xref: /aosp_15_r20/build/soong/rust/compiler.go (revision 333d2b3687b3a337dbcca9d65000bca186795e39)
1// Copyright 2019 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 rust
16
17import (
18	"android/soong/cc"
19	"errors"
20	"fmt"
21	"path/filepath"
22	"strings"
23
24	"github.com/google/blueprint/proptools"
25
26	"android/soong/android"
27	"android/soong/rust/config"
28)
29
30type RustLinkage int
31
32const (
33	DefaultLinkage RustLinkage = iota
34	RlibLinkage
35	DylibLinkage
36)
37
38type compiler interface {
39	initialize(ctx ModuleContext)
40	compilerFlags(ctx ModuleContext, flags Flags) Flags
41	cfgFlags(ctx ModuleContext, flags Flags) Flags
42	featureFlags(ctx ModuleContext, module *Module, flags Flags) Flags
43	compilerProps() []interface{}
44	compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput
45	compilerDeps(ctx DepsContext, deps Deps) Deps
46	crateName() string
47	edition() string
48	features(ctx android.ConfigurableEvaluatorContext, module *Module) []string
49	rustdoc(ctx ModuleContext, flags Flags, deps PathDeps) android.OptionalPath
50	Thinlto() bool
51
52	// Output directory in which source-generated code from dependencies is
53	// copied. This is equivalent to Cargo's OUT_DIR variable.
54	cargoOutDir() android.OptionalPath
55
56	// cargoPkgVersion returns the value of the Cargo_pkg_version property.
57	cargoPkgVersion() string
58
59	// cargoEnvCompat returns whether Cargo environment variables should be used.
60	cargoEnvCompat() bool
61
62	inData() bool
63	install(ctx ModuleContext)
64	relativeInstallPath() string
65	everInstallable() bool
66
67	nativeCoverage() bool
68
69	Disabled() bool
70	SetDisabled()
71
72	stdLinkage(ctx *depsContext) RustLinkage
73	noStdlibs() bool
74
75	unstrippedOutputFilePath() android.Path
76	strippedOutputFilePath() android.OptionalPath
77
78	checkedCrateRootPath() (android.Path, error)
79
80	Aliases() map[string]string
81}
82
83func (compiler *baseCompiler) edition() string {
84	return proptools.StringDefault(compiler.Properties.Edition, config.DefaultEdition)
85}
86
87func (compiler *baseCompiler) setNoStdlibs() {
88	compiler.Properties.No_stdlibs = proptools.BoolPtr(true)
89}
90
91func (compiler *baseCompiler) disableLints() {
92	compiler.Properties.Lints = proptools.StringPtr("none")
93}
94
95func NewBaseCompiler(dir, dir64 string, location installLocation) *baseCompiler {
96	return &baseCompiler{
97		Properties: BaseCompilerProperties{},
98		dir:        dir,
99		dir64:      dir64,
100		location:   location,
101	}
102}
103
104type installLocation int
105
106const (
107	InstallInSystem installLocation = 0
108	InstallInData                   = iota
109
110	incorrectSourcesError = "srcs can only contain one path for a rust file and source providers prefixed by \":\""
111	genSubDir             = "out/"
112)
113
114type BaseCompilerProperties struct {
115	// path to the source file that is the main entry point of the program (e.g. main.rs or lib.rs).
116	// Only a single source file can be defined. Modules which generate source can be included by prefixing
117	// the module name with ":", for example ":libfoo_bindgen"
118	//
119	// If no source file is defined, a single generated source module can be defined to be used as the main source.
120	Srcs []string `android:"path,arch_variant"`
121
122	// Entry point that is passed to rustc to begin the compilation. E.g. main.rs or lib.rs.
123	// When this property is set,
124	//    * sandboxing is enabled for this module, and
125	//    * the srcs attribute is interpreted as a list of all source files potentially
126	//          used in compilation, including the entrypoint, and
127	//    * compile_data can be used to add additional files used in compilation that
128	//          not directly used as source files.
