AAPT2: Implement attribute compat versioning

This change defines some hardcoded rules to degrade
attributes in newer SDKs to specific older attributes.

An attribute with a degrade rule will generate a new XML for the API
in which the attribute resulting from the degradation was introduced.

Since API 22 (Lollipop MR1), attributes are correctly ignored and do
not need to be versioned. In XML files defined for APIs 22+, the
original and degraded attributes coexist in the same XML file.

One such example is paddingHorizontal, introduced in API 26.
paddingHorizontal degrades to paddingLeft and paddingRight, which
were both introduced in API 1.

Bug: 35763493
Test: make aapt2_tests
Change-Id: I4aa8755a9ee2c0cc5afdc55c3d30093fd3a47f3d

1 files changed, 15 insertions, 13 deletions

diff --git a/tools/aapt2/SdkConstants.cpp b/tools/aapt2/SdkConstants.cpp
index e8067143dc75..041cb4fa96cd 100644
--- a/tools/aapt2/SdkConstants.cpp
+++ b/tools/aapt2/SdkConstants.cpp
@@ -26,9 +26,9 @@ using android::StringPiece;
 namespace aapt {
 
 static const char* sDevelopmentSdkCodeName = "O";
-static int sDevelopmentSdkLevel = 26;
+static ApiVersion sDevelopmentSdkLevel = 26;
 
-static const std::vector<std::pair<uint16_t, size_t>> sAttrIdMap = {
+static const std::vector<std::pair<uint16_t, ApiVersion>> sAttrIdMap = {
     {0x021c, 1},
     {0x021d, 2},
     {0x0269, SDK_CUPCAKE},
@@ -48,26 +48,29 @@ static const std::vector<std::pair<uint16_t, size_t>> sAttrIdMap = {
     {0x03f1, SDK_KITKAT},
     {0x03f6, SDK_KITKAT_WATCH},
     {0x04ce, SDK_LOLLIPOP},
+    {0x04d8, SDK_LOLLIPOP_MR1},
+    {0x04f1, SDK_MARSHMALLOW},
+    {0x0527, SDK_NOUGAT},
+    {0x0530, SDK_NOUGAT_MR1},
+    {0x0568, SDK_O},
 };
 
-static bool less_entry_id(const std::pair<uint16_t, size_t>& p,
-                        uint16_t entryId) {
+static bool less_entry_id(const std::pair<uint16_t, ApiVersion>& p, uint16_t entryId) {
   return p.first < entryId;
 }
 
-size_t FindAttributeSdkLevel(const ResourceId& id) {
-  if (id.package_id() != 0x01 && id.type_id() != 0x01) {
+ApiVersion FindAttributeSdkLevel(const ResourceId& id) {
+  if (id.package_id() != 0x01 || id.type_id() != 0x01) {
     return 0;
   }
-  auto iter = std::lower_bound(sAttrIdMap.begin(), sAttrIdMap.end(),
-                               id.entry_id(), less_entry_id);
+  auto iter = std::lower_bound(sAttrIdMap.begin(), sAttrIdMap.end(), id.entry_id(), less_entry_id);
   if (iter == sAttrIdMap.end()) {
     return SDK_LOLLIPOP_MR1;
   }
   return iter->second;
 }
 
-static const std::unordered_map<std::string, size_t> sAttrMap = {
+static const std::unordered_map<std::string, ApiVersion> sAttrMap = {
     {"marqueeRepeatLimit", 2},
     {"windowNoDisplay", 3},
     {"backgroundDimEnabled", 3},
@@ -729,7 +732,7 @@ static const std::unordered_map<std::string, size_t> sAttrMap = {
     {"windowActivityTransitions", 21},
     {"colorEdgeEffect", 21}};
 
-size_t FindAttributeSdkLevel(const ResourceName& name) {
+ApiVersion FindAttributeSdkLevel(const ResourceName& name) {
   if (name.package != "android" && name.type != ResourceType::kAttr) {
     return 0;
   }
@@ -741,9 +744,8 @@ size_t FindAttributeSdkLevel(const ResourceName& name) {
   return SDK_LOLLIPOP_MR1;
 }
 
-std::pair<StringPiece, int> GetDevelopmentSdkCodeNameAndVersion() {
-  return std::make_pair(StringPiece(sDevelopmentSdkCodeName),
-                        sDevelopmentSdkLevel);
+std::pair<StringPiece, ApiVersion> GetDevelopmentSdkCodeNameAndVersion() {
+  return std::make_pair(StringPiece(sDevelopmentSdkCodeName), sDevelopmentSdkLevel);
 }
 
 }  // namespace aapt