platform_build_soong/android/bazel_paths.go

625 lines
26 KiB
Go

// Copyright 2015 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package android
import (
"fmt"
"path/filepath"
"strings"
"android/soong/bazel"
"github.com/google/blueprint"
"github.com/google/blueprint/pathtools"
)
// bazel_paths contains methods to:
// * resolve Soong path and module references into bazel.LabelList
// * resolve Bazel path references into Soong-compatible paths
//
// There is often a similar method for Bazel as there is for Soong path handling and should be used
// in similar circumstances
//
// Bazel Soong
// ==============================================================
// BazelLabelForModuleSrc PathForModuleSrc
// BazelLabelForModuleSrcExcludes PathForModuleSrcExcludes
// BazelLabelForModuleDeps n/a
// tbd PathForSource
// tbd ExistentPathsForSources
// PathForBazelOut PathForModuleOut
//
// Use cases:
// * Module contains a property (often tagged `android:"path"`) that expects paths *relative to the
// module directory*:
// * BazelLabelForModuleSrcExcludes, if the module also contains an excludes_<propname> property
// * BazelLabelForModuleSrc, otherwise
// * Converting references to other modules to Bazel Labels:
// BazelLabelForModuleDeps
// * Converting a path obtained from bazel_handler cquery results:
// PathForBazelOut
//
// NOTE: all Soong globs are expanded within Soong rather than being converted to a Bazel glob
// syntax. This occurs because Soong does not have a concept of crossing package boundaries,
// so the glob as computed by Soong may contain paths that cross package-boundaries. These
// would be unknowingly omitted if the glob were handled by Bazel. By expanding globs within
// Soong, we support identification and detection (within Bazel) use of paths that cross
// package boundaries.
//
// Path resolution:
// * filepath/globs: resolves as itself or is converted to an absolute Bazel label (e.g.
// //path/to/dir:<filepath>) if path exists in a separate package or subpackage.
// * references to other modules (using the ":name{.tag}" syntax). These resolve as a Bazel label
// for a target. If the Bazel target is in the local module directory, it will be returned
// relative to the current package (e.g. ":<target>"). Otherwise, it will be returned as an
// absolute Bazel label (e.g. "//path/to/dir:<target>"). If the reference to another module
// cannot be resolved,the function will panic. This is often due to the dependency not being added
// via an AddDependency* method.
// BazelConversionContext is a minimal context interface to check if a module should be converted by bp2build,
// with functions containing information to match against allowlists and denylists.
// If a module is deemed to be convertible by bp2build, then it should rely on a
// BazelConversionPathContext for more functions for dep/path features.
type BazelConversionContext interface {
Config() Config
Module() Module
OtherModuleType(m blueprint.Module) string
OtherModuleName(m blueprint.Module) string
OtherModuleDir(m blueprint.Module) string
ModuleErrorf(format string, args ...interface{})
}
// A subset of the ModuleContext methods which are sufficient to resolve references to paths/deps in
// order to form a Bazel-compatible label for conversion.
type BazelConversionPathContext interface {
EarlyModulePathContext
BazelConversionContext
ModuleName() string
ModuleType() string
ModuleErrorf(fmt string, args ...interface{})
PropertyErrorf(property, fmt string, args ...interface{})
GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)
ModuleFromName(name string) (blueprint.Module, bool)
AddUnconvertedBp2buildDep(string)
AddMissingBp2buildDep(dep string)
}
// BazelLabelForModuleDeps expects a list of reference to other modules, ("<module>"
// or ":<module>") and returns a Bazel-compatible label which corresponds to dependencies on the
// module within the given ctx.
func BazelLabelForModuleDeps(ctx BazelConversionPathContext, modules []string) bazel.LabelList {
return BazelLabelForModuleDepsWithFn(ctx, modules, BazelModuleLabel)
}
// BazelLabelForModuleWholeDepsExcludes expects two lists: modules (containing modules to include in
// the list), and excludes (modules to exclude from the list). Both of these should contain
// references to other modules, ("<module>" or ":<module>"). It returns a Bazel-compatible label
// list which corresponds to dependencies on the module within the given ctx, and the excluded
// dependencies. Prebuilt dependencies will be appended with _alwayslink so they can be handled as
// whole static libraries.
