From 9b4438378814ba49aac630b689e733decbebbba9 Mon Sep 17 00:00:00 2001
From: Ivan Lozano <ivanlozano@google.com>
Date: Tue, 17 Nov 2020 13:39:30 -0500
Subject: [PATCH] rust: Add header library support to rust_bindgen.

Allow rust_bindgen modules to define dependencies that only provide
headers and may not necessarily need to be linked in.

Bug: 161141999
Test: Soong tests pass.
Test: Example module has appropriate include flags when compiling.
Change-Id: Ic9ce8b1204008ad8dcb18766c914e48bb292d485
---
 cc/compiler.go       | 3 +++
 rust/bindgen.go      | 1 +
 rust/bindgen_test.go | 8 ++++++++
 rust/protobuf.go     | 2 +-
 4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/cc/compiler.go b/cc/compiler.go
index 3c86d208b..04ed80db9 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -687,6 +687,9 @@ type RustBindgenClangProperties struct {
 	// list of shared libraries that provide headers for this binding.
 	Shared_libs []string `android:"arch_variant"`
 
+	// List of libraries which export include paths required for this module
+	Header_libs []string `android:"arch_variant,variant_prepend"`
+
 	// list of clang flags required to correctly interpret the headers.
 	Cflags []string `android:"arch_variant"`
 
diff --git a/rust/bindgen.go b/rust/bindgen.go
index 7cc0fc829..35a807bfd 100644
--- a/rust/bindgen.go
+++ b/rust/bindgen.go
@@ -258,5 +258,6 @@ func (b *bindgenDecorator) SourceProviderDeps(ctx DepsContext, deps Deps) Deps {
 
 	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
 }
diff --git a/rust/bindgen_test.go b/rust/bindgen_test.go
index c7ce42bb4..af04cfc89 100644
--- a/rust/bindgen_test.go
+++ b/rust/bindgen_test.go
@@ -32,6 +32,7 @@ func TestRustBindgen(t *testing.T) {
 			cflags: ["--clang-flag()"],
 			shared_libs: ["libfoo_shared"],
 			static_libs: ["libfoo_static"],
+			header_libs: ["libfoo_header"],
 		}
 		cc_library_shared {
 			name: "libfoo_shared",
@@ -41,6 +42,10 @@ func TestRustBindgen(t *testing.T) {
 			name: "libfoo_static",
 			export_include_dirs: ["static_include"],
 		}
+		cc_library_headers {
+			name: "libfoo_header",
+			export_include_dirs: ["header_include"],
+		}
 		cc_defaults {
 			name: "cc_defaults_flags",
 			cflags: ["--default-flag"],
@@ -60,6 +65,9 @@ func TestRustBindgen(t *testing.T) {
 	if !strings.Contains(libbindgen.Args["cflags"], "-Istatic_include") {
 		t.Errorf("missing static_libs exported includes in rust_bindgen rule: cflags %#v", libbindgen.Args["cflags"])
 	}
+	if !strings.Contains(libbindgen.Args["cflags"], "-Iheader_include") {
+		t.Errorf("missing static_libs exported includes in rust_bindgen rule: cflags %#v", libbindgen.Args["cflags"])
+	}
 	if !strings.Contains(libbindgen.Args["cflags"], "--default-flag") {
 		t.Errorf("rust_bindgen missing cflags defined in cc_defaults: cflags %#v", libbindgen.Args["cflags"])
 	}
diff --git a/rust/protobuf.go b/rust/protobuf.go
index 76fed30fb..7d6e1fd5c 100644
--- a/rust/protobuf.go
+++ b/rust/protobuf.go
@@ -53,7 +53,7 @@ type ProtobufProperties struct {
 	Proto_flags []string `android:"arch_variant"`
 
 	// List of libraries which export include paths required for this module
-	Header_libs []string `android:"arch_variant"`
+	Header_libs []string `android:"arch_variant,variant_prepend"`
 }
 
 type protobufDecorator struct {