checkUnusedHals: use hidl metadata

Use libhidlmetadata to infer relationships between interfaces. For
example, if GNSS@2.0 is listed as "optional", but a manifest lists
GNSS@1.1 and 2.0 (because 2.0 inherits from 1.1), do not complain
about an unused 1.1 HAL.

Bug: 131717099
Test: drop GNSS 1.1 from matrix and `m check-vintf-all`

Change-Id: I1c0ef715bf64cacf99de590ed6627afa2b60f4b1
Merged-In: I1c0ef715bf64cacf99de590ed6627afa2b60f4b1
diff --git a/Android.bp b/Android.bp
index bfbd353..12ab161 100644
--- a/Android.bp
+++ b/Android.bp
@@ -63,6 +63,9 @@
         "libtinyxml2",
         "libz",
     ],
+    header_libs: [
+        "libhidlmetadata_headers",
+    ],
     export_include_dirs: ["include", "."],
     local_include_dirs: ["include/vintf"],
 
@@ -70,7 +73,9 @@
         "libbase",
         "libhidl-gen-utils",
     ],
-
+    export_header_lib_headers: [
+        "libhidlmetadata_headers",
+    ],
     target: {
         host: {
             srcs: [
@@ -113,6 +118,7 @@
     static_libs: [
         "libbase",
         "libhidl-gen-utils",
+        "libhidlmetadata",
         "liblog",
         "libvintf",
         "libutils",
diff --git a/HalManifest.cpp b/HalManifest.cpp
index bd0379a..9118773 100644
--- a/HalManifest.cpp
+++ b/HalManifest.cpp
@@ -227,15 +227,44 @@
     return ret;
 }
 
-std::set<std::string> HalManifest::checkUnusedHals(const CompatibilityMatrix& mat) const {
+std::set<std::string> HalManifest::checkUnusedHals(
+    const CompatibilityMatrix& mat, const std::vector<HidlInterfaceMetadata>& hidlMetadata) const {
+    std::multimap<std::string, std::string> childrenMap;
+    for (const auto& child : hidlMetadata) {
+        for (const auto& parent : child.inherited) {
+            childrenMap.emplace(parent, child.name);
+        }
+    }
+
     std::set<std::string> ret;
 
-    forEachInstance([&ret, &mat](const auto& manifestInstance) {
-        if (!mat.matchInstance(manifestInstance.format(), manifestInstance.package(),
-                               manifestInstance.version(), manifestInstance.interface(),
-                               manifestInstance.instance())) {
-            ret.insert(manifestInstance.description());
+    forEachInstance([&ret, &mat, &childrenMap](const auto& manifestInstance) {
+        if (mat.matchInstance(manifestInstance.format(), manifestInstance.package(),
+                              manifestInstance.version(), manifestInstance.interface(),
+                              manifestInstance.instance())) {
+            // manifestInstance exactly matches an instance in |mat|.
+            return true;
         }
+        // For HIDL instances, If foo@2.0 inherits from foo@1.0, manifest may contain both, but
+        // matrix may contain only 2.0 if 1.0 is considered deprecated. Hence, if manifestInstance
+        // is 1.0, check all its children in the matrix too.
+        // If there is at least one match, do not consider it unused.
+        if (manifestInstance.format() == HalFormat::HIDL) {
+            auto range =
+                childrenMap.equal_range(manifestInstance.getFqInstance().getFqName().string());
+            for (auto it = range.first; it != range.second; ++it) {
+                FQName fqName;
+                CHECK(fqName.setTo(it->second));
+                if (mat.matchInstance(manifestInstance.format(), fqName.package(),
+                                      fqName.getVersion(), fqName.name(),
+                                      manifestInstance.instance())) {
+                    return true;
+                }
+            }
+        }
+
+        // If no match is found, consider it unused.
+        ret.insert(manifestInstance.description());
         return true;
     });
 
diff --git a/VintfObject.cpp b/VintfObject.cpp
index 4f47622..320f97f 100644
--- a/VintfObject.cpp
+++ b/VintfObject.cpp
@@ -25,6 +25,7 @@
 #include <android-base/logging.h>
 #include <android-base/result.h>
 #include <android-base/strings.h>
+#include <hidl/metadata.h>
 