func BazelLabelForModuleDepsExcludes(ctx BazelConversionPathContext, modules, excludes []string) bazel.LabelList {
return BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, BazelModuleLabel)
}
// BazelLabelForModuleDepsWithFn expects a list of reference to other modules, ("<module>"
// or ":<module>") and applies moduleToLabelFn to determine and return a Bazel-compatible label
// which corresponds to dependencies on the module within the given ctx.
func BazelLabelForModuleDepsWithFn(ctx BazelConversionPathContext, modules []string,
moduleToLabelFn func(BazelConversionPathContext, blueprint.Module) string) bazel.LabelList {
var labels bazel.LabelList
// In some cases, a nil string list is different than an explicitly empty list.
if len(modules) == 0 && modules != nil {
labels.Includes = []bazel.Label{}
return labels
}
modules = FirstUniqueStrings(modules)
for _, module := range modules {
bpText := module
if m := SrcIsModule(module); m == "" {
module = ":" + module
}
if m, t := SrcIsModuleWithTag(module); m != "" {
l := getOtherModuleLabel(ctx, m, t, moduleToLabelFn)
if l != nil {
l.OriginalModuleName = bpText
labels.Includes = append(labels.Includes, *l)
}
} else {
ctx.ModuleErrorf("%q, is not a module reference", module)
}
}
return labels
}
// BazelLabelForModuleDepsExcludesWithFn expects two lists: modules (containing modules to include in the
// list), and excludes (modules to exclude from the list). Both of these should contain references
// to other modules, ("<module>" or ":<module>"). It applies moduleToLabelFn to determine and return a
// Bazel-compatible label list which corresponds to dependencies on the module within the given ctx, and
// the excluded dependencies.
func BazelLabelForModuleDepsExcludesWithFn(ctx BazelConversionPathContext, modules, excludes []string,
moduleToLabelFn func(BazelConversionPathContext, blueprint.Module) string) bazel.LabelList {
moduleLabels := BazelLabelForModuleDepsWithFn(ctx, RemoveListFromList(modules, excludes), moduleToLabelFn)
if len(excludes) == 0 {
return moduleLabels
}
excludeLabels := BazelLabelForModuleDepsWithFn(ctx, excludes, moduleToLabelFn)
return bazel.LabelList{
Includes: moduleLabels.Includes,
Excludes: excludeLabels.Includes,
}
}
func BazelLabelForModuleSrcSingle(ctx BazelConversionPathContext, path string) bazel.Label {
if srcs := BazelLabelForModuleSrcExcludes(ctx, []string{path}, []string(nil)).Includes; len(srcs) > 0 {
return srcs[0]
}
return bazel.Label{}
}
func BazelLabelForModuleDepSingle(ctx BazelConversionPathContext, path string) bazel.Label {
if srcs := BazelLabelForModuleDepsExcludes(ctx, []string{path}, []string(nil)).Includes; len(srcs) > 0 {
return srcs[0]
}
return bazel.Label{}
}
// BazelLabelForModuleSrc expects a list of path (relative to local module directory) and module
// references (":<module>") and returns a bazel.LabelList{} containing the resolved references in
// paths, relative to the local module, or Bazel-labels (absolute if in a different package or
// relative if within the same package).
// Properties must have been annotated with struct tag `android:"path"` so that dependencies modules
// will have already been handled by the pathdeps mutator.
func BazelLabelForModuleSrc(ctx BazelConversionPathContext, paths []string) bazel.LabelList {
return BazelLabelForModuleSrcExcludes(ctx, paths, []string(nil))
}
// BazelLabelForModuleSrc expects lists of path and excludes (relative to local module directory)
// and module references (":<module>") and returns a bazel.LabelList{} containing the resolved
// references in paths, minus those in excludes, relative to the local module, or Bazel-labels
// (absolute if in a different package or relative if within the same package).
