Add the preprocessor tool for sfz files

devtools/CMakeLists.txt

@@ -13,3 +13,6 @@ if(JACK_FOUND AND TARGET Qt5::Widgets)
     target_link_libraries(sfizz_capture_eg PRIVATE sfizz-sndfile Qt5::Widgets ${JACK_LIBRARIES})
     set_target_properties(sfizz_capture_eg PROPERTIES AUTOUIC ON)
 endif()
+
+add_executable(sfizz_preprocessor Preprocessor.cpp)
+target_link_libraries(sfizz_preprocessor sfizz_parser)

devtools/Preprocessor.cpp

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+/*
+  This program reads a SFZ file, and outputs it back into a single file
+  with all the includes and definitions processed.
+
+  It can serve to facilitate identifying problems, whether these are related to
+  the parser or complicated instrument structures.
+ */
+
+#include "parser/Parser.h"
+#include <iostream>
+
+class MyParserListener : public sfz::Parser::Listener {
+public:
+    explicit MyParserListener(sfz::Parser& parser)
+        : _parser(parser)
+    {
+    }
+
+protected:
+    void onParseFullBlock(const std::string& header, const std::vector<sfz::Opcode>& opcodes) override
+    {
+        std::cout << '\n';
+        std::cout << '<' << header << '>' << '\n';
+        for (const sfz::Opcode& opc : opcodes)
+            std::cout << opc.opcode << '=' << opc.value << '\n';
+    }
+
+    void onParseError(const sfz::SourceRange& range, const std::string& message) override
+    {
+        const auto relativePath = range.start.filePath->lexically_relative(_parser.originalDirectory());
+        std::cerr << "Parse error in " << relativePath << " at line " << range.start.lineNumber + 1 << ": " << message << '\n';
+    }
+
+    void onParseWarning(const sfz::SourceRange& range, const std::string& message) override
+    {
+        const auto relativePath = range.start.filePath->lexically_relative(_parser.originalDirectory());
+        std::cerr << "Parse warning in " << relativePath << " at line " << range.start.lineNumber + 1 << ": " << message << '\n';
+    }
+
+private:
+    sfz::Parser& _parser;
+};
+
+int main(int argc, char *argv[])
+{
+    if (argc != 2) {
+        std::cerr << "Please indicate the SFZ file path.\n";
+        return 1;
+    }
+
+    const fs::path sfzFilePath { argv[1] };
+
+    sfz::Parser parser;
+    MyParserListener listener(parser);
+
+    parser.setListener(&listener);
+    parser.parseFile(argv[1]);
+
+    if (parser.getErrorCount() > 0)
+        return 1;
+
+    return 0;
+}