commit adb9e705092bbf03eebe0edaf687090266b64fcc
author Tom Sepez <tsepez@chromium.org> Tue Nov 27 18:43:10 2018 +0000
committer Chromium commit bot <commit-bot@chromium.org> Tue Nov 27 18:43:10 2018 +0000
tree f1538791ed216c543150fd0f6b0831fb967b92b3
parent b4c95fe2ded4695b9e5cf04fe2361c97424a50f5

Add Widestring::{To,From,Is}ASCII()

Straight widening/narrowing of 7-bit values with no funny business.
Precursor to converting some L"" literals containing only single-byte
values.

Change-Id: I811a87c92d806744dc4bfbe23eb6aa3e27057103
Reviewed-on: https://pdfium-review.googlesource.com/c/45792
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

core/fxcrt/widestring.cpp

diff --git a/core/fxcrt/widestring.cpp b/core/fxcrt/widestring.cpp
index 234270e..d699b42 100644
--- a/core/fxcrt/widestring.cpp
+++ b/core/fxcrt/widestring.cpp
@@ -635,7 +635,22 @@
   return m_pData ? m_pData->m_nRefs : 0;
 }
 
-// static
+bool WideString::IsASCII() const {
+  for (wchar_t wc : *this) {
+    if (wc <= 0 || wc > 127)  // Questionable signedness of wchar_t.
+      return false;
+  }
+  return true;
+}
+
+ByteString WideString::ToASCII() const {
+  ByteString result;
+  result.Reserve(GetLength());
+  for (wchar_t wc : *this)
+    result.InsertAtBack(static_cast<char>(wc & 0x7f));
+  return result;
+}
+
 ByteString WideString::ToDefANSI() const {
   int src_len = GetLength();
   int dest_len = FXSYS_WideCharToMultiByte(
@@ -864,6 +879,15 @@
 }
 
 // static
+WideString WideString::FromASCII(const ByteStringView& bstr) {
+  WideString result;
+  result.Reserve(bstr.GetLength());
+  for (char c : bstr)
+    result.InsertAtBack(static_cast<wchar_t>(c & 0x7f));
+  return result;
+}
+
+// static
 WideString WideString::FromDefANSI(const ByteStringView& bstr) {
   int src_len = bstr.GetLength();
   int dest_len = FXSYS_MultiByteToWideChar(