rust: Add whole_static_libs, revert static_lib

Revert the static_lib behavior to the previous behavior (pass static
libs to the linker rather than via to rustc using `-lstatic=<lib>`). To
bundle static libraries into libraries, provide the whole_static_libs
property which retains the current static_libs behavior.

Passing all static libraries via -lstatic was resulting in odd bloat
where in some cases static symbols were duplicated in binaries and
libraries. This split makes it possible to be explicit about when static
libraries should be bundled.

Bug: 183182230
Test: mma system/bt; mma system/security/keystore2; mma external/rust

Change-Id: Ic2dde5d1542dca5ce145aa3a3fbd9ea54440d991

4 files changed, 55 insertions, 27 deletions

diff --git a/cc/linkable.go b/cc/linkable.go
index 58919a060..1b36762c8 100644
--- a/cc/linkable.go
+++ b/cc/linkable.go
@@ -157,8 +157,16 @@ func SharedDepTag() blueprint.DependencyTag {
 }
 
 // StaticDepTag returns the dependency tag for any C++ static libraries.
-func StaticDepTag() blueprint.DependencyTag {
-	return libraryDependencyTag{Kind: staticLibraryDependency}
+func StaticDepTag(wholeStatic bool) blueprint.DependencyTag {
+	return libraryDependencyTag{Kind: staticLibraryDependency, wholeStatic: wholeStatic}
+}
+
+// IsWholeStaticLib whether a dependency tag is a whole static library dependency.
+func IsWholeStaticLib(depTag blueprint.DependencyTag) bool {
+	if tag, ok := depTag.(libraryDependencyTag); ok {
+		return tag.wholeStatic
+	}
+	return false
 }
 
 // HeaderDepTag returns the dependency tag for any C++ "header-only" libraries.
diff --git a/rust/compiler.go b/rust/compiler.go
index 200af9061..41b73719a 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -97,13 +97,25 @@ type BaseCompilerProperties struct {
 	// list of C shared library dependencies
 	Shared_libs []string `android:"arch_variant"`
 
-	// list of C static library dependencies. Note, static libraries prefixed by "lib" will be passed to rustc
-	// along with "-lstatic=<name>". This will bundle the static library into rlib/static libraries so dependents do
-	// not need to also declare the static library as a dependency. Static libraries which are not prefixed by "lib"
-	// cannot be passed to rustc with this flag and will not be bundled into rlib/static libraries, and thus must
-	// be redeclared in dependents.
+	// list of C static library dependencies. These dependencies do not normally propagate to dependents
+	// and may need to be redeclared. See whole_static_libs for bundling static dependencies into a library.
 	Static_libs []string `android:"arch_variant"`
 
+	// Similar to static_libs, but will bundle the static library dependency into a library. This is helpful
+	// to avoid having to redeclare the dependency for dependents of this library, but in some cases may also
+	// result in bloat if multiple dependencies all include the same static library whole.
+	//
+	// The common use case for this is when the static library is unlikely to be a dependency of other modules to avoid
+	// having to redeclare the static library dependency for every dependent module.
+	// If you are not sure what to, for rust_library modules most static dependencies should go in static_libraries,
+	// and for rust_ffi modules most static dependencies should go into whole_static_libraries.
+	//
+	// For rust_ffi static variants, these libraries will be included in the resulting static library archive.
+	//
+	// For rust_library rlib variants, these libraries will be bundled into the resulting rlib library. This will
+	// include all of the static libraries symbols in any dylibs or binaries which use this rlib as well.
+	Whole_static_libs []string `android:"arch_variant"`
+
 	// crate name, required for modules which produce Rust libraries: rust_library, rust_ffi and SourceProvider
 	// modules which create library variants (rust_bindgen). This must be the expected extern crate name used in
 	// source, and is required to conform to an enforced format matching library output files (if the output file is
@@ -266,6 +278,7 @@ func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
 	deps.Rustlibs = append(deps.Rustlibs, compiler.Properties.Rustlibs...)
 	deps.ProcMacros = append(deps.ProcMacros, compiler.Properties.Proc_macros...)
 	deps.StaticLibs = append(deps.StaticLibs, compiler.Properties.Static_libs...)
+	deps.WholeStaticLibs = append(deps.WholeStaticLibs, compiler.Properties.Whole_static_libs...)
 	deps.SharedLibs = append(deps.SharedLibs, compiler.Properties.Shared_libs...)
 
