cc/bp2build.go

// Copyright 2021 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 cc

import (
	"path/filepath"
	"strings"

	"android/soong/android"
	"android/soong/bazel"

	"github.com/google/blueprint"

	"github.com/google/blueprint/proptools"
)

// staticOrSharedAttributes are the Bazel-ified versions of StaticOrSharedProperties --
// properties which apply to either the shared or static version of a cc_library module.
type staticOrSharedAttributes struct {
	Srcs    bazel.LabelListAttribute
	Srcs_c  bazel.LabelListAttribute
	Srcs_as bazel.LabelListAttribute
	Copts   bazel.StringListAttribute

	Deps                        bazel.LabelListAttribute
	Implementation_deps         bazel.LabelListAttribute
	Dynamic_deps                bazel.LabelListAttribute
	Implementation_dynamic_deps bazel.LabelListAttribute
	Whole_archive_deps          bazel.LabelListAttribute

	System_dynamic_deps bazel.LabelListAttribute
}

func groupSrcsByExtension(ctx android.TopDownMutatorContext, srcs bazel.LabelListAttribute) (cppSrcs, cSrcs, asSrcs bazel.LabelListAttribute) {
	// Check that a module is a filegroup type named <label>.
	isFilegroupNamed := func(m android.Module, fullLabel string) bool {
		if ctx.OtherModuleType(m) != "filegroup" {
			return false
		}
		labelParts := strings.Split(fullLabel, ":")
		if len(labelParts) > 2 {
			// There should not be more than one colon in a label.
			ctx.ModuleErrorf("%s is not a valid Bazel label for a filegroup", fullLabel)
		}
		return m.Name() == labelParts[len(labelParts)-1]
	}

	// Convert filegroup dependencies into extension-specific filegroups filtered in the filegroup.bzl
	// macro.
	addSuffixForFilegroup := func(suffix string) bazel.LabelMapper {
		return func(ctx bazel.OtherModuleContext, label string) (string, bool) {
			m, exists := ctx.ModuleFromName(label)
			if !exists {
				return label, false
			}
			aModule, _ := m.(android.Module)
			if !isFilegroupNamed(aModule, label) {
				return label, false
			}
			return label + suffix, true
		}
	}

	// TODO(b/190006308): Handle language detection of sources in a Bazel rule.
	partitioned := bazel.PartitionLabelListAttribute(ctx, &srcs, bazel.LabelPartitions{
		"c":  bazel.LabelPartition{Extensions: []string{".c"}, LabelMapper: addSuffixForFilegroup("_c_srcs")},
		"as": bazel.LabelPartition{Extensions: []string{".s", ".S"}, LabelMapper: addSuffixForFilegroup("_as_srcs")},
		// C++ is the "catch-all" group, and comprises generated sources because we don't
		// know the language of these sources until the genrule is executed.
		"cpp": bazel.LabelPartition{Extensions: []string{".cpp", ".cc", ".cxx", ".mm"}, LabelMapper: addSuffixForFilegroup("_cpp_srcs"), Keep_remainder: true},
	})

	cSrcs = partitioned["c"]
	asSrcs = partitioned["as"]
	cppSrcs = partitioned["cpp"]
	return
}

// bp2BuildParseLibProps returns the attributes for a variant of a cc_library.
func bp2BuildParseLibProps(ctx android.TopDownMutatorContext, module *Module, isStatic bool) staticOrSharedAttributes {
	lib, ok := module.compiler.(*libraryDecorator)
	if !ok {
		return staticOrSharedAttributes{}
	}
	return bp2buildParseStaticOrSharedProps(ctx, module, lib, isStatic)
}

// bp2buildParseSharedProps returns the attributes for the shared variant of a cc_library.
func bp2BuildParseSharedProps(ctx android.TopDownMutatorContext, module *Module) staticOrSharedAttributes {
	return bp2BuildParseLibProps(ctx, module, false)
}

