build_soong/rust/proc_macro.go

// Copyright 2019 The Android Open Source Project
//
// 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 rust

import (
	"fmt"

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

func init() {
	android.RegisterModuleType("rust_proc_macro", ProcMacroFactory)
}

type ProcMacroCompilerProperties struct {
}

type procMacroDecorator struct {
	*baseCompiler
	*flagExporter

	Properties ProcMacroCompilerProperties
}

type procMacroInterface interface {
	ProcMacro() bool
}

var _ compiler = (*procMacroDecorator)(nil)
var _ exportedFlagsProducer = (*procMacroDecorator)(nil)

func ProcMacroFactory() android.Module {
	module, _ := NewProcMacro(android.HostSupportedNoCross)
	return module.Init()
}

func NewProcMacro(hod android.HostOrDeviceSupported) (*Module, *procMacroDecorator) {
	module := newModule(hod, android.MultilibFirst)

	android.InitBazelModule(module)

	procMacro := &procMacroDecorator{
		baseCompiler: NewBaseCompiler("lib", "lib64", InstallInSystem),
		flagExporter: NewFlagExporter(),
	}

	// Don't sanitize procMacros
	module.sanitize = nil
	module.compiler = procMacro

	return module, procMacro
}

func (procMacro *procMacroDecorator) compilerProps() []interface{} {
	return append(procMacro.baseCompiler.compilerProps(),
		&procMacro.Properties)
}

func (procMacro *procMacroDecorator) compilerFlags(ctx ModuleContext, flags Flags) Flags {
	flags = procMacro.baseCompiler.compilerFlags(ctx, flags)
	flags.RustFlags = append(flags.RustFlags, "--extern proc_macro")
	return flags
}

func (procMacro *procMacroDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput {
	fileName := procMacro.getStem(ctx) + ctx.toolchain().ProcMacroSuffix()
	outputFile := android.PathForModuleOut(ctx, fileName)

	srcPath := procMacro.crateRootPath(ctx)
	ret := TransformSrctoProcMacro(ctx, srcPath, deps, flags, outputFile)
	procMacro.baseCompiler.unstrippedOutputFile = outputFile
	return ret
}

func (procMacro *procMacroDecorator) getStem(ctx ModuleContext) string {
	stem := procMacro.baseCompiler.getStemWithoutSuffix(ctx)
	validateLibraryStem(ctx, stem, procMacro.crateName())

	return stem + String(procMacro.baseCompiler.Properties.Suffix)
}

func (procMacro *procMacroDecorator) autoDep(ctx android.BottomUpMutatorContext) autoDep {
	return rlibAutoDep
}

func (procMacro *procMacroDecorator) ProcMacro() bool {
	return true
}

func (procMacro *procMacroDecorator) everInstallable() bool {
	// Proc_macros are never installed
	return false
}

type procMacroAttributes struct {
	Srcs           bazel.LabelListAttribute
	Compile_data   bazel.LabelListAttribute
	Crate_name     bazel.StringAttribute
	Edition        bazel.StringAttribute
	Crate_features bazel.StringListAttribute
	Deps           bazel.LabelListAttribute
	Rustc_flags    bazel.StringListAttribute
}

func procMacroBp2build(ctx android.Bp2buildMutatorContext, m *Module) {
	procMacro := m.compiler.(*procMacroDecorator)
	srcs, compileData := srcsAndCompileDataAttrs(ctx, *procMacro.baseCompiler)
	deps := android.BazelLabelForModuleDeps(ctx, append(
		procMacro.baseCompiler.Properties.Rustlibs,
		procMacro.baseCompiler.Properties.Rlibs...,
	))

	var rustcFLags []string
	for _, cfg := range procMacro.baseCompiler.Properties.Cfgs {
		rustcFLags = append(rustcFLags, fmt.Sprintf("--cfg=%s", cfg))
	}

	attrs := &procMacroAttributes{
		Srcs: bazel.MakeLabelListAttribute(
			srcs,
		),
		Compile_data: bazel.MakeLabelListAttribute(
			compileData,
		),
		Crate_name: bazel.StringAttribute{
			Value: &procMacro.baseCompiler.Properties.Crate_name,
		},
		Edition: bazel.StringAttribute{
			Value: procMacro.baseCompiler.Properties.Edition,
		},
		Crate_features: bazel.StringListAttribute{
			Value: procMacro.baseCompiler.Properties.Features,
		},
		Deps: bazel.MakeLabelListAttribute(
			deps,
		),
		Rustc_flags: bazel.StringListAttribute{
			Value: append(
				rustcFLags,
				procMacro.baseCompiler.Properties.Flags...,
			),
		},
	}
	// m.IsConvertedByBp2build()
	ctx.CreateBazelTargetModule(
		bazel.BazelTargetModuleProperties{
			Rule_class:        "rust_proc_macro",
			Bzl_load_location: "@rules_rust//rust:defs.bzl",
		},
		android.CommonAttributes{
			Name: m.Name(),
		},
		attrs,
	)
}