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1// Copyright 2016 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 cc
16
17import (
18	"fmt"
19	"path/filepath"
20
21	"android/soong/android"
22	"android/soong/cc/config"
23
24	"github.com/google/blueprint"
25	"github.com/google/blueprint/proptools"
26)
27
28// This file contains the basic functionality for linking against static libraries and shared
29// libraries.  Final linking into libraries or executables is handled in library.go, binary.go, etc.
30
31const (
32	packRelocationsDefault = true
33)
34
35type BaseLinkerProperties struct {
36	// list of modules whose object files should be linked into this module
37	// in their entirety.  For static library modules, all of the .o files from the intermediate
38	// directory of the dependency will be linked into this modules .a file.  For a shared library,
39	// the dependency's .a file will be linked into this module using -Wl,--whole-archive.
40	Whole_static_libs []string `android:"arch_variant,variant_prepend"`
41
42	// list of modules that should be statically linked into this module.
43	Static_libs []string `android:"arch_variant,variant_prepend"`
44
45	// list of modules that should be dynamically linked into this module.
46	Shared_libs []string `android:"arch_variant"`
47
48	// list of modules that should only provide headers for this module.
49	Header_libs []string `android:"arch_variant,variant_prepend"`
50
51	// list of module-specific flags that will be used for all link steps
52	Ldflags []string `android:"arch_variant"`
53
54	// list of system libraries that will be dynamically linked to
55	// shared library and executable modules.  If unset, generally defaults to libc,
56	// libm, and libdl.  Set to [] to prevent linking against the defaults.
57	System_shared_libs []string `android:"arch_variant"`
58
59	// allow the module to contain undefined symbols.  By default,
60	// modules cannot contain undefined symbols that are not satisified by their immediate
61	// dependencies.  Set this flag to true to remove --no-undefined from the linker flags.
62	// This flag should only be necessary for compiling low-level libraries like libc.
63	Allow_undefined_symbols *bool `android:"arch_variant"`
64
65	// don't link in libclang_rt.builtins-*.a
66	No_libcrt *bool `android:"arch_variant"`
67
68	// Use clang lld instead of gnu ld.
69	Use_clang_lld *bool `android:"arch_variant"`
70
71	// -l arguments to pass to linker for host-provided shared libraries
72	Host_ldlibs []string `android:"arch_variant"`
73
74	// list of shared libraries to re-export include directories from. Entries must be
75	// present in shared_libs.
76	Export_shared_lib_headers []string `android:"arch_variant"`
77
78	// list of static libraries to re-export include directories from. Entries must be
79	// present in static_libs.
80	Export_static_lib_headers []string `android:"arch_variant"`
81
82	// list of header libraries to re-export include directories from. Entries must be
83	// present in header_libs.
84	Export_header_lib_headers []string `android:"arch_variant"`
85
86	// list of generated headers to re-export include directories from. Entries must be
87	// present in generated_headers.
88	Export_generated_headers []string `android:"arch_variant"`
89
90	// don't link in crt_begin and crt_end.  This flag should only be necessary for
91	// compiling crt or libc.
92	Nocrt *bool `android:"arch_variant"`
93
94	// deprecated and ignored because lld makes it unnecessary. See b/189475744.
95	Group_static_libs *bool `android:"arch_variant"`
96
97	// list of modules that should be installed with this module.  This is similar to 'required'
98	// but '.vendor' suffix will be appended to the module names if the shared libraries have
99	// vendor variants and this module uses VNDK.
100	Runtime_libs []string `android:"arch_variant"`
101
102	// list of runtime libs that should not be installed along with this module.
103	Exclude_runtime_libs []string `android:"arch_variant"`
104
105	Target struct {
106		Vendor, Product struct {
107			// list of shared libs that only should be used to build vendor or
108			// product variant of the C/C++ module.
109			Shared_libs []string
110
111			// list of static libs that only should be used to build vendor or
112			// product variant of the C/C++ module.
113			Static_libs []string
114
115			// list of ehader libs that only should be used to build vendor or product
116			// variant of the C/C++ module.
117			Header_libs []string
118
119			// list of shared libs that should not be used to build vendor or
120			// product variant of the C/C++ module.
121			Exclude_shared_libs []string
122
123			// list of static libs that should not be used to build vendor or
124			// product variant of the C/C++ module.
125			Exclude_static_libs []string
126
127			// list of header libs that should not be used to build vendor or
128			// product variant of the C/C++ module.
