DecodeHints: provide c++ ABI backward compatibility with 2.1.0

axxel · axxel · commit d3a8d5f793ed · 2023-12-09T12:26:34.000+01:00
This might end up in a 2.2.1 release.
diff --git a/core/CMakeLists.txt b/core/CMakeLists.txt
@@ -105,6 +105,7 @@ if (BUILD_READERS)
         src/Content.h
         src/Content.cpp
         src/DecodeHints.h
+        src/DecodeHints.cpp
         src/DecoderResult.h
         src/DetectorResult.h
         src/Error.h
diff --git a/core/src/DecodeHints.cpp b/core/src/DecodeHints.cpp
@@ -0,0 +1,30 @@
+/*
+* Copyright 2023 Axel Waggershauser
+*/
+// SPDX-License-Identifier: Apache-2.0
+
+#define HIDE_DECODE_HINTS_ALIAS
+
+#include "ReadBarcode.h"
+
+namespace ZXing {
+
+// Provide a struct that is binary compatible with ReaderOptions and is actually called DecodeHints so that
+// the compiler generates a correctly mangled pair of ReadBarcode(s) symbols to keep backward ABI compatibility.
+
+struct DecodeHints
+{
+	char data[sizeof(ReaderOptions)];
+};
+
+Result ReadBarcode(const ImageView& image, const DecodeHints& hints = {})
+{
+	return ReadBarcode(image, reinterpret_cast<const ReaderOptions&>(hints));
+}
+
+Results ReadBarcodes(const ImageView& image, const DecodeHints& hints = {})
+{
+	return ReadBarcodes(image, reinterpret_cast<const ReaderOptions&>(hints));
+}
+
+} // ZXing
diff --git a/core/src/ReaderOptions.h b/core/src/ReaderOptions.h
@@ -172,6 +172,8 @@ class ReaderOptions
 	bool hasFormat(BarcodeFormats f) const noexcept { return _formats.testFlags(f) || _formats.empty(); }
 };
 
+#ifndef HIDE_DECODE_HINTS_ALIAS
 using DecodeHints [[deprecated]] = ReaderOptions;
+#endif
 
 } // ZXing