129	Crate_root *string `android:"path,arch_variant"`
130
131	// name of the lint set that should be used to validate this module.
132	//
133	// Possible values are "default" (for using a sensible set of lints
134	// depending on the module's location), "android" (for the strictest
135	// lint set that applies to all Android platform code), "vendor" (for
136	// a relaxed set) and "none" (for ignoring all lint warnings and
137	// errors). The default value is "default".
138	Lints *string
139
140	// flags to pass to rustc. To enable configuration options or features, use the "cfgs" or "features" properties.
141	Flags []string `android:"arch_variant"`
142
143	// flags to pass to the linker
144	Ld_flags []string `android:"arch_variant"`
145
146	// Rust crate dependencies to rename. Each entry should be a string of the form "dependencyname:alias".
147	//
148	// "dependencyname" here should be the name of the crate, not the Android module. This is
149	// equivalent to writing `alias = { package = "dependencyname" }` in a `Cargo.toml`.
150	Aliases []string
151
152	// list of rust rlib crate dependencies
153	Rlibs []string `android:"arch_variant"`
154
155	// list of rust automatic crate dependencies.
156	// Rustlibs linkage is rlib for host targets and dylib for device targets.
157	Rustlibs proptools.Configurable[[]string] `android:"arch_variant"`
158
159	// list of rust proc_macro crate dependencies
160	Proc_macros []string `android:"arch_variant"`
161
162	// list of C shared library dependencies
163	Shared_libs []string `android:"arch_variant"`
164
165	// list of C static library dependencies. These dependencies do not normally propagate to dependents
166	// and may need to be redeclared. See whole_static_libs for bundling static dependencies into a library.
167	Static_libs []string `android:"arch_variant"`
168
169	// Similar to static_libs, but will bundle the static library dependency into a library. This is helpful
170	// to avoid having to redeclare the dependency for dependents of this library, but in some cases may also
171	// result in bloat if multiple dependencies all include the same static library whole.
172	//
173	// The common use case for this is when the static library is unlikely to be a dependency of other modules to avoid
174	// having to redeclare the static library dependency for every dependent module.
175	// If you are not sure what to, for rust_library modules most static dependencies should go in static_libraries,
176	// and for rust_ffi modules most static dependencies should go into whole_static_libraries.
177	//
178	// For rust_ffi static variants, these libraries will be included in the resulting static library archive.
179	//
180	// For rust_library rlib variants, these libraries will be bundled into the resulting rlib library. This will
181	// include all of the static libraries symbols in any dylibs or binaries which use this rlib as well.
182	Whole_static_libs []string `android:"arch_variant"`
183
184	// list of Rust system library dependencies.
185	//
186	// This is usually only needed when `no_stdlibs` is true, in which case it can be used to depend on system crates
187	// like `core` and `alloc`.
188	Stdlibs []string `android:"arch_variant"`
189
190	// crate name, required for modules which produce Rust libraries: rust_library, rust_ffi and SourceProvider
191	// modules which create library variants (rust_bindgen). This must be the expected extern crate name used in
192	// source, and is required to conform to an enforced format matching library output files (if the output file is
193	// lib<someName><suffix>, the crate_name property must be <someName>).
194	Crate_name string `android:"arch_variant"`
195
196	// list of features to enable for this crate
197	Features proptools.Configurable[[]string] `android:"arch_variant"`
198
199	// list of configuration options to enable for this crate. To enable features, use the "features" property.
200	Cfgs proptools.Configurable[[]string] `android:"arch_variant"`
201
202	// specific rust edition that should be used if the default version is not desired
203	Edition *string `android:"arch_variant"`
204
205	// sets name of the output
206	Stem *string `android:"arch_variant"`
207
208	// append to name of output
209	Suffix *string `android:"arch_variant"`
210
211	// install to a subdirectory of the default install path for the module
212	Relative_install_path *string `android:"arch_variant"`
213
214	// whether to suppress inclusion of standard crates - defaults to false
215	No_stdlibs *bool `android:"arch_variant"`
216
217	// Change the rustlibs linkage to select rlib linkage by default for device targets.
