Add SourceProviders and a rust_bindgen module type
Add SourceProvider modules which provides a base interface for more
complex code generation usecases such as bindgen. Also adds the
rust_bindgen module type which calls bindgen to generate Rust FFI
bindings to C.
Bug: 159064919
Test: Local test module generates bindings.
Test: New Soong tests pass.
Change-Id: Ie31467bbbe423497666ad837cf5fe1acd1e76bd8
diff --git a/rust/bindgen.go b/rust/bindgen.go
new file mode 100644
index 0000000..859223a
--- /dev/null
+++ b/rust/bindgen.go
@@ -0,0 +1,172 @@
+// 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 (
+ "github.com/google/blueprint"
+ "strings"
+
+ "android/soong/android"
+ "android/soong/cc"
+ ccConfig "android/soong/cc/config"
+)
+
+var (
+ defaultBindgenFlags = []string{"--no-rustfmt-bindings"}
+
+ // bindgen should specify its own Clang revision so updating Clang isn't potentially blocked on bindgen failures.
+ bindgenClangVersion = "clang-r383902c"
+ bindgenLibClangSoGit = "11git"
+
+ //TODO(b/160803703) Use a prebuilt bindgen instead of the built bindgen.
+ _ = pctx.SourcePathVariable("bindgenCmd", "out/host/${config.HostPrebuiltTag}/bin/bindgen")
+ _ = pctx.SourcePathVariable("bindgenClang",
+ "${ccConfig.ClangBase}/${config.HostPrebuiltTag}/"+bindgenClangVersion+"/bin/clang")
+ _ = pctx.SourcePathVariable("bindgenLibClang",
+ "${ccConfig.ClangBase}/${config.HostPrebuiltTag}/"+bindgenClangVersion+"/lib64/libclang.so."+bindgenLibClangSoGit)
+
+ //TODO(ivanlozano) Switch this to RuleBuilder
+ bindgen = pctx.AndroidStaticRule("bindgen",
+ blueprint.RuleParams{
+ Command: "CLANG_PATH=$bindgenClang LIBCLANG_PATH=$bindgenLibClang $bindgenCmd $flags $in -o $out -- $cflags",
+ CommandDeps: []string{"$bindgenCmd"},
+ },
+ "flags", "cflags")
+)
+
+func init() {
+ android.RegisterModuleType("rust_bindgen", RustBindgenFactory)
+}
+
+var _ SourceProvider = (*bindgenDecorator)(nil)
+
+type BindgenProperties struct {
+ // The wrapper header file
+ Wrapper_src *string `android:"path,arch_variant"`
+
+ // list of bindgen-specific flags and options
+ Flags []string `android:"arch_variant"`
+
+ // list of clang flags required to correctly interpret the headers.
+ Cflags []string `android:"arch_variant"`
+
+ // list of directories relative to the Blueprints file that will
+ // be added to the include path using -I
+ Local_include_dirs []string `android:"arch_variant,variant_prepend"`
+
+ // list of static libraries that provide headers for this binding.
+ Static_libs []string `android:"arch_variant,variant_prepend"`
+
+ // list of shared libraries that provide headers for this binding.
+ Shared_libs []string `android:"arch_variant"`
+
+ //TODO(b/161141999) Add support for headers from cc_library_header modules.
+}
+
+type bindgenDecorator struct {
+ *baseSourceProvider
+
+ Properties BindgenProperties
+}
+
+func (b *bindgenDecorator) libraryExports(ctx android.ModuleContext) (android.Paths, []string) {
+ var libraryPaths android.Paths
+ var libraryFlags []string
+
+ for _, static_lib := range b.Properties.Static_libs {
+ if dep, ok := ctx.GetDirectDepWithTag(static_lib, cc.StaticDepTag).(*cc.Module); ok {
+ libraryPaths = append(libraryPaths, dep.ExportedIncludeDirs()...)
+ libraryFlags = append(libraryFlags, dep.ExportedFlags()...)
+ }
+ }
+ for _, shared_lib := range b.Properties.Shared_libs {
+ if dep, ok := ctx.GetDirectDepWithTag(shared_lib, cc.SharedDepTag).(*cc.Module); ok {
+ libraryPaths = append(libraryPaths, dep.ExportedIncludeDirs()...)
+ libraryFlags = append(libraryFlags, dep.ExportedFlags()...)
+ }
+ }
+
+ return libraryPaths, libraryFlags
+}
+
+func (b *bindgenDecorator) generateSource(ctx android.ModuleContext) android.Path {
+ ccToolchain := ccConfig.FindToolchain(ctx.Os(), ctx.Arch())
+ includes, exportedFlags := b.libraryExports(ctx)
+
+ var cflags []string
+ cflags = append(cflags, b.Properties.Cflags...)
+ cflags = append(cflags, "-target "+ccToolchain.ClangTriple())
+ cflags = append(cflags, strings.ReplaceAll(ccToolchain.ToolchainClangCflags(), "${config.", "${ccConfig."))
+ cflags = append(cflags, exportedFlags...)
+ for _, include := range includes {
+ cflags = append(cflags, "-I"+include.String())
+ }
+ for _, include := range b.Properties.Local_include_dirs {
+ cflags = append(cflags, "-I"+android.PathForModuleSrc(ctx, include).String())
+ }
+
+ bindgenFlags := defaultBindgenFlags
+ bindgenFlags = append(bindgenFlags, strings.Join(b.Properties.Flags, " "))
+
+ wrapperFile := android.OptionalPathForModuleSrc(ctx, b.Properties.Wrapper_src)
+ if !wrapperFile.Valid() {
+ ctx.PropertyErrorf("wrapper_src", "invalid path to wrapper source")
+ }
+
+ outputFile := android.PathForModuleOut(ctx, b.baseSourceProvider.getStem(ctx)+".rs")
+
+ ctx.Build(pctx, android.BuildParams{
+ Rule: bindgen,
+ Description: "bindgen " + wrapperFile.Path().Rel(),
+ Output: outputFile,
+ Input: wrapperFile.Path(),
+ Implicits: includes,
+ Args: map[string]string{
+ "flags": strings.Join(bindgenFlags, " "),
+ "cflags": strings.Join(cflags, " "),
+ },
+ })
+ b.baseSourceProvider.outputFile = outputFile
+ return outputFile
+}
+
+func (b *bindgenDecorator) sourceProviderProps() []interface{} {
+ return append(b.baseSourceProvider.sourceProviderProps(),
+ &b.Properties)
+}
+
+func RustBindgenFactory() android.Module {
+ module, _ := NewRustBindgen(android.HostAndDeviceSupported)
+ return module.Init()
+}
+
+func NewRustBindgen(hod android.HostOrDeviceSupported) (*Module, *bindgenDecorator) {
+ module := newModule(hod, android.MultilibBoth)
+
+ bindgen := &bindgenDecorator{
+ baseSourceProvider: NewSourceProvider(),
+ Properties: BindgenProperties{},
+ }
+ module.sourceProvider = bindgen
+
+ return module, bindgen
+}
+
+func (b *bindgenDecorator) sourceProviderDeps(ctx DepsContext, deps Deps) Deps {
+ deps = b.baseSourceProvider.sourceProviderDeps(ctx, deps)
+ deps.SharedLibs = append(deps.SharedLibs, b.Properties.Shared_libs...)
+ deps.StaticLibs = append(deps.StaticLibs, b.Properties.Static_libs...)
+ return deps
+}