// bp2buildParseStaticProps returns the attributes for the static variant of a cc_library.
func bp2BuildParseStaticProps(ctx android.TopDownMutatorContext, module *Module) staticOrSharedAttributes {
	return bp2BuildParseLibProps(ctx, module, true)
}

type depsPartition struct {
	export         bazel.LabelList
	implementation bazel.LabelList
}

type bazelLabelForDepsFn func(android.TopDownMutatorContext, []string) bazel.LabelList

func partitionExportedAndImplementationsDeps(ctx android.TopDownMutatorContext, allDeps, exportedDeps []string, fn bazelLabelForDepsFn) depsPartition {
	implementation, export := android.FilterList(allDeps, exportedDeps)

	return depsPartition{
		export:         fn(ctx, export),
		implementation: fn(ctx, implementation),
	}
}

type bazelLabelForDepsExcludesFn func(android.TopDownMutatorContext, []string, []string) bazel.LabelList

func partitionExportedAndImplementationsDepsExcludes(ctx android.TopDownMutatorContext, allDeps, excludes, exportedDeps []string, fn bazelLabelForDepsExcludesFn) depsPartition {
	implementation, export := android.FilterList(allDeps, exportedDeps)

	return depsPartition{
		export:         fn(ctx, export, excludes),
		implementation: fn(ctx, implementation, excludes),
	}
}

func bp2buildParseStaticOrSharedProps(ctx android.TopDownMutatorContext, module *Module, lib *libraryDecorator, isStatic bool) staticOrSharedAttributes {
	attrs := staticOrSharedAttributes{}

	setAttrs := func(axis bazel.ConfigurationAxis, config string, props StaticOrSharedProperties) {
		attrs.Copts.SetSelectValue(axis, config, props.Cflags)
		attrs.Srcs.SetSelectValue(axis, config, android.BazelLabelForModuleSrc(ctx, props.Srcs))
		attrs.System_dynamic_deps.SetSelectValue(axis, config, bazelLabelForSharedDeps(ctx, props.System_shared_libs))

		staticDeps := partitionExportedAndImplementationsDeps(ctx, props.Static_libs, props.Export_static_lib_headers, bazelLabelForStaticDeps)
		attrs.Deps.SetSelectValue(axis, config, staticDeps.export)
		attrs.Implementation_deps.SetSelectValue(axis, config, staticDeps.implementation)

		sharedDeps := partitionExportedAndImplementationsDeps(ctx, props.Shared_libs, props.Export_shared_lib_headers, bazelLabelForSharedDeps)
		attrs.Dynamic_deps.SetSelectValue(axis, config, sharedDeps.export)
		attrs.Implementation_dynamic_deps.SetSelectValue(axis, config, sharedDeps.implementation)

		attrs.Whole_archive_deps.SetSelectValue(axis, config, bazelLabelForWholeDeps(ctx, props.Whole_static_libs))
	}
	// system_dynamic_deps distinguishes between nil/empty list behavior:
	//    nil -> use default values
	//    empty list -> no values specified
	attrs.System_dynamic_deps.ForceSpecifyEmptyList = true

	if isStatic {
		for axis, configToProps := range module.GetArchVariantProperties(ctx, &StaticProperties{}) {
			for config, props := range configToProps {
				if staticOrSharedProps, ok := props.(*StaticProperties); ok {
					setAttrs(axis, config, staticOrSharedProps.Static)
				}
			}
		}
	} else {
		for axis, configToProps := range module.GetArchVariantProperties(ctx, &SharedProperties{}) {
			for config, props := range configToProps {
				if staticOrSharedProps, ok := props.(*SharedProperties); ok {
					setAttrs(axis, config, staticOrSharedProps.Shared)
				}
			}
		}
	}

	cppSrcs, cSrcs, asSrcs := groupSrcsByExtension(ctx, attrs.Srcs)
	attrs.Srcs = cppSrcs
	attrs.Srcs_c = cSrcs
	attrs.Srcs_as = asSrcs

	return attrs
}

// Convenience struct to hold all attributes parsed from prebuilt properties.
type prebuiltAttributes struct {
	Src bazel.LabelAttribute
}