218	// Also link libstd as an rlib as well on device targets.
219	// Note: This is the default behavior for host targets.
220	//
221	// This is primarily meant for rust_binary and rust_ffi modules where the default
222	// linkage of libstd might need to be overridden in some use cases. This should
223	// generally be avoided with other module types since it may cause collisions at
224	// linkage if all dependencies of the root binary module do not link against libstd
225	// the same way.
226	Prefer_rlib *bool `android:"arch_variant"`
227
228	// Enables emitting certain Cargo environment variables. Only intended to be used for compatibility purposes.
229	// Will set CARGO_CRATE_NAME to the crate_name property's value.
230	// Will set CARGO_BIN_NAME to the output filename value without the extension.
231	Cargo_env_compat *bool
232
233	// If cargo_env_compat is true, sets the CARGO_PKG_VERSION env var to this value.
234	Cargo_pkg_version *string
235
236	// Control whether LTO is used for the final (Rust) linkage. This does not impact
237	// cross-language LTO.
238	Lto struct {
239		// Whether thin LTO should be enabled. By default this is true.
240		// LTO provides such a large code size benefit for Rust, this should always
241		// be enabled for production builds unless there's a clear need to disable it.
242		Thin *bool `android:"arch_variant"`
243	} `android:"arch_variant"`
244}
245
246type baseCompiler struct {
247	Properties BaseCompilerProperties
248
249	// Install related
250	dir      string
251	dir64    string
252	subDir   string
253	relative string
254	path     android.InstallPath
255	location installLocation
256	sanitize *sanitize
257
258	distFile android.OptionalPath
259
260	installDeps android.InstallPaths
261
262	// unstripped output file.
263	unstrippedOutputFile android.Path
264
265	// stripped output file.
266	strippedOutputFile android.OptionalPath
267
268	// If a crate has a source-generated dependency, a copy of the source file
269	// will be available in cargoOutDir (equivalent to Cargo OUT_DIR).
270	// This is stored internally because it may not be available during
271	// singleton-generation passes like rustdoc/rust_project.json, but should
272	// be stashed during initial generation.
273	cachedCargoOutDir android.ModuleOutPath
274	// Calculated crate root cached internally because ModuleContext is not
275	// available to singleton targets like rustdoc/rust_project.json
276	cachedCrateRootPath android.Path
277	// If cachedCrateRootPath is nil after initialization, this will contain
278	// an explanation of why
279	cachedCrateRootError error
280}
281
282func (compiler *baseCompiler) Disabled() bool {
283	return false
284}
285
286// Thin LTO is enabled by default.
287func (compiler *baseCompiler) Thinlto() bool {
288	return BoolDefault(compiler.Properties.Lto.Thin, true)
289}
290
291func (compiler *baseCompiler) SetDisabled() {
292	panic("baseCompiler does not implement SetDisabled()")
293}
294
295func (compiler *baseCompiler) noStdlibs() bool {
296	return Bool(compiler.Properties.No_stdlibs)
297}
298
299func (compiler *baseCompiler) coverageOutputZipPath() android.OptionalPath {
300	panic("baseCompiler does not implement coverageOutputZipPath()")
301}
302
303func (compiler *baseCompiler) preferRlib() bool {
304	return Bool(compiler.Properties.Prefer_rlib)
305}
306
307func (compiler *baseCompiler) Aliases() map[string]string {
308	aliases := map[string]string{}
309	for _, entry := range compiler.Properties.Aliases {
310		dep, alias, found := strings.Cut(entry, ":")
311		if !found {
312			panic(fmt.Errorf("invalid aliases entry %q missing ':'", entry))
313		}
314		aliases[dep] = alias
315	}
316	return aliases
317}
318
319func (compiler *baseCompiler) stdLinkage(ctx *depsContext) RustLinkage {
320	// For devices, we always link stdlibs in as dylibs by default.