 	if !Bool(compiler.Properties.No_stdlibs) {
diff --git a/rust/rust.go b/rust/rust.go
index 8ebdb727c..99ff028d6 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -269,14 +269,15 @@ func (mod *Module) SplitPerApiLevel() bool {
 }
 
 type Deps struct {
-	Dylibs     []string
-	Rlibs      []string
-	Rustlibs   []string
-	Stdlibs    []string
-	ProcMacros []string
-	SharedLibs []string
-	StaticLibs []string
-	HeaderLibs []string
+	Dylibs          []string
+	Rlibs           []string
+	Rustlibs        []string
+	Stdlibs         []string
+	ProcMacros      []string
+	SharedLibs      []string
+	StaticLibs      []string
+	WholeStaticLibs []string
+	HeaderLibs      []string
 
 	CrtBegin, CrtEnd string
 }
@@ -751,7 +752,7 @@ func (mod *Module) deps(ctx DepsContext) Deps {
 	deps.ProcMacros = android.LastUniqueStrings(deps.ProcMacros)
 	deps.SharedLibs = android.LastUniqueStrings(deps.SharedLibs)
 	deps.StaticLibs = android.LastUniqueStrings(deps.StaticLibs)
-
+	deps.WholeStaticLibs = android.LastUniqueStrings(deps.WholeStaticLibs)
 	return deps
 
 }
@@ -911,16 +912,13 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 			exportDep := false
 			switch {
 			case cc.IsStaticDepTag(depTag):
-				// Only pass -lstatic for rlibs as it results in dylib bloat.
-				if lib, ok := ctx.Module().(*Module).compiler.(libraryInterface); ok && lib.rlib() {
-					// Link cc static libraries using "-lstatic" so rustc can reason about how to handle these
-					// (for example, bundling them into rlibs).
-					//
-					// rustc does not support linking libraries with the "-l" flag unless they are prefixed by "lib".
-					// If we need to link a library that isn't prefixed by "lib", we'll just link to it directly through
-					// linkObjects; such a library may need to be redeclared by static dependents.
+				if cc.IsWholeStaticLib(depTag) {
+					// rustc will bundle static libraries when they're passed with "-lstatic=<lib>". This will fail
+					// if the library is not prefixed by "lib".
 					if libName, ok := libNameFromFilePath(linkObject.Path()); ok {
 						depPaths.depFlags = append(depPaths.depFlags, "-lstatic="+libName)
+					} else {
+						ctx.ModuleErrorf("'%q' cannot be listed as a whole_static_library in Rust modules unless the output is prefixed by 'lib'", depName, ctx.ModuleName())
 					}
 				}
 
@@ -1099,7 +1097,10 @@ func (mod *Module) DepsMutator(actx android.BottomUpMutatorContext) {
 		cc.SharedDepTag(), deps.SharedLibs...)
 	actx.AddVariationDependencies(append(commonDepVariations,
 		blueprint.Variation{Mutator: "link", Variation: "static"}),
-		cc.StaticDepTag(), deps.StaticLibs...)
+		cc.StaticDepTag(false), deps.StaticLibs...)
+	actx.AddVariationDependencies(append(commonDepVariations,
+		blueprint.Variation{Mutator: "link", Variation: "static"}),
+		cc.StaticDepTag(true), deps.WholeStaticLibs...)
 
 	actx.AddVariationDependencies(nil, cc.HeaderDepTag(), deps.HeaderLibs...)
 
diff --git a/rust/rust_test.go b/rust/rust_test.go
index bed28ec8f..418bd93a4 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -149,6 +149,11 @@ func TestDepsTracking(t *testing.T) {
 			srcs: ["foo.rs"],
 			crate_name: "static",
 		}
+		rust_ffi_host_static {
+			name: "libwholestatic",
+			srcs: ["foo.rs"],
+			crate_name: "wholestatic",
+		}
 		rust_ffi_host_shared {
 			name: "libshared",
 			srcs: ["foo.rs"],
@@ -164,6 +169,7 @@ func TestDepsTracking(t *testing.T) {
 			srcs: ["foo.rs"],
 			crate_name: "rlib",
 			static_libs: ["libstatic"],
+			whole_static_libs: ["libwholestatic"],
 		}
 		rust_proc_macro {
 			name: "libpm",
@@ -204,8 +210,8 @@ func TestDepsTracking(t *testing.T) {
 		t.Errorf("Static library dependency not detected (dependency missing from AndroidMkStaticLibs)")
 	}
 
-	if !strings.Contains(rustc.Args["rustcFlags"], "-lstatic=static") {
-		t.Errorf("-lstatic flag not being passed to rustc for static library")
+	if !strings.Contains(rustc.Args["rustcFlags"], "-lstatic=wholestatic") {
+		t.Errorf("-lstatic flag not being passed to rustc for static library %#v", rustc.Args["rustcFlags"])
 	}
 
 }