// NOTE: Used outside of Soong repo project, in the clangprebuilts.go bootstrap_go_package
func Bp2BuildParsePrebuiltLibraryProps(ctx android.TopDownMutatorContext, module *Module) prebuiltAttributes {
	var srcLabelAttribute bazel.LabelAttribute

	for axis, configToProps := range module.GetArchVariantProperties(ctx, &prebuiltLinkerProperties{}) {
		for config, props := range configToProps {
			if prebuiltLinkerProperties, ok := props.(*prebuiltLinkerProperties); ok {
				if len(prebuiltLinkerProperties.Srcs) > 1 {
					ctx.ModuleErrorf("Bp2BuildParsePrebuiltLibraryProps: Expected at most once source file for %s %s\n", axis, config)
					continue
				} else if len(prebuiltLinkerProperties.Srcs) == 0 {
					continue
				}
				src := android.BazelLabelForModuleSrcSingle(ctx, prebuiltLinkerProperties.Srcs[0])
				srcLabelAttribute.SetSelectValue(axis, config, src)
			}
		}
	}

	return prebuiltAttributes{
		Src: srcLabelAttribute,
	}
}

// Convenience struct to hold all attributes parsed from compiler properties.
type compilerAttributes struct {
	// Options for all languages
	copts bazel.StringListAttribute
	// Assembly options and sources
	asFlags bazel.StringListAttribute
	asSrcs  bazel.LabelListAttribute
	// C options and sources
	conlyFlags bazel.StringListAttribute
	cSrcs      bazel.LabelListAttribute
	// C++ options and sources
	cppFlags bazel.StringListAttribute
	srcs     bazel.LabelListAttribute

	rtti bazel.BoolAttribute
	stl  *string

	localIncludes    bazel.StringListAttribute
	absoluteIncludes bazel.StringListAttribute
}

// bp2BuildParseCompilerProps returns copts, srcs and hdrs and other attributes.
func bp2BuildParseCompilerProps(ctx android.TopDownMutatorContext, module *Module) compilerAttributes {
	var srcs bazel.LabelListAttribute
	var copts bazel.StringListAttribute
	var asFlags bazel.StringListAttribute
	var conlyFlags bazel.StringListAttribute
	var cppFlags bazel.StringListAttribute
	var rtti bazel.BoolAttribute
	var localIncludes bazel.StringListAttribute
	var absoluteIncludes bazel.StringListAttribute

	parseCommandLineFlags := func(soongFlags []string) []string {
		var result []string
		for _, flag := range soongFlags {
			// Soong's cflags can contain spaces, like `-include header.h`. For
			// Bazel's copts, split them up to be compatible with the
			// no_copts_tokenization feature.
			result = append(result, strings.Split(flag, " ")...)
		}
		return result
	}

	// Parse srcs from an arch or OS's props value.
	parseSrcs := func(baseCompilerProps *BaseCompilerProperties) bazel.LabelList {
		// Add srcs-like dependencies such as generated files.
		// First create a LabelList containing these dependencies, then merge the values with srcs.
		generatedHdrsAndSrcs := baseCompilerProps.Generated_headers
		generatedHdrsAndSrcs = append(generatedHdrsAndSrcs, baseCompilerProps.Generated_sources...)
		generatedHdrsAndSrcsLabelList := android.BazelLabelForModuleDeps(ctx, generatedHdrsAndSrcs)

		allSrcsLabelList := android.BazelLabelForModuleSrcExcludes(ctx, baseCompilerProps.Srcs, baseCompilerProps.Exclude_srcs)
		return bazel.AppendBazelLabelLists(allSrcsLabelList, generatedHdrsAndSrcsLabelList)
	}

	archVariantCompilerProps := module.GetArchVariantProperties(ctx, &BaseCompilerProperties{})
	for axis, configToProps := range archVariantCompilerProps {
		for config, props := range configToProps {
			if baseCompilerProps, ok := props.(*BaseCompilerProperties); ok {
				// If there's arch specific srcs or exclude_srcs, generate a select entry for it.
				// TODO(b/186153868): do this for OS specific srcs and exclude_srcs too.
				if len(baseCompilerProps.Srcs) > 0 || len(baseCompilerProps.Exclude_srcs) > 0 {
					srcsList := parseSrcs(baseCompilerProps)
					srcs.SetSelectValue(axis, config, srcsList)
				}

