Move StringPiece to libandroidfw

libandroidfw needs to make use of StringPiece, so
move it to libandroidfw and update all code referencing
StringPiece in aapt2.

Test: make libandroidfw_tests libaapt2_tests
Change-Id: I68d7f0fc7c651b048d9d1f5e7971f10ef5349fa1
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index f034607..aa840e2 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -35,6 +35,8 @@
 #include <direct.h>
 #endif
 
+using android::StringPiece;
+
 namespace aapt {
 namespace file {
 
@@ -72,10 +74,9 @@
 
 inline static int MkdirImpl(const StringPiece& path) {
 #ifdef _WIN32
-  return _mkdir(path.ToString().c_str());
+  return _mkdir(path.to_string().c_str());
 #else
-  return mkdir(path.ToString().c_str(),
-               S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP);
+  return mkdir(path.to_string().c_str(), S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP);
 #endif
 }
 
@@ -184,7 +185,7 @@
                         std::vector<std::string>* out_arglist,
                         std::string* out_error) {
   std::string contents;
-  if (!android::base::ReadFileToString(path.ToString(), &contents)) {
+  if (!android::base::ReadFileToString(path.to_string(), &contents)) {
     if (out_error) *out_error = "failed to read argument-list file";
     return false;
   }
@@ -192,7 +193,7 @@
   for (StringPiece line : util::Tokenize(contents, ' ')) {
     line = util::TrimWhitespace(line);
     if (!line.empty()) {
-      out_arglist->push_back(line.ToString());
+      out_arglist->push_back(line.to_string());
     }
   }
   return true;
diff --git a/tools/aapt2/util/Files.h b/tools/aapt2/util/Files.h
index a157dbd..95c492f 100644
--- a/tools/aapt2/util/Files.h
+++ b/tools/aapt2/util/Files.h
@@ -22,12 +22,12 @@
 #include <vector>
 
 #include "android-base/macros.h"
+#include "androidfw/StringPiece.h"
 #include "utils/FileMap.h"
 
 #include "Diagnostics.h"
 #include "Maybe.h"
 #include "Source.h"
-#include "util/StringPiece.h"
 
 namespace aapt {
 namespace file {
@@ -50,51 +50,49 @@
   kSocket,
 };
 
-FileType GetFileType(const StringPiece& path);
+FileType GetFileType(const android::StringPiece& path);
 
 /*
  * Appends a path to `base`, separated by the directory separator.
  */
-void AppendPath(std::string* base, StringPiece part);
+void AppendPath(std::string* base, android::StringPiece part);
 
 /*
  * Makes all the directories in `path`. The last element in the path
  * is interpreted as a directory.
  */
-bool mkdirs(const StringPiece& path);
+bool mkdirs(const android::StringPiece& path);
 
 /**
  * Returns all but the last part of the path.
  */
-StringPiece GetStem(const StringPiece& path);
+android::StringPiece GetStem(const android::StringPiece& path);
 
 /**
  * Returns the last part of the path with extension.
  */
-StringPiece GetFilename(const StringPiece& path);
+android::StringPiece GetFilename(const android::StringPiece& path);
 
 /**
  * Returns the extension of the path. This is the entire string after
  * the first '.' of the last part of the path.
  */
-StringPiece GetExtension(const StringPiece& path);
+android::StringPiece GetExtension(const android::StringPiece& path);
 
 /**
  * Converts a package name (com.android.app) to a path: com/android/app
  */
-std::string PackageToPath(const StringPiece& package);
+std::string PackageToPath(const android::StringPiece& package);
 
 /**
  * Creates a FileMap for the file at path.
  */
-Maybe<android::FileMap> MmapPath(const StringPiece& path,
-                                 std::string* out_error);
+Maybe<android::FileMap> MmapPath(const android::StringPiece& path, std::string* out_error);
 
 /**
  * Reads the file at path and appends each line to the outArgList vector.
  */
-bool AppendArgsFromFile(const StringPiece& path,
-                        std::vector<std::string>* out_arglist,
+bool AppendArgsFromFile(const android::StringPiece& path, std::vector<std::string>* out_arglist,
                         std::string* out_error);
 
 /*
@@ -120,7 +118,7 @@
    * - Otherwise the full string is matched.
    * - match is not case-sensitive.
    */
-  bool SetPattern(const StringPiece& pattern);
+  bool SetPattern(const android::StringPiece& pattern);
 
