Add system_ext support to build_prop module

As some partitions have build.prop under etc/, this change adds
relative_install_path property to build_prop module. Also this change
adds system_ext related Soong variables and system_ext support in
gen_build_prop.py.

Bug: 322090587
Test: build and compare system_ext/etc/build.prop
Change-Id: I416662b8bae09383af0cdd3d8444a5c300006b7b

Android.bp

@@ -141,3 +141,12 @@ build_prop {
         "//packages/modules/Virtualization/microdroid",
     ],
 }
+
+build_prop {
+    name: "system_ext-build.prop",
+    stem: "build.prop",
+    system_ext_specific: true,
+    product_config: ":product_config",
+    relative_install_path: "etc", // system_ext/etc/build.prop
+    visibility: ["//visibility:private"],
+}

android/build_prop.go

@@ -37,6 +37,9 @@ type buildPropProperties struct {
 
 	// Path to a JSON file containing product configs.
 	Product_config *string `android:"path"`
+
+	// Optional subdirectory under which this file is installed into
+	Relative_install_path *string
 }
 
 type buildPropModule struct {
@@ -56,6 +59,8 @@ func (p *buildPropModule) propFiles(ctx ModuleContext) Paths {
 	partition := p.PartitionTag(ctx.DeviceConfig())
 	if partition == "system" {
 		return ctx.Config().SystemPropFiles(ctx)
+	} else if partition == "system_ext" {
+		return ctx.Config().SystemExtPropFiles(ctx)
 	}
 	return nil
 }
@@ -84,8 +89,8 @@ func (p *buildPropModule) GenerateAndroidBuildActions(ctx ModuleContext) {
 	}
 
 	partition := p.PartitionTag(ctx.DeviceConfig())
-	if partition != "system" {
+	if partition != "system" && partition != "system_ext" {
-		ctx.PropertyErrorf("partition", "unsupported partition %q: only \"system\" is supported", partition)
+		ctx.PropertyErrorf("partition", "unsupported partition %q: only \"system\" and \"system_ext\" are supported", partition)
 		return
 	}
 
@@ -134,7 +139,7 @@ func (p *buildPropModule) GenerateAndroidBuildActions(ctx ModuleContext) {
 
 	rule.Build(ctx.ModuleName(), "generating build.prop")
 
-	p.installPath = PathForModuleInstall(ctx)
+	p.installPath = PathForModuleInstall(ctx, proptools.String(p.properties.Relative_install_path))
 	ctx.InstallFile(p.installPath, p.stem(), p.outputFilePath)
 
 	ctx.SetOutputFiles(Paths{p.outputFilePath}, "")

android/config.go

@@ -2110,6 +2110,10 @@ func (c *config) SystemPropFiles(ctx PathContext) Paths {
 	return PathsForSource(ctx, c.productVariables.SystemPropFiles)
 }
 
+func (c *config) SystemExtPropFiles(ctx PathContext) Paths {
+	return PathsForSource(ctx, c.productVariables.SystemExtPropFiles)
+}
+
 func (c *config) EnableUffdGc() string {
 	return String(c.productVariables.EnableUffdGc)
 }

android/variable.go

@@ -534,6 +534,7 @@ type ProductVariables struct {
 	ArtTargetIncludeDebugBuild *bool `json:",omitempty"`
 
 	SystemPropFiles    []string `json:",omitempty"`
+	SystemExtPropFiles []string `json:",omitempty"`
 
 	EnableUffdGc *string `json:",omitempty"`
 }

scripts/gen_build_prop.py

@@ -129,16 +129,16 @@ def generate_common_build_props(args):
     print(f"ro.product.{partition}.name={config['DeviceProduct']}")
 
   if partition != "system":
-    if config["ModelForAttestation"]:
+    if config["ProductModelForAttestation"]:
-        print(f"ro.product.model_for_attestation={config['ModelForAttestation']}")
+        print(f"ro.product.model_for_attestation={config['ProductModelForAttestation']}")
-    if config["BrandForAttestation"]:
+    if config["ProductBrandForAttestation"]:
-        print(f"ro.product.brand_for_attestation={config['BrandForAttestation']}")
+        print(f"ro.product.brand_for_attestation={config['ProductBrandForAttestation']}")
-    if config["NameForAttestation"]:
+    if config["ProductNameForAttestation"]:
-        print(f"ro.product.name_for_attestation={config['NameForAttestation']}")
+        print(f"ro.product.name_for_attestation={config['ProductNameForAttestation']}")
-    if config["DeviceForAttestation"]:
+    if config["ProductDeviceForAttestation"]:
-        print(f"ro.product.device_for_attestation={config['DeviceForAttestation']}")
+        print(f"ro.product.device_for_attestation={config['ProductDeviceForAttestation']}")
-    if config["ManufacturerForAttestation"]:
+    if config["ProductManufacturerForAttestation"]:
-        print(f"ro.product.manufacturer_for_attestation={config['ManufacturerForAttestation']}")
+        print(f"ro.product.manufacturer_for_attestation={config['ProductManufacturerForAttestation']}")
 
   if config["ZygoteForce64"]:
     if partition == "vendor":
@@ -511,6 +511,15 @@ def build_system_prop(args):
 
   build_prop(args, gen_build_info=True, gen_common_build_props=True, variables=variables)
 
+def build_system_ext_prop(args):
+  config = args.config
+
+  # Order matters here. When there are duplicates, the last one wins.
+  # TODO(b/117892318): don't allow duplicates so that the ordering doesn't matter
+  variables = ["PRODUCT_SYSTEM_EXT_PROPERTIES"]
+
+  build_prop(args, gen_build_info=False, gen_common_build_props=True, variables=variables)
+
 '''
 def build_vendor_prop(args):
   config = args.config
@@ -563,6 +572,8 @@ def main():
   with contextlib.redirect_stdout(args.out):
     if args.partition == "system":
       build_system_prop(args)
+    elif args.partition == "system_ext":
+      build_system_ext_prop(args)
       '''
     elif args.partition == "vendor":
       build_vendor_prop(args)