// Properties must have been annotated with struct tag `android:"path"` so that dependencies modules
// will have already been handled by the pathdeps mutator.
func BazelLabelForModuleSrcExcludes(ctx BazelConversionPathContext, paths, excludes []string) bazel.LabelList {
excludeLabels := expandSrcsForBazel(ctx, excludes, []string(nil))
excluded := make([]string, 0, len(excludeLabels.Includes))
for _, e := range excludeLabels.Includes {
excluded = append(excluded, e.Label)
}
labels := expandSrcsForBazel(ctx, paths, excluded)
labels.Excludes = excludeLabels.Includes
labels = TransformSubpackagePaths(ctx.Config(), ctx.ModuleDir(), labels)
return labels
}
func BazelLabelForSrcPatternExcludes(ctx BazelConversionPathContext, dir, pattern string, excludes []string) bazel.LabelList {
topRelPaths, err := ctx.GlobWithDeps(filepath.Join(dir, pattern), excludes)
if err != nil {
ctx.ModuleErrorf("Could not search dir: %s for pattern %s due to %v\n", dir, pattern, err)
}
// An intermediate list of labels relative to `dir` that assumes that there no subpacakges beneath `dir`
dirRelLabels := []bazel.Label{}
for _, topRelPath := range topRelPaths {
dirRelPath := Rel(ctx, dir, topRelPath)
dirRelLabels = append(dirRelLabels, bazel.Label{Label: "./" + dirRelPath})
}
// Return the package boudary resolved labels
return TransformSubpackagePaths(ctx.Config(), dir, bazel.MakeLabelList(dirRelLabels))
}
// Returns true if a prefix + components[:i] is a package boundary.
//
// A package boundary is determined by a BUILD file in the directory. This can happen in 2 cases:
//
// 1. An Android.bp exists, which bp2build will always convert to a sibling BUILD file.
// 2. An Android.bp doesn't exist, but a checked-in BUILD/BUILD.bazel file exists, and that file
// is allowlisted by the bp2build configuration to be merged into the symlink forest workspace.
func isPackageBoundary(config Config, prefix string, components []string, componentIndex int) bool {
prefix = filepath.Join(prefix, filepath.Join(components[:componentIndex+1]...))
if exists, _, _ := config.fs.Exists(filepath.Join(prefix, "Android.bp")); exists {
return true
} else if config.Bp2buildPackageConfig.ShouldKeepExistingBuildFileForDir(prefix) {
if exists, _, _ := config.fs.Exists(filepath.Join(prefix, "BUILD")); exists {
return true
} else if exists, _, _ := config.fs.Exists(filepath.Join(prefix, "BUILD.bazel")); exists {
return true
}
}
return false
}
// Transform a path (if necessary) to acknowledge package boundaries
//
// e.g. something like
//
// async_safe/include/async_safe/CHECK.h
//
// might become
//
// //bionic/libc/async_safe:include/async_safe/CHECK.h
//
// if the "async_safe" directory is actually a package and not just a directory.
//
// In particular, paths that extend into packages are transformed into absolute labels beginning with //.
func transformSubpackagePath(cfg Config, dir string, path bazel.Label) bazel.Label {
var newPath bazel.Label
// Don't transform OriginalModuleName
newPath.OriginalModuleName = path.OriginalModuleName
// if it wasn't a module, store the original path. We may need the original path to replace
// references if it is actually in another package
if path.OriginalModuleName == "" {
newPath.OriginalModuleName = path.Label
}
if strings.HasPrefix(path.Label, "//") {
// Assume absolute labels are already correct (e.g. //path/to/some/package:foo.h)
newPath.Label = path.Label
return newPath
}
if strings.HasPrefix(path.Label, "./") {
// Drop "./" for consistent handling of paths.
// Specifically, to not let "." be considered a package boundary.
// Say `inputPath` is `x/Android.bp` and that file has some module
// with `srcs=["y/a.c", "z/b.c"]`.
// And say the directory tree is:
// x
// ├── Android.bp
// ├── y
// │ ├── a.c
// │ └── Android.bp
// └── z
// └── b.c
// Then bazel equivalent labels in srcs should be:
// //x/y:a.c, x/z/b.c
// The above should still be the case if `x/Android.bp` had
// srcs=["./y/a.c", "./z/b.c"]
// However, if we didn't strip "./", we'd get
// //x/./y:a.c, //x/.:z/b.c
path.Label = strings.TrimPrefix(path.Label, "./")
}
pathComponents := strings.Split(path.Label, "/")
newLabel := ""
foundPackageBoundary := false
// Check the deepest subdirectory first and work upwards
for i := len(pathComponents) - 1; i >= 0; i-- {
pathComponent := pathComponents[i]
var sep string
if !foundPackageBoundary && isPackageBoundary(cfg, dir, pathComponents, i) {
sep = ":"
foundPackageBoundary = true
} else {
sep = "/"
}
if newLabel == "" {
newLabel = pathComponent
} else {
newLabel = pathComponent + sep + newLabel
}
}
if foundPackageBoundary {
// Ensure paths end up looking like //bionic/... instead of //./bionic/...
