1// Copyright (C) 2020 The Android Open Source Project
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 linkerconfig
16
17import (
18	"fmt"
19	"sort"
20	"strings"
21
22	"github.com/google/blueprint/proptools"
23
24	"android/soong/android"
25	"android/soong/cc"
26	"android/soong/etc"
27)
28
29var (
30	pctx = android.NewPackageContext("android/soong/linkerconfig")
31)
32
33func init() {
34	pctx.HostBinToolVariable("conv_linker_config", "conv_linker_config")
35	registerLinkerConfigBuildComponent(android.InitRegistrationContext)
36}
37
38func registerLinkerConfigBuildComponent(ctx android.RegistrationContext) {
39	ctx.RegisterModuleType("linker_config", linkerConfigFactory)
40}
41
42type linkerConfigProperties struct {
43	// source linker configuration property file
44	Src *string `android:"path"`
45
46	// If set to true, allow module to be installed to one of the partitions.
47	// Default value is true.
48	// Installable should be marked as false for APEX configuration to avoid
49	// conflicts of configuration on /system/etc directory.
50	Installable *bool
51}
52
53type linkerConfig struct {
54	android.ModuleBase
55	properties linkerConfigProperties
56
57	outputFilePath android.OutputPath
58	installDirPath android.InstallPath
59}
60
61// Implement PrebuiltEtcModule interface to fit in APEX prebuilt list.
62var _ etc.PrebuiltEtcModule = (*linkerConfig)(nil)
63
64func (l *linkerConfig) BaseDir() string {
65	return "etc"
66}
67
68func (l *linkerConfig) SubDir() string {
69	return ""
70}
71
72func (l *linkerConfig) OutputFile() android.OutputPath {
73	return l.outputFilePath
74}
75
76var _ android.OutputFileProducer = (*linkerConfig)(nil)
77
78func (l *linkerConfig) OutputFiles(tag string) (android.Paths, error) {
79	switch tag {
80	case "":
81		return android.Paths{l.outputFilePath}, nil
82	default:
83		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
84	}
85}
86
87func (l *linkerConfig) GenerateAndroidBuildActions(ctx android.ModuleContext) {
88	input := android.PathForModuleSrc(ctx, android.String(l.properties.Src))
89	output := android.PathForModuleOut(ctx, "linker.config.pb").OutputPath
90
91	builder := android.NewRuleBuilder(pctx, ctx)
92	BuildLinkerConfig(ctx, builder, input, nil, output)
93	builder.Build("conv_linker_config", "Generate linker config protobuf "+output.String())
94
95	l.outputFilePath = output
96	l.installDirPath = android.PathForModuleInstall(ctx, "etc")
97	if !proptools.BoolDefault(l.properties.Installable, true) {
98		l.SkipInstall()
99	}
100	ctx.InstallFile(l.installDirPath, l.outputFilePath.Base(), l.outputFilePath)
101}
102
103func BuildLinkerConfig(ctx android.ModuleContext, builder *android.RuleBuilder,
104	input android.Path, otherModules []android.Module, output android.OutputPath) {
105
106	// First, convert the input json to protobuf format
107	interimOutput := android.PathForModuleOut(ctx, "temp.pb")
108	builder.Command().
109		BuiltTool("conv_linker_config").
110		Flag("proto").
111		FlagWithInput("-s ", input).
112		FlagWithOutput("-o ", interimOutput)
113
114	// Secondly, if there's provideLibs gathered from otherModules, append them
115	var provideLibs []string
116	for _, m := range otherModules {
117		if c, ok := m.(*cc.Module); ok && cc.IsStubTarget(c) {
118			for _, ps := range c.PackagingSpecs() {
119				provideLibs = append(provideLibs, ps.FileName())
120			}
121		}
122	}
123	provideLibs = android.FirstUniqueStrings(provideLibs)
124	sort.Strings(provideLibs)
125	if len(provideLibs) > 0 {
126		builder.Command().
127			BuiltTool("conv_linker_config").
128			Flag("append").
129			FlagWithInput("-s ", interimOutput).
130			FlagWithOutput("-o ", output).
131			FlagWithArg("--key ", "provideLibs").
132			FlagWithArg("--value ", proptools.ShellEscapeIncludingSpaces(strings.Join(provideLibs, " ")))
133	} else {
134		// If nothing to add, just cp to the final output
135		builder.Command().Text("cp").Input(interimOutput).Output(output)
136	}
137	builder.Temporary(interimOutput)
138	builder.DeleteTemporaryFiles()
139}
140
141// linker_config generates protobuf file from json file. This protobuf file will be used from
142// linkerconfig while generating ld.config.txt. Format of this file can be found from
143// https://android.googlesource.com/platform/system/linkerconfig/+/master/README.md
144func linkerConfigFactory() android.Module {
145	m := &linkerConfig{}
146	m.AddProperties(&m.properties)
147	android.InitAndroidArchModule(m, android.HostAndDeviceSupported, android.MultilibFirst)
148	return m
149}
150
151func (l *linkerConfig) AndroidMkEntries() []android.AndroidMkEntries {
152	installable := proptools.BoolDefault(l.properties.Installable, true)
153	return []android.AndroidMkEntries{android.AndroidMkEntries{
154		Class:      "ETC",
155		OutputFile: android.OptionalPathForPath(l.outputFilePath),
156		ExtraEntries: []android.AndroidMkExtraEntriesFunc{
157			func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
158				entries.SetString("LOCAL_MODULE_PATH", l.installDirPath.ToMakePath().String())
159				entries.SetString("LOCAL_INSTALLED_MODULE_STEM", l.outputFilePath.Base())
160				entries.SetBoolIfTrue("LOCAL_UNINSTALLABLE_MODULE", !installable)
161				entries.SetString("LINKER_CONFIG_PATH_"+l.Name(), l.OutputFile().String())
162			},
163		},
164	}}
165}
166