321	if compiler.preferRlib() {
322		return RlibLinkage
323	} else if ctx.Device() {
324		return DylibLinkage
325	} else {
326		return RlibLinkage
327	}
328}
329
330var _ compiler = (*baseCompiler)(nil)
331
332func (compiler *baseCompiler) inData() bool {
333	return compiler.location == InstallInData
334}
335
336func (compiler *baseCompiler) compilerProps() []interface{} {
337	return []interface{}{&compiler.Properties}
338}
339
340func cfgsToFlags(cfgs []string) []string {
341	flags := make([]string, 0, len(cfgs))
342	for _, cfg := range cfgs {
343		flags = append(flags, "--cfg '"+cfg+"'")
344	}
345
346	return flags
347}
348
349func (compiler *baseCompiler) features(ctx android.ConfigurableEvaluatorContext, module *Module) []string {
350	eval := module.ConfigurableEvaluator(ctx)
351	return compiler.Properties.Features.GetOrDefault(eval, nil)
352}
353
354func (compiler *baseCompiler) featuresToFlags(ctx android.ConfigurableEvaluatorContext, module *Module) []string {
355	flags := []string{}
356	for _, feature := range compiler.features(ctx, module) {
357		flags = append(flags, "--cfg 'feature=\""+feature+"\"'")
358	}
359
360	return flags
361}
362
363func (compiler *baseCompiler) featureFlags(ctx ModuleContext, module *Module, flags Flags) Flags {
364	flags.RustFlags = append(flags.RustFlags, compiler.featuresToFlags(ctx, module)...)
365	flags.RustdocFlags = append(flags.RustdocFlags, compiler.featuresToFlags(ctx, module)...)
366
367	return flags
368}
369
370func CommonDefaultCfgFlags(flags Flags, vendor bool, product bool) Flags {
371	var cfgs []string
372	if vendor || product {
373		cfgs = append(cfgs, "android_vndk")
374		if vendor {
375			cfgs = append(cfgs, "android_vendor")
376		} else if product {
377			cfgs = append(cfgs, "android_product")
378		}
379	}
380
381	flags.RustFlags = append(flags.RustFlags, cfgsToFlags(cfgs)...)
382	flags.RustdocFlags = append(flags.RustdocFlags, cfgsToFlags(cfgs)...)
383	return flags
384}
385
386func (compiler *baseCompiler) cfgFlags(ctx ModuleContext, flags Flags) Flags {
387	flags = CommonDefaultCfgFlags(flags, ctx.RustModule().InVendor(), ctx.RustModule().InProduct())
388
389	cfgFlags := cfgsToFlags(compiler.Properties.Cfgs.GetOrDefault(ctx, nil))
390	flags.RustFlags = append(flags.RustFlags, cfgFlags...)
391	flags.RustdocFlags = append(flags.RustdocFlags, cfgFlags...)
392
393	return flags
394}
395
396func CommonDefaultFlags(ctx android.ModuleContext, toolchain config.Toolchain, flags Flags) Flags {
397	flags.GlobalRustFlags = append(flags.GlobalRustFlags, config.GlobalRustFlags...)
398	flags.GlobalRustFlags = append(flags.GlobalRustFlags, toolchain.ToolchainRustFlags())
399	flags.GlobalLinkFlags = append(flags.GlobalLinkFlags, toolchain.ToolchainLinkFlags())
400	flags.EmitXrefs = ctx.Config().EmitXrefRules()
401
402	if ctx.Host() && !ctx.Windows() {
403		flags.LinkFlags = append(flags.LinkFlags, cc.RpathFlags(ctx)...)