129			Exclude_header_libs []string
130
131			// list of runtime libs that should not be installed along with the
132			// vendor or product variant of the C/C++ module.
133			Exclude_runtime_libs []string
134
135			// version script for vendor or product variant
136			Version_script *string `android:"arch_variant"`
137		} `android:"arch_variant"`
138		Recovery struct {
139			// list of shared libs that only should be used to build the recovery
140			// variant of the C/C++ module.
141			Shared_libs []string
142
143			// list of static libs that only should be used to build the recovery
144			// variant of the C/C++ module.
145			Static_libs []string
146
147			// list of shared libs that should not be used to build
148			// the recovery variant of the C/C++ module.
149			Exclude_shared_libs []string
150
151			// list of static libs that should not be used to build
152			// the recovery variant of the C/C++ module.
153			Exclude_static_libs []string
154
155			// list of header libs that should not be used to build the recovery variant
156			// of the C/C++ module.
157			Exclude_header_libs []string
158
159			// list of runtime libs that should not be installed along with the
160			// recovery variant of the C/C++ module.
161			Exclude_runtime_libs []string
162		}
163		Ramdisk struct {
164			// list of static libs that only should be used to build the recovery
165			// variant of the C/C++ module.
166			Static_libs []string
167
168			// list of shared libs that should not be used to build
169			// the ramdisk variant of the C/C++ module.
170			Exclude_shared_libs []string
171
172			// list of static libs that should not be used to build
173			// the ramdisk variant of the C/C++ module.
174			Exclude_static_libs []string
175
176			// list of runtime libs that should not be installed along with the
177			// ramdisk variant of the C/C++ module.
178			Exclude_runtime_libs []string
179		}
180		Vendor_ramdisk struct {
181			// list of shared libs that should not be used to build
182			// the recovery variant of the C/C++ module.
183			Exclude_shared_libs []string
184
185			// list of static libs that should not be used to build
186			// the vendor ramdisk variant of the C/C++ module.
187			Exclude_static_libs []string
188
189			// list of runtime libs that should not be installed along with the
190			// vendor ramdisk variant of the C/C++ module.
191			Exclude_runtime_libs []string
192		}
193		Platform struct {
194			// list of shared libs that should be use to build the platform variant
195			// of a module that sets sdk_version.  This should rarely be necessary,
196			// in most cases the same libraries are available for the SDK and platform
197			// variants.
198			Shared_libs []string
199
200			// list of ehader libs that only should be used to build platform variant of
201			// the C/C++ module.
202			Header_libs []string
203
204			// list of shared libs that should not be used to build the platform variant
205			// of the C/C++ module.
206			Exclude_shared_libs []string
207		}
208		Apex struct {
209			// list of shared libs that should not be used to build the apex variant of
210			// the C/C++ module.
211			Exclude_shared_libs []string
212
213			// list of static libs that should not be used to build the apex
214			// variant of the C/C++ module.
215			Exclude_static_libs []string
216		}
217	} `android:"arch_variant"`
218
219	// make android::build:GetBuildNumber() available containing the build ID.
220	Use_version_lib *bool `android:"arch_variant"`
221
222	// Generate compact dynamic relocation table, default true.
223	Pack_relocations *bool `android:"arch_variant"`
224
225	// local file name to pass to the linker as --version-script
226	Version_script *string `android:"path,arch_variant"`
227
228	// local file name to pass to the linker as --dynamic-list
229	Dynamic_list *string `android:"path,arch_variant"`
230
231	// local files to pass to the linker as --script
232	Linker_scripts []string `android:"path,arch_variant"`
233
234	// list of static libs that should not be used to build this module
235	Exclude_static_libs []string `android:"arch_variant"`
236
237	// list of shared libs that should not be used to build this module
238	Exclude_shared_libs []string `android:"arch_variant"`
239}
240
241func (blp *BaseLinkerProperties) crt() bool {
242	// Since crt is enabled for almost every module compiling against the Bionic runtime,
243	// we interpret `nil` as  enabled.