moduleDir := dir
if strings.HasPrefix(moduleDir, ".") {
moduleDir = moduleDir[1:]
}
// Make the path into an absolute label (e.g. //bionic/libc/foo:bar.h instead of just foo:bar.h)
if moduleDir == "" {
newLabel = "//" + newLabel
} else {
newLabel = "//" + moduleDir + "/" + newLabel
}
}
newPath.Label = newLabel
return newPath
}
// Transform paths to acknowledge package boundaries
// See transformSubpackagePath() for more information
func TransformSubpackagePaths(cfg Config, dir string, paths bazel.LabelList) bazel.LabelList {
var newPaths bazel.LabelList
for _, include := range paths.Includes {
newPaths.Includes = append(newPaths.Includes, transformSubpackagePath(cfg, dir, include))
}
for _, exclude := range paths.Excludes {
newPaths.Excludes = append(newPaths.Excludes, transformSubpackagePath(cfg, dir, exclude))
}
return newPaths
}
// Converts root-relative Paths to a list of bazel.Label relative to the module in ctx.
func RootToModuleRelativePaths(ctx BazelConversionPathContext, paths Paths) []bazel.Label {
var newPaths []bazel.Label
for _, path := range PathsWithModuleSrcSubDir(ctx, paths, "") {
s := path.Rel()
newPaths = append(newPaths, bazel.Label{Label: s})
}
return newPaths
}
// expandSrcsForBazel returns bazel.LabelList with paths rooted from the module's local source
// directory and Bazel target labels, excluding those included in the excludes argument (which
// should already be expanded to resolve references to Soong-modules). Valid elements of paths
// include:
// - filepath, relative to local module directory, resolves as a filepath relative to the local
// source directory
// - glob, relative to the local module directory, resolves as filepath(s), relative to the local
// module directory. Because Soong does not have a concept of crossing package boundaries, the
// glob as computed by Soong may contain paths that cross package-boundaries that would be
// unknowingly omitted if the glob were handled by Bazel. To allow identification and detect
// (within Bazel) use of paths that cross package boundaries, we expand globs within Soong rather
// than converting Soong glob syntax to Bazel glob syntax. **Invalid for excludes.**
// - other modules using the ":name{.tag}" syntax. These modules must implement SourceFileProducer
// or OutputFileProducer. These resolve as a Bazel label for a target. If the Bazel target is in
// the local module directory, it will be returned relative to the current package (e.g.
// ":<target>"). Otherwise, it will be returned as an absolute Bazel label (e.g.
// "//path/to/dir:<target>"). If the reference to another module cannot be resolved,the function
// will panic.
//
// Properties passed as the paths or excludes argument must have been annotated with struct tag
// `android:"path"` so that dependencies on other modules will have already been handled by the
// pathdeps mutator.
func expandSrcsForBazel(ctx BazelConversionPathContext, paths, expandedExcludes []string) bazel.LabelList {
if paths == nil {
return bazel.LabelList{}
}
labels := bazel.LabelList{
Includes: []bazel.Label{},
}
// expandedExcludes contain module-dir relative paths, but root-relative paths
// are needed for GlobFiles later.
var rootRelativeExpandedExcludes []string
for _, e := range expandedExcludes {
rootRelativeExpandedExcludes = append(rootRelativeExpandedExcludes, filepath.Join(ctx.ModuleDir(), e))
}
for _, p := range paths {
if m, tag := SrcIsModuleWithTag(p); m != "" {
l := getOtherModuleLabel(ctx, m, tag, BazelModuleLabel)
if l != nil && !InList(l.Label, expandedExcludes) {
if strings.HasPrefix(m, "//") {
// this is a module in a soong namespace
// It appears as //<namespace>:<module_name> in srcs, and not ://<namespace>:<module_name>
l.OriginalModuleName = m
} else {
l.OriginalModuleName = fmt.Sprintf(":%s", m)
}
labels.Includes = append(labels.Includes, *l)
}
} else {
var expandedPaths []bazel.Label
if pathtools.IsGlob(p) {
// e.g. turn "math/*.c" in
// external/arm-optimized-routines to external/arm-optimized-routines/math/*.c
rootRelativeGlobPath := pathForModuleSrc(ctx, p).String()
expandedPaths = RootToModuleRelativePaths(ctx, GlobFiles(ctx, rootRelativeGlobPath, rootRelativeExpandedExcludes))
} else {
if !InList(p, expandedExcludes) {
expandedPaths = append(expandedPaths, bazel.Label{Label: p})
}
}
labels.Includes = append(labels.Includes, expandedPaths...)
