always_allow_unfrozen

Add a way to allow unfrozen interfaces, even
when RELEASE_AIDL_USE_UNFROZEN is set. This
will avoid the build check and behavior changes,
but there would still be an associated failure
in vts_treble_vintf_vendor_test. Still, this
is requested by some partners and teams to ease
the development process.

Bug: 317387425
Test: added in CL (as soong build test)
Test: libaidlmetadata_test
Change-Id: I85532c719972cc971e7a595f118ba4acc9b24ba9

13 files changed, 163 insertions, 15 deletions

diff --git a/build/Android.bp b/build/Android.bp
index 836a7763..c5b32177 100644
--- a/build/Android.bp
+++ b/build/Android.bp
@@ -390,6 +390,36 @@ aidl_interface {
     ],
 }
 
+aidl_interface {
+    name: "tests-unfrozen-vendor",
+    owner: "google",
+    local_include_dir: "tests_unfrozen_vendor",
+    srcs: ["tests_unfrozen_vendor/vendor/IFoo.aidl"],
+    vendor_available: true,
+    backend: {
+        rust: {
+            enabled: true,
+        },
+    },
+    frozen: false,
+    always_use_unfrozen: true,
+    versions_with_info: [
+        {
+            version: "1",
+            imports: [],
+        },
+    ],
+
+}
+
+cc_library {
+    name: "build_test_aidl_always_use_unfrozen",
+    srcs: ["test_unfrozen_iface.cpp"],
+    shared_libs: [
+        "tests-unfrozen-vendor-V2-cpp",
+    ],
+}
+
 // These test that a parcel imported from A->B->C will have the required dependencies to link in
 // all backends (C++ backends need to link direclty against the constructor of the parcelable
 // in order to work)
diff --git a/build/aidl_api/tests-unfrozen-vendor/1/.hash b/build/aidl_api/tests-unfrozen-vendor/1/.hash
new file mode 100644
index 00000000..f948d9ab
--- /dev/null
+++ b/build/aidl_api/tests-unfrozen-vendor/1/.hash
@@ -0,0 +1 @@
+4c1abd625626228b3aa4a015e3745cd08752ddb6
diff --git a/build/aidl_api/tests-unfrozen-vendor/1/vendor/IFoo.aidl b/build/aidl_api/tests-unfrozen-vendor/1/vendor/IFoo.aidl
new file mode 100644
index 00000000..74eaf385
--- /dev/null
+++ b/build/aidl_api/tests-unfrozen-vendor/1/vendor/IFoo.aidl
@@ -0,0 +1,22 @@
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package vendor;
+interface IFoo {
+  void foo();
+}
diff --git a/build/aidl_api/tests-unfrozen-vendor/current/vendor/IFoo.aidl b/build/aidl_api/tests-unfrozen-vendor/current/vendor/IFoo.aidl
new file mode 100644
index 00000000..9a014420
--- /dev/null
+++ b/build/aidl_api/tests-unfrozen-vendor/current/vendor/IFoo.aidl
@@ -0,0 +1,23 @@
+///////////////////////////////////////////////////////////////////////////////
+// THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
+///////////////////////////////////////////////////////////////////////////////
+
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
+//
+// You must not make a backward incompatible change to any AIDL file built
+// with the aidl_interface module type with versions property set. The module
+// type is used to build AIDL files in a way that they can be used across
+// independently updatable components of the system. If a device is shipped
+// with such a backward incompatible change, it has a high risk of breaking
+// later when a module using the interface is updated, e.g., Mainline modules.
+
+package vendor;
+interface IFoo {
+  void foo();
+  void bar();
+}
diff --git a/build/aidl_gen_rule.go b/build/aidl_gen_rule.go
index ae329509..b9890e34 100644
--- a/build/aidl_gen_rule.go
+++ b/build/aidl_gen_rule.go
@@ -92,6 +92,7 @@ type aidlGenProperties struct {
 	RequireFrozenReason string
 	Visibility          []string
 	Flags               []string
+	UseUnfrozen         bool
 }
 
 type aidlGenRule struct {
@@ -232,23 +233,10 @@ func (g *aidlGenRule) generateBuildActionsForSingleAidl(ctx android.ModuleContex
 	}
 	optionalFlags = append(optionalFlags, wrap("-p", g.deps.preprocessed.Strings(), "")...)
 