404	}
405
406	if ctx.Os() == android.Linux {
407		// Add -lc, -lrt, -ldl, -lpthread, -lm and -lgcc_s to glibc builds to match
408		// the default behavior of device builds.
409		flags.LinkFlags = append(flags.LinkFlags, config.LinuxHostGlobalLinkFlags...)
410	} else if ctx.Os() == android.Darwin {
411		// Add -lc, -ldl, -lpthread and -lm to glibc darwin builds to match the default
412		// behavior of device builds.
413		flags.LinkFlags = append(flags.LinkFlags,
414			"-lc",
415			"-ldl",
416			"-lpthread",
417			"-lm",
418		)
419	}
420	return flags
421}
422
423func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flags {
424
425	flags = CommonDefaultFlags(ctx, ctx.toolchain(), flags)
426	lintFlags, err := config.RustcLintsForDir(ctx.ModuleDir(), compiler.Properties.Lints)
427	if err != nil {
428		ctx.PropertyErrorf("lints", err.Error())
429	}
430
431	// linkage-related flags are disallowed.
432	for _, s := range compiler.Properties.Ld_flags {
433		if strings.HasPrefix(s, "-Wl,-l") || strings.HasPrefix(s, "-Wl,-L") {
434			ctx.PropertyErrorf("ld_flags", "'-Wl,-l' and '-Wl,-L' flags cannot be manually specified")
435		}
436	}
437	for _, s := range compiler.Properties.Flags {
438		if strings.HasPrefix(s, "-l") || strings.HasPrefix(s, "-L") {
439			ctx.PropertyErrorf("flags", "'-l' and '-L' flags cannot be manually specified")
440		}
441		if strings.HasPrefix(s, "--extern") {
442			ctx.PropertyErrorf("flags", "'--extern' flag cannot be manually specified")
443		}
444		if strings.HasPrefix(s, "-Clink-args=") || strings.HasPrefix(s, "-C link-args=") {
445			ctx.PropertyErrorf("flags", "'-C link-args' flag cannot be manually specified")
446		}
447	}
448
449	flags.RustFlags = append(flags.RustFlags, lintFlags)
450	flags.RustFlags = append(flags.RustFlags, compiler.Properties.Flags...)
451	flags.RustFlags = append(flags.RustFlags, "--edition="+compiler.edition())
452	flags.RustdocFlags = append(flags.RustdocFlags, "--edition="+compiler.edition())
453	flags.LinkFlags = append(flags.LinkFlags, compiler.Properties.Ld_flags...)
454
455	return flags
456}
457
458func (compiler *baseCompiler) compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput {
459	panic(fmt.Errorf("baseCrater doesn't know how to crate things!"))
460}
461
462func (compiler *baseCompiler) rustdoc(ctx ModuleContext, flags Flags,
463	deps PathDeps) android.OptionalPath {
464
465	return android.OptionalPath{}
466}
467
468func (compiler *baseCompiler) initialize(ctx ModuleContext) {
469	compiler.cachedCargoOutDir = android.PathForModuleOut(ctx, genSubDir)
470	if compiler.Properties.Crate_root == nil {
471		compiler.cachedCrateRootPath, compiler.cachedCrateRootError = srcPathFromModuleSrcs(ctx, compiler.Properties.Srcs)
472	} else {
473		compiler.cachedCrateRootPath = android.PathForModuleSrc(ctx, *compiler.Properties.Crate_root)
474		compiler.cachedCrateRootError = nil
475	}
476}
477
478func (compiler *baseCompiler) cargoOutDir() android.OptionalPath {
479	return android.OptionalPathForPath(compiler.cachedCargoOutDir)
480}
481
482func (compiler *baseCompiler) cargoEnvCompat() bool {
483	return Bool(compiler.Properties.Cargo_env_compat)
484}
485
486func (compiler *baseCompiler) cargoPkgVersion() string {
487	return String(compiler.Properties.Cargo_pkg_version)
488}
489
490func (compiler *baseCompiler) unstrippedOutputFilePath() android.Path {
491	return compiler.unstrippedOutputFile
492}
493
494func (compiler *baseCompiler) strippedOutputFilePath() android.OptionalPath {
495	return compiler.strippedOutputFile
496}
497
498func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
499	deps.Rlibs = append(deps.Rlibs, compiler.Properties.Rlibs...)