				var archVariantCopts []string
				if axis == bazel.NoConfigAxis {
					// If cpp_std is not specified, don't generate it in the
					// BUILD file. For readability purposes, cpp_std and gnu_extensions are
					// combined into a single -std=<version> copt, except in the
					// default case where cpp_std is nil and gnu_extensions is true or unspecified,
					// then the toolchain's default "gnu++17" will be used.
					if baseCompilerProps.Cpp_std != nil {
						// TODO(b/202491296): Handle C_std.
						// These transformations are shared with compiler.go.
						cppStdVal := parseCppStd(baseCompilerProps.Cpp_std)
						_, cppStdVal = maybeReplaceGnuToC(baseCompilerProps.Gnu_extensions, "", cppStdVal)
						archVariantCopts = append(archVariantCopts, "-std="+cppStdVal)
					} else if baseCompilerProps.Gnu_extensions != nil && !*baseCompilerProps.Gnu_extensions {
						archVariantCopts = append(archVariantCopts, "-std=c++17")
					}
				}
				archVariantCopts = append(archVariantCopts, parseCommandLineFlags(baseCompilerProps.Cflags)...)
				archVariantAsflags := parseCommandLineFlags(baseCompilerProps.Asflags)

				localIncludeDirs := baseCompilerProps.Local_include_dirs
				if axis == bazel.NoConfigAxis && includeBuildDirectory(baseCompilerProps.Include_build_directory) {
					localIncludeDirs = append(localIncludeDirs, ".")
				}

				absoluteIncludes.SetSelectValue(axis, config, baseCompilerProps.Include_dirs)
				localIncludes.SetSelectValue(axis, config, localIncludeDirs)

				copts.SetSelectValue(axis, config, archVariantCopts)
				asFlags.SetSelectValue(axis, config, archVariantAsflags)
				conlyFlags.SetSelectValue(axis, config, parseCommandLineFlags(baseCompilerProps.Conlyflags))
				cppFlags.SetSelectValue(axis, config, parseCommandLineFlags(baseCompilerProps.Cppflags))
				rtti.SetSelectValue(axis, config, baseCompilerProps.Rtti)
			}
		}
	}

	srcs.ResolveExcludes()
	absoluteIncludes.DeduplicateAxesFromBase()
	localIncludes.DeduplicateAxesFromBase()

	productVarPropNameToAttribute := map[string]*bazel.StringListAttribute{
		"Cflags":   &copts,
		"Asflags":  &asFlags,
		"CppFlags": &cppFlags,
	}
	productVariableProps := android.ProductVariableProperties(ctx)
	for propName, attr := range productVarPropNameToAttribute {
		if props, exists := productVariableProps[propName]; exists {
			for _, prop := range props {
				flags, ok := prop.Property.([]string)
				if !ok {
					ctx.ModuleErrorf("Could not convert product variable %s property", proptools.PropertyNameForField(propName))
				}
				newFlags, _ := bazel.TryVariableSubstitutions(flags, prop.ProductConfigVariable)
				attr.SetSelectValue(bazel.ProductVariableConfigurationAxis(prop.FullConfig), prop.FullConfig, newFlags)
			}
		}
	}

	srcs, cSrcs, asSrcs := groupSrcsByExtension(ctx, srcs)

	var stl *string = nil
	stlPropsByArch := module.GetArchVariantProperties(ctx, &StlProperties{})
	for _, configToProps := range stlPropsByArch {
		for _, props := range configToProps {
			if stlProps, ok := props.(*StlProperties); ok {
				if stlProps.Stl != nil {
					if stl == nil {
						stl = stlProps.Stl
					} else {
						if stl != stlProps.Stl {
							ctx.ModuleErrorf("Unsupported conversion: module with different stl for different variants: %s and %s", *stl, stlProps.Stl)
						}
					}
				}
			}
		}
	}

	return compilerAttributes{
		copts:            copts,
		srcs:             srcs,
		asFlags:          asFlags,
		asSrcs:           asSrcs,
		cSrcs:            cSrcs,
		conlyFlags:       conlyFlags,
		cppFlags:         cppFlags,
		rtti:             rtti,
		stl:              stl,
		localIncludes:    localIncludes,
		absoluteIncludes: absoluteIncludes,
	}
}

