1// Copyright 2015 Google Inc. 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 15// Soong is a builder for Android that uses Blueprint to parse Blueprints 16// files and Ninja to do the dependency tracking and subprocess management. 17// Soong itself is responsible for converting the modules read by Blueprint 18// into build rules, which will be written to a build.ninja file by Blueprint. 19// 20// Android build concepts: 21// 22// Device 23// A device is a piece of hardware that will be running Android. It may specify 24// global settings like architecture, filesystem configuration, initialization 25// scripts, and device drivers. A device may support all variants of a single 26// piece of hardware, or multiple devices may be used for different variants. 27// A build is never targeted directly at a device, it is always targeted at a 28// "product". 29// 30// Product 31// A product is a configuration of a device, often for a specific market or 32// use case. It is sometimes referred to as a "SKU". A product defines 33// global settings like supported languages, supported use cases, preinstalled 34// modules, and user-visible behavior choices. A product selects one and only 35// one device. 36// 37// Module 38// A module is a definition of something to be built. It may be a C library or 39// binary, a java library, an Android app, etc. A module may be built for multiple 40// targets, even in a single build, for example host and device, or 32-bit device 41// and 64-bit device. 42// 43// Installed module 44// An installed module is one that has been requested by the selected product, 45// or a dependency of an installed module. 46// 47// Target architecture 48// The target architecture is the preferred architecture supported by the selected 49// device. It is most commonly 32-bit arm, but may also be 64-bit arm, 32-bit 50// x86, or 64-bit x86. 51// 52// Secondary architecture 53// The secondary architecture specifies the architecture to compile a second copy 54// of some modules for devices that support multiple architectures, for example 55// 64-bit devices that also support 32-bit binaries. 56package soong 57