   /**
    * Applies the filter, returning true for pass, false for fail.
diff --git a/tools/aapt2/util/StringPiece.h b/tools/aapt2/util/StringPiece.h
deleted file mode 100644
index 5144b1f..0000000
--- a/tools/aapt2/util/StringPiece.h
+++ /dev/null
@@ -1,298 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef AAPT_STRING_PIECE_H
-#define AAPT_STRING_PIECE_H
-
-#include <ostream>
-#include <string>
-
-#include "utils/JenkinsHash.h"
-#include "utils/String8.h"
-#include "utils/Unicode.h"
-
-namespace aapt {
-
-/**
- * Read only wrapper around basic C strings.
- * Prevents excessive copying.
- *
- * WARNING: When creating from std::basic_string<>, moving the original
- * std::basic_string<> will invalidate the data held in a BasicStringPiece<>.
- * BasicStringPiece<> should only be used transitively.
- */
-template <typename TChar>
-class BasicStringPiece {
- public:
-  using const_iterator = const TChar*;
-  using difference_type = size_t;
-
-  // End of string marker.
-  constexpr static const size_t npos = static_cast<size_t>(-1);
-
-  BasicStringPiece();
-  BasicStringPiece(const BasicStringPiece<TChar>& str);
-  BasicStringPiece(const std::basic_string<TChar>& str);  // NOLINT(implicit)
-  BasicStringPiece(const TChar* str);                     // NOLINT(implicit)
-  BasicStringPiece(const TChar* str, size_t len);
-
-  BasicStringPiece<TChar>& operator=(const BasicStringPiece<TChar>& rhs);
-  BasicStringPiece<TChar>& assign(const TChar* str, size_t len);
-
-  BasicStringPiece<TChar> substr(size_t start, size_t len = npos) const;
-  BasicStringPiece<TChar> substr(
-      BasicStringPiece<TChar>::const_iterator begin,
-      BasicStringPiece<TChar>::const_iterator end) const;
-
-  const TChar* data() const;
-  size_t length() const;
-  size_t size() const;
-  bool empty() const;
-  std::basic_string<TChar> ToString() const;
-
-  bool contains(const BasicStringPiece<TChar>& rhs) const;
-  int compare(const BasicStringPiece<TChar>& rhs) const;
-  bool operator<(const BasicStringPiece<TChar>& rhs) const;
-  bool operator>(const BasicStringPiece<TChar>& rhs) const;
-  bool operator==(const BasicStringPiece<TChar>& rhs) const;
-  bool operator!=(const BasicStringPiece<TChar>& rhs) const;
-
-  const_iterator begin() const;
-  const_iterator end() const;
-
- private:
-  const TChar* data_;
-  size_t length_;
-};
-
-using StringPiece = BasicStringPiece<char>;
-using StringPiece16 = BasicStringPiece<char16_t>;
-
-//
-// BasicStringPiece implementation.
-//
-
-template <typename TChar>
-constexpr const size_t BasicStringPiece<TChar>::npos;
-
-template <typename TChar>
-inline BasicStringPiece<TChar>::BasicStringPiece()
-    : data_(nullptr), length_(0) {}
-
-template <typename TChar>
-inline BasicStringPiece<TChar>::BasicStringPiece(
-    const BasicStringPiece<TChar>& str)
-    : data_(str.data_), length_(str.length_) {}
-
-template <typename TChar>
-inline BasicStringPiece<TChar>::BasicStringPiece(
-    const std::basic_string<TChar>& str)
-    : data_(str.data()), length_(str.length()) {}
-
-template <>
-inline BasicStringPiece<char>::BasicStringPiece(const char* str)
-    : data_(str), length_(str != nullptr ? strlen(str) : 0) {}
-
-template <>
-inline BasicStringPiece<char16_t>::BasicStringPiece(const char16_t* str)
-    : data_(str), length_(str != nullptr ? strlen16(str) : 0) {}
-
-template <typename TChar>
-inline BasicStringPiece<TChar>::BasicStringPiece(const TChar* str, size_t len)
-    : data_(str), length_(len) {}
-
-template <typename TChar>
-inline BasicStringPiece<TChar>& BasicStringPiece<TChar>::operator=(
-    const BasicStringPiece<TChar>& rhs) {
-  data_ = rhs.data_;
-  length_ = rhs.length_;
-  return *this;
-}
-
-template <typename TChar>
-inline BasicStringPiece<TChar>& BasicStringPiece<TChar>::assign(
-    const TChar* str, size_t len) {
