From f76cdf7c20d87796324d935e5d5f23605cf2af4f Mon Sep 17 00:00:00 2001
From: Ivan Lozano <ivanlozano@google.com>
Date: Fri, 12 Feb 2021 09:55:06 -0500
Subject: [PATCH] rust: Emit android vndk cfg flag.

Pass an "android_vndk" cfg flag that indicates this code
targets the vndk. This can be useful in instances where code
might need to behave differently.

This also includes a fix to make sure our vendor Soong tests
are correctly configured.

Bug: 179907868
Test: Soong tests pass.
Test: Example module emits new cfg flags.
Change-Id: I01cdf91f6f9d42cd8a759266d5170479664bf4bc
---
 rust/compiler.go   |  4 ++++
 rust/image_test.go | 25 ++++++++++++++++++++++---
 rust/rust_test.go  | 17 +++++++++++++++++
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/rust/compiler.go b/rust/compiler.go
index 586063e91..e4120d035 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -232,6 +232,10 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flag
 		flags.LinkFlags = append(flags.LinkFlags, "-Wl,-rpath,"+rpathPrefix+"../"+rpath)
 	}
 
+	if ctx.RustModule().UseVndk() {
+		flags.RustFlags = append(flags.RustFlags, "--cfg 'android_vndk'")
+	}
+
 	return flags
 }
 
diff --git a/rust/image_test.go b/rust/image_test.go
index 1515aa264..e40599c3a 100644
--- a/rust/image_test.go
+++ b/rust/image_test.go
@@ -15,6 +15,7 @@
 package rust
 
 import (
+	"strings"
 	"testing"
 
 	"android/soong/android"
@@ -23,7 +24,7 @@ import (
 
 // Test that cc modules can link against vendor_available rust_ffi_static libraries.
 func TestVendorLinkage(t *testing.T) {
-	ctx := testRust(t, `
+	ctx := testRustVndk(t, `
 			cc_binary {
 				name: "fizz_vendor",
 				static_libs: ["libfoo_vendor"],
@@ -37,16 +38,34 @@ func TestVendorLinkage(t *testing.T) {
 			}
 		`)
 
-	vendorBinary := ctx.ModuleForTests("fizz_vendor", "android_arm64_armv8-a").Module().(*cc.Module)
+	vendorBinary := ctx.ModuleForTests("fizz_vendor", "android_vendor.VER_arm64_armv8-a").Module().(*cc.Module)
 
 	if !android.InList("libfoo_vendor", vendorBinary.Properties.AndroidMkStaticLibs) {
 		t.Errorf("vendorBinary should have a dependency on libfoo_vendor")
 	}
 }
 
+// Test that variants which use the vndk emit the appropriate cfg flag.
+func TestImageVndkCfgFlag(t *testing.T) {
+	ctx := testRustVndk(t, `
+			rust_ffi_static {
+				name: "libfoo",
+				crate_name: "foo",
+				srcs: ["foo.rs"],
+				vendor_available: true,
+			}
+		`)
+
+	vendor := ctx.ModuleForTests("libfoo", "android_vendor.VER_arm64_armv8-a_static").Rule("rustc")
+
+	if !strings.Contains(vendor.Args["rustcFlags"], "--cfg 'android_vndk'") {
+		t.Errorf("missing \"--cfg 'android_vndk'\" for libfoo vendor variant, rustcFlags: %#v", vendor.Args["rustcFlags"])
+	}
+}
+
 // Test that cc modules can link against vendor_ramdisk_available rust_ffi_static libraries.
 func TestVendorRamdiskLinkage(t *testing.T) {
-	ctx := testRust(t, `
+	ctx := testRustVndk(t, `
 			cc_library_static {
 				name: "libcc_vendor_ramdisk",
 				static_libs: ["libfoo_vendor_ramdisk"],
diff --git a/rust/rust_test.go b/rust/rust_test.go
index 88d964300..a0ed5345f 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -64,6 +64,14 @@ func testRust(t *testing.T, bp string) *android.TestContext {
 	return tctx.parse(t)
 }
 
+func testRustVndk(t *testing.T, bp string) *android.TestContext {
+	tctx := newTestRustCtx(t, bp)
+	tctx.useMockedFs()
+	tctx.generateConfig()
+	tctx.setVndk(t)
+	return tctx.parse(t)
+}
+
 // testRustCov returns a TestContext in which a basic environment has been
 // setup. This environment explicitly enables coverage.
 func testRustCov(t *testing.T, bp string) *android.TestContext {
@@ -140,6 +148,15 @@ func (tctx *testRustCtx) enableCoverage(t *testing.T) {
 	tctx.config.TestProductVariables.NativeCoveragePaths = []string{"*"}
 }
 
+func (tctx *testRustCtx) setVndk(t *testing.T) {
+	if tctx.config == nil {
+		t.Fatalf("tctx.config not been generated yet. Please call generateConfig first.")
+	}
+	tctx.config.TestProductVariables.DeviceVndkVersion = StringPtr("current")
+	tctx.config.TestProductVariables.ProductVndkVersion = StringPtr("current")
+	tctx.config.TestProductVariables.Platform_vndk_version = StringPtr("VER")
+}
+
 // parse validates the configuration and parses the Blueprint file. It returns
 // a TestContext which can be used to retrieve the generated modules via
 // ModuleForTests.