-	unfrozen_override := ctx.Config().Getenv("AIDL_USE_UNFROZEN_OVERRIDE")
-	var use_unfrozen bool
-	if unfrozen_override != "" {
-		if unfrozen_override == "true" {
-			use_unfrozen = true
-		} else if unfrozen_override == "false" {
-			use_unfrozen = false
-		} else {
-			ctx.PropertyErrorf("AIDL_USE_UNFROZEN_OVERRIDE has unexpected value of \"%s\". Should be \"true\" or \"false\".", unfrozen_override)
-		}
-	} else {
-		use_unfrozen = ctx.DeviceConfig().Release_aidl_use_unfrozen()
-	}
 	// If this is an unfrozen version of a previously frozen interface, we want (1) the location
 	// of the previously frozen source and (2) the previously frozen hash so the generated
 	// library can behave like both versions at run time.
-	if !use_unfrozen && previousVersion != "" &&
+	if !g.properties.UseUnfrozen && previousVersion != "" &&
 		!proptools.Bool(g.properties.Unstable) && g.hashFile == nil {
 		apiDirPath := android.ExistentPathForSource(ctx, previousApiDir)
 		if apiDirPath.Valid() {
diff --git a/build/aidl_interface.go b/build/aidl_interface.go
index db476d03..9b3affa7 100644
--- a/build/aidl_interface.go
+++ b/build/aidl_interface.go
@@ -334,6 +334,17 @@ type aidlInterfaceProperties struct {
 	// List of .aidl files which compose this interface.
 	Srcs []string `android:"path"`
 
+	// Normally, in release configurations, such as next, unfrozen AIDL
+	// interfaces may be disabled. However, for some partners developing
+	// on Android, they may prefer to use the release configuration
+	// while making a small amount of changes for development. In this
+	// case, the VTS test vts_treble_vintf_vendor_test would still fail.
+	// However, the build would be unblocked.
+	//
+	// Note: this will not work for AOSP android.* interfaces because they
+	// will not be available in the compatibility matrix.
+	Always_use_unfrozen *bool
+
 	// List of aidl_interface modules that this uses. If one of your AIDL interfaces uses an
 	// interface or parcelable from another aidl_interface, you should put its name here.
 	// It could be an aidl_interface solely or with version(such as -V1)
@@ -490,6 +501,31 @@ func (i *aidlInterface) shouldGenerateRustBackend() bool {
 	return i.properties.Backend.Rust.Enabled != nil && *i.properties.Backend.Rust.Enabled
 }
 
+func (i *aidlInterface) useUnfrozen(ctx android.EarlyModuleContext) bool {
+	var use_unfrozen bool
+
+	unfrozen_override := ctx.Config().Getenv("AIDL_USE_UNFROZEN_OVERRIDE")
+	if unfrozen_override != "" {
+		if unfrozen_override == "true" {
+			use_unfrozen = true
+		} else if unfrozen_override == "false" {
+			use_unfrozen = false
+		} else {
+			ctx.PropertyErrorf("AIDL_USE_UNFROZEN_OVERRIDE has unexpected value of \"%s\". Should be \"true\" or \"false\".", unfrozen_override)
+		}
+	} else {
+		use_unfrozen = ctx.DeviceConfig().Release_aidl_use_unfrozen()
+	}
+
+	// could check this earlier and return, but make sure we always verify
+	// environmental variables
+	if proptools.Bool(i.properties.Always_use_unfrozen) {
+		use_unfrozen = true
+	}
+
+	return use_unfrozen
+}
+
 func (i *aidlInterface) minSdkVersion(lang string) *string {
 	var ver *string
 	switch lang {
diff --git a/build/aidl_interface_backends.go b/build/aidl_interface_backends.go
index a7653d68..8f515aa7 100644
--- a/build/aidl_interface_backends.go
+++ b/build/aidl_interface_backends.go
@@ -94,6 +94,7 @@ func addCppLibrary(mctx android.DefaultableHookContext, i *aidlInterface, versio
 		NotFrozen:           notFrozen,
 		RequireFrozenReason: requireFrozenReason,
 		Flags:               i.flagsForAidlGenRule(version),
+		UseUnfrozen:         i.useUnfrozen(mctx),
 	},
 	)
 