-  data_ = str;
-  length_ = len;
-  return *this;
-}
-
-template <typename TChar>
-inline BasicStringPiece<TChar> BasicStringPiece<TChar>::substr(
-    size_t start, size_t len) const {
-  if (len == npos) {
-    len = length_ - start;
-  }
-
-  if (start > length_ || start + len > length_) {
-    return BasicStringPiece<TChar>();
-  }
-  return BasicStringPiece<TChar>(data_ + start, len);
-}
-
-template <typename TChar>
-inline BasicStringPiece<TChar> BasicStringPiece<TChar>::substr(
-    BasicStringPiece<TChar>::const_iterator begin,
-    BasicStringPiece<TChar>::const_iterator end) const {
-  return BasicStringPiece<TChar>(begin, end - begin);
-}
-
-template <typename TChar>
-inline const TChar* BasicStringPiece<TChar>::data() const {
-  return data_;
-}
-
-template <typename TChar>
-inline size_t BasicStringPiece<TChar>::length() const {
-  return length_;
-}
-
-template <typename TChar>
-inline size_t BasicStringPiece<TChar>::size() const {
-  return length_;
-}
-
-template <typename TChar>
-inline bool BasicStringPiece<TChar>::empty() const {
-  return length_ == 0;
-}
-
-template <typename TChar>
-inline std::basic_string<TChar> BasicStringPiece<TChar>::ToString() const {
-  return std::basic_string<TChar>(data_, length_);
-}
-
-template <>
-inline bool BasicStringPiece<char>::contains(
-    const BasicStringPiece<char>& rhs) const {
-  if (!data_ || !rhs.data_) {
-    return false;
-  }
-  if (rhs.length_ > length_) {
-    return false;
-  }
-  return strstr(data_, rhs.data_) != nullptr;
-}
-
-template <>
-inline int BasicStringPiece<char>::compare(
-    const BasicStringPiece<char>& rhs) const {
-  const char nullStr = '\0';
-  const char* b1 = data_ != nullptr ? data_ : &nullStr;
-  const char* e1 = b1 + length_;
-  const char* b2 = rhs.data_ != nullptr ? rhs.data_ : &nullStr;
-  const char* e2 = b2 + rhs.length_;
-
-  while (b1 < e1 && b2 < e2) {
-    const int d = static_cast<int>(*b1++) - static_cast<int>(*b2++);
-    if (d) {
-      return d;
-    }
-  }
-  return static_cast<int>(length_ - rhs.length_);
-}
-
-inline ::std::ostream& operator<<(::std::ostream& out,
-                                  const BasicStringPiece<char16_t>& str) {
-  android::String8 utf8(str.data(), str.size());
-  return out.write(utf8.string(), utf8.size());
-}
-
-template <>
-inline bool BasicStringPiece<char16_t>::contains(
-    const BasicStringPiece<char16_t>& rhs) const {
-  if (!data_ || !rhs.data_) {
-    return false;
-  }
-  if (rhs.length_ > length_) {
-    return false;
-  }
-  return strstr16(data_, rhs.data_) != nullptr;
-}
-
-template <>
-inline int BasicStringPiece<char16_t>::compare(
-    const BasicStringPiece<char16_t>& rhs) const {
-  const char16_t nullStr = u'\0';
-  const char16_t* b1 = data_ != nullptr ? data_ : &nullStr;
-  const char16_t* b2 = rhs.data_ != nullptr ? rhs.data_ : &nullStr;
-  return strzcmp16(b1, length_, b2, rhs.length_);
-}
-
-template <typename TChar>
-inline bool BasicStringPiece<TChar>::operator<(
-    const BasicStringPiece<TChar>& rhs) const {
-  return compare(rhs) < 0;
-}
-
-template <typename TChar>
-inline bool BasicStringPiece<TChar>::operator>(
-    const BasicStringPiece<TChar>& rhs) const {
-  return compare(rhs) > 0;
-}
-
-template <typename TChar>
-inline bool BasicStringPiece<TChar>::operator==(
-    const BasicStringPiece<TChar>& rhs) const {
-  return compare(rhs) == 0;
-}
-
-template <typename TChar>
-inline bool BasicStringPiece<TChar>::operator!=(
-    const BasicStringPiece<TChar>& rhs) const {
-  return compare(rhs) != 0;
-}
-
-template <typename TChar>
-inline typename BasicStringPiece<TChar>::const_iterator
-BasicStringPiece<TChar>::begin() const {
-  return data_;
-}
-
-template <typename TChar>
-inline typename BasicStringPiece<TChar>::const_iterator
-BasicStringPiece<TChar>::end() const {
