+    toolchain = ":cc-compiler-armeabi-v7a",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+cc_toolchain(
+    name = "cc-compiler-ios_x86_64",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 0,
+)
+
+toolchain(
+    name = "cc-toolchain-ios_x86_64",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:osx",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:ios",
+    ],
+    toolchain = ":cc-compiler-ios_x86_64",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+filegroup(
+    name = "link_dynamic_library",
+    srcs = ["link_dynamic_library.sh"],
+)
diff --git a/tools/cpp/BUILD.static.windows b/tools/cpp/BUILD.static.windows
new file mode 100644
index 0000000..6281a05
--- /dev/null
+++ b/tools/cpp/BUILD.static.windows
@@ -0,0 +1,200 @@
+# Copyright 2018 The Bazel Authors. All rights reserved.
+#
+# 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.
+
+# This becomes the BUILD file for @local_config_cc// under Windows.
+
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "malloc",
+)
+
+cc_library(
+    name = "stl",
+)
+
+filegroup(
+    name = "empty",
+    srcs = [],
+)
+
+# Hardcoded toolchain, legacy behaviour.
+cc_toolchain_suite(
+    name = "toolchain",
+    toolchains = {
+        "armeabi-v7a|compiler": ":cc-compiler-armeabi-v7a",
+        "x64_windows|msvc-cl": ":cc-compiler-x64_windows",
+        "x64_windows|msys-gcc": ":cc-compiler-x64_windows_msys",
+        "x64_windows|mingw-gcc": ":cc-compiler-x64_windows_mingw",
+        "ios_x86_64|compiler": ":cc-compiler-ios_x86_64",
+    },
+)
+
+cc_toolchain(
+    name = "cc-compiler-x64_windows_msys",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 1,
+)
+
+toolchain(
+    name = "cc-toolchain-x64_windows_msys",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+        "@bazel_tools//tools/cpp:msys",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    toolchain = ":cc-compiler-x64_windows_msys",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+cc_toolchain(
+    name = "cc-compiler-x64_windows_mingw",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "x64_windows",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 0,
+)
+
+toolchain(
+    name = "cc-toolchain-x64_windows_mingw",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+        "@bazel_tools//tools/cpp:mingw",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    toolchain = ":cc-compiler-x64_windows_mingw",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+cc_toolchain(
+    name = "cc-compiler-x64_windows",
+    all_files = ":every-file-x64_windows",
+    compiler_files = ":compile-x64_windows",
+    cpu = "x64_windows",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 1,
+)
+
+toolchain(
+    name = "cc-toolchain-x64_windows",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:windows",
+    ],
+    toolchain = ":cc-compiler-x64_windows",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+cc_toolchain(
+    name = "cc-compiler-armeabi-v7a",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 1,
+)
+
+toolchain(
+    name = "cc-toolchain-armeabi-v7a",
+    exec_compatible_with = [
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:arm",
+        "@bazel_tools//platforms:android",
+    ],
+    toolchain = ":cc-compiler-armeabi-v7a",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+cc_toolchain(
+    name = "cc-compiler-ios_x86_64",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "local",
+    dwp_files = ":empty",
+    dynamic_runtime_libs = [":empty"],
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    static_runtime_libs = [":empty"],
+    strip_files = ":empty",
+    supports_param_files = 0,
+)
+
+toolchain(
+    name = "cc-toolchain-ios_x86_64",
+    exec_compatible_with = [
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:ios",
+    ],
+    toolchain = ":cc-compiler-ios_x86_64",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+filegroup(
+    name = "every-file-x64_windows",
+    srcs = [
+        ":compile-x64_windows",
+    ],
+)
+
+filegroup(
+    name = "compile-x64_windows",
+    srcs = glob([
+        "wrapper/bin/msvc_*",
+        "wrapper/bin/pydir/msvc*",
+    ]),
+)
+
+filegroup(
+    name = "link_dynamic_library",
+    srcs = ["link_dynamic_library.sh"],
+)
diff --git a/tools/cpp/BUILD.tpl b/tools/cpp/BUILD.tpl
index edf2ba6..f2bf8cd 100644
--- a/tools/cpp/BUILD.tpl
+++ b/tools/cpp/BUILD.tpl
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# This becomes the BUILD file for @local_config_cc// under non-FreeBSD unixes.
+
 package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])  # Apache 2.0
@@ -65,6 +67,19 @@
     supports_param_files = %{supports_param_files},
 )
 
+toolchain(
+    name = "cc-toolchain-%{name}",
+    exec_compatible_with = [
+        # This toolchain will only work with the local autoconfigured platforms.
+        "@bazel_tools//platforms:autoconfigured",
+        # TODO(katre): add autodiscovered constraints for host CPU and OS.
+    ],
+    target_compatible_with = [
+        # TODO(katre): add autodiscovered constraints for host CPU and OS.
+    ],
+    toolchain = ":cc-compiler-%{name}",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
 
