Set compile_multilib for SDK snapshots for device.

Previously compile_multilib was ignored for device and defaulted to
"both", which could lead to an internal inconsistency in the snapshot
if a member was 32- or 64-only.

This also implements common property optimisation for compile_multilib,
by adding a struct that can be extended to other properties in the
future.

Test: m nothing
Bug: 151303681
Change-Id: I3e96222858e5e755173aca03508a23c431977e2a

2 files changed, 41 insertions, 29 deletions

diff --git a/sdk/cc_sdk_test.go b/sdk/cc_sdk_test.go
index 497f14bde..17afdb804 100644
--- a/sdk/cc_sdk_test.go
+++ b/sdk/cc_sdk_test.go
@@ -73,7 +73,6 @@ func TestSdkCompileMultilibOverride(t *testing.T) {
 	result := testSdkWithCc(t, `
 		sdk {
 			name: "mysdk",
-			device_supported: false,
 			host_supported: true,
 			native_shared_libs: ["sdkmember"],
 			compile_multilib: "64",
@@ -81,7 +80,6 @@ func TestSdkCompileMultilibOverride(t *testing.T) {
 
 		cc_library_shared {
 			name: "sdkmember",
-			device_supported: false,
 			host_supported: true,
 			srcs: ["Test.cpp"],
 			stl: "none",
@@ -96,14 +94,16 @@ func TestSdkCompileMultilibOverride(t *testing.T) {
 cc_prebuilt_library_shared {
     name: "mysdk_sdkmember@current",
     sdk_member_name: "sdkmember",
-    device_supported: false,
     host_supported: true,
     installable: false,
     stl: "none",
     compile_multilib: "64",
-    arch: {
-        x86_64: {
-            srcs: ["x86_64/lib/sdkmember.so"],
+    target: {
+        android_arm64: {
+            srcs: ["android/arm64/lib/sdkmember.so"],
+        },
+        linux_glibc_x86_64: {
+            srcs: ["linux_glibc/x86_64/lib/sdkmember.so"],
         },
     },
 }
@@ -111,31 +111,29 @@ cc_prebuilt_library_shared {
 cc_prebuilt_library_shared {
     name: "sdkmember",
     prefer: false,
-    device_supported: false,
     host_supported: true,
     stl: "none",
     compile_multilib: "64",
-    arch: {
-        x86_64: {
-            srcs: ["x86_64/lib/sdkmember.so"],
+    target: {
+        android_arm64: {
+            srcs: ["android/arm64/lib/sdkmember.so"],
+        },
+        linux_glibc_x86_64: {
+            srcs: ["linux_glibc/x86_64/lib/sdkmember.so"],
         },
     },
 }
 
 sdk_snapshot {
     name: "mysdk@current",
-    device_supported: false,
     host_supported: true,
     native_shared_libs: ["mysdk_sdkmember@current"],
-    target: {
-        linux_glibc: {
-            compile_multilib: "64",
-        },
-    },
+    compile_multilib: "64",
 }
 `),
 		checkAllCopyRules(`
-.intermediates/sdkmember/linux_glibc_x86_64_shared/sdkmember.so -> x86_64/lib/sdkmember.so
+.intermediates/sdkmember/android_arm64_armv8-a_shared/sdkmember.so -> android/arm64/lib/sdkmember.so
+.intermediates/sdkmember/linux_glibc_x86_64_shared/sdkmember.so -> linux_glibc/x86_64/lib/sdkmember.so
 `))
 }
 
@@ -1527,11 +1525,7 @@ module_exports_snapshot {
     device_supported: false,
     host_supported: true,
     native_static_libs: ["myexports_mynativelib@current"],
-    target: {
-        linux_glibc: {
-            compile_multilib: "64",
-        },
-    },
+    compile_multilib: "64",
 }`),
 		checkAllCopyRules(`
 include/Test.h -> include/include/Test.h
diff --git a/sdk/update.go b/sdk/update.go
index b8d73c63f..25d50d217 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -323,19 +323,37 @@ func (s *sdk) buildSnapshot(ctx android.ModuleContext, sdkVariants []*sdk) andro
 	// Add properties common to all os types.
 	s.addMemberPropertiesToPropertySet(builder, snapshotModule, commonDynamicMemberProperties)
 
+	// Optimize other per-variant properties, besides the dynamic member lists.
+	type variantProperties struct {
+		Compile_multilib string `android:"arch_variant"`
+	}
+	var variantPropertiesContainers []propertiesContainer
+	variantToProperties := make(map[*sdk]*variantProperties)
+	for _, sdkVariant := range sdkVariants {
+		props := &variantProperties{
+			Compile_multilib: sdkVariant.multilibUsages.String(),
+		}
+		variantPropertiesContainers = append(variantPropertiesContainers, &dynamicMemberPropertiesContainer{sdkVariant, props})
+		variantToProperties[sdkVariant] = props
+	}
+	commonVariantProperties := variantProperties{}
+	extractor = newCommonValueExtractor(commonVariantProperties)
+	extractCommonProperties(ctx, extractor, &commonVariantProperties, variantPropertiesContainers)
+	if commonVariantProperties.Compile_multilib != "" && commonVariantProperties.Compile_multilib != "both" {
+		// Compile_multilib defaults to both so only needs to be set when it's
+		// specified and not both.
+		snapshotModule.AddProperty("compile_multilib", commonVariantProperties.Compile_multilib)
+	}
+
 	// Iterate over the os types in a fixed order.
 	targetPropertySet := snapshotModule.AddPropertySet("target")
 	for _, osType := range s.getPossibleOsTypes() {
 		if sdkVariant, ok := osTypeToMemberProperties[osType]; ok {
 			osPropertySet := targetPropertySet.AddPropertySet(sdkVariant.Target().Os.Name)
 
-			// Compile_multilib defaults to both and must always be set to both on the
-			// device and so only needs to be set when targeted at the host and is neither
-			// unspecified or both.
-			multilib := sdkVariant.multilibUsages
-			if (osType.Class == android.Host || osType.Class == android.HostCross) &&
-				multilib != multilibNone && multilib != multilibBoth {
-				osPropertySet.AddProperty("compile_multilib", multilib.String())
+			variantProps := variantToProperties[sdkVariant]
+			if variantProps.Compile_multilib != "" && variantProps.Compile_multilib != "both" {
+				osPropertySet.AddProperty("compile_multilib", variantProps.Compile_multilib)
 			}
 
 			s.addMemberPropertiesToPropertySet(builder, osPropertySet, sdkVariant.dynamicMemberTypeListProperties)