1# Copyright 2019 The Bazel Authors. All rights reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15load( 16 "//go/private:platforms.bzl", 17 "GOARCH_CONSTRAINTS", 18 "GOOS_CONSTRAINTS", 19 "PLATFORMS", 20) 21 22def declare_constraints(): 23 """Generates constraint_values and platform targets for valid platforms. 24 25 Each constraint_value corresponds to a valid goos or goarch. 26 The goos and goarch values belong to the constraint_settings 27 @platforms//os:os and @platforms//cpu:cpu, respectively. 28 To avoid redundancy, if there is an equivalent value in @platforms, 29 we define an alias here instead of another constraint_value. 30 31 Each platform defined here selects a goos and goarch constraint value. 32 These platforms may be used with --platforms for cross-compilation, 33 though users may create their own platforms (and 34 @bazel_tools//platforms:default_platform will be used most of the time). 35 """ 36 for goos, constraint in GOOS_CONSTRAINTS.items(): 37 if constraint.startswith("@io_bazel_rules_go//go/toolchain:"): 38 native.constraint_value( 39 name = goos, 40 constraint_setting = "@platforms//os:os", 41 ) 42 else: 43 native.alias( 44 name = goos, 45 actual = constraint, 46 ) 47 48 for goarch, constraint in GOARCH_CONSTRAINTS.items(): 49 if constraint.startswith("@io_bazel_rules_go//go/toolchain:"): 50 native.constraint_value( 51 name = goarch, 52 constraint_setting = "@platforms//cpu:cpu", 53 ) 54 else: 55 native.alias( 56 name = goarch, 57 actual = constraint, 58 ) 59 60 native.constraint_setting( 61 name = "cgo_constraint", 62 ) 63 64 native.constraint_value( 65 name = "cgo_on", 66 constraint_setting = ":cgo_constraint", 67 ) 68 69 native.constraint_value( 70 name = "cgo_off", 71 constraint_setting = ":cgo_constraint", 72 ) 73 74 for p in PLATFORMS: 75 native.platform( 76 name = p.name, 77 constraint_values = p.constraints, 78 ) 79