}
}
return labels
}
// getOtherModuleLabel returns a bazel.Label for the given dependency/tag combination for the
// module. The label will be relative to the current directory if appropriate. The dependency must
// already be resolved by either deps mutator or path deps mutator.
func getOtherModuleLabel(ctx BazelConversionPathContext, dep, tag string,
labelFromModule func(BazelConversionPathContext, blueprint.Module) string) *bazel.Label {
m, _ := ctx.ModuleFromName(dep)
// The module was not found in an Android.bp file, this is often due to:
// * a limited manifest
// * a required module not being converted from Android.mk
if m == nil {
ctx.AddMissingBp2buildDep(dep)
return &bazel.Label{
Label: ":" + dep + "__BP2BUILD__MISSING__DEP",
}
}
if !convertedToBazel(ctx, m) {
ctx.AddUnconvertedBp2buildDep(dep)
}
label := BazelModuleLabel(ctx, ctx.Module())
otherLabel := labelFromModule(ctx, m)
// TODO(b/165114590): Convert tag (":name{.tag}") to corresponding Bazel implicit output targets.
if samePackage(label, otherLabel) {
otherLabel = bazelShortLabel(otherLabel)
}
return &bazel.Label{
Label: otherLabel,
}
}
func BazelModuleLabel(ctx BazelConversionPathContext, module blueprint.Module) string {
// TODO(b/165114590): Convert tag (":name{.tag}") to corresponding Bazel implicit output targets.
if !convertedToBazel(ctx, module) || isGoModule(module) {
return bp2buildModuleLabel(ctx, module)
}
b, _ := module.(Bazelable)
return b.GetBazelLabel(ctx, module)
}
func bazelShortLabel(label string) string {
i := strings.Index(label, ":")
if i == -1 {
panic(fmt.Errorf("Could not find the ':' character in '%s', expected a fully qualified label.", label))
}
return label[i:]
}
func bazelPackage(label string) string {
i := strings.Index(label, ":")
if i == -1 {
panic(fmt.Errorf("Could not find the ':' character in '%s', expected a fully qualified label.", label))
}
return label[0:i]
}
func samePackage(label1, label2 string) bool {
return bazelPackage(label1) == bazelPackage(label2)
}
func bp2buildModuleLabel(ctx BazelConversionContext, module blueprint.Module) string {
moduleName := moduleNameWithPossibleOverride(ctx, module, ctx.OtherModuleName(module))
moduleDir := moduleDirWithPossibleOverride(ctx, module, ctx.OtherModuleDir(module))
if moduleDir == Bp2BuildTopLevel {
moduleDir = ""
}
if a, ok := module.(Module); ok && IsModulePrebuilt(a) {
moduleName = RemoveOptionalPrebuiltPrefix(moduleName)
}
return fmt.Sprintf("//%s:%s", moduleDir, moduleName)
}
// BazelOutPath is a Bazel output path compatible to be used for mixed builds within Soong/Ninja.
type BazelOutPath struct {
OutputPath
}
// ensure BazelOutPath implements Path
var _ Path = BazelOutPath{}
// ensure BazelOutPath implements genPathProvider
var _ genPathProvider = BazelOutPath{}
// ensure BazelOutPath implements objPathProvider
var _ objPathProvider = BazelOutPath{}
func (p BazelOutPath) genPathWithExt(ctx ModuleOutPathContext, subdir, ext string) ModuleGenPath {
return PathForModuleGen(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
}
func (p BazelOutPath) objPathWithExt(ctx ModuleOutPathContext, subdir, ext string) ModuleObjPath {
return PathForModuleObj(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
}
// PathForBazelOutRelative returns a BazelOutPath representing the path under an output directory dedicated to
// bazel-owned outputs. Calling .Rel() on the result will give the input path as relative to the given
// relativeRoot.