244	return blp.Nocrt == nil || !*blp.Nocrt
245}
246
247func (blp *BaseLinkerProperties) libCrt() bool {
248	return blp.No_libcrt == nil || !*blp.No_libcrt
249}
250
251func NewBaseLinker(sanitize *sanitize) *baseLinker {
252	return &baseLinker{sanitize: sanitize}
253}
254
255// baseLinker provides support for shared_libs, static_libs, and whole_static_libs properties
256type baseLinker struct {
257	Properties        BaseLinkerProperties
258	dynamicProperties struct {
259		BuildStubs bool `blueprint:"mutated"`
260	}
261
262	sanitize *sanitize
263}
264
265func (linker *baseLinker) appendLdflags(flags []string) {
266	linker.Properties.Ldflags = append(linker.Properties.Ldflags, flags...)
267}
268
269// linkerInit initializes dynamic properties of the linker.
270func (linker *baseLinker) linkerInit(ctx BaseModuleContext) {
271}
272
273func (linker *baseLinker) linkerProps() []interface{} {
274	return []interface{}{&linker.Properties, &linker.dynamicProperties}
275}
276
277func (linker *baseLinker) linkerDeps(ctx DepsContext, deps Deps) Deps {
278	deps.WholeStaticLibs = append(deps.WholeStaticLibs, linker.Properties.Whole_static_libs...)
279	deps.HeaderLibs = append(deps.HeaderLibs, linker.Properties.Header_libs...)
280	deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Static_libs...)
281	deps.SharedLibs = append(deps.SharedLibs, linker.Properties.Shared_libs...)
282	deps.RuntimeLibs = append(deps.RuntimeLibs, linker.Properties.Runtime_libs...)
283
284	deps.ReexportHeaderLibHeaders = append(deps.ReexportHeaderLibHeaders, linker.Properties.Export_header_lib_headers...)
285	deps.ReexportStaticLibHeaders = append(deps.ReexportStaticLibHeaders, linker.Properties.Export_static_lib_headers...)
286	deps.ReexportSharedLibHeaders = append(deps.ReexportSharedLibHeaders, linker.Properties.Export_shared_lib_headers...)
287	deps.ReexportGeneratedHeaders = append(deps.ReexportGeneratedHeaders, linker.Properties.Export_generated_headers...)
288
289	deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Exclude_shared_libs)
290	deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Exclude_static_libs)
291	deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Exclude_static_libs)
292	deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Exclude_runtime_libs)
293
294	// Record the libraries that need to be excluded when building for APEX. Unlike other
295	// target.*.exclude_* properties, SharedLibs and StaticLibs are not modified here because
296	// this module hasn't yet passed the apexMutator. Therefore, we can't tell whether this is
297	// an apex variant of not. Record the exclude list in the deps struct for now. The info is
298	// used to mark the dependency tag when adding dependencies to the deps. Then inside
299	// GenerateAndroidBuildActions, the marked dependencies are ignored (i.e. not used) for APEX
300	// variants.
301	deps.ExcludeLibsForApex = append(deps.ExcludeLibsForApex, linker.Properties.Target.Apex.Exclude_shared_libs...)
302	deps.ExcludeLibsForApex = append(deps.ExcludeLibsForApex, linker.Properties.Target.Apex.Exclude_static_libs...)
303
304	if Bool(linker.Properties.Use_version_lib) {
305		deps.WholeStaticLibs = append(deps.WholeStaticLibs, "libbuildversion")
306	}
307
308	if ctx.inVendor() {
309		deps.SharedLibs = append(deps.SharedLibs, linker.Properties.Target.Vendor.Shared_libs...)
310		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Vendor.Exclude_shared_libs)
311		deps.ReexportSharedLibHeaders = removeListFromList(deps.ReexportSharedLibHeaders, linker.Properties.Target.Vendor.Exclude_shared_libs)
312		deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Target.Vendor.Static_libs...)
313		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Vendor.Exclude_static_libs)
314		deps.HeaderLibs = append(deps.HeaderLibs, linker.Properties.Target.Vendor.Header_libs...)
315		deps.HeaderLibs = removeListFromList(deps.HeaderLibs, linker.Properties.Target.Vendor.Exclude_header_libs)
316		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Vendor.Exclude_static_libs)
317		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Vendor.Exclude_static_libs)
318		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Vendor.Exclude_runtime_libs)
319	}
320
321	if ctx.inProduct() {
322		deps.SharedLibs = append(deps.SharedLibs, linker.Properties.Target.Product.Shared_libs...)
323		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Product.Exclude_shared_libs)
324		deps.ReexportSharedLibHeaders = removeListFromList(deps.ReexportSharedLibHeaders, linker.Properties.Target.Product.Exclude_shared_libs)
325		deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Target.Product.Static_libs...)