@@ -237,6 +238,7 @@ func addCppAnalyzerLibrary(mctx android.DefaultableHookContext, i *aidlInterface
 		NotFrozen:           notFrozen,
 		RequireFrozenReason: requireFrozenReason,
 		Flags:               i.flagsForAidlGenRule(version),
+		UseUnfrozen:         i.useUnfrozen(mctx),
 	})
 
 	importExportDependencies := []string{}
@@ -337,6 +339,7 @@ func addJavaLibrary(mctx android.DefaultableHookContext, i *aidlInterface, versi
 		NotFrozen:           notFrozen,
 		RequireFrozenReason: requireFrozenReason,
 		Flags:               i.flagsForAidlGenRule(version),
+		UseUnfrozen:         i.useUnfrozen(mctx),
 	})
 
 	mctx.CreateModule(aidlImplementationGeneratorFactory, &nameProperties{
@@ -392,6 +395,7 @@ func addRustLibrary(mctx android.DefaultableHookContext, i *aidlInterface, versi
 		NotFrozen:           notFrozen,
 		RequireFrozenReason: requireFrozenReason,
 		Flags:               i.flagsForAidlGenRule(version),
+		UseUnfrozen:         i.useUnfrozen(mctx),
 	})
 
 	versionedRustName := fixRustName(i.versionedName(version))
diff --git a/build/aidl_interface_metadata_singleton.go b/build/aidl_interface_metadata_singleton.go
index ef3af3c8..cab183a3 100644
--- a/build/aidl_interface_metadata_singleton.go
+++ b/build/aidl_interface_metadata_singleton.go
@@ -33,11 +33,12 @@ var (
 			`echo "\"types\": [${types}]," && ` +
 			`echo "\"hashes\": [${hashes}]," && ` +
 			`echo "\"has_development\": ${has_development}," && ` +
+			`echo "\"use_unfrozen\": ${use_unfrozen}," && ` +
 			`echo "\"versions\": [${versions}]" && ` +
 			`echo '}' ` +
 			`;} >> ${out}`,
 		Description: "AIDL metadata: ${out}",
-	}, "name", "stability", "types", "hashes", "has_development", "versions")
+	}, "name", "stability", "types", "hashes", "has_development", "use_unfrozen", "versions")
 
 	joinJsonObjectsToArrayRule = pctx.StaticRule("joinJsonObjectsToArrayRule", blueprint.RuleParams{
 		Rspfile:        "$out.rsp",
@@ -84,6 +85,7 @@ func (m *aidlInterfacesMetadataSingleton) GenerateAndroidBuildActions(ctx androi
 		ComputedTypes  []string
 		HashFiles      []string
 		HasDevelopment android.WritablePath
+		UseUnfrozen    bool
 		Versions       []string
 	}
 
