1// Copyright 2019 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
15package android
16
17// ImageInterface is implemented by modules that need to be split by the imageMutator.
18type ImageInterface interface {
19	// ImageMutatorBegin is called before any other method in the ImageInterface.
20	ImageMutatorBegin(ctx BaseModuleContext)
21
22	// CoreVariantNeeded should return true if the module needs a core variant (installed on the system image).
23	CoreVariantNeeded(ctx BaseModuleContext) bool
24
25	// RamdiskVariantNeeded should return true if the module needs a ramdisk variant (installed on the
26	// ramdisk partition).
27	RamdiskVariantNeeded(ctx BaseModuleContext) bool
28
29	// RecoveryVariantNeeded should return true if the module needs a recovery variant (installed on the
30	// recovery partition).
31	RecoveryVariantNeeded(ctx BaseModuleContext) bool
32
33	// ExtraImageVariations should return a list of the additional variations needed for the module.  After the
34	// variants are created the SetImageVariation method will be called on each newly created variant with the
35	// its variation.
36	ExtraImageVariations(ctx BaseModuleContext) []string
37
38	// SetImageVariation will be passed a newly created recovery variant of the module.  ModuleBase implements
39	// SetImageVariation, most module types will not need to override it, and those that do must call the
40	// overridden method.  Implementors of SetImageVariation must be careful to modify the module argument
41	// and not the receiver.
42	SetImageVariation(ctx BaseModuleContext, variation string, module Module)
43}
44
45const (
46	// CoreVariation is the variant used for framework-private libraries, or
47	// SDK libraries. (which framework-private libraries can use), which
48	// will be installed to the system image.
49	CoreVariation string = ""
50
51	// RecoveryVariation means a module to be installed to recovery image.
52	RecoveryVariation string = "recovery"
53
54	// RamdiskVariation means a module to be installed to ramdisk image.
55	RamdiskVariation string = "ramdisk"
56)
57
58// imageMutator creates variants for modules that implement the ImageInterface that
59// allow them to build differently for each partition (recovery, core, vendor, etc.).
60func imageMutator(ctx BottomUpMutatorContext) {
61	if ctx.Os() != Android {
62		return
63	}
64
65	if m, ok := ctx.Module().(ImageInterface); ok {
66		m.ImageMutatorBegin(ctx)
67
68		var variations []string
69
70		if m.CoreVariantNeeded(ctx) {
71			variations = append(variations, CoreVariation)
72		}
73		if m.RamdiskVariantNeeded(ctx) {
74			variations = append(variations, RamdiskVariation)
75		}
76		if m.RecoveryVariantNeeded(ctx) {
77			variations = append(variations, RecoveryVariation)
78		}
79
80		extraVariations := m.ExtraImageVariations(ctx)
81		variations = append(variations, extraVariations...)
82
83		if len(variations) == 0 {
84			return
85		}
86
87		mod := ctx.CreateVariations(variations...)
88		for i, v := range variations {
89			mod[i].base().setImageVariation(v)
90			m.SetImageVariation(ctx, v, mod[i])
91		}
92	}
93}
94