func PathForBazelOutRelative(ctx PathContext, relativeRoot string, path string) BazelOutPath {
validatedPath, err := validatePath(filepath.Join("execroot", "__main__", path))
if err != nil {
reportPathError(ctx, err)
}
var relativeRootPath string
if pathComponents := strings.SplitN(path, "/", 4); len(pathComponents) >= 3 &&
pathComponents[0] == "bazel-out" && pathComponents[2] == "bin" {
// If the path starts with something like: bazel-out/linux_x86_64-fastbuild-ST-b4ef1c4402f9/bin/
// make it relative to that folder. bazel-out/volatile-status.txt is an example
// of something that starts with bazel-out but is not relative to the bin folder
relativeRootPath = filepath.Join("execroot", "__main__", pathComponents[0], pathComponents[1], pathComponents[2], relativeRoot)
} else {
relativeRootPath = filepath.Join("execroot", "__main__", relativeRoot)
}
var relPath string
if relPath, err = filepath.Rel(relativeRootPath, validatedPath); err != nil || strings.HasPrefix(relPath, "../") {
// We failed to make this path relative to execroot/__main__, fall back to a non-relative path
// One case where this happens is when path is ../bazel_tools/something
relativeRootPath = ""
relPath = validatedPath
}
outputPath := OutputPath{
basePath{"", ""},
ctx.Config().soongOutDir,
ctx.Config().BazelContext.OutputBase(),
}
return BazelOutPath{
// .withRel() appends its argument onto the current path, and only the most
// recently appended part is returned by outputPath.rel().
// So outputPath.rel() will return relPath.
OutputPath: outputPath.withRel(relativeRootPath).withRel(relPath),
}
}
// PathForBazelOut returns a BazelOutPath representing the path under an output directory dedicated to
// bazel-owned outputs.
func PathForBazelOut(ctx PathContext, path string) BazelOutPath {
return PathForBazelOutRelative(ctx, "", path)
}
// PathsForBazelOut returns a list of paths representing the paths under an output directory
// dedicated to Bazel-owned outputs.
func PathsForBazelOut(ctx PathContext, paths []string) Paths {
outs := make(Paths, 0, len(paths))
for _, p := range paths {
outs = append(outs, PathForBazelOut(ctx, p))
}
return outs
}
// BazelStringOrLabelFromProp splits a Soong module property that can be
// either a string literal, path (with android:path tag) or a module reference
// into separate bazel string or label attributes. Bazel treats string and label
// attributes as distinct types, so this function categorizes a string property
// into either one of them.
//
// e.g. apex.private_key = "foo.pem" can either refer to:
//
// 1. "foo.pem" in the current directory -> file target
// 2. "foo.pem" module -> rule target
// 3. "foo.pem" file in a different directory, prefixed by a product variable handled
// in a bazel macro. -> string literal
//
// For the first two cases, they are defined using the label attribute. For the third case,
// it's defined with the string attribute.
func BazelStringOrLabelFromProp(
ctx Bp2buildMutatorContext,
propToDistinguish *string) (bazel.LabelAttribute, bazel.StringAttribute) {
var labelAttr bazel.LabelAttribute
var strAttr bazel.StringAttribute
if propToDistinguish == nil {
// nil pointer
return labelAttr, strAttr
}
prop := String(propToDistinguish)
if SrcIsModule(prop) != "" {
// If it's a module (SrcIsModule will return the module name), set the
// resolved label to the label attribute.
labelAttr.SetValue(BazelLabelForModuleDepSingle(ctx, prop))
} else {
// Not a module name. This could be a string literal or a file target in
// the current dir. Check if the path exists:
path := ExistentPathForSource(ctx, ctx.ModuleDir(), prop)
if path.Valid() && parentDir(path.String()) == ctx.ModuleDir() {
// If it exists and the path is relative to the current dir, resolve the bazel label
// for the _file target_ and set it to the label attribute.
//
// Resolution is necessary because this could be a file in a subpackage.
labelAttr.SetValue(BazelLabelForModuleSrcSingle(ctx, prop))
} else {
// Otherwise, treat it as a string literal and assign to the string attribute.
strAttr.Value = propToDistinguish
}
}
return labelAttr, strAttr
}