326		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Product.Exclude_static_libs)
327		deps.HeaderLibs = removeListFromList(deps.HeaderLibs, linker.Properties.Target.Product.Exclude_header_libs)
328		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Product.Exclude_static_libs)
329		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Product.Exclude_static_libs)
330		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Product.Exclude_runtime_libs)
331	}
332
333	if ctx.inRecovery() {
334		deps.SharedLibs = append(deps.SharedLibs, linker.Properties.Target.Recovery.Shared_libs...)
335		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Recovery.Exclude_shared_libs)
336		deps.ReexportSharedLibHeaders = removeListFromList(deps.ReexportSharedLibHeaders, linker.Properties.Target.Recovery.Exclude_shared_libs)
337		deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Target.Recovery.Static_libs...)
338		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Recovery.Exclude_static_libs)
339		deps.HeaderLibs = removeListFromList(deps.HeaderLibs, linker.Properties.Target.Recovery.Exclude_header_libs)
340		deps.ReexportHeaderLibHeaders = removeListFromList(deps.ReexportHeaderLibHeaders, linker.Properties.Target.Recovery.Exclude_header_libs)
341		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Recovery.Exclude_static_libs)
342		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Recovery.Exclude_static_libs)
343		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Recovery.Exclude_runtime_libs)
344	}
345
346	if ctx.inRamdisk() {
347		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Ramdisk.Exclude_shared_libs)
348		deps.ReexportSharedLibHeaders = removeListFromList(deps.ReexportSharedLibHeaders, linker.Properties.Target.Ramdisk.Exclude_shared_libs)
349		deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Target.Ramdisk.Static_libs...)
350		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Ramdisk.Exclude_static_libs)
351		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Ramdisk.Exclude_static_libs)
352		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Ramdisk.Exclude_static_libs)
353		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Ramdisk.Exclude_runtime_libs)
354	}
355
356	if ctx.inVendorRamdisk() {
357		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Vendor_ramdisk.Exclude_shared_libs)
358		deps.ReexportSharedLibHeaders = removeListFromList(deps.ReexportSharedLibHeaders, linker.Properties.Target.Vendor_ramdisk.Exclude_shared_libs)
359		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Vendor_ramdisk.Exclude_static_libs)
360		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Vendor_ramdisk.Exclude_static_libs)
361		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Vendor_ramdisk.Exclude_static_libs)
362		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Vendor_ramdisk.Exclude_runtime_libs)
363	}
364
365	if !ctx.useSdk() {
366		deps.SharedLibs = append(deps.SharedLibs, linker.Properties.Target.Platform.Shared_libs...)
367		deps.SharedLibs = removeListFromList(deps.SharedLibs, linker.Properties.Target.Platform.Exclude_shared_libs)
368		deps.HeaderLibs = append(deps.HeaderLibs, linker.Properties.Target.Platform.Header_libs...)
369	}
370
371	deps.SystemSharedLibs = linker.Properties.System_shared_libs
372	if deps.SystemSharedLibs == nil {
373		// Provide a default system_shared_libs if it is unspecified. Note: If an
374		// empty list [] is specified, it implies that the module declines the
375		// default system_shared_libs.
376		deps.SystemSharedLibs = append(deps.SystemSharedLibs, ctx.toolchain().DefaultSharedLibraries()...)
377	}
378
379	if ctx.toolchain().Bionic() {
380		// libclang_rt.builtins has to be last on the command line
381		if linker.Properties.libCrt() && !ctx.header() {
382			deps.UnexportedStaticLibs = append(deps.UnexportedStaticLibs, config.BuiltinsRuntimeLibrary(ctx.toolchain()))
383		}
384
385		if inList("libdl", deps.SharedLibs) {
386			// If system_shared_libs has libc but not libdl, make sure shared_libs does not
387			// have libdl to avoid loading libdl before libc.
388			if inList("libc", deps.SystemSharedLibs) {
389				if !inList("libdl", deps.SystemSharedLibs) {
390					ctx.PropertyErrorf("shared_libs",
391						"libdl must be in system_shared_libs, not shared_libs")
392				}
393				_, deps.SharedLibs = removeFromList("libdl", deps.SharedLibs)
394			}
395		}
396
397		// If libc and libdl are both in system_shared_libs make sure libdl comes after libc
398		// to avoid loading libdl before libc.