500	deps.Rustlibs = append(deps.Rustlibs, compiler.Properties.Rustlibs.GetOrDefault(ctx, nil)...)
501	deps.ProcMacros = append(deps.ProcMacros, compiler.Properties.Proc_macros...)
502	deps.StaticLibs = append(deps.StaticLibs, compiler.Properties.Static_libs...)
503	deps.WholeStaticLibs = append(deps.WholeStaticLibs, compiler.Properties.Whole_static_libs...)
504	deps.SharedLibs = append(deps.SharedLibs, compiler.Properties.Shared_libs...)
505	deps.Stdlibs = append(deps.Stdlibs, compiler.Properties.Stdlibs...)
506
507	if !Bool(compiler.Properties.No_stdlibs) {
508		for _, stdlib := range config.Stdlibs {
509			// If we're building for the build host, use the prebuilt stdlibs, unless the host
510			// is linux_bionic which doesn't have prebuilts.
511			if ctx.Host() && !ctx.Target().HostCross && ctx.Target().Os != android.LinuxBionic {
512				stdlib = "prebuilt_" + stdlib
513			}
514			deps.Stdlibs = append(deps.Stdlibs, stdlib)
515		}
516	}
517	return deps
518}
519
520func bionicDeps(ctx DepsContext, deps Deps, static bool) Deps {
521	bionicLibs := []string{}
522	bionicLibs = append(bionicLibs, "liblog")
523	bionicLibs = append(bionicLibs, "libc")
524	bionicLibs = append(bionicLibs, "libm")
525	bionicLibs = append(bionicLibs, "libdl")
526
527	if static {
528		deps.StaticLibs = append(deps.StaticLibs, bionicLibs...)
529	} else {
530		deps.SharedLibs = append(deps.SharedLibs, bionicLibs...)
531	}
532	if ctx.RustModule().StaticExecutable() {
533		deps.StaticLibs = append(deps.StaticLibs, "libunwind")
534	}
535	if libRuntimeBuiltins := config.BuiltinsRuntimeLibrary(ctx.toolchain()); libRuntimeBuiltins != "" {
536		deps.StaticLibs = append(deps.StaticLibs, libRuntimeBuiltins)
537	}
538	return deps
539}
540
541func muslDeps(ctx DepsContext, deps Deps, static bool) Deps {
542	muslLibs := []string{"libc_musl"}
543	if static {
544		deps.StaticLibs = append(deps.StaticLibs, muslLibs...)
545	} else {
546		deps.SharedLibs = append(deps.SharedLibs, muslLibs...)
547	}
548	if libRuntimeBuiltins := config.BuiltinsRuntimeLibrary(ctx.toolchain()); libRuntimeBuiltins != "" {
549		deps.StaticLibs = append(deps.StaticLibs, libRuntimeBuiltins)
550	}
551
552	return deps
553}
554
555func (compiler *baseCompiler) crateName() string {
556	return compiler.Properties.Crate_name
557}
558
559func (compiler *baseCompiler) everInstallable() bool {
560	// Most modules are installable, so return true by default.