@@ -100,6 +102,7 @@ func (m *aidlInterfacesMetadataSingleton) GenerateAndroidBuildActions(ctx androi
 			info.Stability = proptools.StringDefault(t.properties.Stability, "")
 			info.ComputedTypes = t.computedTypes
 			info.Versions = t.getVersions()
+			info.UseUnfrozen = t.useUnfrozen(ctx)
 			moduleInfos[t.ModuleBase.Name()] = info
 		case *aidlGenRule:
 			info := moduleInfos[t.properties.BaseName]
@@ -138,6 +141,11 @@ func (m *aidlInterfacesMetadataSingleton) GenerateAndroidBuildActions(ctx androi
 				")\" = \"1\" ]; then echo true; else echo false; fi)"
 		}
 
+		useUnfrozenValue := "false"
+		if info.UseUnfrozen {
+			useUnfrozenValue = "true"
+		}
+
 		ctx.Build(pctx, android.BuildParams{
 			Rule:      aidlMetadataRule,
 			Implicits: implicits,
@@ -149,6 +157,7 @@ func (m *aidlInterfacesMetadataSingleton) GenerateAndroidBuildActions(ctx androi
 				"types":           strings.Join(wrap(`\"`, info.ComputedTypes, `\"`), ", "),
 				"hashes":          readHashes,
 				"has_development": hasDevelopmentValue,
+				"use_unfrozen":    useUnfrozenValue,
 				"versions":        strings.Join(info.Versions, ", "),
 			},
 		})
diff --git a/build/test_unfrozen_iface.cpp b/build/test_unfrozen_iface.cpp
new file mode 100644
index 00000000..a0b313c9
--- /dev/null
+++ b/build/test_unfrozen_iface.cpp
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vendor/IFoo.h>
+
+static_assert(vendor::IFoo::VERSION == 2, "version must always be 2");
diff --git a/build/tests_unfrozen_vendor/vendor/IFoo.aidl b/build/tests_unfrozen_vendor/vendor/IFoo.aidl
new file mode 100644
index 00000000..48539408
--- /dev/null
+++ b/build/tests_unfrozen_vendor/vendor/IFoo.aidl
@@ -0,0 +1,6 @@
+package vendor;
+
+interface IFoo {
+    void foo(); // V1
+    void bar(); // V2 ** UNFROZEN **
+}
diff --git a/metadata/include/aidl/metadata.h b/metadata/include/aidl/metadata.h
index 09c60ba3..fe602c4b 100644
--- a/metadata/include/aidl/metadata.h
+++ b/metadata/include/aidl/metadata.h
@@ -37,6 +37,10 @@ struct AidlInterfaceMetadata {
   // true if the interface is different from the last frozen version
   bool has_development;
 
+  // true if the unfrozen interface is allowed to be used at runtime
+  // in this build configuration
+  bool use_unfrozen;
+
   // list of all frozen versions
   std::vector<size_t> versions;
 
diff --git a/metadata/parser.cpp b/metadata/parser.cpp
index 646a77b4..e457e937 100644
--- a/metadata/parser.cpp
+++ b/metadata/parser.cpp
@@ -57,6 +57,7 @@ int main(int argc, char** argv) {
     }
     std::cout << "}," << std::endl;
     std::cout << entry["has_development"].asString() << "," << std::endl;
+    std::cout << entry["use_unfrozen"].asString() << "," << std::endl;
     std::cout << "std::vector<size_t>{" << std::endl;
     for (const Json::Value& intf : entry["versions"]) {
       std::cout << intf.asString() << "," << std::endl;
diff --git a/metadata/test.cpp b/metadata/test.cpp
index 7d7d3313..4df5082e 100644
--- a/metadata/test.cpp
+++ b/metadata/test.cpp
@@ -55,3 +55,8 @@ TEST(AidlMetadata, HasTestInstancesNoDevelopment) {
   EXPECT_THAT(info->versions, ElementsAre(1));
   EXPECT_EQ(info->has_development, false);
 }
+
+TEST(AidlMetadata, UseUnfrozen) {
+  const auto& info = metadataForModule("tests-unfrozen-vendor");
+  EXPECT_TRUE(info->use_unfrozen);
+}