AAPT2: Differentiate between Android and Java package names

Android package names are more strict (ASCII only) than Java package names.
Also fixed an issue where trailing underscores were disallowed in Android
package names.

Bug: 68468089
Test: make aapt2_tests
Change-Id: I1052e9e82b6617db6065ce448d9bf7972bb68d59

1 files changed, 34 insertions, 50 deletions

diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index a9b49d9d9904..e42145dff47e 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -24,6 +24,7 @@
 #include "androidfw/StringPiece.h"
 #include "utils/Unicode.h"
 
+#include "text/Unicode.h"
 #include "text/Utf8Iterator.h"
 #include "util/BigBuffer.h"
 #include "util/Maybe.h"
@@ -94,72 +95,55 @@ StringPiece TrimWhitespace(const StringPiece& str) {
   return StringPiece(start, end - start);
 }
 
-StringPiece::const_iterator FindNonAlphaNumericAndNotInSet(
-    const StringPiece& str, const StringPiece& allowed_chars) {
-  const auto end_iter = str.end();
-  for (auto iter = str.begin(); iter != end_iter; ++iter) {
-    char c = *iter;
-    if ((c >= u'a' && c <= u'z') || (c >= u'A' && c <= u'Z') ||
-        (c >= u'0' && c <= u'9')) {
-      continue;
-    }
-
-    bool match = false;
-    for (char i : allowed_chars) {
-      if (c == i) {
-        match = true;
-        break;
-      }
-    }
-
-    if (!match) {
-      return iter;
+static int IsJavaNameImpl(const StringPiece& str) {
+  int pieces = 0;
+  for (const StringPiece& piece : Tokenize(str, '.')) {
+    pieces++;
+    if (!text::IsJavaIdentifier(piece)) {
+      return -1;
     }
   }
-  return end_iter;
+  return pieces;
 }
 
 bool IsJavaClassName(const StringPiece& str) {
-  size_t pieces = 0;
-  for (const StringPiece& piece : Tokenize(str, '.')) {
-    pieces++;
-    if (piece.empty()) {
-      return false;
-    }
-
-    // Can't have starting or trailing $ character.
-    if (piece.data()[0] == '$' || piece.data()[piece.size() - 1] == '$') {
-      return false;
-    }
-
-    if (FindNonAlphaNumericAndNotInSet(piece, "$_") != piece.end()) {
-      return false;
-    }
-  }
-  return pieces >= 2;
+  return IsJavaNameImpl(str) >= 2;
 }
 
 bool IsJavaPackageName(const StringPiece& str) {
-  if (str.empty()) {
-    return false;
-  }
+  return IsJavaNameImpl(str) >= 1;
+}
 
-  size_t pieces = 0;
+static int IsAndroidNameImpl(const StringPiece& str) {
+  int pieces = 0;
   for (const StringPiece& piece : Tokenize(str, '.')) {
-    pieces++;
     if (piece.empty()) {
-      return false;
+      return -1;
     }
 
-    if (piece.data()[0] == '_' || piece.data()[piece.size() - 1] == '_') {
-      return false;
+    const char first_character = piece.data()[0];
+    if (!::isalpha(first_character)) {
+      return -1;
     }
 
-    if (FindNonAlphaNumericAndNotInSet(piece, "_") != piece.end()) {
-      return false;
+    bool valid = std::all_of(piece.begin() + 1, piece.end(), [](const char c) -> bool {
+      return ::isalnum(c) || c == '_';
+    });
+
+    if (!valid) {
+      return -1;
     }
+    pieces++;
   }
-  return pieces >= 1;
+  return pieces;
+}
+
+bool IsAndroidPackageName(const StringPiece& str) {
+  return IsAndroidNameImpl(str) > 1 || str == "android";
+}
+
+bool IsAndroidSplitName(const StringPiece& str) {
+  return IsAndroidNameImpl(str) > 0;
 }
 
 Maybe<std::string> GetFullyQualifiedClassName(const StringPiece& package,
@@ -176,7 +160,7 @@ Maybe<std::string> GetFullyQualifiedClassName(const StringPiece& package,
     return {};
   }
 
-  std::string result(package.data(), package.size());
+  std::string result = package.to_string();
   if (classname.data()[0] != '.') {
     result += '.';
   }