561	return true
562}
563
564func (compiler *baseCompiler) installDir(ctx ModuleContext) android.InstallPath {
565	dir := compiler.dir
566	if ctx.toolchain().Is64Bit() && compiler.dir64 != "" {
567		dir = compiler.dir64
568	}
569	if ctx.Target().NativeBridge == android.NativeBridgeEnabled {
570		dir = filepath.Join(dir, ctx.Target().NativeBridgeRelativePath)
571	}
572	if !ctx.Host() && ctx.Config().HasMultilibConflict(ctx.Arch().ArchType) {
573		dir = filepath.Join(dir, ctx.Arch().ArchType.String())
574	}
575
576	if compiler.location == InstallInData && ctx.RustModule().InVendorOrProduct() {
577		if ctx.RustModule().InProduct() {
578			dir = filepath.Join(dir, "product")
579		} else if ctx.RustModule().InVendor() {
580			dir = filepath.Join(dir, "vendor")
581		} else {
582			ctx.ModuleErrorf("Unknown data+VNDK installation kind")
583		}
584	}
585
586	return android.PathForModuleInstall(ctx, dir, compiler.subDir,
587		compiler.relativeInstallPath(), compiler.relative)
588}
589
590func (compiler *baseCompiler) nativeCoverage() bool {
591	return false
592}
593
594func (compiler *baseCompiler) install(ctx ModuleContext) {
595	path := ctx.RustModule().OutputFile()
596	compiler.path = ctx.InstallFile(compiler.installDir(ctx), path.Path().Base(), path.Path(), compiler.installDeps...)
597}
598
599func (compiler *baseCompiler) installTestData(ctx ModuleContext, data []android.DataPath) {
600	installedData := ctx.InstallTestData(compiler.installDir(ctx), data)
601	compiler.installDeps = append(compiler.installDeps, installedData...)
602}
603
604func (compiler *baseCompiler) getStem(ctx android.ModuleContext) string {
605	return compiler.getStemWithoutSuffix(ctx) + String(compiler.Properties.Suffix)
606}
607
608func (compiler *baseCompiler) getStemWithoutSuffix(ctx android.BaseModuleContext) string {
609	stem := ctx.ModuleName()
610	if String(compiler.Properties.Stem) != "" {
611		stem = String(compiler.Properties.Stem)
612	}
613
614	return stem
615}
616
617func (compiler *baseCompiler) relativeInstallPath() string {
618	return String(compiler.Properties.Relative_install_path)
619}
620
621func (compiler *baseCompiler) checkedCrateRootPath() (android.Path, error) {
622	return compiler.cachedCrateRootPath, compiler.cachedCrateRootError
623}
624
625func crateRootPath(ctx ModuleContext, compiler compiler) android.Path {
626	root, err := compiler.checkedCrateRootPath()
627	if err != nil {
628		ctx.PropertyErrorf("srcs", err.Error())
629	}
630	return root
631}
632
633// Returns the Path for the main source file along with Paths for generated source files from modules listed in srcs.
634func srcPathFromModuleSrcs(ctx ModuleContext, srcs []string) (android.Path, error) {
635	// The srcs can contain strings with prefix ":".
636	// They are dependent modules of this module, with android.SourceDepTag.
637	// They are not the main source file compiled by rustc.
638	numSrcs := 0
639	srcIndex := 0
640	for i, s := range srcs {
641		if android.SrcIsModule(s) == "" {
642			numSrcs++
643			srcIndex = i
644		}
645	}
646	if numSrcs > 1 {
647		return nil, errors.New(incorrectSourcesError)
648	}
649
650	// If a main source file is not provided we expect only a single SourceProvider module to be defined
651	// within srcs, with the expectation that the first source it provides is the entry point.
652	if srcIndex != 0 {
653		return nil, errors.New("main source file must be the first in srcs")
654	} else if numSrcs > 1 {
655		return nil, errors.New("only a single generated source module can be defined without a main source file.")
656	}
657
658	// TODO: b/297264540 - once all modules are sandboxed, we need to select the proper
659	// entry point file from Srcs rather than taking the first one
660	paths := android.PathsForModuleSrc(ctx, srcs)
661	if len(paths) == 0 {
662		return nil, errors.New("srcs must not be empty")
663	}
664	return paths[srcIndex], nil
665}
666