platform_build_soong/rust/bindgen.go

264 lines
8.9 KiB
Go

// Copyright 2020 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 (
"strings"
"github.com/google/blueprint"
"github.com/google/blueprint/proptools"
"android/soong/android"
"android/soong/cc"
cc_config "android/soong/cc/config"
)
var (
defaultBindgenFlags = []string{""}
// bindgen should specify its own Clang revision so updating Clang isn't potentially blocked on bindgen failures.
bindgenClangVersion = "clang-r399163b"
//TODO(b/160803703) Use a prebuilt bindgen instead of the built bindgen.
_ = pctx.HostBinToolVariable("bindgenCmd", "bindgen")
_ = pctx.SourcePathVariable("bindgenClang",
"${cc_config.ClangBase}/${config.HostPrebuiltTag}/"+bindgenClangVersion+"/bin/clang")
_ = pctx.SourcePathVariable("bindgenLibClang",
"${cc_config.ClangBase}/${config.HostPrebuiltTag}/"+bindgenClangVersion+"/lib64/")
//TODO(ivanlozano) Switch this to RuleBuilder
bindgen = pctx.AndroidStaticRule("bindgen",
blueprint.RuleParams{
Command: "CLANG_PATH=$bindgenClang LIBCLANG_PATH=$bindgenLibClang RUSTFMT=${config.RustBin}/rustfmt " +
"$cmd $flags $in -o $out -- -MD -MF $out.d $cflags",
CommandDeps: []string{"$cmd"},
Deps: blueprint.DepsGCC,
Depfile: "$out.d",
},
"cmd", "flags", "cflags")
)
func init() {
android.RegisterModuleType("rust_bindgen", RustBindgenFactory)
android.RegisterModuleType("rust_bindgen_host", RustBindgenHostFactory)
}
var _ SourceProvider = (*bindgenDecorator)(nil)
type BindgenProperties struct {
// The wrapper header file. By default this is assumed to be a C header unless the extension is ".hh" or ".hpp".
// This is used to specify how to interpret the header and determines which '-std' flag to use by default.
//
// If your C++ header must have some other extension, then the default behavior can be overridden by setting the
// cpp_std property.
Wrapper_src *string `android:"path,arch_variant"`
// list of bindgen-specific flags and options
Bindgen_flags []string `android:"arch_variant"`
// module name of a custom binary/script which should be used instead of the 'bindgen' binary. This custom
// binary must expect arguments in a similar fashion to bindgen, e.g.
//
// "my_bindgen [flags] wrapper_header.h -o [output_path] -- [clang flags]"
Custom_bindgen string `android:"path"`
}
type bindgenDecorator struct {
*BaseSourceProvider
Properties BindgenProperties
ClangProperties cc.RustBindgenClangProperties
}
func (b *bindgenDecorator) getStdVersion(ctx ModuleContext, src android.Path) (string, bool) {
// Assume headers are C headers
isCpp := false
stdVersion := ""
switch src.Ext() {
case ".hpp", ".hh":
isCpp = true
}
if String(b.ClangProperties.Cpp_std) != "" && String(b.ClangProperties.C_std) != "" {
ctx.PropertyErrorf("c_std", "c_std and cpp_std cannot both be defined at the same time.")
}
if String(b.ClangProperties.Cpp_std) != "" {
if String(b.ClangProperties.Cpp_std) == "experimental" {
stdVersion = cc_config.ExperimentalCppStdVersion
} else if String(b.ClangProperties.Cpp_std) == "default" {
stdVersion = cc_config.CppStdVersion
} else {
stdVersion = String(b.ClangProperties.Cpp_std)
}
} else if b.ClangProperties.C_std != nil {
if String(b.ClangProperties.C_std) == "experimental" {
stdVersion = cc_config.ExperimentalCStdVersion
} else if String(b.ClangProperties.C_std) == "default" {
stdVersion = cc_config.CStdVersion
} else {
stdVersion = String(b.ClangProperties.C_std)
}
} else if isCpp {
stdVersion = cc_config.CppStdVersion
} else {
stdVersion = cc_config.CStdVersion
}
return stdVersion, isCpp
}
func (b *bindgenDecorator) GenerateSource(ctx ModuleContext, deps PathDeps) android.Path {
ccToolchain := ctx.RustModule().ccToolchain(ctx)
var cflags []string
var implicits android.Paths
implicits = append(implicits, deps.depGeneratedHeaders...)
// Default clang flags
cflags = append(cflags, "${cc_config.CommonClangGlobalCflags}")
if ctx.Device() {
cflags = append(cflags, "${cc_config.DeviceClangGlobalCflags}")
}
// Toolchain clang flags
cflags = append(cflags, "-target "+ccToolchain.ClangTriple())
cflags = append(cflags, strings.ReplaceAll(ccToolchain.ToolchainClangCflags(), "${config.", "${cc_config."))