399		if inList("libdl", deps.SystemSharedLibs) && inList("libc", deps.SystemSharedLibs) &&
400			indexList("libdl", deps.SystemSharedLibs) < indexList("libc", deps.SystemSharedLibs) {
401			ctx.PropertyErrorf("system_shared_libs", "libdl must be after libc")
402		}
403	} else if ctx.toolchain().Musl() {
404		if linker.Properties.libCrt() && !ctx.header() {
405			deps.UnexportedStaticLibs = append(deps.UnexportedStaticLibs, config.BuiltinsRuntimeLibrary(ctx.toolchain()))
406		}
407	}
408
409	deps.LateSharedLibs = append(deps.LateSharedLibs, deps.SystemSharedLibs...)
410
411	if ctx.Windows() && ctx.ModuleName() != "libwinpthread" {
412		deps.LateStaticLibs = append(deps.LateStaticLibs, "libwinpthread")
413	}
414
415	return deps
416}
417
418func (linker *baseLinker) useClangLld(ctx ModuleContext) bool {
419	if linker.Properties.Use_clang_lld != nil {
420		return Bool(linker.Properties.Use_clang_lld)
421	}
422	return true
423}
424
425// Check whether the SDK version is not older than the specific one
426func CheckSdkVersionAtLeast(ctx ModuleContext, SdkVersion android.ApiLevel) bool {
427	if ctx.minSdkVersion() == "current" {
428		return true
429	}
430	parsedSdkVersion, err := nativeApiLevelFromUser(ctx, ctx.minSdkVersion())
431	if err != nil {
432		ctx.PropertyErrorf("min_sdk_version",
433			"Invalid min_sdk_version value (must be int or current): %q",
434			ctx.minSdkVersion())
435	}
436	if parsedSdkVersion.LessThan(SdkVersion) {
437		return false
438	}
439	return true
440}
441
442// ModuleContext extends BaseModuleContext
443// BaseModuleContext should know if LLD is used?
444func (linker *baseLinker) linkerFlags(ctx ModuleContext, flags Flags) Flags {
445	toolchain := ctx.toolchain()
446
447	hod := "Host"
448	if ctx.Os().Class == android.Device {
449		hod = "Device"
450	}
451
452	if linker.useClangLld(ctx) {
453		flags.Global.LdFlags = append(flags.Global.LdFlags, fmt.Sprintf("${config.%sGlobalLldflags}", hod))
454		if !BoolDefault(linker.Properties.Pack_relocations, packRelocationsDefault) {
455			flags.Global.LdFlags = append(flags.Global.LdFlags, "-Wl,--pack-dyn-relocs=none")
456		} else if ctx.Device() {
457			// SHT_RELR relocations are only supported at API level >= 30.
458			// ANDROID_RELR relocations were supported at API level >= 28.
459			// Relocation packer was supported at API level >= 23.
460			// Do the best we can...
461			if (!ctx.useSdk() && ctx.minSdkVersion() == "") || CheckSdkVersionAtLeast(ctx, android.FirstShtRelrVersion) {
462				flags.Global.LdFlags = append(flags.Global.LdFlags, "-Wl,--pack-dyn-relocs=android+relr")
463			} else if CheckSdkVersionAtLeast(ctx, android.FirstAndroidRelrVersion) {
464				flags.Global.LdFlags = append(flags.Global.LdFlags,
465					"-Wl,--pack-dyn-relocs=android+relr",
466					"-Wl,--use-android-relr-tags")
467			} else if CheckSdkVersionAtLeast(ctx, android.FirstPackedRelocationsVersion) {
468				flags.Global.LdFlags = append(flags.Global.LdFlags, "-Wl,--pack-dyn-relocs=android")
469			}
470		}
471	} else {
472		flags.Global.LdFlags = append(flags.Global.LdFlags, fmt.Sprintf("${config.%sGlobalLdflags}", hod))
473	}
474	if Bool(linker.Properties.Allow_undefined_symbols) {
475		if ctx.Darwin() {
476			// darwin defaults to treating undefined symbols as errors
477			flags.Global.LdFlags = append(flags.Global.LdFlags, "-Wl,-undefined,dynamic_lookup")
478		}
479	} else if !ctx.Darwin() && !ctx.Windows() {
480		flags.Global.LdFlags = append(flags.Global.LdFlags, "-Wl,--no-undefined")
481	}
482
483	if linker.useClangLld(ctx) {
484		flags.Global.LdFlags = append(flags.Global.LdFlags, toolchain.Lldflags())
485	} else {
486		flags.Global.LdFlags = append(flags.Global.LdFlags, toolchain.Ldflags())
487	}
488
489	if !ctx.toolchain().Bionic() && ctx.Os() != android.LinuxMusl {
490		CheckBadHostLdlibs(ctx, "host_ldlibs", linker.Properties.Host_ldlibs)
491
492		flags.Local.LdFlags = append(flags.Local.LdFlags, linker.Properties.Host_ldlibs...)