-  return data_ + length_;
-}
-
-inline ::std::ostream& operator<<(::std::ostream& out,
-                                  const BasicStringPiece<char>& str) {
-  return out.write(str.data(), str.size());
-}
-
-}  // namespace aapt
-
-inline ::std::ostream& operator<<(::std::ostream& out,
-                                  const std::u16string& str) {
-  android::String8 utf8(str.data(), str.size());
-  return out.write(utf8.string(), utf8.size());
-}
-
-namespace std {
-
-template <typename TChar>
-struct hash<aapt::BasicStringPiece<TChar>> {
-  size_t operator()(const aapt::BasicStringPiece<TChar>& str) const {
-    uint32_t hashCode = android::JenkinsHashMixBytes(
-        0, reinterpret_cast<const uint8_t*>(str.data()),
-        sizeof(TChar) * str.size());
-    return static_cast<size_t>(hashCode);
-  }
-};
-
-}  // namespace std
-
-#endif  // AAPT_STRING_PIECE_H
diff --git a/tools/aapt2/util/StringPiece_test.cpp b/tools/aapt2/util/StringPiece_test.cpp
deleted file mode 100644
index 048961d..0000000
--- a/tools/aapt2/util/StringPiece_test.cpp
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "util/StringPiece.h"
-
-#include <algorithm>
-#include <string>
-#include <vector>
-
-#include "test/Test.h"
-
-namespace aapt {
-
-TEST(StringPieceTest, CompareNonNullTerminatedPiece) {
-  StringPiece a("hello world", 5);
-  StringPiece b("hello moon", 5);
-  EXPECT_EQ(a, b);
-
-  StringPiece16 a16(u"hello world", 5);
-  StringPiece16 b16(u"hello moon", 5);
-  EXPECT_EQ(a16, b16);
-}
-
-TEST(StringPieceTest, PiecesHaveCorrectSortOrder) {
-  std::string testing("testing");
-  std::string banana("banana");
-  std::string car("car");
-
-  EXPECT_TRUE(StringPiece(testing) > banana);
-  EXPECT_TRUE(StringPiece(testing) > car);
-  EXPECT_TRUE(StringPiece(banana) < testing);
-  EXPECT_TRUE(StringPiece(banana) < car);
-  EXPECT_TRUE(StringPiece(car) < testing);
-  EXPECT_TRUE(StringPiece(car) > banana);
-}
-
-TEST(StringPieceTest, PiecesHaveCorrectSortOrderUtf8) {
-  std::string testing("testing");
-  std::string banana("banana");
-  std::string car("car");
-
-  EXPECT_TRUE(StringPiece(testing) > banana);
-  EXPECT_TRUE(StringPiece(testing) > car);
-  EXPECT_TRUE(StringPiece(banana) < testing);
-  EXPECT_TRUE(StringPiece(banana) < car);
-  EXPECT_TRUE(StringPiece(car) < testing);
-  EXPECT_TRUE(StringPiece(car) > banana);
-}
-
-TEST(StringPieceTest, ContainsOtherStringPiece) {
-  StringPiece text("I am a leaf on the wind.");
-  StringPiece start_needle("I am");
-  StringPiece end_needle("wind.");
-  StringPiece middle_needle("leaf");
-  StringPiece empty_needle("");
-  StringPiece missing_needle("soar");
-  StringPiece long_needle("This string is longer than the text.");
-
-  EXPECT_TRUE(text.contains(start_needle));
-  EXPECT_TRUE(text.contains(end_needle));
-  EXPECT_TRUE(text.contains(middle_needle));
-  EXPECT_TRUE(text.contains(empty_needle));
-  EXPECT_FALSE(text.contains(missing_needle));
-  EXPECT_FALSE(text.contains(long_needle));
-
-  StringPiece16 text16(u"I am a leaf on the wind.");
-  StringPiece16 start_needle16(u"I am");
-  StringPiece16 end_needle16(u"wind.");
-  StringPiece16 middle_needle16(u"leaf");
-  StringPiece16 empty_needle16(u"");
-  StringPiece16 missing_needle16(u"soar");
-  StringPiece16 long_needle16(u"This string is longer than the text.");
-
-  EXPECT_TRUE(text16.contains(start_needle16));
-  EXPECT_TRUE(text16.contains(end_needle16));
-  EXPECT_TRUE(text16.contains(middle_needle16));
-  EXPECT_TRUE(text16.contains(empty_needle16));
-  EXPECT_FALSE(text16.contains(missing_needle16));
-  EXPECT_FALSE(text16.contains(long_needle16));
-}
-
-}  // namespace aapt
diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index d5c0c8a..cf22322 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -15,9 +15,6 @@
  */
 
