From 328c15189d661503fbf6561731e550064e6a5567 Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Fri, 28 Oct 2022 19:52:33 -0400
Subject: [PATCH] cmGeneratedFileStream: Add support for a temporary alternate
 encoding

The Ninja generator needs to be able to write some file content in a
different encoding than the rest of the file.  Add a method to do this.
---
 Source/cmGeneratedFileStream.cxx | 14 ++++++++++++++
 Source/cmGeneratedFileStream.h   |  6 ++++++
 2 files changed, 20 insertions(+)

diff --git a/Source/cmGeneratedFileStream.cxx b/Source/cmGeneratedFileStream.cxx
index 6212bbde2b..215c3c24be 100644
--- a/Source/cmGeneratedFileStream.cxx
+++ b/Source/cmGeneratedFileStream.cxx
@@ -239,6 +239,20 @@ void cmGeneratedFileStream::SetTempExt(std::string const& ext)
   this->TempExt = ext;
 }
 
+void cmGeneratedFileStream::WriteAltEncoding(std::string const& data,
+                                             Encoding encoding)
+{
+#ifndef CMAKE_BOOTSTRAP
+  std::locale prevLocale =
+    this->imbue(std::locale(this->getloc(), new codecvt(encoding)));
+  this->write(data.data(), data.size());
+  this->imbue(prevLocale);
+#else
+  static_cast<void>(encoding);
+  this->write(data.data(), data.size());
+#endif
+}
+
 void cmGeneratedFileStream::WriteRaw(std::string const& data)
 {
 #ifndef CMAKE_BOOTSTRAP
diff --git a/Source/cmGeneratedFileStream.h b/Source/cmGeneratedFileStream.h
index bb7e3bf52f..77fd7ef46a 100644
--- a/Source/cmGeneratedFileStream.h
+++ b/Source/cmGeneratedFileStream.h
@@ -147,6 +147,12 @@ public:
    */
   void SetTempExt(std::string const& ext);
 
+  /**
+   * Write a specific string using an alternate encoding.
+   * Afterward, the original encoding is restored.
+   */
+  void WriteAltEncoding(std::string const& data, Encoding encoding);
+
   /**
    * Writes the given string directly to the file without changing the
    * encoding.