// Convenience struct to hold all attributes parsed from linker properties.
type linkerAttributes struct {
	deps                      bazel.LabelListAttribute
	implementationDeps        bazel.LabelListAttribute
	dynamicDeps               bazel.LabelListAttribute
	implementationDynamicDeps bazel.LabelListAttribute
	wholeArchiveDeps          bazel.LabelListAttribute
	systemDynamicDeps         bazel.LabelListAttribute

	linkCrt                       bazel.BoolAttribute
	useLibcrt                     bazel.BoolAttribute
	linkopts                      bazel.StringListAttribute
	versionScript                 bazel.LabelAttribute
	stripKeepSymbols              bazel.BoolAttribute
	stripKeepSymbolsAndDebugFrame bazel.BoolAttribute
	stripKeepSymbolsList          bazel.StringListAttribute
	stripAll                      bazel.BoolAttribute
	stripNone                     bazel.BoolAttribute
}

// FIXME(b/187655838): Use the existing linkerFlags() function instead of duplicating logic here
func getBp2BuildLinkerFlags(linkerProperties *BaseLinkerProperties) []string {
	flags := linkerProperties.Ldflags
	if !BoolDefault(linkerProperties.Pack_relocations, true) {
		flags = append(flags, "-Wl,--pack-dyn-relocs=none")
	}
	return flags
}

// bp2BuildParseLinkerProps parses the linker properties of a module, including
// configurable attribute values.
func bp2BuildParseLinkerProps(ctx android.TopDownMutatorContext, module *Module) linkerAttributes {

	var headerDeps bazel.LabelListAttribute
	var implementationHeaderDeps bazel.LabelListAttribute
	var deps bazel.LabelListAttribute
	var implementationDeps bazel.LabelListAttribute
	var dynamicDeps bazel.LabelListAttribute
	var implementationDynamicDeps bazel.LabelListAttribute
	var wholeArchiveDeps bazel.LabelListAttribute
	systemSharedDeps := bazel.LabelListAttribute{ForceSpecifyEmptyList: true}

	var linkopts bazel.StringListAttribute
	var versionScript bazel.LabelAttribute
	var linkCrt bazel.BoolAttribute
	var useLibcrt bazel.BoolAttribute

	var stripKeepSymbols bazel.BoolAttribute
	var stripKeepSymbolsAndDebugFrame bazel.BoolAttribute
	var stripKeepSymbolsList bazel.StringListAttribute
	var stripAll bazel.BoolAttribute
	var stripNone bazel.BoolAttribute

	for axis, configToProps := range module.GetArchVariantProperties(ctx, &StripProperties{}) {
		for config, props := range configToProps {
			if stripProperties, ok := props.(*StripProperties); ok {
				stripKeepSymbols.SetSelectValue(axis, config, stripProperties.Strip.Keep_symbols)
				stripKeepSymbolsList.SetSelectValue(axis, config, stripProperties.Strip.Keep_symbols_list)
				stripKeepSymbolsAndDebugFrame.SetSelectValue(axis, config, stripProperties.Strip.Keep_symbols_and_debug_frame)
				stripAll.SetSelectValue(axis, config, stripProperties.Strip.All)
				stripNone.SetSelectValue(axis, config, stripProperties.Strip.None)
			}
		}
	}

	// Use a single variable to capture usage of nocrt in arch variants, so there's only 1 error message for this module
	var disallowedArchVariantCrt bool

	for axis, configToProps := range module.GetArchVariantProperties(ctx, &BaseLinkerProperties{}) {
		for config, props := range configToProps {
			if baseLinkerProps, ok := props.(*BaseLinkerProperties); ok {