 # Android tooling requires a default toolchain for the armeabi-v7a cpu.
 cc_toolchain(
@@ -81,6 +96,19 @@
     supports_param_files = 1,
 )
 
+toolchain(
+    name = "cc-toolchain-armeabi-v7a",
+    exec_compatible_with = [
+        # TODO(katre): add autodiscovered constraints for host CPU and OS.
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:arm",
+        "@bazel_tools//platforms:android",
+    ],
+    toolchain = ":cc-compiler-armabi-v7a",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
 # ios crosstool configuration requires a default toolchain for the
 # ios_x86_64 cpu.
 cc_toolchain(
@@ -97,17 +125,15 @@
     supports_param_files = 1,
 )
 
-cc_toolchain_type(name = "toolchain_type")
-
-# A dummy toolchain is necessary to satisfy toolchain resolution until platforms
-# are used in c++ by default.
-# TODO(b/64754003): Remove once platforms are used in c++ by default.
 toolchain(
-    name = "dummy_cc_toolchain",
-    toolchain = "dummy_cc_toolchain_impl",
-    toolchain_type = ":toolchain_type",
+    name = "cc-toolchain-ios_x86_64",
+    exec_compatible_with = [
+        # TODO(katre): add autodiscovered constraints for host CPU and OS.
+    ],
+    target_compatible_with = [
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//platforms:ios",
+    ],
+    toolchain = ":cc-compiler-ios_x86_64",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
 )
-
-load(":dummy_toolchain.bzl", "dummy_toolchain")
-
-dummy_toolchain(name = "dummy_cc_toolchain_impl")
diff --git a/tools/cpp/cc_configure.bzl b/tools/cpp/cc_configure.bzl
index 858c5bc..925ecbc 100644
--- a/tools/cpp/cc_configure.bzl
+++ b/tools/cpp/cc_configure.bzl
@@ -13,7 +13,6 @@
 # limitations under the License.
 """Rules for configuring the C++ toolchain (experimental)."""
 
-
 load("@bazel_tools//tools/cpp:windows_cc_configure.bzl", "configure_windows_toolchain")
 load("@bazel_tools//tools/cpp:osx_cc_configure.bzl", "configure_osx_toolchain")
 load("@bazel_tools//tools/cpp:unix_cc_configure.bzl", "configure_unix_toolchain")
@@ -30,7 +29,7 @@
     # straightforward to add but we cannot run it in a docker container so
     # skipping until we have proper tests for FreeBSD.
     repository_ctx.symlink(Label("@bazel_tools//tools/cpp:CROSSTOOL"), "CROSSTOOL")
-    repository_ctx.symlink(Label("@bazel_tools//tools/cpp:BUILD.static"), "BUILD")
+    repository_ctx.symlink(Label("@bazel_tools//tools/cpp:BUILD.static.freebsd"), "BUILD")
   elif cpu_value == "x64_windows":
     # TODO(ibiryukov): overriden_tools are only supported in configure_unix_toolchain.
     # We might want to add that to Windows too(at least for msys toolchain).
@@ -42,7 +41,6 @@
     configure_unix_toolchain(repository_ctx, cpu_value, overriden_tools)
 
 cc_autoconf = repository_rule(
-    implementation = cc_autoconf_impl,
     environ = [
         "ABI_LIBC_VERSION",
         "ABI_VERSION",
@@ -72,10 +70,15 @@
         "VS100COMNTOOLS",
         "VS110COMNTOOLS",
         "VS120COMNTOOLS",
-        "VS140COMNTOOLS"])
-
+        "VS140COMNTOOLS",
+    ],
+    implementation = cc_autoconf_impl,
+)
 
 def cc_configure():
   """A C++ configuration rules that generate the crosstool file."""
   cc_autoconf(name="local_config_cc")
   native.bind(name="cc_toolchain", actual="@local_config_cc//:toolchain")
+  native.register_toolchains(
+      # Use register_toolchain's target pattern expansion to register all toolchains in the package.
+      "@local_config_cc//:all")
diff --git a/tools/cpp/windows_cc_configure.bzl b/tools/cpp/windows_cc_configure.bzl
index f7f7df1..605760d 100644
--- a/tools/cpp/windows_cc_configure.bzl
+++ b/tools/cpp/windows_cc_configure.bzl
@@ -27,7 +27,6 @@
     "is_cc_configure_debug",
 )
 
-
 def _get_escaped_windows_msys_crosstool_content(repository_ctx, use_mingw = False):
   """Return the content of msys crosstool which is still the default CROSSTOOL on Windows."""
   bazel_sh = get_env_var(repository_ctx, "BAZEL_SH").replace("\\", "/").lower()
@@ -71,7 +70,6 @@
       '   feature { name: "targets_windows" implies: "copy_dynamic_libraries_to_binary" enabled: true }' +
       '   feature { name: "copy_dynamic_libraries_to_binary" }' )
 