 #include "util/Util.h"
-#include "util/BigBuffer.h"
-#include "util/Maybe.h"
-#include "util/StringPiece.h"
 
 #include <utils/Unicode.h>
 #include <algorithm>
@@ -25,6 +22,14 @@
 #include <string>
 #include <vector>
 
+#include "androidfw/StringPiece.h"
+
+#include "util/BigBuffer.h"
+#include "util/Maybe.h"
+
+using android::StringPiece;
+using android::StringPiece16;
+
 namespace aapt {
 namespace util {
 
@@ -36,7 +41,7 @@
   StringPiece::const_iterator current;
   do {
     current = std::find(start, end, sep);
-    parts.emplace_back(str.substr(start, current).ToString());
+    parts.emplace_back(str.substr(start, current).to_string());
     if (f) {
       std::string& part = parts.back();
       std::transform(part.begin(), part.end(), part.begin(), f);
@@ -162,7 +167,7 @@
   }
 
   if (util::IsJavaClassName(classname)) {
-    return classname.ToString();
+    return classname.to_string();
   }
 
   if (package.empty()) {
diff --git a/tools/aapt2/util/Util.h b/tools/aapt2/util/Util.h
index 05e9cc5..f8fa80e 100644
--- a/tools/aapt2/util/Util.h
+++ b/tools/aapt2/util/Util.h
@@ -24,11 +24,11 @@
 #include <vector>
 
 #include "androidfw/ResourceTypes.h"
+#include "androidfw/StringPiece.h"
 #include "utils/ByteOrder.h"
 
 #include "util/BigBuffer.h"
 #include "util/Maybe.h"
-#include "util/StringPiece.h"
 
 #ifdef _WIN32
 // TODO(adamlesinski): remove once http://b/32447322 is resolved.
@@ -44,26 +44,24 @@
 namespace aapt {
 namespace util {
 
-std::vector<std::string> Split(const StringPiece& str, char sep);
-std::vector<std::string> SplitAndLowercase(const StringPiece& str, char sep);
+std::vector<std::string> Split(const android::StringPiece& str, char sep);
+std::vector<std::string> SplitAndLowercase(const android::StringPiece& str, char sep);
 
 /**
  * Returns true if the string starts with prefix.
  */
-bool StartsWith(const StringPiece& str, const StringPiece& prefix);
+bool StartsWith(const android::StringPiece& str, const android::StringPiece& prefix);
 
 /**
  * Returns true if the string ends with suffix.
  */
-bool EndsWith(const StringPiece& str, const StringPiece& suffix);
+bool EndsWith(const android::StringPiece& str, const android::StringPiece& suffix);
 
 /**
  * Creates a new StringPiece16 that points to a substring
  * of the original string without leading or trailing whitespace.
  */
-StringPiece TrimWhitespace(const StringPiece& str);
-
-StringPiece TrimWhitespace(const StringPiece& str);
+android::StringPiece TrimWhitespace(const android::StringPiece& str);
 
 /**
  * UTF-16 isspace(). It basically checks for lower range characters that are
@@ -75,18 +73,18 @@
  * Returns an iterator to the first character that is not alpha-numeric and that
  * is not in the allowedChars set.
  */
-StringPiece::const_iterator FindNonAlphaNumericAndNotInSet(
-    const StringPiece& str, const StringPiece& allowed_chars);
+android::StringPiece::const_iterator FindNonAlphaNumericAndNotInSet(
+    const android::StringPiece& str, const android::StringPiece& allowed_chars);
 