				// Excludes to parallel Soong:
				// https://cs.android.com/android/platform/superproject/+/master:build/soong/cc/linker.go;l=247-249;drc=088b53577dde6e40085ffd737a1ae96ad82fc4b0
				staticLibs := android.FirstUniqueStrings(baseLinkerProps.Static_libs)
				staticDeps := partitionExportedAndImplementationsDepsExcludes(ctx, staticLibs, baseLinkerProps.Exclude_static_libs, baseLinkerProps.Export_static_lib_headers, bazelLabelForStaticDepsExcludes)
				deps.SetSelectValue(axis, config, staticDeps.export)
				implementationDeps.SetSelectValue(axis, config, staticDeps.implementation)

				wholeStaticLibs := android.FirstUniqueStrings(baseLinkerProps.Whole_static_libs)
				wholeArchiveDeps.SetSelectValue(axis, config, bazelLabelForWholeDepsExcludes(ctx, wholeStaticLibs, baseLinkerProps.Exclude_static_libs))

				systemSharedLibs := baseLinkerProps.System_shared_libs
				// systemSharedLibs distinguishes between nil/empty list behavior:
				//    nil -> use default values
				//    empty list -> no values specified
				if len(systemSharedLibs) > 0 {
					systemSharedLibs = android.FirstUniqueStrings(systemSharedLibs)
				}
				systemSharedDeps.SetSelectValue(axis, config, bazelLabelForSharedDeps(ctx, systemSharedLibs))

				sharedLibs := android.FirstUniqueStrings(baseLinkerProps.Shared_libs)
				sharedDeps := partitionExportedAndImplementationsDepsExcludes(ctx, sharedLibs, baseLinkerProps.Exclude_shared_libs, baseLinkerProps.Export_shared_lib_headers, bazelLabelForSharedDepsExcludes)
				dynamicDeps.SetSelectValue(axis, config, sharedDeps.export)
				implementationDynamicDeps.SetSelectValue(axis, config, sharedDeps.implementation)

				headerLibs := android.FirstUniqueStrings(baseLinkerProps.Header_libs)
				hDeps := partitionExportedAndImplementationsDeps(ctx, headerLibs, baseLinkerProps.Export_header_lib_headers, bazelLabelForHeaderDeps)

				headerDeps.SetSelectValue(axis, config, hDeps.export)
				implementationHeaderDeps.SetSelectValue(axis, config, hDeps.implementation)

				linkopts.SetSelectValue(axis, config, getBp2BuildLinkerFlags(baseLinkerProps))
				if baseLinkerProps.Version_script != nil {
					versionScript.SetSelectValue(axis, config, android.BazelLabelForModuleSrcSingle(ctx, *baseLinkerProps.Version_script))
				}
				useLibcrt.SetSelectValue(axis, config, baseLinkerProps.libCrt())

				// it's very unlikely for nocrt to be arch variant, so bp2build doesn't support it.
				if baseLinkerProps.crt() != nil {
					if axis == bazel.NoConfigAxis {
						linkCrt.SetSelectValue(axis, config, baseLinkerProps.crt())
					} else if axis == bazel.ArchConfigurationAxis {
						disallowedArchVariantCrt = true
					}
				}
			}
		}
	}

	if disallowedArchVariantCrt {
		ctx.ModuleErrorf("nocrt is not supported for arch variants")
	}

	type productVarDep struct {
		// the name of the corresponding excludes field, if one exists
		excludesField string
		// reference to the bazel attribute that should be set for the given product variable config
		attribute *bazel.LabelListAttribute

		depResolutionFunc func(ctx android.TopDownMutatorContext, modules, excludes []string) bazel.LabelList
	}

	productVarToDepFields := map[string]productVarDep{
		// product variables do not support exclude_shared_libs
		"Shared_libs":       productVarDep{attribute: &implementationDynamicDeps, depResolutionFunc: bazelLabelForSharedDepsExcludes},
		"Static_libs":       productVarDep{"Exclude_static_libs", &implementationDeps, bazelLabelForStaticDepsExcludes},
		"Whole_static_libs": productVarDep{"Exclude_static_libs", &wholeArchiveDeps, bazelLabelForWholeDepsExcludes},
	}

