adb/base: fix adb push of Unicode filenames on Win32

ae5a6c06cdd9ae1a0a7cdc42711f0a5594e54dcd made adb push use
android::base::ReadFileToString() for small files, but that API did not
support UTF-8 filenames on Windows, until this fix which does the
following:

- Add android::base::{WideToUTF8,UTF8ToWide}() which are only available
  on Windows. The signatures are based on Chromium's APIs of the same
  name.

- Add the namespace android::base::utf8 which has versions of APIs that
  take UTF-8 strings. To use this, make sure your code is in a namespace
  and then do "using namespace android::base::utf8;". On Windows, this will
  make calls to open() call android::base::utf8::open(), and on other
  platforms, it will just call the regular ::open().

- Make ReadFileToString() and WriteStringToFile() use utf8::open() and
  utf8::unlink().

- Adapt unittests from Chromium.

- fastboot needs to link with libcutils because it links with libbase
  which depends on libcutils for gettid() for logging.

Change-Id: I1aeac40ff358331d7a1ff457ce894bfb17863904
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>

1 files changed, 170 insertions, 0 deletions

diff --git a/base/utf8.cpp b/base/utf8.cpp
new file mode 100755
index 000000000..62a118f56
--- /dev/null
+++ b/base/utf8.cpp
@@ -0,0 +1,170 @@
+/*
+ * 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 <windows.h>
+
+#include "base/utf8.h"
+
+#include <fcntl.h>
+
+#include <string>
+
+#include "base/logging.h"
+
+namespace android {
+namespace base {
+
+bool WideToUTF8(const wchar_t* utf16, const size_t size, std::string* utf8) {
+  utf8->clear();
+
+  if (size == 0) {
+    return true;
+  }
+
+  // TODO: Consider using std::wstring_convert once libcxx is supported on
+  // Windows.
+
+  // Only Vista or later has this flag that causes WideCharToMultiByte() to
+  // return an error on invalid characters.
+  const DWORD flags =
+#if (WINVER >= 0x0600)
+    WC_ERR_INVALID_CHARS;
+#else
+    0;
+#endif
+
+  const int chars_required = WideCharToMultiByte(CP_UTF8, flags, utf16, size,
+                                                 NULL, 0, NULL, NULL);
+  if (chars_required <= 0) {
+    return false;
+  }
+
+  // This could potentially throw a std::bad_alloc exception.
+  utf8->resize(chars_required);
+
+  const int result = WideCharToMultiByte(CP_UTF8, flags, utf16, size,
+                                         &(*utf8)[0], chars_required, NULL,
+                                         NULL);
+  if (result != chars_required) {
+    CHECK_LE(result, chars_required) << "WideCharToMultiByte wrote " << result
+        << " chars to buffer of " << chars_required << " chars";
+    utf8->clear();
+    return false;
+  }
+
+  return true;
+}
+
+bool WideToUTF8(const wchar_t* utf16, std::string* utf8) {
+  // Compute string length of NULL-terminated string with wcslen().
+  return WideToUTF8(utf16, wcslen(utf16), utf8);
+}
+
+bool WideToUTF8(const std::wstring& utf16, std::string* utf8) {
+  // Use the stored length of the string which allows embedded NULL characters
+  // to be converted.
+  return WideToUTF8(utf16.c_str(), utf16.length(), utf8);
+}
+
+// Internal helper function that takes MultiByteToWideChar() flags.
+static bool _UTF8ToWideWithFlags(const char* utf8, const size_t size,
+                                 std::wstring* utf16, const DWORD flags) {
+  utf16->clear();
+
+  if (size == 0) {
+    return true;
+  }
+
+  // TODO: Consider using std::wstring_convert once libcxx is supported on
+  // Windows.
+  const int chars_required = MultiByteToWideChar(CP_UTF8, flags, utf8, size,
+                                                 NULL, 0);
+  if (chars_required <= 0) {
+    return false;
+  }
+
+  // This could potentially throw a std::bad_alloc exception.
+  utf16->resize(chars_required);
+
+  const int result = MultiByteToWideChar(CP_UTF8, flags, utf8, size,
+                                         &(*utf16)[0], chars_required);
+  if (result != chars_required) {
+    CHECK_LE(result, chars_required) << "MultiByteToWideChar wrote " << result
+        << " chars to buffer of " << chars_required << " chars";
+    utf16->clear();
+    return false;
+  }
+
+  return true;
+}
+
+bool UTF8ToWide(const char* utf8, const size_t size, std::wstring* utf16) {
+  // If strictly interpreting as UTF-8 succeeds, return success.
+  if (_UTF8ToWideWithFlags(utf8, size, utf16, MB_ERR_INVALID_CHARS)) {
+    return true;
+  }
+
+  // Fallback to non-strict interpretation, allowing invalid characters and
+  // converting as best as possible, and return false to signify a problem.
+  (void)_UTF8ToWideWithFlags(utf8, size, utf16, 0);
+  return false;
+}
+
+bool UTF8ToWide(const char* utf8, std::wstring* utf16) {
+  // Compute string length of NULL-terminated string with strlen().
+  return UTF8ToWide(utf8, strlen(utf8), utf16);
+}
+
+bool UTF8ToWide(const std::string& utf8, std::wstring* utf16) {
+  // Use the stored length of the string which allows embedded NULL characters
+  // to be converted.
+  return UTF8ToWide(utf8.c_str(), utf8.length(), utf16);
+}
+
+// Versions of standard library APIs that support UTF-8 strings.
+namespace utf8 {
+
+int open(const char* name, int flags, ...) {
+  std::wstring name_utf16;
+  if (!UTF8ToWide(name, &name_utf16)) {
+    errno = EINVAL;
+    return -1;
+  }
+
+  int mode = 0;
+  if ((flags & O_CREAT) != 0) {
+    va_list args;
+    va_start(args, flags);
+    mode = va_arg(args, int);
+    va_end(args);
+  }
+
+  return _wopen(name_utf16.c_str(), flags, mode);
+}
+
+int unlink(const char* name) {
+  std::wstring name_utf16;
+  if (!UTF8ToWide(name, &name_utf16)) {
+    errno = EINVAL;
+    return -1;
+  }
+
+  return _wunlink(name_utf16.c_str());
+}
+
+}  // namespace utf8
+}  // namespace base
+}  // namespace android