493
494		if !ctx.Windows() {
495			// Add -ldl, -lpthread, -lm and -lrt to host builds to match the default behavior of device
496			// builds
497			flags.Global.LdFlags = append(flags.Global.LdFlags,
498				"-ldl",
499				"-lpthread",
500				"-lm",
501			)
502			if !ctx.Darwin() {
503				flags.Global.LdFlags = append(flags.Global.LdFlags, "-lrt")
504			}
505		}
506	}
507
508	CheckBadLinkerFlags(ctx, "ldflags", linker.Properties.Ldflags)
509
510	flags.Local.LdFlags = append(flags.Local.LdFlags, proptools.NinjaAndShellEscapeList(linker.Properties.Ldflags)...)
511
512	if ctx.Host() && !ctx.Windows() && !ctx.static() {
513		flags.Global.LdFlags = append(flags.Global.LdFlags, RpathFlags(ctx)...)
514	}
515
516	if ctx.useSdk() {
517		// The bionic linker now has support gnu style hashes (which are much faster!), but shipping
518		// to older devices requires the old style hash. Fortunately, we can build with both and
519		// it'll work anywhere.
520		flags.Global.LdFlags = append(flags.Global.LdFlags, "-Wl,--hash-style=both")
521	}
522
523	flags.Global.LdFlags = append(flags.Global.LdFlags, toolchain.ToolchainLdflags())
524
525	// Version_script is not needed when linking stubs lib where the version
526	// script is created from the symbol map file.
527	if !linker.dynamicProperties.BuildStubs {
528		versionScript := ctx.ExpandOptionalSource(
529			linker.Properties.Version_script, "version_script")
530
531		if ctx.inVendor() && linker.Properties.Target.Vendor.Version_script != nil {
532			versionScript = ctx.ExpandOptionalSource(
533				linker.Properties.Target.Vendor.Version_script,
534				"target.vendor.version_script")
535		} else if ctx.inProduct() && linker.Properties.Target.Product.Version_script != nil {
536			versionScript = ctx.ExpandOptionalSource(
537				linker.Properties.Target.Product.Version_script,
538				"target.product.version_script")
539		}
540
541		if versionScript.Valid() {
542			if ctx.Darwin() {
543				ctx.PropertyErrorf("version_script", "Not supported on Darwin")
544			} else {
545				flags.Local.LdFlags = append(flags.Local.LdFlags,
546					config.VersionScriptFlagPrefix+versionScript.String())
547				flags.LdFlagsDeps = append(flags.LdFlagsDeps, versionScript.Path())
548
549				if linker.sanitize.isSanitizerEnabled(cfi) {
550					cfiExportsMap := android.PathForSource(ctx, cfiExportsMapPath+"/"+cfiExportsMapFilename)
551					flags.Local.LdFlags = append(flags.Local.LdFlags,
552						config.VersionScriptFlagPrefix+cfiExportsMap.String())
553					flags.LdFlagsDeps = append(flags.LdFlagsDeps, cfiExportsMap)
554				}
555			}
556		}
557
558		dynamicList := android.OptionalPathForModuleSrc(ctx, linker.Properties.Dynamic_list)
559		if dynamicList.Valid() {
560			if ctx.Darwin() {
561				ctx.PropertyErrorf("dynamic_list", "Not supported on Darwin")
562			} else {
563				flags.Local.LdFlags = append(flags.Local.LdFlags,
564					"-Wl,--dynamic-list,"+dynamicList.String())
565				flags.LdFlagsDeps = append(flags.LdFlagsDeps, dynamicList.Path())
566			}
567		}
568
569		linkerScriptPaths := android.PathsForModuleSrc(ctx, linker.Properties.Linker_scripts)
570		if len(linkerScriptPaths) > 0 && (ctx.Darwin() || ctx.Windows()) {
571			ctx.PropertyErrorf("linker_scripts", "Only supported for ELF files")
572		} else {
573			for _, linkerScriptPath := range linkerScriptPaths {
574				flags.Local.LdFlags = append(flags.Local.LdFlags,
575					"-Wl,--script,"+linkerScriptPath.String())
576				flags.LdFlagsDeps = append(flags.LdFlagsDeps, linkerScriptPath)
577			}