	productVariableProps := android.ProductVariableProperties(ctx)
	for name, dep := range productVarToDepFields {
		props, exists := productVariableProps[name]
		excludeProps, excludesExists := productVariableProps[dep.excludesField]
		// if neither an include or excludes property exists, then skip it
		if !exists && !excludesExists {
			continue
		}
		// collect all the configurations that an include or exclude property exists for.
		// we want to iterate all configurations rather than either the include or exclude because for a
		// particular configuration we may have only and include or only an exclude to handle
		configs := make(map[string]bool, len(props)+len(excludeProps))
		for config := range props {
			configs[config] = true
		}
		for config := range excludeProps {
			configs[config] = true
		}

		for config := range configs {
			prop, includesExists := props[config]
			excludesProp, excludesExists := excludeProps[config]
			var includes, excludes []string
			var ok bool
			// if there was no includes/excludes property, casting fails and that's expected
			if includes, ok = prop.Property.([]string); includesExists && !ok {
				ctx.ModuleErrorf("Could not convert product variable %s property", name)
			}
			if excludes, ok = excludesProp.Property.([]string); excludesExists && !ok {
				ctx.ModuleErrorf("Could not convert product variable %s property", dep.excludesField)
			}

			dep.attribute.SetSelectValue(bazel.ProductVariableConfigurationAxis(config), config, dep.depResolutionFunc(ctx, android.FirstUniqueStrings(includes), excludes))
		}
	}

	headerDeps.Append(deps)
	implementationHeaderDeps.Append(implementationDeps)

	headerDeps.ResolveExcludes()
	implementationHeaderDeps.ResolveExcludes()
	dynamicDeps.ResolveExcludes()
	implementationDynamicDeps.ResolveExcludes()
	wholeArchiveDeps.ResolveExcludes()

	return linkerAttributes{
		deps:                      headerDeps,
		implementationDeps:        implementationHeaderDeps,
		dynamicDeps:               dynamicDeps,
		implementationDynamicDeps: implementationDynamicDeps,
		wholeArchiveDeps:          wholeArchiveDeps,
		systemDynamicDeps:         systemSharedDeps,

		linkCrt:       linkCrt,
		linkopts:      linkopts,
		useLibcrt:     useLibcrt,
		versionScript: versionScript,

		// Strip properties
		stripKeepSymbols:              stripKeepSymbols,
		stripKeepSymbolsAndDebugFrame: stripKeepSymbolsAndDebugFrame,
		stripKeepSymbolsList:          stripKeepSymbolsList,
		stripAll:                      stripAll,
		stripNone:                     stripNone,
	}
}

// Relativize a list of root-relative paths with respect to the module's
// directory.
//
// include_dirs Soong prop are root-relative (b/183742505), but
// local_include_dirs, export_include_dirs and export_system_include_dirs are
// module dir relative. This function makes a list of paths entirely module dir
// relative.
//
// For the `include` attribute, Bazel wants the paths to be relative to the
// module.
func bp2BuildMakePathsRelativeToModule(ctx android.BazelConversionPathContext, paths []string) []string {
	var relativePaths []string
	for _, path := range paths {
		// Semantics of filepath.Rel: join(ModuleDir, rel(ModuleDir, path)) == path
		relativePath, err := filepath.Rel(ctx.ModuleDir(), path)
		if err != nil {
			panic(err)
		}
		relativePaths = append(relativePaths, relativePath)
	}
	return relativePaths
}

// BazelIncludes contains information about -I and -isystem paths from a module converted to Bazel
// attributes.
type BazelIncludes struct {
	Includes       bazel.StringListAttribute
	SystemIncludes bazel.StringListAttribute
}

func bp2BuildParseExportedIncludes(ctx android.TopDownMutatorContext, module *Module) BazelIncludes {
	libraryDecorator := module.linker.(*libraryDecorator)
	return bp2BuildParseExportedIncludesHelper(ctx, module, libraryDecorator)
}