 /**
  * Tests that the string is a valid Java class name.
  */
-bool IsJavaClassName(const StringPiece& str);
+bool IsJavaClassName(const android::StringPiece& str);
 
 /**
  * Tests that the string is a valid Java package name.
  */
-bool IsJavaPackageName(const StringPiece& str);
+bool IsJavaPackageName(const android::StringPiece& str);
 
 /**
  * Converts the class name to a fully qualified class name from the given
@@ -97,8 +95,8 @@
  * .a.b         --> package.a.b
  * asdf.adsf    --> asdf.adsf
  */
-Maybe<std::string> GetFullyQualifiedClassName(const StringPiece& package,
-                                              const StringPiece& class_name);
+Maybe<std::string> GetFullyQualifiedClassName(const android::StringPiece& package,
+                                              const android::StringPiece& class_name);
 
 /**
  * Makes a std::unique_ptr<> with the template parameter inferred by the
@@ -138,7 +136,7 @@
  * stored as UTF-8,
  * the conversion to UTF-16 happens within ResStringPool.
  */
-StringPiece16 GetString16(const android::ResStringPool& pool, size_t idx);
+android::StringPiece16 GetString16(const android::ResStringPool& pool, size_t idx);
 
 /**
  * Helper method to extract a UTF-8 string from a StringPool. If the string is
@@ -159,11 +157,11 @@
  * which will
  * break the string interpolation.
  */
-bool VerifyJavaStringFormat(const StringPiece& str);
+bool VerifyJavaStringFormat(const android::StringPiece& str);
 
 class StringBuilder {
  public:
-  StringBuilder& Append(const StringPiece& str);
+  StringBuilder& Append(const android::StringPiece& str);
   const std::string& ToString() const;
   const std::string& Error() const;
 
@@ -194,8 +192,8 @@
 /**
  * Converts a UTF8 string to a UTF16 string.
  */
-std::u16string Utf8ToUtf16(const StringPiece& utf8);
-std::string Utf16ToUtf8(const StringPiece16& utf16);
+std::u16string Utf8ToUtf16(const android::StringPiece& utf8);
+std::string Utf16ToUtf8(const android::StringPiece16& utf16);
 
 /**
  * Writes the entire BigBuffer to the output stream.
@@ -220,22 +218,22 @@
 
     iterator& operator++();
 
-    StringPiece operator*() { return token_; }
+    android::StringPiece operator*() { return token_; }
     bool operator==(const iterator& rhs) const;
     bool operator!=(const iterator& rhs) const;
 
    private:
     friend class Tokenizer;
 
-    iterator(StringPiece s, char sep, StringPiece tok, bool end);
+    iterator(android::StringPiece s, char sep, android::StringPiece tok, bool end);
 
-    StringPiece str_;
+    android::StringPiece str_;
     char separator_;
-    StringPiece token_;
+    android::StringPiece token_;
     bool end_;
   };
 
-  Tokenizer(StringPiece str, char sep);
+  Tokenizer(android::StringPiece str, char sep);
 
   iterator begin() { return begin_; }
 
@@ -246,9 +244,7 @@
   const iterator end_;
 };
 
-inline Tokenizer Tokenize(const StringPiece& str, char sep) {
-  return Tokenizer(str, sep);
-}
+inline Tokenizer Tokenize(const android::StringPiece& str, char sep) { return Tokenizer(str, sep); }
 
 inline uint16_t HostToDevice16(uint16_t value) { return htods(value); }
 
@@ -267,8 +263,8 @@
  *
  * Returns true if successful.
  */
-bool ExtractResFilePathParts(const StringPiece& path, StringPiece* out_prefix,
-                             StringPiece* out_entry, StringPiece* out_suffix);
+bool ExtractResFilePathParts(const android::StringPiece& path, android::StringPiece* out_prefix,
+                             android::StringPiece* out_entry, android::StringPiece* out_suffix);
 
 }  // namespace util
 
diff --git a/tools/aapt2/util/Util_test.cpp b/tools/aapt2/util/Util_test.cpp
index cac3de4..e49aee5 100644
--- a/tools/aapt2/util/Util_test.cpp
+++ b/tools/aapt2/util/Util_test.cpp
@@ -20,6 +20,8 @@
 
 #include "test/Test.h"
 
+using android::StringPiece;
+
 namespace aapt {
 
 TEST(UtilTest, TrimOnlyWhitespace) {