 #include "CompatibilityMatrix.h"
 #include "parse_string.h"
@@ -833,7 +834,8 @@
     return false;
 }
 
-android::base::Result<void> VintfObject::checkUnusedHals() {
+android::base::Result<void> VintfObject::checkUnusedHals(
+    const std::vector<HidlInterfaceMetadata>& hidlMetadata) {
     auto matrix = getFrameworkCompatibilityMatrix();
     if (matrix == nullptr) {
         return android::base::Error(-NAME_NOT_FOUND) << "Missing framework matrix.";
@@ -842,7 +844,7 @@
     if (manifest == nullptr) {
         return android::base::Error(-NAME_NOT_FOUND) << "Missing device manifest.";
     }
-    auto unused = manifest->checkUnusedHals(*matrix);
+    auto unused = manifest->checkUnusedHals(*matrix, hidlMetadata);
     if (!unused.empty()) {
         return android::base::Error()
                << "The following instances are in the device manifest but "
diff --git a/check_vintf.cpp b/check_vintf.cpp
index f2a239a..c2a20a1 100644
--- a/check_vintf.cpp
+++ b/check_vintf.cpp
@@ -26,6 +26,7 @@
 #include <android-base/parseint.h>
 #include <android-base/result.h>
 #include <android-base/strings.h>
+#include <hidl/metadata.h>
 #include <utils/Errors.h>
 #include <vintf/KernelConfigParser.h>
 #include <vintf/VintfObject.h>
@@ -380,7 +381,8 @@
     }
     auto targetFcm = deviceManifest->level();
     if (*hasFcmExt || (targetFcm != Level::UNSPECIFIED && targetFcm >= Level::R)) {
-        return vintfObject->checkUnusedHals();
+        auto hidlMetadata = HidlInterfaceMetadata::all();
+        return vintfObject->checkUnusedHals(hidlMetadata);
     }
     LOG(INFO) << "Skip checking unused HALs.";
     return {};
diff --git a/include/vintf/HalManifest.h b/include/vintf/HalManifest.h
index e7b2a0e..41298f0 100644
--- a/include/vintf/HalManifest.h
+++ b/include/vintf/HalManifest.h
@@ -24,6 +24,8 @@
 #include <string>
 #include <vector>
 
+#include <hidl/metadata.h>
+
 #include "CheckFlags.h"
 #include "FileSystem.h"
 #include "HalGroup.h"
@@ -175,7 +177,9 @@
     // required HAL.
     // That is, return empty list iff
     // (instance in manifest) => (instance in matrix).
-    std::set<std::string> checkUnusedHals(const CompatibilityMatrix& mat) const;
+    std::set<std::string> checkUnusedHals(
+        const CompatibilityMatrix& mat,
+        const std::vector<HidlInterfaceMetadata>& hidlMetadata) const;
 
     // Check that manifest has no entries.
     bool empty() const;
diff --git a/include/vintf/VintfObject.h b/include/vintf/VintfObject.h
index 900a90a..2a40271 100644
--- a/include/vintf/VintfObject.h
+++ b/include/vintf/VintfObject.h
@@ -21,6 +21,7 @@
 #include <optional>
 
 #include <android-base/result.h>
+#include <hidl/metadata.h>
 
 #include "CheckFlags.h"
 #include "CompatibilityMatrix.h"
@@ -213,7 +214,8 @@
      * - !result.ok() && result.error().code() != 0 if any error. Check
      *     result.error() for detailed message.
      */
-    android::base::Result<void> checkUnusedHals();
+    android::base::Result<void> checkUnusedHals(
+        const std::vector<HidlInterfaceMetadata>& hidlMetadata);
 
    private:
     std::unique_ptr<FileSystem> mFileSystem;
diff --git a/test/LibVintfTest.cpp b/test/LibVintfTest.cpp
index c22220b..fac2306 100644
--- a/test/LibVintfTest.cpp
+++ b/test/LibVintfTest.cpp
@@ -125,7 +125,7 @@
         return cm1->addAllXmlFilesAsOptional(cm2, e);
     }
     std::set<std::string> checkUnusedHals(const HalManifest& m, const CompatibilityMatrix& cm) {
-        return m.checkUnusedHals(cm);
+        return m.checkUnusedHals(cm, {});
     }
 
     std::map<std::string, HalInterface> testHalInterfaces() {