-
 def _get_system_root(repository_ctx):
   r"""Get System root path on Windows, default is C:\\Windows. Doesn't %-escape the result."""
   if "SYSTEMROOT" in repository_ctx.os.environ:
@@ -79,7 +77,6 @@
   auto_configure_warning("SYSTEMROOT is not set, using default SYSTEMROOT=C:\\Windows")
   return "C:\\Windows"
 
-
 def _find_cuda(repository_ctx):
   """Find out if and where cuda is installed. Doesn't %-escape the result."""
   if "CUDA_PATH" in repository_ctx.os.environ:
@@ -89,7 +86,6 @@
     return nvcc[:-len("/bin/nvcc.exe")]
   return None
 
-
 def _find_python(repository_ctx):
   """Find where is python on Windows. Doesn't %-escape the result."""
   if "BAZEL_PYTHON" in repository_ctx.os.environ:
@@ -102,7 +98,6 @@
   auto_configure_warning("Python found at %s" % python_binary)
   return python_binary
 
-
 def _add_system_root(repository_ctx, env):
   r"""Running VCVARSALL.BAT and VCVARSQUERYREGISTRY.BAT need %SYSTEMROOT%\\system32 in PATH."""
   if "PATH" not in env:
@@ -110,7 +105,6 @@
   env["PATH"] = env["PATH"] + ";" + _get_system_root(repository_ctx) + "\\system32"
   return env
 
-
 def find_vc_path(repository_ctx):
   """Find Visual C++ build tools install path. Doesn't %-escape the result."""
   # 1. Check if BAZEL_VC or BAZEL_VS is already set by user.
@@ -167,7 +161,6 @@
   auto_configure_warning("Visual C++ build tools found at %s" % vc_dir)
   return vc_dir
 
-
 def _is_vs_2017(vc_path):
   """Check if the installed VS version is Visual Studio 2017."""
   # In VS 2017, the location of VC is like:
@@ -176,7 +169,6 @@
   # C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\
   return vc_path.find("2017") != -1
 
-
 def _find_vcvarsall_bat_script(repository_ctx, vc_path):
   """Find vcvarsall.bat script. Doesn't %-escape the result."""
   if _is_vs_2017(vc_path):
@@ -189,7 +181,6 @@
 
   return vcvarsall
 
-
 def setup_vc_env_vars(repository_ctx, vc_path):
   """Get environment variables set by VCVARSALL.BAT. Doesn't %-escape the result!"""
   vcvarsall = _find_vcvarsall_bat_script(repository_ctx, vc_path)
@@ -208,7 +199,6 @@
     env_map[key] = escape_string(value.replace("\\", "\\\\"))
   return env_map
 
-
 def find_msvc_tool(repository_ctx, vc_path, tool):
   """Find the exact path of a specific build tool in MSVC. Doesn't %-escape the result."""
   tool_path = ""
@@ -246,7 +236,6 @@
 
   return missing_tools
 
-
 def _is_support_whole_archive(repository_ctx, vc_path):
   """Run MSVC linker alone to see if it supports /WHOLEARCHIVE."""
   env = repository_ctx.os.environ
@@ -256,20 +245,17 @@
   result = execute(repository_ctx, [linker], expect_failure = True)
   return result.find("/WHOLEARCHIVE") != -1
 
-
 def _is_support_debug_fastlink(repository_ctx, vc_path):
   """Run MSVC linker alone to see if it supports /DEBUG:FASTLINK."""
   linker = find_msvc_tool(repository_ctx, vc_path, "link.exe")
   result = execute(repository_ctx, [linker], expect_failure = True)
   return result.find("/DEBUG[:{FASTLINK|FULL|NONE}]") != -1
 
-
 def _is_use_msvc_wrapper(repository_ctx):
   """Returns True if USE_MSVC_WRAPPER is set to 1."""
   env = repository_ctx.os.environ
   return "USE_MSVC_WRAPPER" in env and env["USE_MSVC_WRAPPER"] == "1"
 
-
 def _get_compilation_mode_content():
   """Return the content for adding flags for different compilation modes when using MSVC wrapper."""
   return  "\n".join([
@@ -289,7 +275,6 @@
       "      linker_flag: '-Xcompilation-mode=opt'",
       "    }"])
 
-
 def _escaped_cuda_compute_capabilities(repository_ctx):
   """Returns a %-escaped list of strings representing cuda compute capabilities."""
 
@@ -306,10 +291,9 @@
       auto_configure_fail("Invalid compute capability: %s" % capability)
   return capabilities
 
-
 def configure_windows_toolchain(repository_ctx):
   """Configure C++ toolchain on Windows."""
-  repository_ctx.symlink(Label("@bazel_tools//tools/cpp:BUILD.static"), "BUILD")
+  repository_ctx.symlink(Label("@bazel_tools//tools/cpp:BUILD.static.windows"), "BUILD")
 
   vc_path = find_vc_path(repository_ctx)
   missing_tools = None