hiddenapi: Accept Unsupported/Sdk conflict

The hiddenapi tool currently doesn't accept a API being labeled as both
Unsupported, as well as part of the Sdk.

In order to enable migrations from UAU to Sdk with flags, this conflict
must be tolerated in the flag enabled case. UAU must remain for the
flag disabled case.

Test: Builds with API with @UAU and @SystemApi
Bug: 358250700
Change-Id: I70821a8c57ec06fe9fd9957da5f4a597a875b1ca

1 files changed, 29 insertions, 1 deletions

diff --git a/libartbase/base/hiddenapi_flags.h b/libartbase/base/hiddenapi_flags.h
index 9d0a18e78f..0d7938aca1 100644
--- a/libartbase/base/hiddenapi_flags.h
+++ b/libartbase/base/hiddenapi_flags.h
@@ -263,11 +263,37 @@ class ApiList {
   bool operator<(const ApiList& other) const { return dex_flags_ < other.dex_flags_; }
   bool operator>(const ApiList& other) const { return dex_flags_ > other.dex_flags_; }
 
+  // In order to correctly handle flagged changes from Unsupported to the Sdk, where both will be
+  // set when the flag is enabled, consider Sdk to take precedence over any form of unsupported.
+  // Note, this is not necessary in the inverse direction, because API flagging does not currently
+  // support API removal. Moving from the blocklist to unsupported is also a case we don't have to
+  // consider.
+  // If this is true, the conflict resolves to Value::kSdk.
+  static bool is_conflicting_flags_acceptable(Value x, Value y) {
+    const auto predicate_non_symmetric = [] (auto l, auto r) {
+      if (l != Value::kSdk) return false;
+      switch (r) {
+        case Value::kSdk:
+        case Value::kUnsupported:
+        case Value::kMaxTargetO:
+        case Value::kMaxTargetP:
+        case Value::kMaxTargetQ:
+        case Value::kMaxTargetR:
+        case Value::kMaxTargetS:
+          return true;
+        default:
+          return false;
+      }
+    };
+    return predicate_non_symmetric(x, y) || predicate_non_symmetric(y, x);
+  }
+
   // Returns true if combining this ApiList with `other` will succeed.
   bool CanCombineWith(const ApiList& other) const {
     const Value val1 = GetValue();
     const Value val2 = other.GetValue();
-    return (val1 == val2) || (val1 == Value::kInvalid) || (val2 == Value::kInvalid);
+    return (val1 == val2) || (val1 == Value::kInvalid) || (val2 == Value::kInvalid) ||
+           is_conflicting_flags_acceptable(val1, val2);
   }
 
   // Combine two ApiList instances.
@@ -285,6 +311,8 @@ class ApiList {
       return ApiList(val2, domain_apis);
     } else if (val2 == Value::kInvalid) {
       return ApiList(val1, domain_apis);
+    } else if (is_conflicting_flags_acceptable(val1, val2)) {
+      return ApiList(Value::kSdk, domain_apis);
     } else {
       LOG(FATAL) << "Invalid combination of values " << Dumpable(ApiList(val1))
           << " and " << Dumpable(ApiList(val2));