578		}
579	}
580
581	return flags
582}
583
584// RpathFlags returns the rpath linker flags for current target to search the following directories relative
585// to the binary:
586//
587//   - "." to find libraries alongside tests
588//   - "lib[64]" to find libraries in a subdirectory of the binaries' directory
589//   - "../lib[64]" to find libraries when the binaries are in a bin directory
590//   - "../../lib[64]" to find libraries in out/host/linux-x86/lib64 when the test or binary is in
591//     out/host/linux-x86/nativetest/<test dir>/<test>
592//   - "../../../lib[[64] to find libraries in out/host/linux-x86/lib64 when the test or binary is in
593//     out/host/linux-x86/testcases/<test dir>/<CPU>/<test>
594func RpathFlags(ctx android.ModuleContext) []string {
595	key := struct {
596		os   android.OsType
597		arch android.ArchType
598	}{ctx.Target().Os, ctx.Target().Arch.ArchType}
599
600	return ctx.Config().OnceStringSlice(android.NewCustomOnceKey(key), func() []string {
601		rpathPrefix := `\$$ORIGIN/`
602		if key.os == android.Darwin {
603			rpathPrefix = "@loader_path/"
604		}
605
606		var libDir string
607		if key.arch.Multilib == "lib64" {
608			libDir = "lib64"
609		} else {
610			libDir = "lib"
611		}
612
613		return []string{
614			"-Wl,-rpath," + rpathPrefix,
615			"-Wl,-rpath," + rpathPrefix + libDir,
616			"-Wl,-rpath," + rpathPrefix + filepath.Join("..", libDir),
617			"-Wl,-rpath," + rpathPrefix + filepath.Join("../..", libDir),
618			"-Wl,-rpath," + rpathPrefix + filepath.Join("../../..", libDir),
619		}
620	})
621}
622
623func (linker *baseLinker) link(ctx ModuleContext,
624	flags Flags, deps PathDeps, objs Objects) android.Path {
625	panic(fmt.Errorf("baseLinker doesn't know how to link"))
626}
627
628func (linker *baseLinker) linkerSpecifiedDeps(specifiedDeps specifiedDeps) specifiedDeps {
629	specifiedDeps.sharedLibs = append(specifiedDeps.sharedLibs, linker.Properties.Shared_libs...)
630
631	// Must distinguish nil and [] in system_shared_libs - ensure that [] in
632	// either input list doesn't come out as nil.
633	if specifiedDeps.systemSharedLibs == nil {
634		specifiedDeps.systemSharedLibs = linker.Properties.System_shared_libs
635	} else {
636		specifiedDeps.systemSharedLibs = append(specifiedDeps.systemSharedLibs, linker.Properties.System_shared_libs...)
637	}
638
639	return specifiedDeps
640}
641
642// Injecting version symbols
643// Some host modules want a version number, but we don't want to rebuild it every time.  Optionally add a step
644// after linking that injects a constant placeholder with the current version number.
645
646func init() {
647	pctx.HostBinToolVariable("symbolInjectCmd", "symbol_inject")
648}
649
650var injectVersionSymbol = pctx.AndroidStaticRule("injectVersionSymbol",
651	blueprint.RuleParams{
652		Command: "$symbolInjectCmd -i $in -o $out -s soong_build_number " +
653			"-from 'SOONG BUILD NUMBER PLACEHOLDER' -v $$(cat $buildNumberFile)",
654		CommandDeps: []string{"$symbolInjectCmd"},
655	},
656	"buildNumberFile")
657
658func (linker *baseLinker) injectVersionSymbol(ctx ModuleContext, in android.Path, out android.WritablePath) {
659	buildNumberFile := ctx.Config().BuildNumberFile(ctx)
660	ctx.Build(pctx, android.BuildParams{
661		Rule:        injectVersionSymbol,
662		Description: "inject version symbol",
663		Input:       in,
664		Output:      out,
665		OrderOnly:   android.Paths{buildNumberFile},
666		Args: map[string]string{
667			"buildNumberFile": buildNumberFile.String(),
668		},
669	})
670}
671