AAPT2: Allow compatible duplicate Attributes

If a resource XML file defines two compatible Attributes, they should
be merged without throwing an error. Ex:

<declare-styleable>
  <attr name="conflict" format="string" />
</declare-styleable>

<declare-styleable>
  <attr name="conflict" format="string|reference" />
</declare-styleable>

In this case, string|reference and string are the same, so these should
merge correctly.

Bug: 65699599
Test: make aapt2_tests
Test: make AaptBasicTest
Change-Id: I7b0f956d2332f7f0b458acd59ca0a606b2cfdf95

1 files changed, 7 insertions, 2 deletions

diff --git a/tools/aapt2/ResourceValues.h b/tools/aapt2/ResourceValues.h
index b2ec8bdd7c77..6371c4cbb7b5 100644
--- a/tools/aapt2/ResourceValues.h
+++ b/tools/aapt2/ResourceValues.h
@@ -300,10 +300,15 @@ struct Attribute : public BaseValue<Attribute> {
   int32_t max_int;
   std::vector<Symbol> symbols;
 
-  Attribute();
-  explicit Attribute(bool w, uint32_t t = 0u);
+  explicit Attribute(uint32_t t = 0u);
 
   bool Equals(const Value* value) const override;
+
+  // Returns true if this Attribute's format is compatible with the given Attribute. The basic
+  // rule is that TYPE_REFERENCE can be ignored for both of the Attributes, and TYPE_FLAGS and
+  // TYPE_ENUMS are never compatible.
+  bool IsCompatibleWith(const Attribute& attr) const;
+
   Attribute* Clone(StringPool* new_pool) const override;
   std::string MaskString() const;
   void Print(std::ostream* out) const override;