// Bp2buildParseExportedIncludesForPrebuiltLibrary returns a BazelIncludes with Bazel-ified values
// to export includes from the underlying module's properties.
func Bp2BuildParseExportedIncludesForPrebuiltLibrary(ctx android.TopDownMutatorContext, module *Module) BazelIncludes {
	prebuiltLibraryLinker := module.linker.(*prebuiltLibraryLinker)
	libraryDecorator := prebuiltLibraryLinker.libraryDecorator
	return bp2BuildParseExportedIncludesHelper(ctx, module, libraryDecorator)
}

// bp2BuildParseExportedIncludes creates a string list attribute contains the
// exported included directories of a module.
func bp2BuildParseExportedIncludesHelper(ctx android.TopDownMutatorContext, module *Module, libraryDecorator *libraryDecorator) BazelIncludes {
	exported := BazelIncludes{}
	for axis, configToProps := range module.GetArchVariantProperties(ctx, &FlagExporterProperties{}) {
		for config, props := range configToProps {
			if flagExporterProperties, ok := props.(*FlagExporterProperties); ok {
				if len(flagExporterProperties.Export_include_dirs) > 0 {
					exported.Includes.SetSelectValue(axis, config, flagExporterProperties.Export_include_dirs)
				}
				if len(flagExporterProperties.Export_system_include_dirs) > 0 {
					exported.SystemIncludes.SetSelectValue(axis, config, flagExporterProperties.Export_system_include_dirs)
				}
			}
		}
	}
	exported.Includes.DeduplicateAxesFromBase()
	exported.SystemIncludes.DeduplicateAxesFromBase()

	return exported
}

func bazelLabelForStaticModule(ctx android.TopDownMutatorContext, m blueprint.Module) string {
	label := android.BazelModuleLabel(ctx, m)
	if aModule, ok := m.(android.Module); ok {
		if ctx.OtherModuleType(aModule) == "cc_library" && !android.GenerateCcLibraryStaticOnly(m.Name()) {
			label += "_bp2build_cc_library_static"
		}
	}
	return label
}

func bazelLabelForSharedModule(ctx android.TopDownMutatorContext, m blueprint.Module) string {
	// cc_library, at it's root name, propagates the shared library, which depends on the static
	// library.
	return android.BazelModuleLabel(ctx, m)
}

func bazelLabelForStaticWholeModuleDeps(ctx android.TopDownMutatorContext, m blueprint.Module) string {
	label := bazelLabelForStaticModule(ctx, m)
	if aModule, ok := m.(android.Module); ok {
		if android.IsModulePrebuilt(aModule) {
			label += "_alwayslink"
		}
	}
	return label
}

func bazelLabelForWholeDeps(ctx android.TopDownMutatorContext, modules []string) bazel.LabelList {
	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForStaticWholeModuleDeps)
}

func bazelLabelForWholeDepsExcludes(ctx android.TopDownMutatorContext, modules, excludes []string) bazel.LabelList {
	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForStaticWholeModuleDeps)
}

func bazelLabelForStaticDepsExcludes(ctx android.TopDownMutatorContext, modules, excludes []string) bazel.LabelList {
	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForStaticModule)
}

func bazelLabelForStaticDeps(ctx android.TopDownMutatorContext, modules []string) bazel.LabelList {
	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForStaticModule)
}

func bazelLabelForSharedDeps(ctx android.TopDownMutatorContext, modules []string) bazel.LabelList {
	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForSharedModule)
}

func bazelLabelForHeaderDeps(ctx android.TopDownMutatorContext, modules []string) bazel.LabelList {
	// This is not elegant, but bp2build's shared library targets only propagate
	// their header information as part of the normal C++ provider.
	return bazelLabelForSharedDeps(ctx, modules)
}

func bazelLabelForSharedDepsExcludes(ctx android.TopDownMutatorContext, modules, excludes []string) bazel.LabelList {
	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForSharedModule)
}