// Dependency clang flags and include paths
cflags = append(cflags, deps.depClangFlags...)
for _, include := range deps.depIncludePaths {
cflags = append(cflags, "-I"+include.String())
}
for _, include := range deps.depSystemIncludePaths {
cflags = append(cflags, "-isystem "+include.String())
}
esc := proptools.NinjaAndShellEscapeList
// Filter out invalid cflags
for _, flag := range b.ClangProperties.Cflags {
if flag == "-x c++" || flag == "-xc++" {
ctx.PropertyErrorf("cflags",
"-x c++ should not be specified in cflags; setting cpp_std specifies this is a C++ header, or change the file extension to '.hpp' or '.hh'")
}
if strings.HasPrefix(flag, "-std=") {
ctx.PropertyErrorf("cflags",
"-std should not be specified in cflags; instead use c_std or cpp_std")
}
}
// Module defined clang flags and include paths
cflags = append(cflags, esc(b.ClangProperties.Cflags)...)
for _, include := range b.ClangProperties.Local_include_dirs {
cflags = append(cflags, "-I"+android.PathForModuleSrc(ctx, include).String())
implicits = append(implicits, android.PathForModuleSrc(ctx, include))
}
bindgenFlags := defaultBindgenFlags
bindgenFlags = append(bindgenFlags, esc(b.Properties.Bindgen_flags)...)
wrapperFile := android.OptionalPathForModuleSrc(ctx, b.Properties.Wrapper_src)
if !wrapperFile.Valid() {
ctx.PropertyErrorf("wrapper_src", "invalid path to wrapper source")
}
// Add C std version flag
stdVersion, isCpp := b.getStdVersion(ctx, wrapperFile.Path())
cflags = append(cflags, "-std="+stdVersion)
// Specify the header source language to avoid ambiguity.
if isCpp {
cflags = append(cflags, "-x c++")
// Add any C++ only flags.
cflags = append(cflags, esc(b.ClangProperties.Cppflags)...)
} else {
cflags = append(cflags, "-x c")
}
outputFile := android.PathForModuleOut(ctx, b.BaseSourceProvider.getStem(ctx)+".rs")
var cmd, cmdDesc string
if b.Properties.Custom_bindgen != "" {
cmd = ctx.GetDirectDepWithTag(b.Properties.Custom_bindgen, customBindgenDepTag).(*Module).HostToolPath().String()
cmdDesc = b.Properties.Custom_bindgen
} else {
cmd = "$bindgenCmd"
cmdDesc = "bindgen"
}
ctx.Build(pctx, android.BuildParams{
Rule: bindgen,
Description: strings.Join([]string{cmdDesc, wrapperFile.Path().Rel()}, " "),
Output: outputFile,
Input: wrapperFile.Path(),
Implicits: implicits,
Args: map[string]string{
"cmd": cmd,
"flags": strings.Join(bindgenFlags, " "),
"cflags": strings.Join(cflags, " "),
},
})
b.BaseSourceProvider.OutputFiles = android.Paths{outputFile}
return outputFile
}
func (b *bindgenDecorator) SourceProviderProps() []interface{} {
return append(b.BaseSourceProvider.SourceProviderProps(),
&b.Properties, &b.ClangProperties)
}
// rust_bindgen generates Rust FFI bindings to C libraries using bindgen given a wrapper header as the primary input.
// Bindgen has a number of flags to control the generated source, and additional flags can be passed to clang to ensure
// the header and generated source is appropriately handled. It is recommended to add it as a dependency in the
// rlibs, dylibs or rustlibs property. It may also be added in the srcs property for external crates, using the ":"
// prefix.
func RustBindgenFactory() android.Module {
module, _ := NewRustBindgen(android.HostAndDeviceSupported)
return module.Init()
}
func RustBindgenHostFactory() android.Module {
module, _ := NewRustBindgen(android.HostSupported)
return module.Init()
}
func NewRustBindgen(hod android.HostOrDeviceSupported) (*Module, *bindgenDecorator) {
bindgen := &bindgenDecorator{
BaseSourceProvider: NewSourceProvider(),
Properties: BindgenProperties{},
ClangProperties: cc.RustBindgenClangProperties{},
}
module := NewSourceProviderModule(hod, bindgen, false)
return module, bindgen
}
func (b *bindgenDecorator) SourceProviderDeps(ctx DepsContext, deps Deps) Deps {
deps = b.BaseSourceProvider.SourceProviderDeps(ctx, deps)
if ctx.toolchain().Bionic() {
deps = bionicDeps(deps, false)
}
deps.SharedLibs = append(deps.SharedLibs, b.ClangProperties.Shared_libs...)
deps.StaticLibs = append(deps.StaticLibs, b.ClangProperties.Static_libs...)
deps.HeaderLibs = append(deps.StaticLibs, b.ClangProperties.Header_libs...)
return deps
}